Dissertationen: „Butanol“

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Baral, Nawa Raj. „Techno-economic Analysis of Butanol Production through Acetone-Butanol-Ethanol Fermentation“. The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1480501106426567.

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2

Outram, Victoria. „In situ product recovery of butanol from the acetone butanol ethanol fermentation“. Thesis, University of Newcastle upon Tyne, 2018. http://hdl.handle.net/10443/4152.

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From 1916 the "acetone butanol ethanol", or "ABE", fermentation process was the main production method for n-butanol. It was superseded in the 1950s by a more economical petrochemical process, causing the majority of plants to cease operation. In the fermentation, product inhibition led to low productivity and high energy demand in the downstream processing, making the process unable to compete with the petrochemical route. Overcoming these problems could revive the ABE industry and promote a bio-based economy. In situ product recovery (ISPR) can be applied to the fermentation process to counteract the effects of product toxicity. Productivity increases of greater than 300% are theoretically possible. Many ISPR techniques have been applied to the ABE process at laboratory scale, but a direct comparison of the different techniques has been hindered by experimental inconsistencies. Here, a techno-economic analysis was performed to compare the most developed ISPR techniques, with process simulations providing comparative data on the separation efficiency and energy demand. All the techniques were found to be economically viable, with profit increases compared to an equivalent batch plant of 110-175% and payback times of 2.2-4.5 years. In addition to generating the most profit and having the shortest payback time, perstraction was the only technique to lead to a reduction in overall plant energy demand, by ~5%, compared to a traditional ABE process. Thus perstraction warrants further investigation for application to the ABE process. Perstraction is significantly underdeveloped compared to other ISPR techniques. It was originally designed to overcome various problems associated with liquid-liquid extractions, including solvent toxicity. Here, experiments focused on the use of high-distribution toxic extractants with commercially available membranes. Results showed that high-distribution toxic extractants (1-pentanol, 1-hexanol, 1-heptanol, 1-octanol and 2-ethyl-1-hexanol) have a larger mass transfer coefficient than oleyl alcohol (the main non-toxic extractant), although chemical structure differences, such as branching, can have a greater impact on mass transfer than distribution coefficient. Unfortunately, all extractants investigated here were transferred across the membrane to some extent, which would limit perstraction to non-toxic extractants. However, differences in membrane type have a greater impact on mass transfer than the choice of extractant. Porous membranes have a mass transfer coefficient 10 times greater than non-porous membranes, which would see a factor of 10 reduction in ii membrane size and cost. Overall, this work has confirmed that perstraction is technically viable and compared options for process improvements through membrane and extractant selection.

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Aleksic, Snezana. „Butanol Production from Biomass“. Connect to resource online, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1242762960.

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4

Dong, Jie. „Butanol Production from Lignocellulosic Biomass and Agriculture Residues by Acetone-Butanol-Ethanol Fermentation“. The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1404312445.

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5

Santos, Graciete Mary dos 1982. „Efeito da vinhaça na produção biológica de álcoois e ácidos orgânicos voláteis por meio de consórcio microbiano“. [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/304712.

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Orientadores: Ariovaldo José da Silva, Bruna de Souza Moraes
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
Made available in DSpace on 2018-08-30T07:46:17Z (GMT). No. of bitstreams: 1 Santos_GracieteMarydos_M.pdf: 3271887 bytes, checksum: 539f68130eb11eac441d2bca07c2e7da (MD5) Previous issue date: 2015
Resumo: No Brasil, o efluente industrial produzido em maior quantidade é a vinhaça, caracterizada por altos níveis de ácidos orgânicos, fósforo, cálcio, potássio e magnésio. O reaproveitamento energético da vinhaça mostra-se como uma alternativa interessante para produção de biocombustíveis ou sub-produtos. Este trabalho avaliou o potencial da vinhaça como fonte de substrato e nutrientes para produção de álcoois e ácidos orgânicos voláteis (AOV) por meio fermentação em batelada utilizando consórcio anaeróbio (lodo de bovinocultura) pré-tratados com choque térmico (TT) e choque ácido-térmico (AT). Foram utilizados dois meios diferentes, de sacarose (S) e de vinhaça (V), sendo a sacarose a principal fonte de carbono. A vinhaça provou ser uma excelente fonte de nutrientes para os microrganismos envolvidos na fermentação butírica, uma vez que a adição de vinhaça melhora significativamente a produção de ácido butírico em comparação com meio de cultura sintético. As máximas concentrações de ácido butírico, iso-butírico e acético foram de 14,13 ± 0,77 g L-1 na amostra ATV B3; 10,34 ± 0,43 g L-1na amostra ATV B2 e; 4,13 ± 0,06 g L-1na amostra TTV B3, respectivamente. O rendimento dos AOV acético, iso-butírico e butírico e de etanol foi mais elevado nas amostras ATV B3 e TTV B3, atingindo valores máximos de 0,14; 0,28; 0,69 e; 0,26 g g-1 carboidratos totais, respectivamente. Não foram encontradas diferenças significativas entre métodos de pré-tratamento e enriquecimento de inóculo, AT e TT no que diz respeito a produção de ácido butírico e etanol. Em escala maior, operando em reator de 1,5 L, a fermentação de vinhaça bruta e melado de cana por consórcio microbiano AU mostrou potencial para produção de solventes como o butanol, uma vez que concentrações elevadas de ácido butírico foram produzidas, com concentração máxima, rendimento e produtividade de 13,85 g L-1; 0,64 g g-1 e; 199,98 mg L h-1, respectivamente. A caracterização microbiológica, pirosequenciamento, revelou a ocorrência em maior abundância de bactérias do gênero Clostridium, principalmente no consórcio AU e Lactobacillus mais abundante nos consórcios TT e AT. Foi identificada uma espécie conhecida pela produção de butanol, o C. pasteurianum no consórcio AU. Contudo, o presente trabalho representa um passo importante no desenvolvimento de um processo industrial para reutilização da vinhaça. A exploração de novos microrganismos e estudo dos fatores que interferem no processo de fermentação como pH, temperatura, nutrientes, densidade da cultura, cargas aplicadas e características do substrato, são fundamentais para o entendimento dos efeitos sinérgicos e antagônicos da associação de culturas
Abstract: In Brazil, industrial waste produced in the greatest amount is vinasse, characterized by high levels of organic acids, phosphorus, calcium, potassium and magnesium. The energy reuse of vinasse shows up as an interesting alternative for the production of biofuels or byproducts. This study evaluated the potential of vinasse as a source of substrate and nutrients for the production of alcohols and volatile fatty acids (VFA) through fermentation batch using anaerobic consortium (cattle sludge) pre-treated with heat shock (TT) and acid-shock thermal (AT). We used two different media, sucrose (S) and vinasse (V), with sucrose being the main source of carbon. The vinasse proved to be an excellent source of nutrients for microorganisms involved in the butyric fermentation, since the addition of vinasse significantly improves the production of butyric acid as compared to synthetic culture medium. The maximum concentrations of butyric acid, iso-butyric and acetic acid were 14.13 ± 0.77 g L-1 in the sample ATV B3; 10.34 ± 0.43 g L-1 in ATV B2 and 4.13 ± 0.06 g L-1 in TTV B3, respectively. The yield of acetate, iso-butyric acid, butyrate and ethanol was higher in ATV B3 and TTV B3 samples, reaching maximum values of 0.14; 0.28; And 0.69; 0.26 g g-1 total carbohydrates, respectively. There were no significant differences between pretreatment and enrichment methods inoculum, TA and TT as regards the production of butyric acid and ethanol. On a larger scale, operating at 1.5 L reactor, crude fermentation vinasse and molasses of sugar cane from AU microbial consortium showed potential for producing butanol as the solvent, since high concentrations of butyric acid was produced, with maximum concentration, yield and productivity of 13.85 g L-1 0.64 g g-1 and 199.98 mg h L-1, respectively. Microbiological characterization, pyrosequencing, revealed the occurrence in greater abundance of the genus Clostridium bacteria, particularly the AU and most abundant Lactobacillus in consortium TT and AT consortia. C. pasteurianum, known for the production of butanol was identified in AU consortium. However, this study represents an important step in the development of an industrial process for reuse of vinasse. The exploration of new microorganisms and study of the factors that interfere in fermentation process such as pH, temperature, nutrients, cultures, applied loads and characteristics of the substrate are critical for understanding the synergistic and antagonistic effects of culture associatio
Mestrado
Agua e Solo
Mestra em Engenharia Agrícola

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Lu, Congcong. „Butanol Production from Lignocellulosic Feedstocks by Acetone-Butanol-Ethanol Fermentation with Integrated Product Recovery“. The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306823156.

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7

Markskog, Linda. „Investigation of butanol tolerance in Saccharomyces cerevisiae and of genes linked to butanol tolerance“. Thesis, Linköpings universitet, Biologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138357.

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The global warming on earth has been obvious since the 1950’s. Fossil fuels have a big impact on the observed warming and it is time to replace them with more environmentally friendly fuels. Biobutanol has been proven to be a preferred substitute to fossil fuels. The yeast Saccharomyces cerevisiae is a potential butanol producer. A problem in the biobutanol production is that the product, butanol, is toxic to the producer. In this study four S. cerevisiae strains were investigated for 1- and 2-butanol tolerance with spot tests and growth measurements with different concentrations of 1- and 2-butanol. One of the four strains, an ale yeast, showed a higher tolerance for 1- and 2-butanol. 2-butanol was overall more tolerated by the yeast. The gene expression for the genes TMC1, LPL1, FLR1 and RPN4 was also investigated at exposure of 3 % 2-butanol. RPN4 is important in the proteasome protein degradation, which is associated with butanol tolerance. TMC1, LPL1 and FLR1 are associated to RPN4, which make them potential genes coupled to butanol tolerance. The genes TMC1 and RPN4 showed an up-regulation when exposed to 3 % 2-butanol. In conclusion, 2-butanol is preferred as a biofuel produced by ale yeast and the ideal genes to use in genetic engineering to achieve a higher butanol tolerance is TMC1 and RPN4. These results contribute to the development of an effective production of biobutanol by S. cerevisiae.

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Teixeira, Miguel Monteiro. „Mixotrophic fermentation for butanol production“. Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22401.

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Mestrado em Biotecnologia
The current economy is still dominated by the fossil-based chemical industry that represents a nefarious contribution to the environment. To avoid the permanence of this industry, the necessity to optimize fermentations to cost-competitive processes started to arise. It is known that heterotrophic organisms can transform organic carbon into fermentation products with great economic interest. However, for most fermentations where sugars are used as carbon source, over one-third of the sugar carbon is lost to CO2. The CO2 evolves from the Embden-Meyerhof-Parnas (EMP) glycolysis decarboxylation reaction that converts pyruvate into acetyl-CoA. To overcome this carbon loss, one route to recapture evolved CO2 using the Wood-Ljungdahl carbon fixation pathway (WLP), in a process called anaerobic, non-photosynthetic (ANP) mixotrophy, was reviewed in the present work. The ANP mixotrophy is defined as the concurrent utilization of organic (for example, sugars) and inorganic (for example, CO2) substrates in a single organism. Comparing with the EMP glycolysis, this metabolism allows higher productivities and lower CO2 emissions during fermentations. With the purpose of increasing the biobutanol productivity in anaerobic ABE fermentations performed by Clostridium beijerickii NCIMB 8052, a genetic engineering strategy was designed to enable the ANP mixotrophic metabolism in this strain. Through a set of different fermentations and bioinformatic researches, it was concluded that Clostridium beijerickii NCIMB 8052 is not naturally capable of performing the ANP mixotrophic metabolism due to a group of genes, considered as essential for the WLP, that were found to be missing in this strain. Several cloning techniques were used to insert and overexpress, via plasmid, these genes into Clostridium beijerickii NCIMB 8052. At the end, none of the genes were successfully transformed.
Os organismos heterotróficos têm a capacidade de metabolizar carbono orgânico para gerar produtos de fermentação indispensáveis para a sociedade atual. Numa economia ainda dominada pela industria química à base de recursos fósseis, a urgência em otimizar e viabilizar os processos fermentativos é cada vez mais significativa. Em fermentações onde os açucares são utilizados como fonte principal de carbono, sabe-se que cerca de um terço do carbono proveniente do açúcar é perdido na forma de CO2. Este fenómeno deve-se a uma reação de descarboxilação, durante a via glicolítica Embden-Meyerhof-Parnas (EMP), responsável por converter o piruvato em acetil-CoA. Numa tentativa de colmatar estas perdas de carbono, o presente trabalho revê uma via alternativa para recapturar o CO2 desenvolvido usando o metabolismo de fixação de CO2 Wood-Ljungdahl (WLP), num processo chamado fermentação mixotrófica anaeróbia, não-fotossintética (ANP). O mixotrofismo ANP, definido como a utilização simultânea de substratos orgânicos (como açucares) e inorgânicos (como CO2) por um único organismo, evita as perdas de carbono, aumentando os rendimentos de produção e reduzindo as emissões de CO2 durante as fermentações. O objetivo deste trabalho foi o de tentar aumentar a produtividade de biobutanol em fermentações anaeróbias Acetona-Butanol-Etanol (ABE) realizadas pela bactéria Clostridium beijerickii NCIMB 8052. Para isso delineou-se uma estratégia de engenharia genética para ativar o metabolismo ANP mixotrófico na estirpe em causa. Através de um conjunto de diferentes fermentações experimentais e de diferentes análises bioinformáticas, concluiu-se que C. beijerickii NCIMB 8052 não é capaz de realizar o metabolismo mixotrófico ANP de forma natural e que isso se deve à ausência, no seu genoma, de um grupo de genes considerados essenciais para o funcionamento do metabolismo de WLP. Usaram-se várias técnicas de clonagem na tentativa de inserir os respetivos genes, via plasmídeo, em C. beijerickii NCIMB 8052, mas não foram obtidos os resultados esperados. Comprovou-se que nenhum dos genes de interesse foi clonado com sucesso

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Chung, Gregory. „Planar laser-induced fluorescence of nitric oxide in isomeric butanol and butane stagnation flames“. Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107877.

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The significant efforts to reduce global fossil fuel dependence have led to the development of biofuels as an alternative. Despite their growing significance, alcohol biofuels still require fundamental study, particularly in the area of NOx emissions. Planar laser-induced fluorescence (PLIF) was used to obtain nitric oxide (NO) production profiles from stagnation flames of premixed n- and iso-butanol; n- and iso-butane flames were also measured to offer context with alkane fuels. PLIF measurements were corrected for laser sheet variations and non-radiative quenching by signalpost-processing and quantified with a NO-seeding calibration method. Particle-image velocimetry (PIV) was performed to characterize the centreline velocity of the experimental flow which was then used for chemical kinetic simulations of the experiment. Simulations were performed for n-butanol and n-butane flames with a combined NOxsubmechanism. Experimentally, butanol fuels were found to produce significantly less NO than butane fuels overall. Although both models accurately predict the production of NO in the post-flame region, there is a disparity in NO production occuring in theflame zone via the prompt-NO pathway, suggesting that the chemical kinetics in the mechanisms require modification. The n-butanol simulation shows poor agreement at all tested equivalence ratios, while n-butane performed poorly for the rich case. This study offers new experimental data to aid in further improvements in kinetic modelling of butanol and butane combustion, and NOx formation.
Les efforts significatifs pour réduire la dépendance globale aux hydrocarbures ont entraîné le développement de biocarburants comme alternative. Malgré leur importance accrue, les biocarburants a base d'alcool nécessitent toujours une étude fondamentale, particulièrement en ce qui à trait aux émissions d'oxydes d'azote (NOx). La fluorescence planaire induite par un laser (PLIF) est utilisée pour obtenir les profils de production d'oxyde nitrique (NO) à partir de flammes de stagnation pré-mélangées de n- et iso-butanol ainsi que de nand iso-butane pour mettre en contexte les carburants alcalins. Les mesures PLIF sont corrigées par un traitement ultérieur et quantifiées par une méthode de calibration. La vélocimétrie particule-image (PIV) est utilisée pour caractériser la vitesse de la ligne-médiane de l'écoulement expérimental qui est ensuite utilisée pour les simulations de cinétique chimique de la flamme expérimentale. Les simulations sont générées pour les flammes de n-butanol et de n-butane et sont combinée à un sous-mécanisme pour le NOx.Même si les deux modèles semblent bien prédire la production de NO dans la région après-flamme, il existe une disparité dans la production de NO dans la région de la flamme, ce qui suggère que les mécanismes cinétiques-chimiques requièrent amélioration. Le n-butanol démontre un piètre accord pour tous les ratios d'équivalence testés. Le n-butane, pour sa part, est imprécis pour le cas riche. Cette étude fourni de nouvelles données expérimentales qui aident à l'amélioration des modèles cinétiques-chimiques du butanol et du butane. Cette étude tend aussi à valider le sous-mécanisme du NOX pour de combustibles à chaînes plus longues.

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Natalense, Júlio César. „Prospecção tecnológica do biobutanol no contexto brasileiro de biocombustíveis“. Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-13082013-091628/.

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Dois exemplos de combustíveis renováveis em uso atualmente são bioetanol e biodiesel. Novas alternativas de combustíveis incluem etanol celulósico e biobutanol. Estes apresentam vantagens pois contribuem para uma melhor produtividade e otimização do uso de biomassa. Possuem ainda boas propriedades que garantem o bom desempenho como combustíveis. A pesquisa e interesse industrial têm crescido sobre o biobutanol, com melhorias no processo tradicional de fermentação ABE (Acetona-Butanol-Etanol), desenvolvimento de novos microorganismos para aumentar o rendimento e técnicas de separação para isolar o solvente do meio fermentativo. Algumas companhias anunciaram planos para a introdução de biobutanol em misturas com gasolina no mercado norte-americano. O interesse por biobutanol no Brasil como combustível ainda é limitado, pois a infraestrutura de comercialização já é adaptada ao uso de bioetanol, e a maior parte da frota de carros circulante utiliza motores adaptados ao uso do bioetanol. A cana-de-açúcar pode ser utilizada como matéria prima no processo produtivo do biobutanol, capacitando o Brasil a tornar-se um importante exportador para suprir o biobutanol para outros países. Em curto prazo, o biobutanol poderá ser produzido no Brasil para substituir o petro-butanol como solvente em aplicações industriais ou para o mercado de exportação como combustível. O presente trabalho propõe o uso da técnica technology roadmapping para o planejamento estratégico do desenvolvimento do biobutanol, alinhando os objetivos de longo prazo com os recursos, linhas de financiamento e prioridades para atender as necessidades do processo de desenvolvimento.
Two examples of renewable fuels in use today are bioethanol and biodiesel. New alternatives on biofuels include cellulosic ethanol and biobutanol. They present several advantages over the conventional biofuels, either in terms of better productivity and optimization of the use of biomass, as well as higher performance attributes. The research and industrial interest has grown on biobutanol, with improvements on the traditional ABE fermentation process, on the development of new microorganism strains to improve yield, and separation techniques to isolate the solvent. Companies have announced plans for the introduction of biobutanol in blends with gasoline in the north-american market. The interest on biobutanol as a fuel in Brazil is still limited, since the infrastructure is tailored to bioethanol already, and most of the car fleet uses engines adapted to this fuel. Sugar cane can be used as a potential feedstock in the butanol production process, enabling Brazil to become a key exporter to supply biobutanol to other countries. For the short future biobutanol will be produced in Brazil to replace petro-butanol as a solvent in industrial applications only, or for the export market as a fuel. This work proposes the use of technology roadmapping as a technique for long term strategic planning of the biobutanol development, aligning long term goals with the resources, funding, and priorities to fulfill the needs in the development process.

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Hansson, Cecilia. „Identification of a butanol tolerant Saccharomyces cerevisiae strain and of a gene associated with enhanced butanol tolerance“. Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-130346.

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Yerushalmi, Laleh. „Physiological aspects of the acetone-butanol fermentation“. Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=71969.

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The effect of the key physiological parameters on the production of solvents in the acetone-butanol fermentation using the anaerobic bacterium Clostridium acetobutylicum was examined in this work.
The theoretical solvent yield was calculated based on expressing stoichiometric relationships between the substrate and the products of the process. The maximum theoretical yield under the acceptable process conditions was established ranging from 38.6% to 39.9%.
A linear correlation was established between the production of solvents and gases which varied with the mixing rate of the fermentation system.
Elevated hydrogen partial pressure affected the metabolism of C. acetobutylicum resulting in increased butanol and ethanol yields (based on glucose) by an average of 18% and 13%, respectively.
A mathematical model for the batch acetone-butanol fermentation was formulated using original experimental data for the microbial growth, sugar consumption and metabolite biosynthesis. This model was used for computer process simulations. Parametric sensitivity analysis indicated the importance of the key process parameters.
A method of systems analysis was applied in analysing pronounced physiological differences in the performance of one of the C. acetobutylicum culture strains. The cellular transport mechanism for substrate (glucose), solvents and acids through the cell membrane was established to depend on its permeability and the number of sugar transport "sites". Experimental results obtained from the study of the uptake of 3-0-methyl glucose (0.7mM) by the "normal culture" and the "retarded culture" confirmed the theoretical predictions of a slower transpost in the "retarded culture". The theoretical predictions were further confirmed by additional experimental results.
A mathematical "Physiological State Model" was developed which includes the culture physiological parameters as well as the internal and the external culture conditions. Using this mathematical model the standard and the substandard acetone-butanol fermentations could be simulated.
These results demonstrate the application of the method of systems analysis in elucidation of the role played by the key culture physiological parameters in the fermentation process.

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Mollah, Abdul Hamid. „Continuous acetone-butanol fermentation with gas stripping“. Thesis, Imperial College London, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318977.

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Chary, Priyanka P. „A Volumetric Study of Aqueous Butanol Solutions“. Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/319.

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Alcohol molecules consist of two distinct regions: a polar, hydrophilic alcohol group, and an aliphatic hydrocarbon chain. These regions interact with solvent water molecules in different ways. While the alcohol group acts as a solvent structure breaker by hydrogen bonding with nearby water molecules, the hydrophobic carbon chain acts instead as a solvent structure maker and causes the surrounding water molecules to align themselves in a Clathrate structure. The presence of these two contrasting solute-solvent interactions affects the properties of the solution, among them the molar volume. The partial molar volume of the alcohol is analyzed with respect to three variables: the size and location of the hydrophilic moiety, the concentration of the alcohol-water solution, and the temperature at which the density measurement is made. We show that all three of these variables have a noticeable effect on the interactions between the solute and solvent molecules, and thus the volume of the solution.

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Shabestery, Kiyan. „Metabolisk modellering av butanol produktion i cyanobakterie“. Thesis, KTH, Skolan för bioteknologi (BIO), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172095.

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Engineering microorganisms at the systems level is recognized to be the future of metabolic engineering. Thanks to the development of genome annotation, mcroorganisms can be understood, as never before, and be reconstructed in the form of computational models. Flux balance analysis provides a deep insight intocellular metabolism and can guide metabolic engineering strategies. In particular, algorithms can assess the cellular complexity of the metabolism and hint at genetic interventions to improve product productivity. In this work, Synechosystis PCC6803 metabolism was invesetigated in silico. Genetic interventions could besuggested to couple butanol synthesis to growth as a way to improve currentproductivities. Cofactor recycling and, in particular, buffering mechanisms were shown to be important targets. Creating a cofacor imbalance and removing thesebuffering mechanisms is an important driving force. This forces a carbon flux through butanol synthesis to maintain cofactor balance and sustain growth.

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Yan, Run-Tao. „Enzymology of butanol formation in Clostridium Beijerinckii“. Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/38617.

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The present study encompasses an investigation of the expression of solvent forming enzymes and purification and characterization of butanol-forming enzymes. More sensitive and accurate procedures for the determination of acids and solvents in cultures have been developed, which led to the recognition of the onset of solvent production at the mid-exponential phase, about two h earlier than previously reported. Activities of solvent-forming enzymes started to increase about one h before the onset of measurable solvent production and the activities of solvent-forming enzymes did not increase simultaneously. CoA-acylating aldehyde dehydrogenase (ALDH) was purified to near homogeneity. The ALDH showed a native M.. of 100,000, and a subunit Mr of 55,000. ALDH could use either NAD(H) or NADP(H) as the coenzyme. ALDH was oxygenlabile. The O2-inactivated enzyme could be reactivated by incubating the enzyme with CoA. Both NADH- and NADPH-dependent alcohol dehydrogenase activities were present in crude extracts. The ratio of NADPH-dependent activity to NADH-dependent activity (the PID ratio) varied in crude extracts. The PID ratio was affected by O~ ionic strength, pH, growth stage of cell, Fe in culture medium and temperature. Two ADHs have been identified in crude extracts. The NADPH-dependent ADH (P-ADH) could be separated from the NADH/NADPH-dependent ADH (D/P-ADH). The D/P-ADH has been extensively purified. The D/P-ADH showed a native Mr of 70,000 and subunits with Mr of 45,300 and 40,000. The D/P-ADH activity could be inactivated by a,a' -dipyridyl and restored by Fe2+.
Ph. D.

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Chen, Tianyi. „Production of n-Butanol by Clostridium Carboxidivorans“. The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1556309785594048.

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Swidah, Reem. „Engineering Saccharomyces cerevisiae toward n‐butanol production“. Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/engineering-saccharomyces-cerevisiae-toward-nbutanol-production(8fbbfed7-9de7-46e9-aabe-69bfa8a6218c).html.

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Biobutanol represents a second generation biofuel, which can be producedfrom renewable resources by microorganisms. A Saccharomyces cerevisiae strainbearing the five butanol synthetic genes (hbd, adhe2, crt, ccr and ERG10) wasconstructed, where the hbd, adhe2, crt and ccr genes are derived from Clostridiumbeijerinckii, while ERG10 is a yeast gene. The genes were transformed individually onsingle cassettes, which integrated into specific chromosomal sites. The single integrantstrains were back‐crossed to create a strain bearing all five butanol synthetic genes. The butanol synthetic enzymes appeared to be highly expressed in the cytosol,however, very little butanol was obtained (< 10 ppm). Therefore, additional geneticmanipulations were made with a view to restoring any redox imbalance channellingthe carbon flux toward the butanol pathway. Deletion of the ADH1 gene in strains withthe butanol pathway improved production to ~250 ppm (203 mg/L) butanol. Furtherimprovement to 360 ppm (292 mg/L) was gained by overexpressing the ALD6 and ACS2genes, that are involved in synthesis of acetyl‐CoA; the precursor for butanolbiosynthesis. However, the replacement of ALD6 with ALD2, which produces NADHinstead of NADPH, didn’t improve butanol yields. In addition, no significantimprovement of butanol yield was obtained when dehydrogenase enzymes from theglycerol biosynthetic pathway were deleted. An initial assessment of the bestconditions for butanol production were semi‐anaerobic growth at 30°C in 2% glucosewith a starting OD600 of 0.1.In this project, another key question was addressed: does the sensitivity of cellsto short chain alcohols like butanol affect butanol production? Previous work in theAshe lab has identified specific point mutations in the translation initiation factor,eIF2B, which generate resistance or sensitive phenotypes to exogenously addedbutanol. Here a comparison of butanol production in sensitive and resistantbackgrounds showed that the butanol yield was 1.5‐2 fold higher in a butanol resistantstrain compared to the sensitive mutant. Generating a ‘super’ butanol resistant strainbearing a GCD2‐S131A mutation in eIF2B promoted a higher butanol yield per cell. However, another consequence of this mutation was reduced growth. So thecombination of these effects meant that the overall butanol concentration in mediawas similar to the control. Overall this work highlights that S. cerevisiae can producebutanol but that further optimisation both at the level of the strain and processengineering would be necessary before this would be of interest to the commercialsector.

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Safinski, Tomasz School of Chemical Engineering &amp Industrial Chemistry UNSW. „Catalytic distillation for the synthesis of tertiary butyl alcohol“. Awarded by:University of New South Wales. School of Chemical Engineering and Industrial Chemistry, 2005. http://handle.unsw.edu.au/1959.4/23068.

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Catalytic Distillation for the synthesis of tertiary butyl alcohol (TBA) is investigated in this thesis. The solvent, ethylene glycol, is proposed as a means of overcoming challenges, which limit the potential benefits of the application of reactive separation for TBA. The proposed action of the solvent is that of extractive distillation entrainer, thus a new unit operation of Catalytic Extractive Distillation (CED) is suggested. The solubility of isobutylene in water, TBA, and ethylene glycol and their binary and ternary mixtures, at different temperatures, is measured and correlated. The solubility is found to be highly non-linear in solutions containing TBA. The kinetics of isobutylene hydration over Amberlyst 15 is characterised in the presence of ethylene glycol. The solvent is found to promote reaction rate, however it is also found to compete for reaction with isobutylene. Water is found to strongly inhibit the reaction of ethylene glycol and isobutylene. The selectivity ratio of TBA to by products is determined and found to improve with increased temperature and lower solvent concentration. Bale packing is chosen as catalytic distillation hardware for the containment of Amberlyst 15 and its two-phase fluid dynamics characterised for the first time. Raschig rings are used as a benchmark for the study. Bale packing is found to exhibit two ranges of backmixing behaviour in the pre-loading regime. This behaviour is attributed to the three levels of porosity of the hardware and indicative of low rates of catalyst/liquid renewal. The effectiveness of ethylene glycol as extractive distillation entrainer for the separation of the TBA/water azeotrope over Bale packing is investigated and the solvent found to be highly effective. The mass transfer resistances to isobutylene transport are determined for countercurrent fixed bed reactor (CFBR) application of Bale packing. It is found that ethylene glycol improves mass transfer coefficients attainable. Catalytic Extractive Distillation is implemented over Bale packing and the ability of the solvent to improve reaction rates and purity of TBA demonstrated. However, the reaction rates achieved have much scope for improvement through increased isobutylene availability. In response to poor liquid renewal of static packing such as Bale packing and the necessity of improved isobutylene transport a new form of catalytic distillation reactor design is proposed, the Basket Impeller Column (BIC). The BIC combines the mass transfer benefits of a rotating basket reactor with that of a dual flow column. Capacity of the new hardware is determined and correlated. Separation and reactive separation are demonstrated to be feasible. It is found that Damk??hler number can be varied directly using the additional process variable of speed of rotation.

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Ogunlabi, Olugbenga. „Metabolic engineering of yeast (Saccharomyces cerevisiae) with a view to optimising butanol production“. Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/metabolic-engineering-of-yeast-saccharomyces-cerevisiae-with-a-view-to-optimising-butanol-production(6820196d-30e9-43fa-a3ee-8983c82374a5).html.

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Global energetic and environmental concerns have generated interest in the biological systems for the production liquid biofuels. Butanol is one such biofuel, which can be naturally produced by some Clostridia species. However, possible limitations in Clostridial engineering and large-scale fermentation have led to an examination of other potential organisms that might house this pathway for butanol production. As a robust industrial host and key model organism in the study of fundamental biological processes, the yeast Saccharomyces cerevisiae has been used to house the Clostridial ABE-butanol pathway. However, butanol yields and titres in this yeast are relatively low. Therefore, in this thesis, three distinct strategies were carried out with the goal of optimising butanol production in the strain of yeast (previously constructed in the Ashe lab) bearing the ABE-butanol pathway: 1. Mutation of genes involved in the regulation of carbon source usage. 2. Deletion of genes where the product is involved in the consumption of cytosolic acetyl-CoA (the starting precursor for the butanol synthetic pathway). 3. Targeted mutagenesis to improve the efficiency of the thiolase enzyme, which catalyses the condensation of 2x acetyl-CoA to initiate the ABE-butanol synthesis pathway. The results showed the first two strategies did not lead to improvements in butanol yields. However, increases of intracellular acetyl-CoA were observed in some mutant strains, even though butanol production did not increase in these strains. In order to make maximum use of the accumulating cytosolic acetyl-CoA, thiolase engineering in the butanol production yeast strain was pursued. The introduced changes caused an increase in butanol (about two fold). Overall, this project has used a minimal engineering approach by modulation of associated pathways or optimisation of the heterologous enzyme with a view to improve butanol production in yeast. To achieve high and scalable butanol production in yeast, a robust approach involving whole synthetic biology - Design, Build Test, and Learn will need to be adopted to create a more efficient yeast-butanol system.

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Steffens, Cristine Munari. „Avaliação de catalisadores de nióbio na reação de desidratação de 1-butanol“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/179586.

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Óxido e fosfato de nióbio, calcinados em diferentes temperaturas, foram usados como catalisadores na reação de desidratação de 1-butanol, onde o efeito da temperatura de reação, da massa de catalisador e da vazão de butanol sobre a conversão e seletividade a butenos foram avaliadas através de um plano experimental. Foram caracterizadas as propriedades cristalográficas dos catalisadores. A maioria dos catalisadores apresentaram uma estrutura amorfa, mas algumas amostras apresentaram uma estrutura cristalina quando calcinadas em maiores temperaturas, 500 e 850 °C para o NbO e NbP, respectivamente. Nos testes reacionais, observou-se que o aumento da temperatura de calcinação dos catalisadores reduziu a conversão de 1-butanol. O catalisador fosfato de nióbio apresentou maior atividade, já que foi obtida uma conversão similar à do óxido de nióbio com uma massa 5 vezes menor, indicando a presença de sítios ácidos mais ativos. Além disso, a variável reacional que teve maior efeito na conversão foi a vazão de alimentação de 1-butanol; e seu aumento causou um decréscimo nos valores de conversão. Este comportamento indicou que a ordem aparente da reação é menor que um, o que foi confirmado por um modelo cinético baseado em lei de potência, o qual ajustado aos dados experimentais resultou em uma ordem aparente em torno de zero Equações fenomenológicas de velocidade de reação baseadas no modelo LHHW foram desenvolvidos. O teste estatístico F de Fisher foi utilizado para comparar os modelos fenomenológicos obtidos: para o óxido de nióbio calcinado em 400 °C o modelo heterogêneo que leva em conta apenas a adsorção de butanol foi considerado o mais adequado; para o fosfato de nióbio calcinado em 400 °C o modelo heterogêneo que leva em conta a adsorção de butanol e de água foi o mais adequado. Para ambos os catalisadores, com exceção do NbO calcinado em 500 °C, foi observada uma significativa isomerização de 1-buteno a 2-buteno, principalmente nas condições que foi obtida uma maior conversão de butanol. Este fato comprova a elevada força ácida destes catalisadores. A seletividade a 2-buteno foi maior ou igual a 1-buteno em todas as temperaturas e condições de reação com fosfato de nióbio. Para o óxido de nióbio, a seletividade a 2-buteno foi maior em poucas condições reacionais.
Niobium oxide and phosphate, calcined at different temperatures, were used as catalysts in the 1-butanol dehydration reaction, where the effect of reaction temperature, catalyst mass and butanol flow rate on conversion and selectivity to butenes were evaluated through an experimental design. The catalysts crystallographic properties were characterized. Most catalysts presented an amorphous structure, but some samples presented a crystalline structure when calcined at higher temperatures, 500 and 850 °C for NbO and NbP, respectively. In the reaction testes, it was observed that the increase in the catalysts calcination temperature decreased the 1-butanol conversion. The niobium phosphate catalyst presented higher activity, since it was obtained a similar conversion to that of niobium oxide with a mass 5 times lower, indicating the presence of more active acidic sites. Furthermore, the reaction variable that had the highest effect on the conversion was in the 1-butanol feeding flow rate; and its growth caused a decrease in the conversion values. This behavior indicated that the apparent reaction order is lower than one, which was confirmed through a kinetic model based on power law, which adjusted to the experimental data resulted in an apparent order around zero Phenomenological equations of reaction rate based on the LHHW model were developed. The Fisher statistical test was used to compare the phenomenological models obtained: for the niobium oxide calcined at 400 °C the heterogeneous model that takes into account only the adsorption of butanol was considered the most adequate; for the niobium phosphate calcined at 400 °C the heterogeneous model that takes into account the adsorption of butanol and of water was the most adequate. For both catalysts, with the exception of NbO calcined at 500 °C, a significant isomerization of 1-butene to 2-butene was observed, mainly in the conditions that were obtained a higher conversion of butanol. This fact proves the elevated acid strength of these catalysts. The selectivity to 2-butene was higher or equal to 1-butene at all reaction temperature and conditions where niobium phosphate was employed. For the niobium oxide, the selectivity to 2-butene was higher in a few reaction conditions.

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Wang, Hengzheng. „The acetone-butanol-ethanol pathway of Clostridium acetobutylicum“. Thesis, University of Nottingham, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.755813.

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Biobutanol is superior biofuel to ethanol. However, the yield of butanol from Clostridium acetobutylicum is not ideal. Yield improvements will require a better understanding of the Acetone-Butanol-Ethanol (ABE) fermentation pathway. One approach to identify bottlenecks would be to differentially express the genes encoding key enzymes, and assess the consequences. This strategy requires either the use of promoters of varying strengths, or ideally, the use of a tightly regulated inducible promoter system in which the level of expression is inducer, dose dependent. To implement this strategy there is a need to identify the key genes to be targeted. Accordingly, the phenotypic consequences of ClosTron insertions in key genes of the ABE pathway (adhE, ctfAB and ptb) were confinned by complementation. This was unsuccessful in the case of the ptb mutant due to a secondary mutation in tlll. A library of promoters was isolated with a range of ’strengths’ and the suitability of various repOlier genes examined, including the gusA and cpg genes, as well as various genes encoding fluorescent proteins. They all, proved inappropriate, and the catP gene was eventually used routinely. It was used to test two inducible systems, one based on IPTG and the addition of a lacO operator to the promoter, and the other based on a lactose inducible system (BgaRIBgaL) from Clostridium per./i’ingens. Whilst both functioned in a dose dependent manner when on a plasmid, only the latter functioned when integrated into the genome. To overcome the effects of lower gene dosage when in the genome, an orthogonal expression system based on either BotR (Clostridium botulinum) or TcdR (Clostridium difficile) was successfully implemented. Attempts to make in-frame deletions in various genes (adhE, adc and ptbibuk) were unsuccessful, despite testing a number of different strategies.

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Sanson, Joseph. „Hemicellulose and Cellulose Hydrolysis for Butanol Fuel Production“. Youngstown State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1371218027.

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Katsikadakos, Dimitrios. „Theoretical and experimental investigation of n-butanol combustion“. Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11171.

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Biofuels, are attracting great interest as an alternative to fossil fuels. n-Butanol has surfaced as a potential biofuel, mainly because it does not suffer from the drawbacks, that the current most widely used biofuel, ethanol, does. In this work a theoretical and experimental investigation of n-butanol combustion is performed, while a baseline investigation of fundamental combustion properties of methane is carried out. The computational work involves the investigation of the various reaction pathways for hydrogen abstraction from n-butanol by CH3 using quantum chemical calculations. The relative significance of hydrogen abstraction reactions from the specific carbon sites of n-butanol are compared with each other and with similar radical reactions initiated by OH and HO2 radicals. While the most stable structural conformer of n-butanol is expected to be the most abundant during the combustion process, the temperatures at which fuel burns, allow higher energy conformers to be accessible. A key feature of this work is to assess if any of these low lying, but not minimum energy conformers, have transition state barriers or product radicals lower in energy than those found for the most stable conformer. Based on the above ab initio calculations the rate constants and product branching ratios for hydrogen abstraction by CH3 from the different sites of n-butanol are computed using three available kinetic programs, namely CanTherm, MultiWell and Variflex, providing accurate data for future detail chemistry mechanism of n-butanol. An exhaustive comparison of the aforementioned kinetic programs is also carried out. The experimental work involves the development of a counterflow burner, specifically designed for the study of flames of pre-vaporised liquid fuels, which provides a very useful idealisation of the combustion process of a real combustor. While the present research focuses on n-butanol combustion, measurements of methane flames are used as a starting point of the experimental work, providing a basic understanding of the combustion aspects under investigation. The natural chemiluminescence of OH* and CH* radicals emitted in preheated premixed methane and n-butanol flames are measured using intensified high speed photography, in order to evaluate the dependence of the chemiluminescent ratio OH*/CH* on equivalence ratio and strain rate for various preheat gas temperatures and the performance of available chemical kinetics mechanisms. The effect of an electric field in counterflow flames is also investigated focusing on two principal themes: the effect of strain rate on the saturation current and the effect of high potential fields on the OH* chemiluminescence.

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Collas, Florent. „Production of isopropanol, butanol and ethanol by metabolic engineered Clostridia“. Thesis, Paris, AgroParisTech, 2012. http://www.theses.fr/2012AGPT0070.

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Au cours des dernières décennies, la fermentation IBE (isopropanol, butanol and éthanol) a connu un regain d'intérêt en vue de la production de carburants ou de composés chimiques à partir de matériaux renouvelables. Dans cette étude, nous avons étudié la production d'IBE avec le producteur naturel Clostridium beijerinckii NRRL B593 et avec des souches modifiées de Clostridium. acetobutylicum ATCC 824. En culture discontinue, la souche C. beijerinckii NRRL B593 excrétait 13.2 g/L d'IBE (dont 4,5 g/L d'isopropanol). Afin d'améliorer la production d'IBE, le gène codant pour l'alcool déshydrogénase secondaire (s-Adh) de NRRL B593, ainsi que différentes combinaisons des gènes des enzymes actives de la conversion de l'acétoacétyl-CoA en acétone, c.-à-d. l'acétoacétyl-CoA acétate/butyrate transférase (ctfA et ctfB) et l'acétoacétate décarboxylase (adc), ont été exprimées dans la souche productrice d'ABE (acétone, butanol éthanol), C. acetobutylicum ATCC 824. Les résultats montrent que la sur-expression des gènes ctfA et ctfB augmentait significativement la productivité et les concentrations finales en IBE tandis que la surexpression du gène adc n'avait qu'un effet limité. Cultivée en discontinu, la meilleure souche, exprimant les gènes adh, ctfA, ctfB et adc a produit 24.4 g/L d'IBE dont 8.8 g/L d'isopropanol avec une productivité de 0.7 g/L h. Cultivée en mode continu à un taux de dilution de 0.1 h-1, la productivité en IBE a été portée à 1.7 g/L h. Puisque le mélange IBE est considéré comme un additif carburant de qualité, les transformants obtenus constituent une avancée réelle vers le développement d'un procédé IBE industriel de production de biocarburants
Over the past decades, the IBE fermentation (isopropanol, butanol and ethanol) has received a renew interest for the production of fuels or biochemicals from renewable materials. In the present study, we have investigated the IBE fermentation using the natural producer C. beijerinckii NRRL B593 and genetically-modified strains of Clostridium acetobutylicum ATCC 824. In batch culture, C. beijerinckii NRRL B593 was found to excrete 13.2 g/L IBE of which 4.5 g/L was isopropanol. To increase IBE production, the gene coding the secondary alcohol dehydrogenase (s-Adh) of C beijerinckii NRRL B593 and different combinations of genes coding for enzymes active in acetoacetyl-CoA to acetone conversion i.e. acetoacetate decarboxylase (adc) and acetoacetyl-CoA: acetate/butyrate: CoA transferase subunits A and B (ctfA and ctfB) were expressed in the ABE (acetone, butanol ethanol) producer C. acetobutylicum ATCC 824. Results showed that the overexpression of the ctfA and ctfB genes significantly increased both speed and extent of the IBE production while the overexpression of the adc gene had only a little effect. In batch culture, the best mutant (expressing adh, ctfA, ctfB and adc) produced 24.4 g/L IBE (of which 8.8 g/L was isopropanol) and displayed an IBE productivity of 0.7 g/L h. Cultivated in continuous mode at the dilution rate of 0.1 h-1, IBE productivity was increased to 1.7 g/L h IBE. As the IBE mix has been considered as a valuable fuel additive, the transformants obtained are a real step forward towards the development of an industrial IBE process for biofuel production

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Lopez, Muñoz Laura Alicia. „Medidas do equilibrio liquido - vapor dos sistemas butanol - acido burico e butanol - acido acetico as pressões de 200 e 400 mmHg“. [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267361.

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Orientador: Maria Alvina Krahenbuhl
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-07-25T16:32:43Z (GMT). No. of bitstreams: 1 LopezMunoz_LauraAlicia_M.pdf: 2311093 bytes, checksum: 2b4ab867e0a31b54e9ac583e8cf2da5d (MD5) Previous issue date: 1999
Resumo: Este trabalho de pesquisa apresenta contribuições para o equilíbrio líquido ¿ vapor (ELV) dos sistemas binários butanol ¿ácido butírico e butanol ¿ ácido acético. Dados isobáricos P-T-x-y de ELV foram medidos em duas faixas de pressão, 200 e 400 mmHg. O equipamento empregado foi um ebuliômetro de fluxo, ideal para sistemas que, ao longo do tempo, venham a reagir entre si. O princípio básico para a determinação do ELV neste tipo de equipamento consiste em promover o equilíbrio e a separação quase que imediata das fases, evitando-se assim a formação de produtos de ração indesejáveis. A qualidade dos dados P-T-x-y medidos foi verificada pela aplicação do teste de consistência termodinâmica de Van Ness ¿ Fredenslund. Os parâmetros de interação binária para os modelos de coeficientes de atividade da fase líquida. Representados pelos modelos, Wilson, UNIQUAC e NRTL, foram ajustados para os sistemas estudados pelo método da máxima verossimilhança. Foi considerada a não idealidade da fase vapor, empregando-se a teoria química com a correlação de Hayden & O¿Connell para o cálculo do segundo coeficiente Virial, e predição da constante de equilíbrio químico de dimerização
Abstract: This research work presents contributions for the vapor ¿ liquid equilibria (VLE) of the binary systems Butanol ¿ Butyric acid and Butanol ¿ Acetic acid. Isobaric data P-T-x-y of VLE were measured in two pressure, 200 and 400 mmHg. The used equipment was a flow ebuliometerm ideal for systems that, along the time, come to react to each other. The basic principle for the determination of VLE in this equipment type consists of almost promoting the equilibrium and the immediate separation of the phases, being avoided the formation of undesirable reaction products. The quality of the measured data P-T-x-y ws verified on applying the thermodynamic consistency test of Van Ness ¿ Fredenslund. The binary interaction parameters for models of activity coefficients of the liquid phase, represented by the models, Wilson, UNIQUAC and NRTL, were adjusted for the studied systems by the maximum likelihood method. The non-ideality of the vapor phase was considered by using the chemical theory with the correlation of hayden & O¿Connell for the calculation of the second Virial coefficient, and prediction of the chemical equilibrium dimerization constant
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química

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Azimi, Hoda. „Pervaporation Separation of Butanol Using PDMS Mixed Matrix Membranes“. Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36836.

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The increased demand of fossil fuel along with the depletion of economical crude oil resources, environmental challenges such as the accumulation of CO2 and other greenhouse gases in the atmosphere and the reduction of the dependence on imported oil are some of the motivations for the huge interest in biofuels. Biobutanol produced from ABE fermentation has been considered to be a good partial replacement for fossil fuels. However, challenges such as the need for inexpensive feed-stocks, improved fermentation performance to achieve higher final butanol concentration and higher yield, an efficient method for solvent recovery, and water recycle are the main obstacles to make the production of this alcohol economically viable. Pervaporation, a membrane-based process, is considered to be an attractive separation method to remove butanol from ABE fermentation broth. Among the membranes used for butanol separation, PDMS membranes showed reasonable performance such as good permeability, and appropriate selectivity for butanol separation by pervaporation. However, PDMS membranes need to be improved in terms of performance to be applicable in large scale butanol production plants. In this study, activated carbon nanoparticles have been embedded into the matrix of the PDMS membrane to improve its separation performance and, in particular, the permeation flux and butanol selectivity. Result showed that the presence of nanoparticles improves the PDMS membrane performance up to a certain particle loading. Moreover, it was shown that the operating conditions have a major impact on the pervaporation membrane separation process. The best membrane for pervaporation separation of butanol from binary aqueous solutions was obtained for a 6 wt% particle concentration where the total permeation flux and butanol selectivity increased by 42.6% and 51.9%, respectively, compared to neat PDMS membranes. Moreover, the best performance for the separation of butanol from ABE model solutions was achieved for an 8 wt% nanoparticle loading. Both the selectivity for butanol and the total permeation flux more than doubled in comparison to neat PDMS membranes prepared in this study. Moreover, in order to compare the PDMS/AC mixed matrix membrane performance for pervaporation separation of butanol from binary and ABE model solutions with PDMS membranes available on the market, experiments were also performed with a commercial PDMS membrane. Result of butanol separation from ABE model solutions showed that mixed matrix membranes with 8 wt% nanoparticles loading had a higher permeation flux than that of the commercial membranes. It was clearly shown that the presence of activated carbon nanoparticles in the matrix of the PDMS would be beneficial for the pervaporation separation of butanol from ABE fermentation broths. To better comprehend how the presence of activated carbon nanoparticles in the polymeric membranes enhance the performance of the membranes, a series of numerical simulations were performed. A finite difference model was developed to simulate the mass transfer of permeating components through mixed matrix membranes by pervaporation for a wide range of relative permeability, nanoparticle loading, particle shape, particle size and different filler adsorption isotherms. Finally, an investigation has been performed to optimize the butanol pervaporation separation process from ABE fermentation broth at an industrial scale.

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Sivagnanam, Kumaran. „Shotgun proteomic analysis of Clostridium acetobutylicum during butanol fermentation“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114480.

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Shotgun proteomic technology is a powerful characterization tool that can be used to investigate the global status of an organism at the molecular level. This dissertation presents the shotgun proteomic analysis of Clostridium acetobutylicum which is capable of converting different sugars present in the lignocellulosic biomass to acetone, butanol, and ethanol through fermentation. In the first study, glucose was found to be the preferred substrate of C. acetobutylicum for butanol production and the subsequent shotgun proteomic analysis identified over 400 proteins using a 6-step mass spectrometry based shotgun proteomics approach. The identified proteins were used to construct a C. acetobutylicum protein interaction map which was the first report of pathways interaction network for C. acetobutylicum. The second study employed a 12-step shotgun proteomics approach and a total of 894 proteins were identified in C. acetobutylicum during butanol fermentation between glucose and xylose substrates. This study revealed significant changes in the proteomic profile of C. acetobutylicum involved in chemotaxis and flagellar mechanisms during butanol fermentation between glucose and xylose substrates. In the third study, the proteomic profile of C. acetobutylicum was analyzed between two different phases of butanol fermentation using xylose substrate. Interestingly, the C. acetobutylicum proteomic profile was found to be significantly different between the exponential growth and stationary growth phases, with proteins directly involved in the butanol production pathway found to be highly expressed in the exponential growth compared to the stationary phase. The final study of this dissertation reports the proteomic analysis of C. acetobutylicum during butanol fermentation using a glucose/xylose mixture. Over 800 C. acetobutylicum proteins were identified and compared with the previous studies. The comparative analysis revealed protein expression from C. acetobutylicum were lower in the glucose/xylose mixture when compared to the preferred glucose substrate for biochemical processes that are vital for fermentation, such as carbohydrate metabolism, butanol production pathway and chemotactic and motility behaviour. These findings provide an in-depth proteomic knowledge base of C. acetobutylicum fermentation and butanol production using the two major sugars present in lignocellulosic biomass. Furthermore, the data presented can be used to develop better fermentation monitoring systems to construct an optimized environment for butanol production and serves as a base for future molecular level butanol research.
La technologie de protéomique shotgun est un outil puissant de caractérisation au niveau moléculaire qui peut être utilisé pour l'investigation sur la situation globale d'un organisme. Cette thèse présente l'analyse protéomique shotgun du Clostridium acetobutylicum qui est capable de convertir les différents sucres présents dans la biomasse lignocellulosique en acétone, butanol et éthanol par fermentation. Dans la première étude, le glucose a été jugé le substrat préféré du C. acetobutylicum pour la production de butanol et l'analyse protéomique shotgun ultérieure a identifié plus de 400 protéines en utilisant l'approche protéomique shotgun basée sur une spectrométrie de masse de 6 étapes. Les protéines identifiées ont été utilisées pour construire une carte d'interactions proteinées du C. acetobutylicum qui était le premier rapport d'un réseau d'interaction protéine-protéine pour C. acetobutylicum. La deuxième étude a utilisé une approche de protéomique shotgun en 12 étapes et un total de 894 protéines ont été identifiées dans C. acetobutylicum pendant la fermentation du butanol entre les substrats glucose et xylose. Cette étude a révélé des changements significatifs dans le profil protéomique du C. acetobutylicum impliqués dans les mécanismes de chimiotactisme et flagellaires pendant la fermentation du butanol entre les substrats glucose et xylose. Dans la troisième étude, le profil protéomique du C. acetobutylicum a été analysé entre deux phases différentes de la fermentation du butanol en utilisant le substrat xylose. Fait intéressant, le profil protéomique du C. acetobutylicum a été jugé significativement différent entre les phases de croissance exponentielle et de croissance stationnaire, où les protéines directement impliquées dans la filière de production de butanol ont été trouvées être fortement exprimées dans la croissance exponentielle par rapport à la phase stationnaire. La dernière étude de cette thèse rend compte de l'analyse protéomique du C. acetobutylicum pendant la fermentation du butanol en utilisant un mélange de glucose/xylose. Plus de 800 protéines du C. acetobutylicum ont été identifiées et comparées avec les études antérieures. L'analyse comparative a révélé que l'expression des protéines du C. acetobutylicum était plus faible dans le mélange de glucose/xylose par rapport au glucose, le substrat préfère les processus biochimiques qui sont vitales pour la fermentation, tels que le métabolisme des glucides, filière de la production de butanol et les comportements chimiotactiques et de motilité. Ces résultats fournissent une connaissance approfondie de la protéomique de la fermentation du C. acetobutylicum et de la production de butanol en utilisant les principaux sucres présents dans la biomasse lignocellulosique. En outre, les données présentées peuvent être utilisées pour développer de meilleurs systèmes de surveillance de fermentation pour la construction d'un environnement optimisé pour la production de butanol et sert de base pour l'avenir de la recherche du butanol au niveau moléculaire.

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Sharif, Rohani Aida. „Multi-objective Optimization of Butanol Production During ABE Fermentation“. Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/30296.

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Liquid biofuels produced from biomass have the potential to partly replace gasoline. One of the most promising biofuels is butanol which is produced in acetone-butanol-ethanol (ABE) fermentation. The ABE fermentation is characterized by its low butanol concentration in the final fermentation broth. In this research, the simulation of three in situ recovery methods, namely, vacuum fermentation, gas stripping and pervaporation, were performed in order to increase the efficiency of the continuous ABE fermentation by decreasing the effect of butanol toxicity. The non-integrated and integrated butanol production systems were simulated and optimized based on a number of objectives such as maximizing the butanol productivity, butanol concentration, and butanol yield. In the optimization of complex industrial processes, where objectives are often conflicting, there exist numerous potentially-optimal solutions which are best obtained using multi-objective optimization (MOO). In this investigation, MOO was used to generate a set of alternative solutions, known as the Pareto domain. The Pareto domain allows to view very clearly the trade-offs existing between the various objective functions. In general, an increase in the butanol productivity resulted in a decrease of butanol yield and sugar conversion. To find the best solution within the Pareto domain, a ranking algorithm (Net Flow Method) was used to rank the solutions based on a set of relative weights and three preference thresholds. Comparing the best optimal solutions in each case study, it was clearly shown that integrating a recovery method with the ABE fermentation significantly increases the overall butanol concentration, butanol productivity, and sugar conversion, whereas butanol yield being microorganism-dependent, remains relatively constant.

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Silva, Douglas Batista da 1988. „Desempenho de reatores anaeróbios de leito fixo para a produção de butanol e etanol a partir de águas residuárias“. [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256744.

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Orientador: Ariovaldo José da Silva
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: A crescente demanda por fontes de energia renováveis vem direcionando esforços e interesses por pesquisas focadas no desenvolvimento de biocombustíveis, a partir da digestão de resíduos provenientes de atividades agrícolas e agroindustriais. Neste contexto, a digestão anaeróbia pode ser direcionada para a produção e aproveitamento de subprodutos intermediários com alto valor agregado, como, por exemplo, etanol e butanol. O objetivo geral deste trabalho foi avaliar o desempenho de reatores anaeróbios de leito fixo e fluxo ascendente no tratamento de água residuária, visando à produção biológica de butanol e etanol a partir de uma cultura mista de micro-organismos selvagens. Foram utilizados dois reatores anaeróbios de leito fixo, com volume total de 3,77 litros. O primeiro reator foi mantido em condição acidogênica e o segundo em condição solventogênica. Os reatores foram operados em cinco diferentes etapas com tempo detenção hidráulica (TDH) de 2, 4 e 12 h e alimentados com água residuária sintética preparada para resultar em DQO em torno de 500 mg L-1, 1.000 mg L-1, 4.000 mg L-1 e 12.000 mg L-1, tendo como principal fonte de carbono sacarose. Além disso, foram avaliadas duas condições de temperaturas diferentes, ambiente (variando de 25ºC a 30ºC) e controlada (35ºC). Em cada etapa também foi avaliada a influência do efeito da recirculação do biogás no desempenho dos reatores, operando-os por um período de 30 dias sem recirculação de biogás e 30 dias com recirculação de biogás. Os resultados mostraram que a suplementação de bicarbonato de sódio no preparo do afluente auxiliou no aumento da capacidade de tamponamento do sistema e a recirculação de biogás favoreceu a estabilidade nos valores de pH durante todo o período experimental nessa condição. A variação crescente do tempo de detenção hidráulica (TDH) e da concentração de matéria orgânica (DQO) conduziu a um aumento na concentração de ácidos voláteis totais (AVT) e na concentração de produtos intermediários resultante da fermentação da sacarose. A concentração média de AVT variou de 89,3 mg L-1 da etapa I para 147,0 mg L-1 na etapa II, quando houve aumento do TDH e da DQO afluente. A variação da temperatura não influenciou a produção de AVT, na etapa III na qual a temperatura foi variável a concentração média de AVT detectada no efluente foi 546,0 mg L-1 e na etapa IV, com temperatura mantida em 35°C a concentração média de AVT no efluente foi 530,4 mg L-1. O melhor desempenho na produção de etanol foi verificado no reator solventogênico, com o pH em torno de 4,5, quando mantido com temperatura controlada a 35°C, TDH de 4 horas e taxa de carregamento orgânico (TCO) de 24 g DQO m-3d-1, sem recirculação de biogás. Nessa condição a concentração média de etanol detectada no efluente foi de 929,52 mg L-1. A produção de etanol não correspondeu ao aumento da TCO aplicado na etapa V, mantendo a concentração média de 993,35 mg L-1 na fase com recirculação de biogás. Butanol foi detectado em concentrações muito baixas, é provável que as condições de pH, tipo de reator e a estratégia de inoculação foram inadequadas para viabilizar a rota metabólica de produção de butanol
Abstract: The growing demand for renewable energy sources has been directing efforts and interests by research focused on the development of biofuels from waste digestion from agricultural and agro-industrial activities. In this respect, anaerobic digestion can be directed to the production and use of intermediates by-products with high added value such as, for example, ethanol and butanol. The aim of this study was to evaluate the performance of anaerobic fixed bed and upward flow in the treatment of wastewater, aiming to organic production of butanol and ethanol from a mixed culture of wild microorganisms. We used two anaerobic fixed bed, with a total volume of 3.77 liters. The first reactor was kept in acidogenic condition and the second in solventogenic condition. The reactors were operated in five different stages with hydraulic retention time (HRT) of 2, 4 and 12 h fed synthetic wastewater prepared to result in COD around 500 mg L-1, 1,000 mg L-1, 4,000 mg L -1 and 12,000 mg L-1, the main carbon source sucrose. In addition, we evaluated two different conditions of temperature, environment (ranging from 25 ° C to 30 ° C) and controlled (35 ° C). At each step was also evaluated the influence of the effect of recirculation of the biogas reactor performance, operating them for a period of 30 days without recirculation of the biogas and 30 days with biogas recirculation. The results show that supplementation of sodium bicarbonate in the preparation of the influent assisted in increased system capacity and buffering biogas recirculation favored stability in pH during the entire experimental period in this condition. The increasing variation of hydraulic retention time (HRT) and the concentration of organic matter (COD) led to an increase in the concentration of volatile fatty acids (VFA) and the concentration of intermediate products resulting from the fermentation of sucrose. The average concentration of AVT ranged from 89.3 mg L-1 from step I to 147.0 mg L-1 in step II, when an increase of the HDT and the influent COD. The variation in temperature did not affect the production of AVT in step III in which the temperature varied from the mean concentration in the effluent was detected AVT 546.0 mg L-1 and stage IV with temperature maintained at 35 ° C the concentration AVT average of the effluent was 530.4 mg L-1. The improved performance in ethanol production was observed in solventogênico reactor with pH around 4.5, when kept at a temperature controlled at 35 ° C for 4 hours and TDH organic loading rate (TCO) 24 g COD m-3d-1, without recirculating the biogas. In this condition average ethanol concentration was detected in the effluent 929.52 mg L-1. Ethanol production did not correspond to the increase in TCO applied to the V phase, keeping the average concentration of 993.35 mg L-1 in phase with biogas recirculation. Butanol was detected at very low concentrations, it is likely that the conditions of pH, type of reactor and inoculation strategy have been inadequate for enabling the metabolic pathway of butanol production. Keywords: anaerobic digestion, solventogenic, butanol and ethanol
Mestrado
Agua e Solo
Mestre em Engenharia Agrícola

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Simões, Jana Marimon. „Produção de butanol a partir de etanol utilizando óxidos mistos de Mg e Al“. Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/12011.

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Butanol is an alcohol with a number of applications in various industries. It has diverse applications as solvent, and now shown to be an interesting substitute component for gasoline. His achievement is made from oil, but these days, many routes of synthesis from renewable raw materials have been studied, one of them the Guerbet reaction. The present concern about the environment shows the need to obtain such alcohol through a clean route. The use of catalysts is a great way to synthesize cleanly and to facilitate reproducibility. The hydrotalcites are inexpensive catalysts, easy synthesis and numerous applicability. This study aims to investigate and analyze the production of butanol from ethanol using mixed oxides of magnesium and aluminum obtained from hydrotalcites with 4 different molar ratios of magnesium and aluminum. For this, the syntheses were made of magnesium and aluminum hydrotalcites with molar ratios equal to 3, 5, 8 and 10 that were further calcined to obtain mixed oxides. The structures of the synthesized materials were analyzed to confirm the desired formation and to verify the properties there of. Preliminary tests were performed in triplicate between them to choose the most suitable catalyst for an attempt to optimize butanol to obtain varying power parameters like nitrogen flow and the fraction of ethanol. Two of the catalysts obtained poor results and two others obtained similar results in terms of selectivity and yield of butanol. To make the decision between the last two catalysts, stability tests were performed. With the stability test was chosen as the molar ratio of magnesium and aluminum catalyst equal to 5. With this catalyst were made over 8 reactions, according to the planning of the star type experiments. And as a result, for all reactions, it was found that increasing conversion of ethanol depends directly on the temperature increase. It was observed that butanol selectivity behavior directly depends on the ethanol fractions and the nitrogen flow in the reactor feed. Ethylene, ethanol dehydration product was the major main product at elevated temperatures, indicating that this reaction is more favored with increasing temperature than the reactions which lead to the production of butanol. Finally it proposed a reaction system that explains the conversion of ethanol in all observed products.
O butanol é um álcool com diversas aplicações em diferentes ramos industriais. Ele possui várias aplicações como solvente, e atualmente mostra-se um interessante componente para substituição da gasolina. Sua obtenção é feita a partir do petróleo, mas hoje em dia, diversas rotas de sínteses a partir de matérias-primas renováveis vêm sendo estudadas, sendo uma delas a reação de Guerbet. A presente preocupação com o meio ambiente mostra a necessidade de obtenção desse álcool através de uma rota limpa. O uso de catalisadores é uma excelente forma de sintetizar de forma limpa além de facilitar a reprodutibilidade. As hidrotalcitas são catalisadores de baixo custo, de fácil síntese e de inúmeras aplicabilidades. O presente trabalho tem por objetivo, investigar e analisar a produção de butanol a partir de etanol utilizando óxidos mistos de magnésio e alumínio obtidos a partir de hidrotalcitas com 4 diferentes razões molares de magnésio e alumínio. Para isso, foram feitas as sínteses das hidrotalcitas de magnésio e alumínio com razões molares iguais a 3, 5, 8 e 10 que posteriormente foram calcinadas para obtenção dos óxidos mistos. As estruturas dos materiais sintetizados foram analisadas para confirmar a formação desejada e para verificar as propriedades dos mesmos. Testes preliminares foram realizados em triplicata para entre eles escolher o catalisador mais adequado para uma tentativa de otimizar a obtenção de butanol variando os parâmetros de alimentação como a vazão de nitrogênio e a fração de etanol. Dois dos catalisadores obtiveram resultados não satisfatórios e os outros dois obtiveram resultados similares em termos de seletividade e rendimento em butanol. Para tomar a decisão entre os dois últimos catalisadores, testes de estabilidade foram realizados. Com o teste de estabilidade foi escolhido o catalisador de razão molar de magnésio e alumínio igual a 5. Com esse catalisador foram realizadas mais 8 reações, de acordo com o planejamento de experimentos do tipo estrela. E como resultados, para todas as reações, verificou-se que o aumento da conversão do etanol depende diretamente do aumento da temperatura. Observou-se que o comportamento da seletividade do butanol depende diretamente das frações de etanol e da vazão de nitrogênio na alimentação do reator. O eteno, produto da desidratação do etanol, foi o principal subproduto em temperaturas elevadas, indicando que esta reação é mais favorecida com a elevação da temperatura do que as reações que levam à produção de butanol. Por fim foi proposto um sistema reacional que explica a conversão do etanol em todos os produtos observados.

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Morrone, Simone Ribeiro. „Determinação experimental do volume excesso de soluções de ciclohexano /2-Propanol, ciclohexano /2-Butanol, N-Hexano/2-Propanol, N-Hexano/2-Butanol a 298,15k e A 288,15K e aplicação do modelo eras“. [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267378.

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Orientador: Artur Zaghini Francesconi
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Os objetivos deste trabalho consistiram no levantamento de dados inéditos do volume excesso, por densitometria, de soluções alcano/alcanol e no teste do modelo de soluções ERAS. Os sistemas estudados foram ciclohexano/2-propanol, ciclohexano/2-butanol, n-hexano/2-propanol, n-hexano/2-butanol à pressão ambiente e às temperaturas de 288,15 K e 298,15 K. Todos os valores do volume excesso foram positivos, sendo o maior valor aproximadamente 0,6 cm3/mol encontrado para ciclohexano/2-butanol, a 298,15 K. As curvas volume excesso em função das frações molares dos alcanos possuem formas parabólicas para o ciclohexano e sigmóides para o n-hexano. Constatou-se que o volume excesso aumenta com: a temperatura, o comprimento da cadeia do alcanol e a esfericidade do alcano. o modelo ERAS, que, ao contrário de outras teorias de solução, responde bem não somente à energia livre de Gibbs em excesso, mas também a outras grandezas excesso, foi desenvolvido por Heintz para sistemas do tipo aicano/alcanol.A principal característica deste modelo é o cálculo simultâneo das grandezas excesso. Os resultados apresentados foram bons, chegando, algumas vezes, a valores bem próximos dos experimentais
Abstract: The aim of this work were to collect new data of the excess volume of alkane alkanol solutions, using a vibrating-tube densimeter, and to test the solution model ERAS. The systems studied were cyclohexane/2-propanol, cyclohexane/2-butanol, n-hexane/2-propanol, n-hexane/2-butanol at 288.15 K and 298.15 K and room pressure. Ali values of the excess volume were positive and the maximum was about 0.6 cm3/mol for the cyclohexane/2-butanol at 298.15 K. The curves excess volume versus mole fractions have parabolic form for systems containing cyclohexane and sigmoid form for the n-hexane systems. It was observed that the excess volume increased with: the temperature, the lenght of the alkanol chain and the sphere shape of the alkane. The ERAS model, regardless of other solution theories, does not present good results only for the excess Gibbs free energy, but also for any excess . property, was developed by Heintz for alkane/alkanol systems. The main feature of this model is the simultaneous calculation of excess properties. The results were good and, in some cases, the values were very close to the experimental ones
Mestrado
Sistemas de Processos Quimicos e Informatica
Mestre em Engenharia Química

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Freddi, Giovanni. „One-pot Butyl Levulinate Production from Fructose and 1-Butanol“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16744/.

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Nowadays fossil fuels such as coal, petroleum, and natural gas provide more than three quarters of the world`s energy. They are also used to produce the most common transportation fuels. In addition over 96% of chemicals containing carbon, used in our society, derive from petroleum. Among all the possibilities, biomass, such as wood waste, aquatic plant, agricultural crops, municipal and animal wastes, has been recognized as the most promising candidate to replace the fossil resources. Biomass, especially lignocellulose type, represents a renewable, plentiful and cheap material for the industrial production, not only in the energy field but also as feedstock for the manufacture of chemicals, solvent and materials, expecting also environmental benefits. In this context, alkyls levulinates are a class of compounds that are widely studied, primarily as additives for diesel but also for their use as aromas, fragrances and green solvents. This work proposes the study of the reaction between fructose and 1-butanol to produce butyl levulinate using as catalyst ionic acid-exchange resins. In particular the determination of the behavior of the catalyst, according to the reaction conditions used such as feed composition and temperature, and therefore the achievement of a greater selectivity to butyl levulinate and lower production of by-products such as formic acid, butyl formate and humins. Results shows that decreasing the amount of water the selectivity to the main product, butyl levulinate, increases and the formation of by-products such as humins, formic acid and butyl formate decreases. In addition, rising the temperature, the reaction rate increases, leading to higher selectivity to butyl levulinate and the reduction of by-products. The best conditions to obtain the selectivity to butyl levulinate up to 59%, is working at 130°C, with no water, Ratio Fru/BuOH (mol/mol) equal to 0,0165 and Rcat(wt/wt) equal to 0.016.

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Steinkemper, Andreas. „Modellierung der Dehydratisierung von t-Butanol unter Vermeidung der Oligomerenbildung“. [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=96299829X.

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Anfelt, Josefine. „Metabolic engineering strategies to increase n-butanol production from cyanobacteria“. Doctoral thesis, KTH, Proteomik och nanobioteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-185548.

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The development of sustainable replacements for fossil fuels has been spurred by concerns over global warming effects. Biofuels are typically produced through fermentation of edible crops, or forest or agricultural residues requiring cost-intensive pretreatment. An alternative is to use photosynthetic cyanobacteria to directly convert CO2 and sunlight into fuel. In this thesis, the cyanobacterium Synechocystis sp. PCC 6803 was genetically engineered to produce the biofuel n-butanol. Several metabolic engineering strategies were explored with the aim to increase butanol titers and tolerance. In papers I-II, different driving forces for n-butanol production were evaluated. Expression of a phosphoketolase increased acetyl-CoA levels and subsequently butanol titers. Attempts to increase the NADH pool further improved titers to 100 mg/L in four days. In paper III, enzymes were co-localized onto a scaffold to aid intermediate channeling. The scaffold was tested on a farnesene and polyhydroxybutyrate (PHB) pathway in yeast and in E. coli, respectively, and could be extended to cyanobacteria. Enzyme co-localization increased farnesene titers by 120%. Additionally, fusion of scaffold-recognizing proteins to the enzymes improved farnesene and PHB production by 20% and 300%, respectively, even in the absence of scaffold. In paper IV, the gene repression technology CRISPRi was implemented in Synechocystis to enable parallel repression of multiple genes. CRISPRi allowed 50-95% repression of four genes simultaneously. The method will be valuable for repression of competing pathways to butanol synthesis. Butanol becomes toxic at high concentrations, impeding growth and thus limiting titers. In papers V-VI, butanol tolerance was increased by overexpressing a heat shock protein or a stress-related sigma factor. Taken together, this thesis demonstrates several strategies to improve butanol production from cyanobacteria. The strategies could ultimately be combined to increase titers further.

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Lee, Jason. „New catalysts for the upgrading of ethanol to butanol biofuels“. Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.682364.

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We propose an alternative method for the sustainable transformation of ethanol to longer-chained alcohols, specifically n-butanol, for use as an advanced biofuel efficient enough to provide an alternative' drop-in' replacement for petrol fuels. Particular attention was made to discovering new catalysts to achieve this transformation, addressing the drawbacks suffered by the first generation catalyst devised within our research group. The first draw back of the first generation catalyst was identified as having intolerance to water build-up during the course of the reaction. This was addressed (chapters 2 and 3) firstly through the screening of water-soluble ruthenium catalysts based on dipyridyl-containing ligands. Optimisation experiments revealed that ruthenium(II) complexes in the presence of N-heterocyclic bidentate ligands and a hydroxide base co-catalyst can successfully couple ethanol to allow unprecedented yields and selectivity to n-butanol to be obtained. These complexes have also shown to remain catalytically active under aqueous conditions, making them ideal candidates for industrial applications. An extensive study into the homogeneity of the catalytic system is reported, indicating that, what may have been anticipated to be homogeneous may in fact possess characteristics of both homogeneous and heterogeneous catalysis. The instability of the first generation catalysts highlighted the second drawback whereby decomposition of the catalysts was often observed due to the harsh reaction conditions. Reported here (chapter 4) is the discovery of a more stable ruthenium-diphosphine catalyst which has shown to be the most active catalyst, to date, toward the coupling of ethanol to higher a1cohols, with unprecedented yields and selectivity to n-butanol achieved. Catalyst loading and catalyst recycling studies were investigated, indicating that catalysts of this type have the greatest potential for the creation of future biofuels. Ruthenium complexes in the presence of higher denticity ligands were studied, highlighting a switch in reaction product from n-butanol to ethyl acetate and 2-butanol.

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Zaplana, Tom. „Optimisation de la fermentation de la biomasse végétale par Lachnoclostridium phytofermentans“. Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASL079.

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Le développement de sources d'énergie renouvelables nécessite l'optimisation de la conversion de la biomasse végétale en biocarburants tels que le butanol. Les Clostridia, et plus particulièrement Lachnoclostridium phytofermentans, sont des bactéries anaérobies capables de dégrader la cellulose et de produire des composés d'intérêt, ce qui en fait des candidates idéales pour cette transformation.Cette thèse vise à repousser les limites de l'ingénierie métabolique de L. phytofermentans pour optimiser la production de butanol. Les objectifs principaux sont : (1) développer une souche évoluée capable de résister à de fortes concentrations de butanol, (2) introduire une voie de synthèse du butanol via des approches de biologie synthétique, et (3) implémenter un système CRISPRi pour moduler le métabolisme central de manière précise.Pour atteindre ces objectifs, plusieurs approches ont été mises en œuvre. L. phytofermentans a été soumise à une évolution dirigée sur 480 jours dans un automate de cultures continues (appelé GM3), aboutissant à une souche résistante au butanol. La caractérisation phénotypique et génomique de cette souche a permis d'identifier plus de 500 mutations associées à la résistance. Parallèlement, une voie de synthèse du butanol a été conçue et transformé dans L.phytofermentans. Un biosenseur spécifique du butanol a été adapté pour détecter sa production.Enfin, un système CRISPRi basé sur dLbCas12a a été développé, permettant le clonage jusqu'à huit guides pour réprimer spécifiquement des gènes clés du métabolisme.La souche évoluée, PHY24.0#6, a montré une tolérance accrue au butanol, un temps de génération réduit de moitié et une densité de croissance maximale augmentée de 1,3 fois. L'analyse de la membrane plasmique a révélé une composition en acides gras plus longs et plus insaturés. Bien que la production de butanol n'ait pas été détectée après l'introduction de la voie de synthèse, le biosenseur spécifique a été intégré avec succès. Le système CRISPRi a permis de réprimer l'expression de gènes du métabolisme central jusqu'à 20 fois, y compris des gènes dont la délétion serait létale, comme le trio Cphy_1326-1327-0089 responsable de la production d'acétate et de dihydrogène.Ces travaux ont permis d'améliorer la tolérance de L.phytofermentans au butanol et de développer des outils moléculaires innovants tels que le système CRISPRi multiplex. Ces avancées contribuent à une meilleure compréhension du métabolisme de cette bactérie et ouvrent des perspectives pour optimiser la production durable de biocarburants à partir de biomasse végétale. Les approches développées pourraient être transposées à d'autres modèles de Clostridia, favorisant ainsi le développement de solutions énergétiques innovantes et respectueuses de l'environnement
The development of renewable energy sources requires optimization of the conversion of plant biomass into biofuels such as butanol. Clostridia, and more specifically Lachnoclostridium phytofermentans, are anaerobic bacteria capable of degrading cellulose and producing compounds of interest, making them ideal candidates for this transformation.This thesis aims to push back the limits of metabolic engineering of L. phytofermentans to optimize butanol production. The main objectives are: (1) to develop an evolved strain capable of withstanding high concentrations of butanol, (2) to introduce a butanol synthesis pathway via synthetic biology approaches, and (3) to implement a CRISPRi system to precisely modulate central metabolism.To achieve these objectives, several approaches were implemented. L. phytofermentans was subjected to directed evolution over 480 days in a continuous culture automaton (called GM3), resulting in a butanol-resistant strain. Phenotypic and genomic characterization of this strain identified over 500 mutations associated with resistance. In parallel, a butanol synthesis pathway was designed and introduced into L. phytofermentans, and a butanol-specific biosensor was adapted to detect its production.Finally, a CRISPRi system based on dLbCas12a was developed, enabling the cloning of up to eight guides into a plasmid to specifically repress key metabolic genes.The evolved strain, PHY24.0#6, showed increased tolerance to butanol, a halved generation time and a 1.3-fold increase in maximum growth density. Analysis of the plasma membrane revealed a composition of longer, more unsaturated fatty acids. Although butanol production was not detected after introduction of the synthetic pathway, the specific biosensor was successfully integrated. The CRISPRi system was able to repress the expression of central metabolism genes up to 20-fold, including genes whose deletion would be lethal, such as the Cphy_1326-1327-0089 trio, responsible for the acetate and dihydrogen production.This work has made it possible to improve the tolerance of L. phytofermentans to butanol, and to develop innovative molecular tools such as the multiplex CRISPRi system. These advances contribute to a better understanding of this bacterium's metabolism and open prospects for optimizing the sustainable production of biofuels from plant biomass. The approaches developed could be transposed to other models of Clostridia, thereby fostering the development of innovative, environmentally friendly energy solutions

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Akhoury, Abhinav. „Redox-responsive polymers for the reversible extraction of butanol from water“. Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65753.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references.
Over the past few decades, increase in the demand for low molecular weight alcohols, like ethanol and butanol, for use as a biofuel has provided a new impetus to their production by the fermentation of polysaccharides, and the subsequent separation from the alcohols from the aqueous fermentation broth. The inhibitory nature of alcohols to their own production necessitates the continuous lowering of the concentration of the alcohol during the fermentation process. The technology for removing alcohol and other organics from aqueous solutions also finds application in industrial waste treatment facilities. The different techniques in use currently for in-situ removal of alcohol from fermentation broth, like distillation, suffer from drawbacks like high energy consumption. The goal of this project was to develop a redox-responsive polymer which has preferential selectivity for butanol causing the polymer to selectively extract butanol from aqueous fermentation broth. On application of electric potential, the redox moieties in the polymer were oxidized and charged resulting in an increase in the hydrophilicity of the chemical environment in the gel and the extracted butanol was released into a stripping medium. The switchable selectivity of the polymer for butanol allows its use for the development of continuous separation system for butanol extraction. In this project, novel co-polymer of hydroxybutyl methacrylate (HBMA) and vinylferrocene (VF) was synthesized by free radical polymerization. The HBMA backbone gave the polymer preferential selectivity for butanol, while the ferrocene (Fc) groups of VF made the polymer redox active. The thermodynamic parameters, equilibrium distribution coefficient and separation factor, which quantify the distribution of a species between two phases were experimentally determined for butanol and water distribution between the polymer and the aqueous phase when the redox moieties in the polymer were in the reduced and the oxidized states respectively. The values of these parameters confirmed that the oxidation and the consequent charging of the redox species resulted in a decrease in the polymer's affinity for hydrophobic molecule, butanol. The optimum composition of the co-polymer was arrived at by comparison of properties of polymers with different compositions. The redox active co-polymer of HBMA and VF was attached to electrically conducting substrates to prepare redox polymer electrodes (RPEs). The RPEs allowed the oxidation and reduction of the ferrocene groups in the polymer by the application of electric potential. Carbon black (CB) and carbon fiber mats, called carbon paper (CP) were used as the substrates. RPEs were prepared using five different techniques-three techniques were based on strategies reported in literature and involved the chemical modification of the functional groups on the surface of CB and CP to allow polymer grafting. In addition, an iCVD based technique was developed which functionalized the CP surface by deposition of a reactive polymer, poly(pentafluorophenyl methacrylate (PFM)-co-ethyleneglycol diacrylate (EGDA)). The polymer layer was chemically modified to allow redox polymer grafting.. Impregnation of porous CP with redox polymer gel resulted in electrodes with highest mass of polymer per unit mass of conducting substrate.
(cont.) The electrochemical activity and reversibility of the RPEs prepared using the different techniques were ascertained by cyclic voltammetry. The impregnated electrodes were used to demonstrate the successful use of the polymer gel to extract butanol from its aqueous solution, and release it into water upon oxidation. Conceptual scheme of a continuous separation system that can be built using these RPEs was proposed and the separation that can be achieved using such a system was determined by simulating the continuous separation process using finite element modeling. It was determined that the separation system integrated with a fermentation reactor can help maintain the concentration of butanol at a value 20% lower than the critical value beyond which fermentation is completely inhibited. The mechanism of electron transport in the polymer coated RPEs was investigated. Diffusion of electrons was found to be the rate controlling step. Further, it was found that diffusion of electrons due to the 'hopping' of electrons from one redox site to the next, and the electronic motion due to the motion of the polymer chains themselves played important roles in determining the apparent diffusivity of electrons. As part of the PhDCEP Capstone project, the potential of butanol produced through fermentation, commonly known as bio-butanol, was analyzed as a blend for gasoline was analyzed. It was found that although the market for gasoline blend is huge and growing, butanol suffers from higher cost of production with respect to its primary competitor, bio-ethanol. Chances of bio-butanol's potential success can be enhanced through a combination of technological breakthroughs including development of strains of high yield bacteria, use of inexpensive lignocellulosic biomass, and process design improvements.
by Abhinav Akhoury.
Ph.D.

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Masngut, Nasratun. „A study of butanol production in a batch oscillatory baffled bioreactor“. Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2321.

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As with many bioprocesses, the acetone-butanol-ethanol (ABE) fermentation faces a number of economic drawbacks when compared to the petrochemical route for butanol production. In the 1920s biobutanol was the second largest biotechnology industry, after bioethanol production. However it became difficult to compete against the petrochemical route for reasons including the low product butanol concentration, because of product inhibition resulted in low butanol productivity and due to slow fermentation and low ABE yields. These lead to uneconomical butanol recovery by the conventional method, distillation, due to the high degree of dilution. Recent interest in biobutanol as a biofuel has led to re-examination of ABE fermentation with the aim of improving solvent yield, volumetric productivity and final solvent concentration to reduce the cost of production and thereby produce biobutanol that is cost-competitive with the chemical synthesis butanol. ABE fermentations were carried out in an intensified plug flow reactor known as the batch oscillatory baffled bioreactor (BOBB). The “BOBB”s were designed and built for this project. The effect of oscillatory flow mixing on ABE fermentation was compared to that of conventional stirred tank reactors (STRs) at power densities in the range 0 to 1.14 Wm⁻³. The maximum butanol concentration in this range in a BOBB was 34% higher than the STR. Some increase in butanol productivity was also observed: 0.13 gL⁻¹h⁻¹ in BOBBs, compared to 0.11 gL⁻¹h⁻¹ in the STRs. It can be concluded that at similar power densities, BOBB fermentation shifts to solventogenesis earlier than in STRs, resulting in higher solvent productivity. It is hypothesised that the reason for early solventogenesis in the BOBB was the higher solvent-producing cell concentration, due to the more uniform shear field in the BOBB, so the cell would be less exposed to high shear thereby reducing the risk of cell lysis. Two-stage ABE fermentations in BOBB increased the butanol productivity by up to 37.5% over the one-stage fermentation. Butanol productivity was further increased by 97% when gas stripping was integrated to the two-stage ABE fermentation. While the one-stage fermentation integrated with gas stripping increased the butanol productivity by 69% to 0.12 gL⁻¹h⁻¹ (as opposed to 0.071 gL⁻¹h⁻¹ in a similar fermentation without gas stripping). A simple model to describe the one-stage at oscillatory Reynolds number (Re₀) 0 and 938, and the two-stage ABE fermentation in BOBB II was developed. The model summarizes the physiological aspects of growth and metabolite synthesis by Clostridium GBL1082. The prediction of the models were in good agreement with experimental results incorporating mixing (Re₀938) and moderately agreed with results from Re₀0 and the two-stage fermentation.

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Esbenshade, Aaron J. „Differential Protein Expression and Butanol Production using Clostridium beijerinckii“. Youngstown State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1364566957.

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Chang, Wei-Lun. „Acetone-Butanol-Ethanol Fermentation by Engineered Clostridium beijerinckii and Clostridium tyrobutyricum“. The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1282108408.

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Castro, Yessica A. „Optimization of Wastewater Microalgae Pretreatment for Acetone, Butanol, and Ethanol Fermentation“. DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/3857.

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Acetone-butanol-ethanol (ABE) fermentation from wastewater microalgae by Clostridium saccharoperbutylacetonicum N1-4 is a novel bioprocess that utilizes waste substrate to generate valuable solvents. Butanol, the most abundant product resulting from ABE fermentation, is an environmentally safe and high performing fuel that can be utilized as a drop-in-fuel; however, high operational costs and low ABE yield present challenge in scale-up of the process. The utilization of algae as a substrate requires pretreatment prior to fermentation to increase the bioavailability of the algal fermentable sugars and to improve the conditions of the pre-fermentation medium. The purpose of this thesis was to optimize wastewater microalgae pretreatment through (1) the optimization of microalgae saccharification, and (2) the use of cheese whey as co-substrate and supplement. Optimal conditions for sugar liberation from wastewater algae through acid hydrolysis were determined for subsequent fermentation to acetone, butanol, and ethanol (ABE). Acid concentration, retention time, and temperature were evaluated to define optimal hydrolysis conditions by assessing sugar and ABE concentrations, and the associated costs. Additionally, the effect of cheese whey as a supplement and substrate was determined for acetone, butanol, and ethanol (ABE) fermentation from wastewater microalgae. Three media constituents, potassium phosphate, magnesium sulfate, and ferrous sulfate, were evaluated to assess their need as supplements in the medium to be inoculated, when 50 g/L of cheese whey was present. The optimization of wastewater microalgae pretreatment results in increasing ABE production and decreasing process costs.

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Nguyen, Ngoc phuong thao. „Metabolic engineering of clostridium acetobutylicum for the production of fuels and chemicals“. Thesis, Toulouse, INSA, 2016. http://www.theses.fr/2016ISAT0051/document.

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À l'heure actuelle, il y a un regain d'intérêt pour Clostridium acetobutylicum, le biocatalyseur du procédé Weizmann historique, pour produire le n-butanol un produit chimique de commodité et un bio-carburant alternatif et renouvelable . Ce mémoire de thèse décrit un procédé de recombinaison homologue, utilisant plasmide réplicatif, pour la délétion ou l'introdu ction de gènes chez C. acetobutylicum avec une élimination facile des marqueurs utilisés. La souche de C. acetobutylicum cacl502upp et ce système de recombinaison homologue ont été utilisés dans d'autres expériences d'ingénierie pour obtenir une souche produisant du n-butanol avec une sélectivité élevée et en éliminant la plupart des co-produits. Le mutant final, C. acetobutylicum (C. acetobutylicum CAB1060) a été généré avec succès. Cette souche CAB1060 a été utilisée dans un nouveau procédé de fermentation continu qui utilise i) l'extraction in situ des alcools par distillation sous pression réduite et ii) des cultures à haute densité cellulaire (et ne faisant pas intervenir de procédé membranaire) pour atteindre des titre, rendement et productivité en n-butanol qui n'ont jam ais été obtenus chez aucun micro-organisme.Un second procédé de recombinaison homologue utilisant un plasmide non réplicatif pour la modification de gène sans marqueur est également décrit dans le présent mémoire. Cette méthode permet d'inactiver simultaném ent deux gènes. Il a été utilisé avec succès pour la construction d'un mutant incapable de produire de l'hydrogène et utile, comme souche plate-forme, pour l'ingénierie de C. acetobutylicum pour produire en continu des produits chimiques de commodité et des bio carburants
Current ly, there is a resurgence of interest in Clostridium acetobutylicum, the biocatalyst of the historical Weizmann process, to produce n-butanol for use both as a bulk chemical and as a renewablc alternative transportation fuel. This thesis describes a method of homologous recombination by replicative plasmid to delete or introduce genes in C. acetobutylicum . This method was successfull y used to delete genes, includin g CACJ502, CAC3535, CAC2879 (upp), to generate C. acetobutylicum. These strains are readily transformable without any previous plasmid methylation and can serve as hosts for a "marker-less" genetic exchange system. A mutant C. acetobutylicum (C. acetobuty licum CAB 1060) was successfully genera ted. This final mutant produces mainly bu tanol, with ethanol and traces of acetate at a molar rati o of 7:1 :1 . This CAB 1060 strain was subjected to a new continuous fermentation process using i) in situ extraction of alcohols by distillation under low pressure and ii) high cell density cultures to increase the titer, yield and productivity of n-butanol production to levels that have never been previously açhieved in any organism . A second homologous recombination method using non-replicative plasmid for marker less gene modification is also described in this thesis. This method allows the simultaneou s inactivation of two genes. lt has been successfully used to construct a mutant unable to produce hydrogen and useful, as a platform strain, for further engineering of C. acetobutylicum to continuously produce bulk chemicals and fuels

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Villanueva, Sandra Bizarria Lopes. „Reações de etanol sobre hidrotalcitas calcinadas“. [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267634.

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Orientador: Renato Sprung
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Materiais do tipo hidrotalcita MgI-xAlx(OH)2(COl)x/2.Y H20 foram sintetizados, calcinados, caracterizados e testados cataliticamente na conversão do etanol. As sínteses foram realizadas com proporções de alumínio correspondentes a valores de x variando de 0,25 e 0,33. Ambos os materiais mostraram diftatogramas típicos de hidrotalcitas, áreas superficiais BET de cerca de 50 m2g-1 e 60 m2g-I, e volumes de mesoporos de 0,16cm3g-1 e 0,38 cm3g-
Abstract: Hydrotalcite-like compounds, Mg1-xAlx(OH)2(Col")xl2.y H20, were synthesized, calcined, characterized, and tested as catalysts for the vapor phase conversion of ethanol. Two hydrotalcite-like compounds were synthesized by varying the fraction x of aluminum in the starting solutions from 0,25 to 0,33. Both materiaIs yielded X-ray diffraction pattems typical ofhydrotalcites, with BET surface areas ofabout 50 and 60 m2g1 and mesopore volumes of 0,16 and 0,38 cm3g-1, respectively. Micropore volumes were negligible. When calcined at temperatures ranging from 500 to 1000°C, the materiaIs flrst yielded aluminum and magnesium double hydroxides for temperatures up to 800°C. By increasing the calcination temperature, the double hydroxides were progressively decomposed into magnesium hydroxide and a magnesium aluminate spinelic phase. The BET surface areas were increased up to about 200 m2g-1 and the mesopores volumes, to 0,68 cm3g-1. Catalytic tests were performed at 350°C and atmospheric pressure by passing 1,96 gIh ethanol diluted in nitrogen at a molar ratio of 1:2 through a fixed bed of calcined hydrotalcite partieles. Ethylene, acetaldehyde, ethyl ether and n-butanol were identifled as the reaction products. The ratio of ether to n-butanol was elose to one for alI the hydrotalcite samples utilized. The global yield of the condensation products, ether and nbutanol, was maximum for materiaIs calcined at 650°C, about 80%, and decreased continuously with increasing calcination temperatures. Acetaldehyde yield was maximum for materiaIs calcined at 1000°C. Total conversions of ethanol were slightly higher when using samples with higher aluminum content (x=0,33); samples calcined at 650°C yielded the highest ethanol conversion, about 14%. No conversion changes were detected over 150 minutes of reactor operation. Catalytic tests performed with magnesium oxide, obtained by calcination of synthesized magnesium hydroxide, yielded acetaldehyde and traces of ethylene. Total conversion of ethanol was typically 1 % after strong catalyst deactivation
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química

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Clarke, Kim Gail. „A reassessment of the production of acetone and butanol by Clostridium acetobutylicum in continuous culture“. Doctoral thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/21918.

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Bibliography: pages 154-195.
The production of acetone and butanol by Clostridium acetobutylicum P 262 was studied in continuous culture under conditions where the nutrients were present in excess of the requirements and the cell growth was limited by the products formed during the fermentation. This system differs from most continuous culture systems used to obtain solvent production where the limitation of a specific nutrient was utilised to limit the cell growth.

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Janošková, Lenka. „Možnosti fermentační výroby butanolu jako suroviny pro motorová paliva - úvodní studie“. Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216365.

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The aim of this work was to map out the theoretical basics of acetone-butanol fermentation. In addition, it is to find available data for possibility of the industrial use of this process and to make conclusion for next procedure. The microorganisms producing butanol, conditions of fermentation and usable raw material were described. Batch, Fed-batch and Continuous fermentation processes are described in more detail from the point of view of productivity of process and yield. Available data was evaluated, but there was a lack of technological data to construct an operational system. Therefore, an experimental pilot plant system was constructed that allowed different types of microorganisms and substrates to be tested. The pilot plant system is for single stage Continuous fermentation with gas stripping product recovery with possibility of expansion to two-stage Continuous fermentation. As well the balance of this process was done.

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Magalhães, Beatriz Leite 1991. „Otimização da produção de butanol por cepas de Clostridium spp. utilizando hidrolisado lignocelulósico“. [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317020.

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Orientador: Marcelo Brocchi
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Atualmente, o maior desafio da indústria de biotecnologia é a produção de combustíveis e compostos de interesse petroquímico, a partir de fontes renováveis, de forma economicamente viável. Dentre estes compostos destaca-se o butanol, um importante precursor químico industrial e com potencial para ser utilizado como combustível. O butanol pode ser produzido a partir de derivados de petróleo ou naturalmente por fermentação de espécies de clostrídio solventogênicas. Este processo fermentativo apresenta como principais produtos acetona, butanol e etanol (ABE), sendo, por isso, conhecido como fermentação ABE. Atualmente, a prática da fermentação ABE em escala industrial apresenta como principais obstáculos o alto custo dos substratos utilizados como matéria-prima e o seu baixo desempenho fermentativo. Neste contexto, o uso de hidrolisado de palha de cana-de-açúcar, um substrato considerado abundante e barato, poderia resolver em parte o problema da viabilidade econômica da fermentação ABE. Porém, para a geração deste hidrolisado, sua fonte de material lignocelulósico deve passar por duas etapas: pré-tratamento e hidrólise. Após este processamento, o hidrolisado gerado se caracteriza por ser uma mistura de hexoses e pentoses, mas também de inibidores de crescimento, o que representa um empecilho para a utilização deste material em uma fermentação. Assim, a busca e seleção de micro-organismos capazes de metabolizar diferentes açúcares e que sejam tolerantes aos inibidores presentes no hidrolisado, é visto como uma estratégia sustentável e barata para viabilizar a utilização de hidrolisados lignocelulósicos para a produção de químicos e combustíveis. Nesse contexto, este projeto visou o estabelecimento de uma condição onde fosse possível a produção microbiológica de n-butanol, a partir de hidrolisado lignocelulósico, com alto rendimento e produtividade. Para isso, o projeto contemplou a seleção de linhagens potenciais, o que resultou na escolha duas linhagens: Clostridium saccharoperbutylacetonicum DSM 14923, devido a sua alta produção de butanol, e Clostridium saccharobutylicum DSM 13864, por mostra-se capaz de co-fermentar glicose e xilose e apresentar maior robustez aos inibidores presentes no hidrolisado lignocelulósico. Além disso, foi realizada a otimização do meio e forma de cultivo para a obtenção de uma maior tolerância aos inibidores dos hidrolisados lignocelulósicos. Através desta abordagem, foi possível atingir uma melhora de 8 e 3,3 vezes na produção de butanol pelas linhagens C. saccharoperbutylacetonicum e C. saccharobutylicum, respectivamente. Além disso, com este meio otimizado foi possível a realização do cultivo das linhagens em maiores concentrações de hidrolisado. Por meio de ensaios fermentativos determinou-se que a linhagem C. saccharobutylicum DSM 13864 se destaca pela sua melhor performance em hidrolisado lignocelulósico, apresentando alto consumo de açúcar inclusive em altas concentrações deste substrato, sendo portanto a linhagem mais adequada para a fermentação neste substrato. Por outro lado, a concentração de butanol produzida ainda tem muito para ser melhorada indicando que o metabolismo desta linhagem em hidrolisado lignocelulósico precisa ser melhor compreendido. Ao final do trabalho, além da indicação da linhagem e o meio de cultivo otimizado para a produção de n-butanol a partir de hidrolisado lignocelulósico, geraram-se dados e resultados básicos que poderão ser empregados na produção de butanol em escala industrial
Abstract: Nowadays the production of fuels and petrochemical compounds from renewable sources with high yield and productivity is one of the biggest challenges of the biotechnology industry. Among these petrochemical compounds, butanol stands out as an important industrial chemical and because of its potential to be used as an alternative fuel. Butanol can be produced either from petroleum derivatives, as naturally by anaerobic fermentation using solventogenic clostridia. This fermentation process is known as ABE fermentation because it has as main products acetone, butanol and ethanol (ABE). Currently, the main obstacles to butanol production on industrial scale are the high cost of substrates and the low fermentation performance. In this context, the use of hydrolysate from sugarcane straw, considered an abundant and cheap substrate, could solve in part the problem of the economic viability of the ABE fermentation. However, for the generation of this hydrolyzate, the row material needs a pre-treatment step followed by hydrolysis. After this processing, the generated hydrolyzate is characterized by being a mixture of hexoses and pentoses sugars and by the presence of certain inhibitors of growth, which represents an obstacle to the use of this material in a fermentation. Thus, the search and selection of microorganisms able to metabolize different sugars and tolerant or resistant to the inhibitors present in the hydrolyzate, is seen as an inexpensive and sustainable strategy to enable the use of lignocellulosic hydrolyzates as feedstock for the production of biochemicals and biofuels. Then, the project had as aim the establishment of a condition where the microbiological production of n-butanol is possible, from lignocellulosic hydrolysate, with high yields and productivities. To achieve this objective, the project contemplated the screening of potential strains, resulting in the selection of strains: Clostridium saccharoperbutylacetonicum DSM 14923, outlined by its high butanol production, and Clostridium saccharobutylicum DSM 13864, outlined by its capacity of co-fermenting glucose and xylose. In addition, it was performed the culture medium optimization to obtain a greater tolerance to lignocellulosic hydrolyzate. Through this approach, it was possible to achieve 8 and 3.3-fold improvement in the production of butanol by the strains C. saccharoperbutylacetonicum and C. saccharobutylicum, respectively. Moreover, with this optimized medium, it was possible to perform the cultivation of these strains in higher concentrations of lignocellulosic hydrolysates. Through fermentation tests, it was determined that C. saccharobutylicum DSM 13864, among the others strains tested, has the best performance in lignocellulosic hydrolyzate, with a high sugar consumption even at high concentrations of these substrate, being the most suitable strain for the fermentation at this substrate. On the other hand, the concentration of butanol produced still can be improved, indicating that much remains to be elucidated about the metabolism of this strain in lignocellulosic hydrolyzate. At the end of the work, in addition of the optimization of the culture cultivation and the indication of the most adequate strain for fermentation in lignocellulosic hydrolysates, all the data and basic results generated can be used for the butanol production on industrial scale
Mestrado
Genetica de Microorganismos
Mestra em Genética e Biologia Molecular

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48

Baiotto, Alexandre. „Reforma a vapor de butanol com catalisadores de Ni,Co/MgAl2O4 : Efeito da composição do catalisador (Ni,Co) e reagentes (H2,H2O,Butanol) nas rotas reacionais de reação“. Universidade Federal de São Carlos, 2016. https://repositorio.ufscar.br/handle/ufscar/8049.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
The effect of metal composition (Ni,Co) and the reactants composition (H2:H2O:Butanol) in the catalytic properties were studied for the Ni,Co/MgAl2O4 catalysts in the reaction of steam reforming of butanol (SRB) The catalysts have been prepared by wet impregnation with alcoholic solution of the Co and Ni nitrates on the support of the spinel MgAl 2O4 kind, prepared by the sol-gel method. The catalysts have been characterized by N2 physisorption, X-ray diffraction (XRD), temperatura programmed reduction (TPR), thermogravimetric analysis (TGA) and X-ray absorption near edge structure (H2-XANES). The catalytic tests had been realized in the 150-650°C temperature range, making testes with He flow and others with H2 flow (strongly reducing atmosphere), evaluating conversion, products distribution and H2 selectivity. The XRD reesults confirmed the formation of MgAl2O4 spinel structure and revealed some traces of NiO in the catalyst with 8% of Ni in mass. The TPR helped in the identification of the reducing temperatures of the catalysts. TPD revealed that the main route of butanol’s decomposition in the catalyst surface is the dehydration, producing butylene and etylene. The catalytic tests have indicated another main route, the oxidative dehydrogenation, forming butyraldehyde as the first relevant product of the reaction. The main difference between TPD and catalytic tests is that during the reaction, the presence of water keept the catalyst oxidized in low temperatures. By the XANES evaluation of the results, along with the comparison between TPD and catalytic tests, is suggested that butanol have the tendency to form butyraldehyde when there are more oxide concentration. The TGA revelead that wasn ́t formed significant quantity of the coke in the catalyst surface, probably due to the steam/carbon rate utilized in the catalytic tests. The catalysts had obtained equivalent performance related to H2 selectivty, having some small diferences related to the intermediate products of the reaction, and in the temperature which they were formed during the catalytc tests, as well.
O efeito da composição de metal (Ni,Co) e a composição dos reagentes (H2:H2O: Butanol) nas propriedades catalíticas foram estudados para os catalisadores Ni,Co/MgAl2O4 na reação de Reforma a Vapor do Butanol (RVB). Os catalisadores foram preparados por impregnação úmida com solução alcoólica dos nitratos de Co e Ni sobre o suporte do tipo espinélio MgAl2 O4, preparado pelo método sol-gel. Os catalisadores foram caracterizados por fisiossorção de N2 , difração de raios X (XRD), redução à temperatura programada (TPR), análise termogravimétrica (TGA) e espectroscopia de absorção de raios X próximo da borda (H2-XANES). Os testes catalíticos foram realizados na faixa de temperatura de 150 a 650°C, fazendo testes com fluxo de He e outros com fluxo de H 2 (superfície fortemente redutora), avaliando a conversão, distribuição de produtos e seletividade para H2. Os resultados de XRD confirmaram a formação da estrutura de espinélio MgAl2O4 e revelaram alguns traços de NiO no catalisador de 8% em massa de Ni. O TPR, por sua vez, ajudou na identificação das temperaturas de redução dos catalisadores. O TPD revelou que o principal caminho de decomposição do butanol na superfície do catalisador é a desidratação, produzindo butileno e etileno. Os testes catalíticos indicaram outro caminho principal, a desidrogenação oxidativa, formando butiraldeído como primeiro produto relevante da reação. A principal diferença entre o TPD e os testes catalíticos é que durante a reação, a presença de água mantém o catalisador oxidado em temperaturas mais baixas. Pela avaliação dos resultados de XANES, juntamente com a comparação do TPD e dos testes catalíticos sugere-se que o butanol tende a formar butiraldeído quando há maior concentração de óxidos. A TGA revelou que não foi formada quantidade significativa de coque na superfície do catalisador, muito devido à relação água/carbono utilizada nos testes catalíticos. Os catalisadores obtiveram desempenhos equivalentes em relação à seletividade à H2, possuindo diferenças em relação a alguns produtos intermediários da reação, bem como na temperatura em que eles foram formados no decorrer dos testes catalíticos.

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Carrié, Maxime. „Etude et modélisation de la fermentation IBE en biofilm“. Electronic Thesis or Diss., université Paris-Saclay, 2021. http://www.theses.fr/2021UPASB053.

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Depuis de nombreuses années, les biotechnologies sont employées dans la conception de nombreux biens de consommation à partir de ressources renouvelables. En effet, ces technologies sont capables de synthétiser des molécules d’intérêts à partir de ressources agricoles. Par exemple, la bactérie Clostridium beijerinckii, mise en culture dans cette thèse, dégrade naturellement des hexoses pour synthétiser des molécules plateformes : du butanol et de l’isopropanol. Cette bactérie souffre malheureusement, en mode « batch », d’une inhibition causée par le butanol, amenant à de faibles productivités. De nouveaux modes de fermentation continue ont donc été développés pour lever cette inhibition en soutirant le produit de réaction et augmenter la productivité volumique. Ils consistent à immobiliser les bactéries au sein d’un support pour maintenir une forte concentration en biomasse dans le réacteur. Ainsi, ce système permet de découpler le temps de séjour de la biomasse du temps de séjour hydraulique, et d’augmenter la productivité volumique du procédé. Pour autant, de nombreux paramètres de fermentation doivent encore être optimisés et compris afin de maximiser les performances et d’assurer la montée en échelle. En effet, la croissance des cellules immobilisées au sein du matériau support dépend de nombreux facteurs comme les propriétés du solide support, la conduite du procédé, ainsi que les conditions hydrodynamiques. Ces propriétés peuvent donc influencer le développement du biofilm et donc la productivité volumique du procédé. Par conséquent, les recherches de cette thèse ont porté sur le développement d’outils expérimentaux et numériques permettant de mieux comprendre les phénomènes mis en jeu. Les modèles dynamiques mis en place dans ce travail sont capables de décrire la croissance du biofilm et permettent de simuler les performances du procédé en prenant en compte les phénomènes de détachement et d’attachement des cellules. De plus, de nouvelles méthodologies de cytométrie en flux et microscopie confocale, appliquées à l’étude des biofilms, ont été mises au point. Elles permettent de quantifier la viabilité des cellules adhérées aux supports. Ces méthodologies permettent de décrire la viabilité du biofilm formé ainsi que de mesurer la croissance des cellules viables qui composent ce dernier. Ces résultats ont ainsi permis d’envisager de nouvelles stratégies de contrôle et/ou de conduite du procédé
For many years, biotechnologies have been employed to design numerous consumers commodities from renewable resources. Those technologies allow to synthetize industrial interest molecules from agricultural commodities. The bacteria Clostridium beijerinckii can consume hexoses to produce two platform chemicals : isopropanol and butanol. However, this bacterium suffers from an inhibition caused by butanol accumulation which causes low productivities in batch fermentation. New continuous fermentation strategies have thus been developed. Bacteria were immobilized on porous support to maintain high cellular concentration and therefore enhance the process productivity. Numerous process parameters must be optimized and understood to maximize the process productivity and ensure the scale-up efficiency. The physicochemical properties of the solid support as well as the hydrodynamic conditions can influence the biofilm development and thus the productivity of the developed process. Consequently, this PhD research is focused on the development of numerical and experimental tools which allow to better understand these phenomena . Kinetic models were used to describe the biofilm development and allowed the simulation of the process performances while taking cells attachment and detachment from biofilm into account. Moreover, new methodologies using flow cytometry and confocal microscopy were developed to characterize biofilm cells viability. Those methodologies are powerful to measure the immobilized cells viability and to describe active cells accumulation within the solid support used during time. The use of flow cytometry to characterize biofilm cells viability also helped to consider new strategies for process control and operation

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50

Assis, Marilia Araujo de. „Resolução de (±)-2-amino-1-butanol, precursor para obtenção de etambutol“. Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-12022019-102334/.

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A emergência de cepas resistentes à isoniazida, principal fármaco utilizado no tratamento da tuberculose, tem causado renovado interesse nos tuberculostáticos denominados de \"segunda escolha\", dentre estes, o etambutol. O desenvolvimento de metodologias de obtenção de fármacos antimicobacterianos que sejam técnica e economicamente acessíveis e a otimização das técnicas existentes consistem em estratégias de grande importância em países em desenvolvimento onde os altos índices de incidência e prevalência estão diretamente relacionados à falta de recursos. Dentre os vários métodos de obtenção de (+)-2,2\'-(etilenodiimino)di-1-butanol, etambutol, a separação dos enantiômeros do (±)-2-amino-1-butanol com (+)-ácido tartárico seguida de condensação com dihaloetano apresenta-se como uma metodologia que atende aos requisitos anteriormente citados. Assim, efetuou-se neste trabalho, a otimização da resolução do 2-aminobutanol racêmico por formação de sais diastereoméricos neutros, (+)-bis-tartaratos de (+) e (-)-2-amino-1-butanol, seguida de separação por cristalização preferencial do sal contendo o isômero dextrógiro, precursor na síntese do etambutol. Pela formação de sais neutros elevou-se o rendimento da resolução em comparação aos resultados citados em literatura obtidos pela formação de sais ácidos em 63%, obtendo-se (+)-2-amino-1-butanol com elevada pureza química e enantiomérica.
The emergence of M. tuberculosis strains resistant to isoniazid, the main drug in tuberculosis treatment, has raised renewed interest in second choice drugs, like ethambutol. Researching into technical and economicaly accessible synthesis of antimycobacterial drugs and improving on existing ones is of great importance in developing countries where the rising of tuberculosis incidence and prevalence is related to the lack of resourses and inadequate control methods. Among various methods of preparation of (+)-2,2\'-(ethylenediimino)di-1-butanol -ethambutol-, resolution of (±)-2-amino-1-butanol with L-(+)-tartaric acid, followed by condensation to ethylene dichloride, consists in a procedure that is in accordance with these previous requirements. Resolution of racemic 2-aminobutanol was optimized, by diastereomeric neutral salts formation followed by preferential crystallization of the diastereomer containing the dextro isomer of 2-amino-1-butanol. This method resulted in yields 63% higher than resolutions performed by hemitartrates formation, and resulted in (+)-2-amino-1-butanol with high chemical and enantiomeric purity.

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Dissertationen zum Thema „Butanol“

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