Dissertations / Theses on the topic 'Solid biofuel'

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
In the sugarcane plantation it was common to use fire to facilitate the cutting and harvesting of sugarcane. However, Law 11,241 / 02 in São Paulo State provides the gradual elimination of this straw burning of sugarcane. The largest producer of sugarcane in Brazil is the São Paulo State, which has about 4.7 million hectares of planted area. It is estimated that one hectare produces about 14 tons of trash. Therefore, the mills have been trying to incorporate this trash in burning with the bagasse for power generation. However, high concentrations of mineral impurities are impossible its use for energy purposes. The aim of the study was to investigate the influence of storage time and particle size in the physicochemical characterization of the sugarcane trash. It was used the sugarcane trash inside and outside of the bale collected at different storage time (0, 1 and 2 years). The collected material was separated into four different particle sizes (> 0.420mm, 0.250-0.420mm, < 0.250mm and mix). The analyzes involved particle size distribution, proximate analysis, the high heating value (HHV), the chemical analysis of the components of the ashes, the images in the Scanning Electron Microscope (SEM), the Klason lignin content, the holocellulose content and extractives. There were variations in the results of the ash content with different particle sizes. It was observed a higher concentration of mineral impurities in smaller particles (< 0.250mm). The HHV varied from 15.9 to 18.3 MJ.kg-1 and showed no statistical difference for the treatments. The results indicate that the sugarcane trash presents problems related to mineral impurities which constrain its use as a solid fuel in the industry. The particle size interferes in their physicochemical characteristics. The trash can be stored in field and the time storage did not affect the quality for use as solid biofuel.
No manejo da cana-de-açúcar era comum a utilização do fogo para facilitar o corte e colheita da cana. No entanto, a Lei 11.241/02 do estado de São Paulo prevê a eliminação gradual da queima da palha da cana-de-açúcar. O maior produtor de cana-de-açúcar do Brasil é o estado de São Paulo, que possui aproximadamente 4,7 milhões de hectares de área plantada. É estimado que 1 hectare produza cerca de 14 toneladas de palha. Logo, as usinas vêm tentando incorporar esta palha na queima para geração de energia, juntamente com o bagaço. Porém, as altas concentrações de impurezas minerais estão impossibilitando seu uso para fins energéticos. O trabalho teve como objetivo o estudo da influência do tempo de estocagem e da granulometria na caracterização físico-química do palhiço da cana-de-açúcar. Foi utilizado o palhiço de canade-açúcar da superfície e do interior do fardo coletados em diferentes períodos de estocagem, 0, 1 e 2 anos. O material coletado foi separado em 4 granulometrias diferentes (> 0,420mm, 0,250-0,420mm, < 0,250mm e mix). As análises realizadas foram a distribuição granulométrica, a análise imediata, o poder calorífico superior (PCS), a análise química dos componentes das cinzas, as imagens no Microscópio Eletrônico de Varredura (MEV), o teor de lignina Klason, a holocelulose e os extrativos. Houve variações nos resultados do teor de cinzas com as diferentes granulometrias. Observou-se maior concentração de impurezas minerais nas partículas mais finas (< 0,250mm). O PCS variou entre 15,9 a 18,3 MJ.kg-1 e não apresentou diferença estatística para os tratamentos. Os resultados indicam que a palha de cana-de-açúcar apresenta problemas relacionados às impurezas minerais, que dificultam e restringem seu uso como combustível sólido na indústria. A granulometria da palha interferiu nas suas características físico-químicas. O palhiço pode ser estocado no campo e o tempo de estocagem não interferiu na qualidade para o uso como combustível sólido.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 143-149).
Significant volumes of biomass waste are generated each year as a result of agricultural practices in India. Despite the negative environmental impacts, in-situ incineration of crop residues is common practice for disposal of this waste. Transportation of raw biomass accounts for a significant portion of the cost of biomass conversion processes due to its low energy density and high bulk volume. The use of raw biomass also reduces the overall efficiency of thermochemical conversion processes due to high moisture content, over-oxidation of the fuel resulting from high oxygen content, and the relatively high oxygen to carbon ratio. There has been much recent interest in improving the properties of biomass prior to gasification and pyrolysis through densification, drying, and mild thermochemical treatments. One approach is a process known as torrefaction, which is a mild pyrolysis process that is shown to produce an energy-dense fuel with improved transport, storage, and feedstock characteristics. Particularly in the Indian context, there is a need for the development of a small-scale system which can densify and upgrade the properties of agricultural residues after harvest. This thesis presents the design and preliminary testing of a lab-scale moving-bed torrefaction reactor. Key learnings from the assembly and testing of this machine are identified and recommendations for improvement are made. A rudimentary model evaluating the heat transfer in packed bed of biomass is developed to provide a framework for analyzing future reactor designs. The functional requirements of a labscale screw conveyor torrefaction reactor are developed based on this analysis and a preliminary reactor architecture is proposed. Multiple studies are recommended to improve the reliability of the heat transfer model. Recommendations are made for future design iterations of the lab-scale screw conveyor torrefaction reactor.
by Megan Lynn O'Brien.
S.M.

Darbe siekiama apibendrinti kietojo biokuro rinkos plėtros aspektus nagrinėjant jos struktūrinius pokyčius bei rinkos dalyvių elgseną. Teorinėje dalyje analizuojamas rinkodaros sprendimų priėmimo procesas ir inovatyviosios rinkodaros priemonių svarba siekiant šios verslo sistemos vystymo. Kietojo biokuro rinkos segmentų valdymo moksliniai-praktiniai sprendimai yra orientuoti taikyti tokias rinkodaros priemones, kurios padėtų gerinti tiekimo sistemos struktūriškumą. Tiriamojoje dalyje, remiantis kietojo biokuro rinkos dalyvių sąveikos įvertinimu, atliekamas jų veiklos plėtros galimybių vertinimas. Empirinio tyrimo pagrindas – apklausa.
The final thesis aims to examine the development aspects of solid biofuel market by summarizing the structural changes and the behavior of market entities. The theoretical analysis includes the marketing decision-making process and innovative marketing tools to achieve development of solid biofuel market. The scientific-practical managerial solutions are oriented towards the application of marketing tools that improve the supply system for the segments of solid biofuel market, which is structural complex and undeveloped. The research covers the basis of solid biofuel market interactions including activities of entities with the feasibility development assessment. The empirical basis of the study – a survey by questionnaire.

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Throughout history, several sources and forms of energy have been used for production of goods and services. especially energy generated from fossil fuels such as oil. Due to the limits of their world reserves; CO2 emissions and ecological disasters from oil well drilling, it is crucial to think in renewable and sustainable sources of energy: those that naturally reconstitute themselves in a short period of time. One the alternatives for solving this problem is the energy coming from biomasses, whether animal or vegetable origin, it can be used to production of energy. The briquette is considered a solid biofuel, made from compaction of lignocellulosic residues much used to energy generation. This paper aimed to study production of briquettes from mixtures of urban pruning waste - RPU, from glycerine and cassava bagasse (Manihot esculenta). A prototype drier was used through solar heating to reduce humidity of RPU and cassava samples. Afterwards, samples of RPU, cassava bagasse and glycerin were mixed, yielding the treatments T1 (100% RPU), T2 (92% RPU and 8% Cassava bagasse), T3 (97% RPU and 3% Glycerin), T4 (89% RPU, 8% Cassava bagasse and 3% Glycerin) and T5 (94.5% RPU, 4% Cassava bagasse and 1,5% Glycerin). Then the analyzes of physical, chemical and energetic parameters the briquettes were carried out. The moisture content of the briquettes was lower in T1 treatment (7.935%). T2 treatment had lower fixed carbon value (16.858%) volatile content (66.520%) and higher ash content (16.621%). The percentages of C, H and N did not differ statistically between the treatments. The values of the upper, lower and useful calorific value were higher on T3 (18.973 MJ kg-1); (17,480 MJ kg-1) and (15,980 MJ kg-1) respectively. The apparent density was higher in T1 (1183 kg m-3) as well as energy density (20778.76 MJ m-3). Treatment T2 had the highest mechanical strength (1,281 kgf cm-2). The results, therefore, showed that treatments T1, T2 and T3 were more efficient, producing briquettes with properties that meet specifications of the market, besides presenting great energetic potential, being good substitutes for firewood. Based on information collected in Vera Cruz do Oeste - PR in 2015, approximately 76.92 t ano-1 of briquettes from urban pruning residues could be produced, thus contributing to generation of revenue in the value of R$ 23,614.44.
Ao longo da história, diversas foram as fontes e as formas de energia utilizadas para a produção de bens e de serviços, em especial a energia gerada a partir de combustíveis fósseis, como o petróleo. Em função dos limites de suas reservas mundiais; as emissões de CO2, e os desastres ecológicos a partir da perfuração de poços de petróleo, é fundamental pensar em fontes de energia renováveis e sustentáveis: aquelas que se reconstituem naturalmente, num curto período de tempo. Uma das alternativas para a solução deste problema é a energia proveniente das biomassas, seja de origem animal ou vegetal, que pode ser utilizada na produção de energia. O briquete é considerado um biocombustível sólido, feito a partir da compactação de resíduos lignocelulósicos muito utilizado para a geração de energia. Neste trabalho objetivou-se estudar a produção de briquetes a partir de misturas de Resíduos de Podas Urbanas - RPU, glicerina e bagaço de mandioca (Manihot esculenta). Para a redução da umidade das amostras de RPU e de mandioca, foi utilizado um secador via aquecimento solar. Posteriormente, as amostras dos RPU, do bagaço de mandioca e a glicerina foram misturadas gerando os tratamentos, T1 (100% RPU), T2 (92% RPU e 8% Bagaço de mandioca), T3 (97% RPU e 3% Glicerina), T4 (89% RPU, 8% Bagaço de mandioca e 3% Glicerina) e T5 (94,5% RPU, 4% Bagaço de mandioca e 1,5% Glicerina). Em seguida, foram realizadas as análises de parâmetros físicos, químicos e energéticos dos briquetes. O teor de umidade dos briquetes foi menor no tratamento T1 (7,935%). O tratamento T2 teve menor valor de carbono fixo (16,858%) e teor de voláteis (66,520%) e maior teor de cinzas (16,621%). As porcentagens de C, H e N não diferiram estatisticamente entre os tratamentos. Os valores do poder calorífico superior, inferior e útil foram maiores no tratamento T3 (18,973 MJ kg-1); (17,480 MJ kg-1) e (15,980 MJ kg-1) respectivamente. A densidade aparente foi maior no tratamento T1 (1.183 kg m-3) bem como a densidade energética (20.778,76 MJ m-3). O tratamento T2 teve a maior resistência mecânica (1,281 kgf cm-2). Os resultados, portanto, demonstraram que os tratamentos T1, T2 e T3 foram mais eficientes, produzindo briquetes com propriedades que atendam as especificações do mercado, além de apresentarem grande potencial energético, sendo bons substitutos à lenha. Com base nas informações coletadas no Município de Vera Cruz do Oeste - PR no ano de 2015, poderiam ser produzidos aproximadamente 76,92 t ano-1 de briquetes oriundos de resíduos de podas urbanas, contribuindo desta forma para a geração de receita no valor de R$ 23.614,44.

The greatest political, scientific, and engineering challenge of the 21st century is finding a viable solution to limit anthropogenic greenhouse gas emissions (CO2) to curb the effects of global climate change. All sectors of society need to contribute to alleviate this problem, but industrial operations must play a significant leadership role. Some of these industries include: metallurgy, cement, power, agriculture and forestry. In particular, the iron/steel, cement, and power generation industries use coal on account of its high energy density among solid fuels. Coal combustion yields 720 tonne CO2/GWh, and produces fine particulates, sulphur and nitrous oxides, along with excess CO2 contributing to climate change. In comparison, biomass (such as agricultural and forestry residues) has a solid fuel rating of 25-100 tonne CO2/GWh; therefore, biomass fuels are considered more sustainable since the living biomass consumed CO2 in the early part of its life cycle. However, biomass has significant industrial shortcomings for its use as fuel at large scale, including low energy content, density, and hydrophobicity relative to coal. In short, biomass fuels cannot be substituted without major infrastructure changes which add economic penalties that industry is currently unwilling to absorb. Biomass upgrading routes were considered in this thesis. These include densification, torrefaction, and integrated torrefaction and densification (ITD). The first half of the methodology involved converting woody biomass (willow residue and poplar bark), agricultural residue (switchgrass plants), and pulp mill waste via a single pellet/briquette press at different densification temperatures and pressures. The second half of the methodology involved product characterization of each batch of pellets and briquettes. In this work, pellets and briquettes were tested for physical characteristics (density and durability), chemical differences (energy content and hydrophobicity), and transport phenomena characteristics (drying profiles). First, results showed that extrusion of torrefied biomass at 300°C with an estimated pressure of 10 MPa creates partially formed pellets from agricultural residues. Using the concept of ITD (temperature range 220-325°C and pressure range 40 and 215 MPa), the density was found to be 1000-1250 kg/m3 for pellets and briquettes. The degree of compression from the loose biomass was on the order of 3-10 which corresponds with theoretical expectations. Material density increased with increasing pressure. The solid yield of pellets and briquettes decreased with increasing temperature, and results aligned with micro-scale thermogravimetric analysis. The larger ITD briquettes (produced at T = 325°C, P = 40 MPa) were evaluated for calorific value and found to fall in the lignite classification (O/C < 0.4 and H/C < 1.2) on a van Krevelen diagram. The resulting ITD pellets and briquettes were found to have a durability similar to commercial materials (durability > 97%), and to be more hydrophobic (8 wt% moisture absorption compared to 35 wt%). The drying time of ITD materials was faster than commercial torrefied briquettes, with an effective diffusivity of 1.5×10-6 m2/s compared to 7.3×10-9 m2/s likely because of a smaller pore volume in ITD briquettes. Further pilot scale studies would help improve the ITD methodology and make the process more appealing for the replacement of coal fuels.

The global energy demand supplies mainly from fossil fuels, which is neither sustainable nor environmentally friendly and aims to global warming. Therefore, both more investments in renewable energy sources such as bioenergy are required, as well as new technologies such as carbon capture and storage (CCS) to handle the emissions from existing combined heat and power (CHP) plants. In this degree project, the focus is to determine the moisture content, ash content, heating value, and elemental compositions of solid biofuel mixtures in real-time by utilizing the optical technique of near-infrared (NIR) spectroscopy. A total number of 150 samples of solid biofuel mixtures were prepared and illuminated by NIR light. All spectra of the samples were recorded in a wavenumber range of 12000 cm-1 – 400 cm-1 in a dish on a turn table which was in a moving mode with a speed of 0.5 m/s. Each sample was scanned three times to avoid, or at least minimize the deviation of the spectra and the samples were mixed between each scan to get more reliable representative spectra data. Partial least square regression models were created to analyze the spectra data. A data split was done randomly, 100 for calibration and 50 for validation. Then the data was pre-processed with different methods including multiplicative scatter correction (MSC), standard normal variate (SNV), Savitzky-Golay 1st derivative (SG 1st), Savitzky-Golay 2nd derivative (SG 2nd), and orthogonal signal correction (OSC) to reduce noise and scatter effect. The results of NIR spectra treated by OSC method obtained  , RMSE and SE of 0.900, 2.241 and 2.204, respectively for prediction of moisture content, 0.424, 0.913 and 0.922 for prediction of ash content, 0.640, 0.370 and 0.368 for prediction of heating value, respectively. The obtained prediction of  , RMSE and SE were 0.687, 0.066 and 0.058 for nitrogen, 0.636, 0.361 and 0.364 for carbon, 0.483, 0.269 and 0.270 for hydrogen, respectively. As the results shows, these models to predict the ash content and hydrogen content has a lower accuracy than what is expected in process modeling while the prediction of moisture content has the highest accuracy.

Šio magistro baigiamojo darbo tikslas buvo ištirti trijų energetinių žolinių augalų biometrines bei energetines savybes ir jas palyginti tarpusavyje. Augalai buvo auginami lauko sąlygomis, kiekvieną augalą tręšiant skirtingomis mineralinio azoto normomis (N0 – kontrolė, N60 – 200 kg ha-1 ir N120 – 400 kg ha-1). Buvo tiriami pagrindiniai biometriniai rodikliai: augalų aukštis, augalų stiebų skaičius, sausoji biomasė, chlorofilo indeksas. Taip pat ištirtas pasirinktų augalų šilumingumas, peleningumas, pagrindiniai elementai (C, H, N, S, O) bei šalutiniai elementai (K, Ca, Mg, P, Al, Si, S), taip pat sunkieji metalai. Visų augalų energetinės savybės palygintos tarpusavyje. Vertinant gautus duomenis, tinkamiausi žoliniai augalai biokurui yra sida ir drambliažolė, kadangi jų peleningumas yra mažiausias. Tačiau nendrinio dryžučio, nors ir išsiskyrė didesniu peleningumu, šilumingumas buvo didžiausias. Cheminės sudėties analizės metu buvo nustatyta, jog papildomas tręšimas azotinėmis trąšomis įvairių elementų kiekiui augaluose didelės įtakos neturėjo, tačiau vertinant šalutinių elementų kiekį augaluose pastebėta tai, jog kai kurių cheminių elementų padidėjimą galėjo lemti ir augalų augimo vieta (atvira pieva, šalia žvyrkelio, šalia kelio, šalia dirbamo lauko ir pan.).
This master's thesis was to analyze three energy plant grass biometric and energy properties and to compare them with each other. Plants were grown in field, every plant fertilized with different rates of nitrogen (N0 - control, N60 - 200 kg ha-1 and N120 - 400 kg ha-1). It was investigated the main biometric parameters: plant height, plant stems, dry biomass and chlorophyll index. Also plants calorific value, ash content, the main elements (C, H, N, S, O) and minor elements (K, Ca, Mg, P, Al, Si, S) and heavy metals. Plant‘s energy properties were compared with each other. Evaluating the data, the optimum herbaceous plant for biofuels are sida and Miscanthus as their ash content is lowest. Reed canary grass calorific value was highest, but it stood higher ash content too. Chemical composition analysis showed that the additional nitrogen fertilization had no major impact of the various elements in plants, but by assessing the amount of elements in plants is noticeable that plant growth and position may impact some chemical elements increase (open meadow, near the gravel, next to the road, arable land, etc.).

The use of bioenergy has been increasing due to efforts in fossil fuels replacement. Modern bioenergy technologies aim for high efficiency and low pollution levels, which increases the need for methods for the on-line characterization of biofuels. Dielectric methods have been identified as useful for the sensing of solid biofuels because they allow for rapid, nonhazardous, nondestructive, and bulk determination of material properties. The dielectric properties describe the interaction between the material and the electromagnetic waves. Dielectric properties are intrinsic of the materials and can therefore be used for the development of prediction models that can be applied regardless of the measurement technique. The study of the dielectric properties is also important as it improves the understanding of the dielectric behavior of the materials. This thesis focuses on the dielectric properties of solid biofuels and their use in the characterization of these materials. The work presented includes the development of new methods permitting the determination of the dielectric properties of solid biofuels with large particle size (waveguide method), broadband measurement of the dielectric properties (coaxial-line probe), and the use of a previously developed method for the accurate determination of the dielectric properties (free-space method). The results includes the dielectric properties of solid biofuels and their dependence on parameters such as frequency, moisture, density, and temperature. This thesis also presents semi-theoretical models for the determination of moisture content, which obtained a RMSEP of 4% for moisture contents between 34 and 67%, and an empirical model that resulted in a RMSEC of 0.3% for moisture contents between 4 and 13%. Finally, this thesis includes measurements of the influence of salt content on the dielectric properties and a discussion of its use for estimation of the ash content of solid biofuels. 

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FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul
A intensa geração de resíduos sólidos urbanos aliada a uma expansão acentuada do consumo energético, apresenta-se como um dos maiores desafios ambientais. Em relação aos resíduos sólidos, fatores como dificuldades de gerenciamento, natureza química dos resíduos e sua complexidade impulsionam a busca de tecnologias limpas e, consequentemente, soluções que atendam à sociedade. Este estudo aplicou a tecnologia de pirólise para conversão de papel moeda descartado com o objetivo de avaliar o potencial de desenvolvimento de biocombustível produzido a partir do bio-óleo gerado no processo pirolítico. O resíduo de papel moeda foi caracterizado por análise imediata, termogravimétrica (TGA) e fluorescência de raio X (FRX). Os ensaios pirolíticos foram conduzidos em reator a vácuo, na temperatura de 500º C e avaliados os rendimentos dos bio-produtos gerados. O bio-óleo foi caracterizado através dos parâmetros de pH, conteúdo de água, ponto de fulgor, condutividade elétrica, índice de acidez, número de cetano, poder calorífico e análise de metais por FRX. O surfactante propilenoglicol, demonstrou a uma temperatura de 25°C, um tempo de estabilização de 107s + 12, o Tween 20 cerca de 57s + 8 e o Monoesterato de glicerina 48s + 11. Misturas binárias de 1%, 2% e 3% (m/m) de bio-óleo pirolítico e diesel petroquímico foram preparadas em diferentes condições de agitação e temperatura, sendo a estabilidade das emulsões avaliada pelo índice de emulsificação (IE). A tecnologia adotada resultou em uma redução mássica de 81,5%, um rendimento de bio-óleo de 43% (m/m) e de bio-carvão 18,5% (m/m). A caracterização físico-química do bio-óleo indicou a ausência de metais oriundos da tinta de impressão do papel moeda. Foi constatado um melhoramento das características físico-químicas do bio-óleo, mediante a elaboração de misturas binárias (emulsões) com o óleo diesel, potencializando a sua utilização em diferentes tecnologias que promovam geração de energia, como motores a diesel, turbinas a gás e caldeiras. Finalmente, emulsões estáveis, com IE de 69% a 77% em 5 horas, foram verificadas nas condições de 2500 rpm e 3500 rpm, respectivamente.
The intense generation of municipal solid waste combined with a marked expansion of energy consumption, is presented as one of the greatest environmental challenges. For solid waste, factors such as management difficulties, chemical nature of the waste and its complexity drive the search for clean technologies and hence solutions that meet the society. This study applied pyrolysis technology to convert paper money droppedin order to assess the development potential of biofuel produced from bio-oil generated in the pyrolytic process. The residue of paper currency was characterized by immediate analysis, thermogravimetric (TGA) and X-ray fluorescence (XRF). Pyrolytic reactor experiments were conducted in vacuum, at a temperature of 500 ° C and evaluated yields of bio-products generated. The bio-oil was characterized by parameters of pH, water content, flash point, electrical conductivity, acidity, number of cetane, heat and power metal analysis by FRX. The surfactant propylene glycol, showed a temperature of 25 ° C a stabilization time of 107s + 12, Tween 20 + 8 about 57s and 48s glycerin monostearate + 11. Binary mixtures of 1%, 2% and 3% (w / w) of pyrolytic bio-oil and petrochemical diesel fuel were prepared at different agitation conditions and temperature stability of the emulsions is assessed by emulsification index (SI). The technology adopted resulted in a weight reduction of 81.5%, a yield of bio-oil 43% (w/w) and bio-coal 18.5% (w/w). The physicochemical characterization of bio-oil indicated the absence of metals originating from ink print paper money. An improvement in physico-chemical characteristics of bio-oil was identified by preparing binary mixtures (emulsions) with diesel oil, enhancing its use in different technologies that promote energy generation such as diesel engines, gas turbines and boilers. Stable emulsions with IE of 69% to 77% in 5 hours, were observed in the conditions of 2500 rpm and 3500 rpm, respectively.

Energy is an important requirement for population growth, technological progress and urbanisation. Worldwide energy demand has been projected to increase by 5-fold by 2100. Fulfilment of these energy requirements cannot be solely from fossil fuels, such as oil, coal and natural gas, on account of their adverse environmental impacts and concomitant depletion of natural resources. As a result multiple approaches for generating alternative energy are being explored globally. In this study, processed municipal solid waste (MSW) fibre was assessed as a substrate for the production of various bio-energy related products. The MSW was characterised and the results showed that there was, as expected, a wide compositional variation between samples. There was a significant amount of lignocellulosic material found in some samples and the potential to exploit this to generate fermentable sugars was explored. Direct enzyme hydrolysis using 30 FPU (Filter Paper Units)/g Cellic® CTec2 gave a 30 % release of available glucose. Pre-treatments- using hot water, dilute acid and dilute alkali are all applied to enhance sugar release but were all found to be ineffective. The possibility of using MSW as a substrate for cellulase enzyme production via solid state fermentation (SSF) by Trichoderma reesei (T. reesei) and Aspergillus niger (A. niger) was explored. Both fungi grew well on the substrate and following optimization a cellulase activity of 26.10±3.09 FPU/g could be produced using T. reesei at 30 °C with a moisture content of 60 % with inoculation of 0.5 million spores/g and incubation for 168 hr. Addition of extra nitrogen and/or carbon did not improve cellulase accumulation. Acid or alkali pre-treatment of MSW led to reduced cellulase production. Crude enzymes produced from MSW by T. reesei were evaluated for their ability to release glucose from MSW. A cellulose hydrolysis yield of cellulase was 24.7 % achieved, which was close to that obtained using a commercial enzyme. Results demonstrated that MSW could be used as an inexpensive lignocellulosic material for the production of cellulase enzymes. High concentrations of toxic heavy metals were found in all MSW samples tested and this precludes the use of this material as a soil enhancer. Thus studies were undertaken to explore the potential for bioleaching as a means to generate compost that meets environmental standards for safe use. A. niger and Saccharomyces cerevisiae NCYC2592 were used and the impact of growth medium and pH tested. Both organisms were effective at solubilising the heavy metals and this may be related to their ability to synthesise organic acids into the fermentation medium that act as chelators.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
This study aimed to investigate different types of materials for the production of compressed biofuel. The selected materials were: tree pruning waste, corrugated cardboard, cartons and sludge of water treatment obtained by flotation technique; these materials were chosen because of its abundance in the urban environment, the ease of finding them in urban areas and also the few studies related to them. The studywas divided into three chapters: in chapter I, was determinedthe physical, chemical and thermal characteristics of the residuesto give support for the subsequent chapters. In chapter II briquettes composed of mixtures of these residues were produced, using the urban pruning residues as the basis for the different blends, mainly because of its lignocellulosic composition; chemical and physical analysis were also made in the briquettes to analyze if the compactation process of the mixtures was effective and if the final product has favorable characteristics for energy use. In chapter III was described the production and evaluation of pellets composed by municipal solid waste, and similarly, we used the urban pruning residues as the main material for the blends with the other materials. After all analysis, it was observed that the urban pruning residues, the corrugated cardboard andthe aseptic cartons showed positivecharacteristics for use as biofuel, but the flotation sludge showed aninorganic character, presenting a low calorific value and high ash content. Nevertheless, the sludge was used for the production of briquettes and pellets in order to evaluate possible mixtures to minimize those problems. Even for the briquettes or for the pellets it was observed that the addition of sludge in the composition provided increases in the strength and density, but reduced the calorific value and increased the ash content. The incorporation of cardboard or carton caused an increase in density and strength and a small reduction in calorific value. It could be concluded that the municipal solid residues used in this researchhad characteristic to use them to produce compressed fuelsas asustainable alternative for energy production. Regards about the mixing ratios of the residues should be taken to optimize the overall process.
Este estudo teve por objetivo pesquisardiversos tipos deresíduos sólidos urbanos para a produção de combustíveis compactados. Foram selecionados resíduos de poda de árvores, papelão ondulado, embalagens cartonadas e lodo de tratamento de águas pela técnica de flotação. Optou-se por estes materiais devido a sua representatividade no ambiente urbano, pela facilidade em encontra-los e também por haver poucos estudos relacionados a eles. O trabalho foi dividido em três etapas, inicialmente, foram determinadas as características físicas, químicas e térmicas dos resíduos como forma de embasamento para os próximos capítulos. Na sequencia foram produzidos briquetes compostos por diferentes proporções destes resíduos, usando como base para as misturas os resíduos de podade árvores devido sua composição lignocelulósica; também foram feitas análises químicas e físicas nos briquetes para avaliar se o processo de compactação das misturas foi eficiente e se o produto final apresentou características energéticas favoráveis ao uso. Finalmente, avaliou-sea produção de pellets produzidos com os resíduos sólidos urbanos, e da mesma forma, utilizaram-se os resíduos de poda urbana como base para as misturas com os outros materiais. Após as análises observou- se que, os resíduos de poda urbana, papelão ondulado e embalagens cartonadas apresentaram características favoráveis para o uso como biocombustível, porém o lodo de flotação apresentou caráter inorgânico, com baixo poder calorífico e alto teor de cinzas. Apesar disso, o lodo foi utilizado para a produção dos briquetes e pellets com o intuito de avaliar possíveis misturas que minimizem estes problemas. Tanto para os briquetes quanto para os pellets, observou-se que a adição de lodo na composição destes materiais proporcionou incrementos na resistência e densidade, porém reduziu o poder calorífico a aumentou o teor de cinzas. A incorporação de papelão ou embalagens cartonadas ocasionou aumento na densidade e na resistência e uma pequena redução no poder calorífico. Conclui-se que os resíduos sólidos urbanos utilizados neste estudo apresentaram potencial para produção de combustíveis compactados, tornando-se uma alternativa sustentável para produção de energia, desde que otimizadas as proporções das misturas de materiais.

This project aimed investigated cellulase in-situ production for large-scale on-farm production of lignocellulosic biofuel. Cellulase activity and glucose released by T. reesei with corn stover and wheat bran as co-substrates for solid state cultivation (SSC) were examined. Co-cultivation has previously increased T. reesei cellulase, but corn stover and wheat bran have not been co-cultivated (Dhillon, Oberoi et al. 2011). This work compared cellulase activity and glucose concentration of corn stover co-cultivated with 0-40% wheat bran in high solids. Samples with at least 20% wheat bran exhibited increased cellulase activity. However, the average glucose concentration without wheat bran was 3.29 g/L compared to 16.7 g/L with wheat bran. Glucose released by T. reesei on pretreated corn stover with 0-40% wheat bran was compared at the optimal temperatures for fungal growth and for cellulase activity after SSC. Previous research has rarely used cellulase from SSC to hydrolyze lignocellulose. Following SSC of T. reesei at 30°C for seven days, samples were warmed to 50°C for five days. Glucose concentration increased to 12.1 and 32.7 g/L for samples with and without wheat bran. This strategy could reduce lignocellulosic fuel production costs by eliminating need for commercial cellulase and is promising for efficient cellulose hydrolysis.

Biofuels production and utilisation can reduce the emission of greenhouse gases, dependence on fossil fuels and also improve energy security. Ethanol is the most important biofuel in the transportation sector; however, its production from lignocelluloses faces some challenges. Conventionally, lignocellulosic hydrolysis and fermentation has mostly been performed by separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF). SHF results in product inhibition during enzymatic hydrolysis and increased contamination risk. During SSF, suboptimal conditions are used and the fermenting organism cannot be reused. Bacterial contamination is another major concern in ethanol production, which usually results in low ethanol yield. In these studies, the above-mentioned challenges have been addressed. A novel method for lignocellulosic ethanol production ‘Simultaneous saccharification filtration and fermentation (SSFF)’ was developed. It circumvents the disadvantages of SSF and SHF; specifically, it uses a membrane for filtration and allows both the hydrolysis and fermentation to be carried out at different optimum conditions. SSFF also offers the possibility of cell reuse for several cultivations. The method was initially applied to pretreated spruce, with a flocculating strain of yeast Saccharomyces cerevisiae. SSFF was further developed and applied to pretreated wheat straw, a xylose rich lignocellulosic material, using encapsulated xylose fermenting strain of S. cerevisiae. High solids loading of 12% suspended solids (SS) was used to combat bacterial contamination and improve ethanol yield. Oil palm empty fruit bunch (OPEFB) was pretreated with fungal and phosphoric acid in order to improve its ethanol yield. An evaluation of biofuel production in Nigeria was also carried out. SSFF resulted in ethanol yield of 85% of the theoretical yield from pretreated spruce with the flocculating strain. Combination of SSFF with encapsulated xylose fermenting strain facilitated simultaneous glucose and xylose utilisation when applied to pretreated wheat straw; this resulted in complete glucose consumption and 80% xylose utilisation and consequently, 90% ethanol yield of the theoretical level. High solids loading of 12% SS of pretreated birch resulted in 47.2 g/L ethanol concentration and kept bacterial infection under control; only 2.9 g/L of lactic acid was produced at the end of fermentation, which lasted for 160 h while high lactic acid concentrations of 42.6 g/L and 35.5 g/L were produced from 10% SS and 8% SS, respectively. Phosphoric acid pretreatment as well as combination of fungal and phosphoric pretreatment improved the ethanol yield of raw OPEFB from 15% to 89% and 63% of the theoretical value, respectively. In conclusion, these studies show that SSFF can potentially replace the conventional methods of lignocellulosic ethanol production and that high solids loading can be used to suppress bacterial infections during ethanol productions, as well as that phosphoric acid pretreatment can improve ethanol yield from lignocellulosic biomass.

Thesis for the degree of Doctor of Philosophy at the University of Borås to be publicly defended on 31 October 2014, 10.00 a. m. in room E310, University of Borås, Allégatan 1, Borås.

Com os planos de descarbonização de diversos países do mundo, o contínuo crescimento do mercado mundial dos pellets de madeira tende a aumentar, e para atender a demanda será necessário à inclusão de países emergentes dos quais revelam potencial o Brasil, dado que possui grande vocação na produção sustentável de florestas para produção de madeira do gênero Eucalyptus ssp., que apresenta produtividade entre 30% a 50% superior a qualquer pais do mundo, tornando-se a espécie ideal para produção em escala de biomassa para energia. O problema central consiste em viabilizar a produção sustentável de pellets de madeira, que possam atender a demanda nacional e internacional. Contudo este estudo inicialmente identificou a oferta e demanda de madeira para energia por tipo e fonte, posteriormente foram levantados os potenciais produtivos de florestas energéticas de curta rotação, para atender a iminente demanda nacional e internacional de madeira para energia, e finalmente foram detectados os problemas presentes na biomassa sólida vegetal do gênero Eucalyptus ssp., no Brasil. Como resultado este estudo mostra o potencial de produção sustentável de eucalipto de curtas rotação a 150 km dos portos brasileiros para produção e exportação de pellets, como também tem como resultado uma patente de invenção (BR 10 2016 023862 5) que resulta na extração a níveis aceitáveis pelas normas ENplus e semelhantes das emissões de cloro da madeira, e de metais alcalinos, fator limitante para o uso da biomassa na produção de pellets combustível. Evitando assim a formação de dioxinas, e organoclorados que prejudicam a saúde humana e propiciando também redução da formação de cinzas, diminuindo a corrosão dos equipamentos de combustão para produção de energia através de biocombustíveis sólidos.
The decarbonization plans worldwide, the world market of wood pellets tends to increase, and to meet the world demand it will be necessary to include emerging countries which show potential such as Brazil, as it has a great vocation in sustainable production of Eucalyptus wood and has higher productivity than any other country in the world, it is the ideal forest species for wood pellets production for energy in Brazil. The central problem is to enable the sustainable production, which can meet domestic and international demand of woody biomass for energy. This study initially identified the wood supply and demand for energy by type and source, and it was later raised to the productive potential of energy forests; finally it was detected the problems in solid biomass in Brazil. Results of this study show the sustainable production potential of short rotation Eucalyptus in range of (150 km) of Brazilian ports, aiming to pellets export, as well as this study has resulted in a patent, number: (BR 10 2016 023862 5), resulting in reduced to acceptable levels (ENplus), by the relevant rules of chlorine emissions, thus preventing the formation of dioxins, and allowing removal of alkali metals thereby reducing the formation of ash and decreasing the corrosion of combustion systems for energy production by solid biofuels.

Orientadores: Rubens Maciel Filho, Célia Maria Araujo Galvão
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: O objetivo deste trabalho foi otimizar a produção de celulases, a partir de substratos alternativos, entre eles o bagaço de cana de açúcar, no processo de fermentação em estado sólido, utilizando o microrganismo Aspergillus niger. Na primeira etapa do trabalho foi realizada a identificação dos componentes do meio de cultura que mais favorecem o aumento da produtividade das celulases, entre eles foram avaliados: substrato (bagaço de cana in natura ou pré-tratado por explosão a vapor); fonte de carbono (lactose e extrato de soja) e a fonte de nitrogênio (peptona e extrato de levedura). Na segunda etapa do trabalho, a partir destas variáveis foi realizada a otimização da produção de celulases de acordo com um delineamento composto central rotacional (DCCR). Para isso foi utilizado um planejamento fatorial completo 2 , incluindo 6 pontos axiais e 4 repetições no ponto central. Finalmente, utilizando a técnica de regressão linear múltipla foi realizada a modelagem matemática para produção de celulases. A produção de celulases foi determinada baseada na atividade enzimática do complexo produzido nos ensaios: celulase total (FPAse); carboximetilcelulase (CMCase) e p- glucosidase. Os resultados mostraram que a máxima produção de celulaces, para um período de fermentação de 4 dias foi: 0,774 UI/g.s.s de FPAse; 14,41 UI/g.s.s de CMCase e 26,37 UI/g.s.s de p-glucosidase. As condições nas quais a máxima produção foi atingida foram: concentração de extrato de soja de 11 g/L; concentração de extrato de levedura de 1,5 g/L e porcentagem de umidade 80%. Esses resultados são bastante promissores levando em conta a identificação do extrato de soja como indutor da produção de celulases e do extrato de levedura, componentes que seriam de fácil e baixo custo de disponibilização no Brasil, que impactariam na redução global do custo de produção de celulases
Abstract: The objective of this work was the optimization of cellulases production, from alternatives substrates, such as sugarcane bagasse, in a process of solid state fermentation by Aspergillus niger. In the first project stage was identified the main components of culture medium: substrate (sugarcane bagasse in natura or pretreated by steam explosion); carbon source (lactose and soybean extract) and the source of nitrogen (peptone and yeast extract). In the second stage of the work, from that variables was optimized cellulases production, according to a central composite rotational design (DCCR). It used a full factorial 2 , including six axial points and 4 replications at the central point. Finally, it using the multiple linear regression was carried out the mathematical models for cellulases production. Thus, we evaluated the influence of selected variables on the production of cellulases quantified as three types of enzymatic activity: total cellulase (FPAse); carboximetilcelulase (CMCase) e p- glucosidase. The maximum production of cellulases was: 0,774 IU/g.d.s of FPAse; 14,41 IU/g.d.s of CMCase and 26,37 IU/g.d.s of p- glucosidase, for a period of 4 days of fermentation. And, the conditions in which maximum production was reached were: concentration of soybean extract 11 g/L, yeast extract concentration of 1,5 g/L and 80% moisture content. These results are very promising, considering the identification of the soybean extract as a inductor of cellulases production, and the least extract, these items are purchased at a low cost in Brazil, that impact in the reduction of global cost of cellulases production
Mestrado
Desenvolvimento de Processos Biotecnologicos
Mestre em Engenharia Química

Ameaças na sustentabilidade do desenvolvimento mundial em consideração ao aquecimento global, a dependência energética e a demanda exponencial pela produção de alimentos têm levado ao crescente interesse por fontes alternativas renováveis de energia como a biomassa vegetal. Neste cenário, a viabilização do etanol sem competição por terra cultivável a partir do bagaço de cana-de-açúcar (BC) pela rota enzimática é peça chave para a produção integrada e sustentável dos biocombustíveis visando otimização de recursos, redução de resíduos e minimização de impactos ambientais negativos. Entretanto, a sua comercialização precisa ser ainda consolidada através da economicidade nos insumos de hidrólise (enzimas celulases) e de uma maior eficiência na etapa de pré-tratamento da lignocelulose. Dessa forma, este trabalho teve como objetivo contribuir na redução dos custos de produção celulases utilizando um resíduo característico da indústria brasileira, o BC, para produção de celulases específicas através da tecnologia de fermentação em estado sólido com o microorganismo Aspergillus niger. A proposta desenvolvida consiste em bioprocesso com pré-tratamento hidrotérmico do BC condizente a seu uso como substrato fermentativo, complementação deste substrato com 35% de farelo de soja e meio de suplementação com acréscimo de protéicas, umidade de fermentação de 80% e uso de circulação forçada em bioreator de coluna instrumentado visando o balanço hídrico e térmico do processo. As celulases específicas assim produzidas exibiram atividades de FPase: 0,045; CMCase: 1,10; xilanase: 9,17 e \'beta\'-glicosidase:0,33 UI/mL, e sua ação sinérgica sobre o BC explodido resultou na conversão em açúcares redutores de 15% após 22 horas de hidrólise. A direta aplicabilidade e especificidade do coquetel enzimático produzido mostram a proposta do bioprocesso como uma tecnologia de elevado potencial de integração no modelo de produção de etanol celulósico, anexo a uma usina convencional. Esta alternativa de desenvolvimento a maior escala indica uma oportunidade nacional para o crescimento sustentável na produção de bioetanol e a expansão das vantagens associadas com o uso de biocombustíveis no âmbito mundial.
Threats to sustainability of world development in regards to global warming, energy dependence and the exponential demand for food production have led to growing interest in alternative renewable sources of energy such as biomass. In this context, the viability of ethanol from sugar cane bagasse cane (SCB) by enzymatic pathway, without competition for farmland, is the key for sustainable and integrated biofuels production aiming to optimize resources, waste reduction and negative environmental impacts minimization. However, its commercialization needs to be further consolidated through the economy of hydrolysis enzymes (cellulases) and efficiency improvements in lignocellulosic pre-treatment. Thus, this study aimed to contribute for the reduction of costs in cellulases production using a traditional brazilian industrial waste, the SCB, in order to obtain specific cellulases with the microorganism Aspergillus niger by solid state fermentation. The proposal of bioprocess developed consists of SCB hydrothermal pre-treatment towards to its use as fermentation substrate, complementation of this substrate with 35% of soybean bran and supplementation medium with protein sources addition, moisture fermentation of 80% and use of a column bioreactor instrumented with forced aeration aiming suitable control of water and thermal balance of the process. Thus, specific cellulases produced exhibited activities of FPase = 0.045; CMCase = 1.10; xylanase = 9.17 and -glucosidase = 0.33 IU/mL, and their synergy action over exploded SCB resulted in 15% of reducing sugar conversion after 22 hours of hydrolysis. The direct applicability and specificity of the enzymatic cocktail produced shows the proposed bioprocess as a high potential technology for integration into the production model of cellulosic ethanol, joint to a conventional power plant. This development alternative to larger scale indicates a national opportunity for sustainable growth in bioethanol production and associated benefits expansion with the worldwide use of biofuels.

Studien syftade till att ge en rekommendation angående hur fjärrvärmebolaget Stockholm Exergi bör utforma sin framtida strategi beträffande fasta oförädlade skogliga biobräanslen. Genom litteraturstudier och intervjuer utreddes dessa bränslens konkurrenskraft utifrån perspektiven klimatneutralitet, politiska direktiv och styrmedel, leveranssäkerhet samt lönsamhet. Resultatet visade bland annat att användningen av grenar och toppar kan medföra klimatnytta. Vidare framkom att implementeringen av EU:s nya förnybartdirektiv inte kommer att ha storskalig påverkan på Stockholm Exergis framtida användning av dessa bränslen. Gällande leveranssäkerhet och lönsamhet påvisades exempelvis en större framtida efterfrågan på skogliga restprodukter från andra sektorer. Ändock kunde slutsatsen dras att skogliga biobräanslen, under vissa förutsäattningar, har en viktig roll i Stockholm Exergis framtida fjärrvärmeproduktion.
The study aimed to give a recommendation regarding how the district heating company Stockholm Exergi should design their future strategy concerning unprocessed solid woody biofuels. Through literature studies and interviews, the competitiveness of the fuels has been assessed based on climate neutrality, political directives and instruments, security of supply as well as profitability. Among other things, the results showed that the use of tree branches and tops can imply positive climate effects. Furthermore, the implementation of EU's new renewable energy directive will only have a marginal impact on Stockholm Exergi's future use of woody biofuels. Regarding the security of supply and profitability,an increased future demand of forest residues in other sectors have been identified. However, the study concludes that, under certain circumstances, woody biofuels have an important role in Stockholm Exergi's future district heating production.

碩士
國立臺灣大學
環境工程學研究所
102
The pulp industry in Taiwan produce tons of organic wastewater sludge and wood waste per year. These biowastes were then converted to organic fertilizers for agriculture uses or soil conditioners. The biowaste can also be used in different ways to mitigate the energy shortage. This study investigates a biowaste-to-energy (BTE) method to convert pulp industry waste into solid biofuel via torrefaction. The pulp waste examined is the mixture of wood waste and secondary sludge obtained from a virgin pulp factory in eastern Taiwan (denoted as wood with pulp sludge, WPS).Two batches of WPS were received and tested, namely, WPS1 and WPS2, which contain about 95 and 80 wt.% combustibles in dry basis. The biowaste WPS has a high content of organic compounds with the dry basis high heating value of 3,757 to 4,374 kcal/kg and can be used as raw materials for producing primary solid biofuel. However, the wet WPS bears high water (>50 wt.%) and volatiles contents and needs de-watering, drying and upgrading. The results of this study show that after 20 min torrefaction at 300 °C, the HHVD of WPS1 can be promoted to 6,570 kcal/kg, while after 20 min torrefaction at 320 °C, the HHVD of WPS2 increases to 4,718 kcal/kg. Both cases also have better combustion performance. The results also indicate that the energy densification of torrefied solid biofuel can rise to 1.26-1.50 time than the raw biowaste. The condensable gaseous by-products portions of were condensed and collected as liquid products which is essentially an organic acid liquid (wood vinegar) having highly economic value. Both condensable liquid and non-condensable gaseous by-products were analyzed. The liquid product of case WPS1 include some esters and amides, while those of case WPS2 consist of some alkanes and alcohols. The carbon numbers of alkanes in liquid of case WPS2 are above 10, which indicate that the liquid products can use for liquid fuels after purification. From this study, WPS1 and WPS have different characteristics due to different operation, collection and handling conditions when producing pulp sludge at different times. Therefore, some characteristics analysis should be conducted before mixing the pulp sludge and wood waste in order to provide information for choosing better torrefaction conditions. Moreover, because the combustion performance of torrefied WPS is similar to that coal, the torrefied solid biofuel can be mixed with coal and used in power plant directly. This thus reduces the usage of fossil fuels.

Current methods of ranking and selecting biomass fuels are based on short lists of factors. The objective of this thesis is to develop and demonstrate a fuel ranking tool. Existing fuel decision methods and bioenergy technology are reviewed. A fuel ranking tool is then developed and demonstrated. Finally, a procedure for evaluating the thermal efficiency of a pellet stove bioenergy system is developed and implemented. The tool is designed to be applied by an engineer working in cooperation with the actual fuel user. The user identifies a list of all available fuels which are compatible with their specific energy system. The ranking tool is suitable for users of any sized bioenergy system used for space heating, processing heating, or electricity generation. Through effective communication the engineer lists the user’s performance requirements. Requirements considered in this thesis are economic cost of fuels, required storage space, combustion equipment cleaning, and air pollutants emitted during biofuel combustion. Performance indicators corresponding to the user’s requirements are then selected or developed by the engineer. Data is then collected by the engineer to be used for the evaluation of these indicators. The indicators are then combined using weighting factors by the engineer to assign a single numerical score to each fuel. These scores allow the fuels to quickly and easily be ranked by the user according to how well they satisfy the user’s requirements. The ranking tool is demonstrated by applying it to a situation of a pellet stove user with 3 available fuel types. The three fuels are ranked in terms of their ability to satisfy the user’s requirements with respect to economic cost, storage space, equipment cleaning, certain air pollutant emissions, and supporting the local economy. A pellet stove thermal efficiency evaluation method is used to determine the percentage of fuel heating value delivered as space heat to the room housing the stove. Natural and forced convection as well as radiation heat transfers are modeled. The procedure results in a thermal efficiency measurement of 62% +/- 1% and 58% +/- 1% for premium wood and wheat straw pellets, respectively.

abstract: Emergent environmental issues, ever-shrinking petroleum reserves, and rising fossil fuel costs continue to spur interest in the development of sustainable biofuels from renewable feed-stocks. Meanwhile, however, the development and viability of biofuel fermentations remain limited by numerous factors such as feedback inhibition and inefficient and generally energy intensive product recovery processes. To circumvent both feedback inhibition and recovery issues, researchers have turned their attention to incorporating energy efficient separation techniques such as adsorption in in situ product recovery (ISPR) approaches. This thesis focused on the characterization of two novel adsorbents for the recovery of alcohol biofuels from model aqueous solutions. First, a hydrophobic silica aerogel was evaluated as a biofuel adsorbent through characterization of equilibrium behavior for conventional second generation biofuels (e.g., ethanol and n-butanol). Longer chain and accordingly more hydrophobic alcohols (i.e., n-butanol and 2-pentanol) were more effectively adsorbed than shorter chain alcohols (i.e., ethanol and i-propanol), suggesting a mechanism of hydrophobic adsorption. Still, the adsorbed alcohol capacity at biologically relevant conditions were low relative to other `model' biofuel adsorbents as a result of poor interfacial contact between the aqueous and sorbent. However, sorbent wettability and adsorption is greatly enhanced at high concentrations of alcohol in the aqueous. Consequently, the sorbent exhibits Type IV adsorption isotherms for all biofuels studied, which results from significant multilayer adsorption at elevated alcohol concentrations in the aqueous. Additionally, sorbent wettability significantly affects the dynamic binding efficiency within a packed adsorption column. Second, mesoporous carbons were evaluated as biofuel adsorbents through characterization of equilibrium and kinetic behavior. Variations in synthetic conditions enabled tuning of specific surface area and pore morphology of adsorbents. The adsorbed alcohol capacity increased with elevated specific surface area of the adsorbents. While their adsorption capacity is comparable to polymeric adsorbents of similar surface area, pore morphology and structure of mesoporous carbons greatly influenced adsorption rates. Multiple cycles of adsorbent regeneration rendered no impact on adsorption equilibrium or kinetics. The high chemical and thermal stability of mesoporous carbons provide potential significant advantages over other commonly examined biofuel adsorbents. Correspondingly, mesoporous carbons should be further studied for biofuel ISPR applications.
Dissertation/Thesis
M.S. Chemical Engineering 2011