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Abraham, Thomas Kannankara. "Kinetic bounds on attainability in the reactor synthesis problem." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1126791863.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvi, 190 p.; also includes graphics (some col.). Includes bibliographical references (p. 182-190). Available online via OhioLINK's ETD Center
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Sahin, Kemal Hunkar. "COMBINED SAFETY AND ECONOMIC OPTIMALITY IN CHEMICAL PROCESS DESIGN." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin973708026.
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Nordström, Peter. "Minimizing Liquid Waste in Peptide Synthesis : A New Application for the Rotating Bed Reactor." Thesis, Umeå universitet, Institutionen för fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184016.
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Peptide drugs are used to treat a broad spectrum of diseases such as cancer and HIV and have many more promising applications, such as new vaccines against SARS-CoV-2. The most popular manufacturing method for peptides is solid-phase peptide synthesis (SPPS). The main drawback of SPPS is that it is a costly and wasteful process. SpinChem is a company that provides technology solutions for chemical processes. Recently, SpinChem has started investigating if their Rotating Bed Reactor (RBR) is suitable for peptide synthesis. The goal of this project is to investigate how the RBR can make processes like SPPS more resource-efficient. The idea is that the RBR-system can maximize the solid-phase to liquid ratio (STL). The STL is the ratio of the volume of solid-phase material and the volume of liquid. By maximizing the STL, it is possible to manufacture peptides using less solvents and chemicals. The main quest of the project is formulated into a single question: How does a high STL affect the efficiency of the RBR-system? To answer the question, Minitab's statistical software and design of experiments (DOE) will be used to plan and perform experiments in both lab- and industrial scales. DOE factorial experiments are used to gain as much information as possible about the new RBR-system. The results are analyzed and summarized to make a solid foundation for the continued work on the new RBR application. Peptide synthesis efficiency in the RBR-system is measured using ionic adsorption. The ionic adsorption rate is measured in both lab-scale and industrial-scale experiments. In the lab-scale experiments, the decrease of ions was on average 86,5% after just 15 s with an average STL of 0,936. The industrial-scale experiments showed a similar result where the average decrease in ions was 92,9% after 20 s with an average STL of 0,947. It was concluded that the RBR-system can reduce the consumption of washing-solvent in SPPS by up to 82%.
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Betke, Annika [Verfasser], and Guido [Akademischer Betreuer] Kickelbick. "A comparison of synthetic strategies for the synthesis of metal oxide nanoparticles : reactive milling and microjet reactor process / Annika Betke. Betreuer: Guido Kickelbick." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2014. http://d-nb.info/1059390477/34.
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Betke, Annika Verfasser], and Guido [Akademischer Betreuer] [Kickelbick. "A comparison of synthetic strategies for the synthesis of metal oxide nanoparticles : reactive milling and microjet reactor process / Annika Betke. Betreuer: Guido Kickelbick." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:291-scidok-59100.
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Mahmoudi, Hamid. "Performance of cobalt-based eggshell catalyst in low-temperature Fischer-Tropsch synthesis process to produce long-chain hydrocarbons from synthesis gas utilizing fixed-bed reactor technology." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5656/.
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Preliminary studies of the Fischer-Tropsch synthesis (FTS) process were begun in 2010 at the University of Birmingham. A mini-scale F-T plant was designed and built at the School of Mechanical Engineering to study the production of long-chain hydrocarbons over a cobalt-based FTS process. For this purpose, a series of eggshell cobalt catalysts supported with silica powder with a dissimilar porous structure were investigated to examine the effect of support variables on the catalysts’ performance. The prepared catalysts were characterized with nitrogen adsorption/desorption, X-Ray Diffraction (XRD), Temperature-Programmed Reduction (TPR), Scanning-Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) experiments to ensure the qualification of the catalysts for the F-T plant. A highly metal-dispersed catalyst was achieved by controlling three key parameters: (i) cobalt content, (ii) impregnation solution and (iii) meso-porous silica of average pore diameter during catalyst preparation. The catalysts were relatively activated at high temperature because of the formation of small particles. The concentration of the active site was maximized in order to enlarge the hydrogenation activity of the cobalt-based eggshell catalyst to produce middle distillates products. The optimisation study of the F-T process at low-temperature and low/medium pressure was performed to acquire the maximum production of liquid diesel fuel in a single-pass F-T process. The orthogonal arrays’ approach was employed to design a set of experiments. The investigations were successful to maximise the conversion in reactants (up to 98%) and lower the activity of the co-reactions at the same time. The change in reactant consumption and hydrocarbons’ selectivity was monitored over the time on stream and the responsible mechanisms for short-term deactivation within the first reaction cycle were studied, to achieve the optimum reaction conditions in terms of later deactivation of the catalyst.
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Seemann, Martin. "Methanation of biosyngas in a fluidized bed reactor : development of a one-step synthesis process, featuring simultaneous methanation, watergas shift and low temperature tar reforming /." Zürich : ETH/ PSI, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16754.
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Pontes, Ricardo de Freitas Fernandes. "Modelagem e síntese ótima de rede de reatores de processos oxidativos avançados para o tratamento de efluentes." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-18122009-131117/.
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Substâncias tóxicas como o fenol e outros compostos aromáticos dificultam o tratamento de efluentes via digestores biológicos. Estes compostos tóxicos em altas concentrações são nocivos aos lodos biológicos, podendo inviabilizar por completo o tratamento. Nas últimas décadas, os Processos Oxidativos Avançados (POAs), como os processos Fenton e foto- Fenton, surgiram como alternativa para o tratamento de compostos tóxicos. Os POAs degradam os compostos orgânicos pela geração de compostos oxidantes fortes, como o radical hidroxila, a partir de reagentes como peróxido de hidrogênio. Os processos Fenton e foto-Fenton fazem uso de ferro (II), um catalisador relativamente barato, para catalisar a decomposição do peróxido de hidrogênio, reação denominada como reação de Fenton. Em virtude dos complexos mecanismos presentes nos processos Fenton e foto-Fenton, torna-se necessária uma compreensão da cinética do processo, que envolve reações térmicas e fotoquímicas, por meio de sua modelagem matemática fenomenológica. A modelagem da degradação do fenol via processos Fenton e foto-Fenton proposta por este trabalho começa pela estequiometria dos dois processos, que descreve as reações químicas, térmicas e fotoquímicas existentes. A partir destas, é possível desenvolver o modelo cinético dos processos Fenton e foto-Fenton, no qual se determina a velocidade com que estas reações ocorrem. O passo seguinte é o da modelagem hidráulica (ou de escoamento) dos reatores de processo Fenton e foto-Fenton, sendo que para o segundo processo, o modelo deve levar em conta a propagação da radiação por dentro de reator. Foram realizados 3 experimentos de degradação de fenol via processo Fenton para análise das variações das concentrações de fenol, catecol e hidroquinona. Os dados experimentais são comparados com resultados simulados com intuito do ajuste das constantes cinéticas do modelo. Com as constantes ajustadas, são realizadas comparações entre os processos Fenton e foto-Fenton para análise de suas eficiências. A partir dos modelos matemáticos dos reatores de processos Fenton e foto-Fenton, é desenvolvido um modelo de otimização baseado em superestrutura de redes de reatores para a síntese de uma planta de tratamento de efluentes contaminados com fenol. Objetivou-se a redução dos custos de capital, operação e depreciação desta planta, sujeitos às restrições de projeto e ao modelo da superestrutura, resultando em modelos de programação não-linear inteira mista. Foram geradas soluções ótimas para o tratamento de efluentes contaminados com fenol em redes de um, dois e três reatores de POAs.Toxic substances such as phenol and other aromatic compounds make the wastewater treatment by biological (aerobic or anaerobic) digestors more difficult. These toxic compounds in high concentrations are harmful for the biological sludge and they may render the treatment impractical. In recent decades, Advanced Oxidative Processes (AOPs) appeared as an alternative for the treatment of toxic compounds. AOPs degrade the organic compounds by generating strong oxidizing compounds, such as the hydroxyl radical, from reactants such as hydrogen peroxide. The Fenton and photo-Fenton processes make use of iron (II), a relatively inexpensive catalyst, to catalyze the hydrogen peroxide decomposition, reaction known as the Fenton reaction. Because of the complex nature of the mechanisms that take place in the Fenton and photo-Fenton processes, the understanding of the process kinetics, which involves thermal and photochemical reactions, becomes necessary through its first-principle mathematical modeling. The modeling of phenol degradation by the Fenton and photo-Fenton processes proposed in this work starts with the stoichiometry of the two processes that enumerates the existing thermal and photochemical reactions. Furthermore, it is possible to develop the Fenton and photo- Fenton kinetic model, which determines the reaction rates. The next step is to model the hydraulic (or flow) behavior of the Fenton and photo-Fenton process reactor, whereas the model for the latter must consider how the radiation propagates inside the reactor. Three experiments of the phenol degradation by the Fenton process were carried out to analyze the concentration variation for phenol, catechol and hydroquinone. The experimental data are compared with simulated results aiming the estimation of the kinetic constants of the model. Using the adjusted constants, the Fenton and photo-Fenton processes were compared to analyze their efficiencies. From the mathematical models of the Fenton and photo-Fenton process reactors, an optimization model based on reactor network superstructure is developed for the synthesis of a phenol contaminated wastewater treatment plant. The objective is to minimize the plant capital, operation and depreciation costs, subject to design constraints and to the superstructure model, thus resulting in mixed integer nonlinear programming models. Optimal solutions were generated for the phenol contaminated wastewater treatment in networks with one, two and three AOP reactors.
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Bezerra, Marcio Barbalho Dantas. "Implementa??o de um modelo computacional para estudo do processo Fischer-Tropsch em reator de leito de lama." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15798.
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Previous issue date: 2010-09-30Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
This work aims at the implementation and adaptation of a computational model for the study of the Fischer-Tropsch reaction in a slurry bed reactor from synthesis gas (CO+H2) for the selective production of hydrocarbons (CnHm), with emphasis on evaluation of the influence of operating conditions on the distribution of products formed during the reaction.The present model takes into account effects of rigorous phase equilibrium in a reactive flash drum, a detailed kinetic model able of predicting the formation of each chemical species of the reaction system, as well as control loops of the process variables for pressure and level of slurry phase. As a result, a system of Differential Algebraic Equations was solved using the computational code DASSL (Petzold, 1982). The consistent initialization for the problem was based on phase equilibrium formed by the existing components in the reactor. In addition, the index of the system was reduced to 1 by the introduction of control laws that govern the output of the reactor products. The results were compared qualitatively with experimental data collected in the Fischer-Tropsch Synthesis plant installed at Laborat?rio de Processamento de G?s - CTG?S-ER-Natal/RN
O presente trabalho tem como objetivo a implementa??o e adapta??o de um modelo computacional de equil?brio de fases visando o estudo do processo Fischer- Tropsch em reator leito de lama a partir de g?s de s?ntese (CO + H2) para a produ??o seletiva de hidrocarbonetos (CnHm), com ?nfase na avalia??o da influ?ncia das condi??es operacionais sobre a distribui??o dos produtos formados durante a rea??o. O modelo em quest?o leva em conta efeitos do equil?brio de fases de modo rigoroso num tambor flash reativo, uma cin?tica detalhada que prev? a forma??o de cada componente do sistema reacional, bem como malhas de controle do processo para as vari?veis press?o e n?vel da fase lama. O sistema de equa??es obtido ? do tipo Alg?brico Diferencial, e foi resolvido utilizando-se o c?digo computacional DASSL (Petzold, 1982). A inicializa??o consistente do sistema de equa??es foi feita com base na condi??o de equil?brio de fases inicial formado pelos componentes j? existentes no reator, sendo o ?ndice do sistema reduzido a 1 pela introdu??o das leis de controle que regem a sa?da de produtos do reator. Os resultados obtidos foram comparados qualitativamente com os dados experimentais coletados na planta de s?ntese de Fischer- Tropsch instalada no Laborat?rio de Processamento de G?s do CTG?S-ER em Natal/RN
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Rincon, Guillermo J. "Photocatalytic Mineralization of Phenol on Fluidized Titanium Oxide-Coated Silica Gel." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2009.
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A bench-scale tubular reactor with recirculation was built in order to study the efficiency of the photocatalytic oxidation of phenol on fluidized titanium oxide-coated silica gel beads. A UV-C lamp placed along the central vertical axes of the reactor was used as source of photons. A bed of silica gel beads was fluidized by means of fluid recirculation and forced to follow upward helical flow around the lamp. Anatase was successfully synthetized on silica gel particles of average diameters 224, 357 and 461 µm, as confirmed by scanning electron micrographs, through a sol-gel technique using a titanium (iv)isopropoxide / hydrochloric acid / ethanol precursor.
Data was obtained from multiple 8-hours photocatalytic experiments using a determined mass of beads fluidized in an aqueous solution of known initial phenol concentration. Contaminant degradation with irradiation time was measured as COD. Beads that had been subjected to three consecutive coating procedures produced an 8-h removal efficiency 10% higher than beads with a single coat. 20 g L-1 of silica beads was found to be the optimum load for the experimental reactor configuration regardless of beads size, although efficiency increased with decreasing size of the latter.
Experimental results confirmed that the efficiency of phenol photocatalytic degradation decreases with increasing pollutant concentration. Also, the highest removal was achieved with initial pH 3, and it decreased with increasing pH. When NaCl was added to the solution, COD removal increased with increasing salinity. Additionally, it was found that dissolved oxygen is indispensable for photocatalysis to proceed, and that saturation of the treated mixture with oxygen was effectively achieved by keeping the liquid surface in contact with pure oxygen at 1 atm.
Finally, statistical analysis of the data showed that photocatalytic mineralization of phenol-derived COD under the experimental conditions follows exponential decay. Based on this finding, a correlation model was proposed for the accurate prediction (minimum R2 = 0.9840) of the COD removal efficiency of the reactor for any given initial COD.
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Conti, G. A. P. "Some aspects of process synthesis with emphasis on reactors and reactions." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234792.
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Two major, largely unknown, areas of process synthesis are explored in this dissertation, and procedures are proposed for the solving of problems within them. In each area, case studies are reported. The work on the first area results in the development of a general procedure for the efficient screening of alternative process routes. The procedure is applied to two examples of commodity chemicals: methyl methacrylate (MMA) and vinyl chloride monomer (VCM). By using suitable knowledge of organic chemistry, thermodynamics, kinetics, and costing, gradual screening of the process alternatives can be achieved from the earliest stages of conceptual design, with minimum calculation effort. The MMA example is concentrated on the selection of raw materials and of chemical routes; by following a number of heuristic and of rigorous rules, a list of prototype raw materials is rapidly developed. From this list it proves possible to create a reaction network connecting the selected raw materials with the target molecule, and 54 routes to MMA (including the two current commercial routes) were found to be of potential interest. Compared with the MMA case study, the VCM example moves further through the procedure to include pre-design capital costing; 14 reactions, resulting in 63 routes to VCM, are rapidly selected, and equilibrium and kinetics calculations reduce the number of promising VCM processes to 24. The operating conditions of the process reactors are also specified, and only three processes are eventually admitted to the final costing stage. 'Elementary plant sections', effecting only one reaction each, are costed separately for the three remaining processes, and it is shown that the three most promising processes can be analysed by joining together the 'sections' relevant to each process. The costing estimates are found to agree well with current practice. Furthermore, a graphical approach is devised to give quick estimates of product selling prices for a wide range of plant capacities and raw materials costs. The second major area of process synthesis considered is the synthesis of reactor networks integrated with the rest of the flowsheet. The complex reaction scheme by Van de Vusse (1964) was employed as an example in a pioneering study. A new procedural approach, which uses a hierarchy of three heuristics, is implemented. In this approach, the designer first devises a simple base case, and then methodically increases its complexity. A powerful analytical tool used is to target for maximum reactor system selectivity, in contrast with the target of maximum reactor yield proposed by previous workers. The dissertation ends with an example illustrating the scope for heat and power integration techniques in the later stages of the design of a flowsheet. A computerised model of a pressurised sulphuric acid plant is developed, and a number of suggestions are made for the improvement of a commercial process, leading to an increase of 15% in steam production.
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Lee, Yong Joon Chemical Sciences & Engineering Faculty of Engineering UNSW. "Synthesis, characterisation, and evaluation of supported cobalt molybdenum nitride for Fischer-Tropsch reaction." Publisher:University of New South Wales. Chemical Sciences & Engineering, 2008. http://handle.unsw.edu.au/1959.4/41487.
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Fischer-Tropsch Synthesis (FTS) is known as the most practical way to convert natural gas to hydrocarbon products including synthetic fuel depending on the catalysts and operating conditions. Australia has 25% of world's natural gas resources hence Australia's crude oil dependency can be reduced extensively by developing catalysts that will facilitate the technique of converting natural gas to synthetic fuel. Molybdenum nitride has been employed in this study for FTS because of its superior mechanical strength, stability, exceptional resistance to carbon deposition & suifur poisoning. In particular, molybdenum nitride is endowed with similar electronic properties to those of noble metals. Other transition metal nitrides such as Co nitride and Co-Mo nitride were also investigated in this study. The physicochemical attributes of nitride catalysts were examined by BET surface area, particle dispersion, acid site strength & concentration, and surface elemental composition. Gas to solid nitridation kinetic was thermogravimetrically monitored. CO hydrogenation activity was measured in a fixed bed reactor using various syngas compositions and temperatures at atmospheric pressure. The effect of nitridation conditions on catalytic properties of nitrides was investigated via 23 factorial design. It has revealed that nitridation parameters; temperature, nitriding gas composition (H2:NH3) and nitridation reaction time were all significantly influencing catalyst properties. The optimal nitridation condition was 973 K, H2:NH3=1: 1, and 4 hours of nitriding time which gave higher alkene selectivity. 20 wt% M02N/Ah03 was found to be the better FT catalyst compare to catalysts with lower Mo loading and other inorganic oxide supports. Nitridation kinetic studied by thermogravimetric analysis showed that successful nitridation of transition metal oxide precursor was dependent of nitridation temperature and hydrogen concentration. Co-Mo nitride has several forms of nitride species, COS.47N, C03M03N, MoN, and Mo2N. It was shown that COS.47N was the most active component favouring the CO hydrogenation rate and alkene selectivity. Mechanistically-based kinetic models suggested that methanation over Co nitride occurs mainly via surface carbon while surface oxygenated intermediates were accountable for methanation over Co-Mo nitride and Mo nitride.
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Abdelhady, Ahmed Mohammed Said lutfi. "Developing novel processes in chemistry for several types of nanoparticles." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/developing-novel-processes-in-chemistry-for-several-types-of-nanoparticles(0712d3c6-e2d5-415a-b787-c9ce457e1355).html.
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The work presented in this thesis reports the use of a series of novel thiobiuret metal complexes [M(SON(CNiPr2)2)n] (M = Cu, Ni, Fe, Zn, Cd or In; n = 2 or 3) for the first time as single source precursors for the colloidal synthesis of metal sulfide nanoparticles. Other single source precursor(s) were also used for the synthesis of CdSe, CdS, CdSe/CdS core/shell, CdSeS alloys and Cu2-xS nanoparticles in microfluidic reactors. Thermolysis experiments of [Cu(SON(CNiPr2)2)2] using only oleylamine produced Cu7S4 nanoparticles as a mixture of monoclinic and orthorhombic phases. Pure orthorhombic Cu7S4 nanoparticles were obtained when a solution of precursor in octadecene was injected into hot oleylamine whereas, Cu1.94S nanoparticles were obtained when a solution of the precursor in oleylamine was injected into hot dodecanethiol. The thermolysis of [Ni(SON(CNiPr2)2)2] gave Ni3S4 in all cases except when precursor solution in oleylamine was injected into hot octadecene which produced NiS nanoparticles. The thermolysis of [Fe(SON(CNiPr2)2)3] in oleylamine/oleylamine produced Fe7S8 nanoparticles but other combinations, in most cases, gave amorphous material. Thermolysis of [Zn(SON(CNiPr2)2)2] in oleylamine produced spherical ZnS nanoparticles. Particles with size smaller than 4.3 nm had a cubic phase, whereas the particles with size larger than 4.3 nm had a hexagonal crystal structure as suggested by the selected area electron diffraction. Powder X-Ray diffraction showed that the CdS nanoparticles obtained from the thermolysis of [Cd(SON(CNiPr2)2)2] in oleylamine were cubic under all reaction conditions except when dodecanethiol was used as an injection solvent which produced hexagonal CdS. β-In2S3 were synthesized from the thermolysis of [In(SON(CNiPr2)2)3]. Transmission electron microscopy showed that the copper, nickel and iron sulfide nanoparticles had various morphologies such as spherical, hexagonal disks, trigonal disks, rods or wires; depending on the reaction temperature, concentration of the precursor, the growth time and the solvent/capping agent combination. The zinc and cadmium sulfide nanoparticles were mostly spherical whereas the indium sulfide nanoparticles were produced in the form of ultra-thin (< 1.0 nm) nanorods or nanowires. ZnxCd1-xS and CuInS2 nanoparticles were synthesised from the 1,1,5,5-tetra-iso-propyl-4-thiobiureto complexes of Zn, Cd and Cu, In, respectively. Powder X-Ray diffraction showed that the obtained ZnxCd1-xS nanoparticles are cubic under all reaction conditions. The ZnxCd1-xS nanoparticles had an average diameter between 3.5 to 6.4 nm as shown by transmission electron microscopy. The optical properties of the ZnxCd1-xS nanoparticles were highly dependent on the ZnS to CdS precursor ratio and the solvents/capping agents. Chalcopyrite (tetragonal), wurtzite (hexagonal) or a mixture of both CuInS2 nanoparticles were obtained depending on the reaction conditions. TEM showed that the CuInS2 nanoparticles could be synthesised with different morphologies (spherical, hexagonal, trigonal or cone). Luminescent CuInS2 nanoparticles were obtained only in the absence of oleylamine. [Cd(S2CNMenHex)2], [Cd(Se2P(iPr)2)2] and [Cu(SON(CNiPr2)2)2] were used as single source precursor(s) for the synthesis of CdS, CdSe, CdSe/CdS core/shell, CdSeS alloys and Cu2-xS in microfludic reactor. The CdS nanoparticles were in size range of 5.0 to 8.0 nm whereas the CdSe nanoparticles were ultra small (ca. 2 nm) with blue luminescence. The CdSe/CdS core/shell and the CdSeS alloys were bluish green or green luminescent depending on their size. The copper sulfide nanoparticles were found to be monoclinic Cu7S4 or monoclinic Cu7S4 with minor impurities of rhombohedral Cu9S5 depending on the reaction conditions.
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Brinkley, Kendra W. "The Synthesis of Solid Supported Palladium Nanoparticles: Effective Catalysts for Batch and Continuous Cross Coupling Reactions." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3959.
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Catalysis is one of the pillars of the chemical industry. While the use of catalyst is typically recognized in the automobile industry, their impact is more widespread as; catalysts are used in the synthesis of 80% of the US commercial chemicals. Despite the improved selectivity provided by catalyst, process inefficiencies still threaten the sustainability of a number of synthesis methods, especially in the pharmaceutical industry. Recyclable solid supported catalysts offer a unique opportunity to address these inefficiencies. Such systems coupled with continuous synthesis techniques, have the potential to significantly reduce the waste to desired product ratio (E-factor) of the production techniques. This research focuses developing sustainable processes to synthesize organic molecules by using continuous synthesis methods. In doing so, solid supported metal catalyst systems were identified, developed, and implemented to assist in the formation of carbon-carbon bonds. Newly developed systems, which utilized metal nanoparticles, showed reactivity and recyclability, comparable to commercially available catalyst.
Nanoparticles are emerging as useful materials in a wide variety of applications including catalysis. These applications include pharmaceutical processes by which complex and useful organic molecules can be prepared. As such, an effective and scalable synthesis method is required for the preparation of nanoparticle catalysts with significant control of the particle size, uniform dispersion, and even distribution of nanoparticles when deposited on the surface of a solid support. This project describes the production of palladium nanoparticles on a variety of solid supports and the evaluation of these nanoparticles for cross coupling reactions.
This report highlights novel synthesis techniques used in the formation of palladium nanoparticles using traditional batch reactions. The procedures developed for the batch formation of palladium nanoparticles on different solid supports, such as graphene and carbon nanotubes, are initially described. The major drawbacks of these methods are discussed, including limited scalability, variation of nanoparticle characteristics from batch to batch, and technical challenges associated with efficient heating of samples.
Furthermore, the necessary conditions and critical parameters to convert the batch synthesis of solid supported palladium nanoparticles to a continuous flow process are presented. This strategy not only alleviates the challenges associated with the robust preparation of the material and the limitations of scalability, but also showcases a new continuous reactor capable of efficient and direct heating of the reaction mixture under microwave irradiation. This strategy was further used in the synthesis of zinc oxide nanoparticles. Particles synthesized using this strategy as well as traditional synthesis methods, were evaluated in the context industrially relevant applications.
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Pholchan, Patiroop. "Manipulation of the degradation of natural and synthetic oestrogens during biological treatment of wastewater in the sequencing batch reactor process." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433513.
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Strompen, Simon [Verfasser], and Andreas [Akademischer Betreuer] Liese. "Process development of a solvent-free, chemoenzymatic reaction sequence for the enantioselective synthesis of beta-amino acid esters / Simon Strompen. Betreuer: Andreas Liese." Hamburg-Harburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2012. http://d-nb.info/1048542920/34.
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Al, Anazi Abdulaziz H. "Synthesis of Recyclable Magnetic Metal-ferrite Nanoparticles for the Removal of Contaminants of Emerging Concern in Water." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1543922143864275.
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Oliveira, André Luiz de. "Influência do tipo de matéria orgânica no processo de desnitrificação em reatores seqüenciais em batelada." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-02022017-113638/.
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Este trabalho apresenta o desempenho de um sistema de reatores seqüenciais em batelada aeróbio/anaeróbio, na remoção de matéria carbonácea (DQO) e nitrogenada, no tratamento de esgoto sanitário sintético, simulando esgoto doméstico. O sistema era composto por dois reatores dispostos em série, um aeróbio (RSBAe), responsável pela remoção de matéria carbonácea e nitrificação e outro, anaeróbio (RSBAn), responsável pela desnitrificação. Os reatores foram construídos em acrílico transparente, com volume total de 16,5 L e volume útil de 13,5 L. A operação dos reatores foi realizada com ciclos de 12h e 24h, na fase de adaptação, e de 24h, nas fases subseqüentes. O RSBAn foi agitado intermitentemente recirculando-se o biogás produzido e o RSBAe foi aerado/misturado continuamente. Foram testadas, como fontes de carbono para a desnitrificação, seis diferentes substratos, sendo que eram compostos por combinações dos constituintes do substrato sintético (variações percentuais de proteínas, carboidratos e lipídeos em termos de DQO), e as outras duas, metanol e etanol. A eficiência atingida, na remoção de DQO, foi em média de 95%, e as eficiências alcançadas na nitrificação e desnitrificação foram em média de 99%, para qualquer uma das fontes de carbono utilizadas.This work presents the performance of (aerobic/anaerobic) sequencing batch reactors in the removal of carbonaceous (COD) and nitrogen matter treating synthetic substrate, simulating domestic wastewater. The system was composed of two reactors in series, one aerobic (RSBAe), responsible for the carbonaceous and nitrogen removal and another, anaerobic (RSBAn), responsible for denitrification. The reactors were built in transparent Plexiglas with total volume of 16,5 L and useful volume of 13,5 L. The reactors operation was carried out with cycles of 12h and 24h, in the adaptation phase, and 24h, in the other phases. The RSBAn were agitated intermittently by recycling the produced biogas and the RSBAe were aerated/agitated continuously. Six different subtracts were tested as carbon sources for denitrification four of them were composed by synthetic substrate combinations (percent variations of protein, carboidrates and lipids as COD) and the other two, methanol and ethanol. The COD removaI efficiency, in the COD removal, was about 95%, and the achieved efficiency in the nitrification and denitrification were about 99%, for any of the carbon source assayed.
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Oeggl, Reinhard Verfasser], Dörte [Akademischer Betreuer] Rother, and Lars Mathias [Akademischer Betreuer] [Blank. "Reaction and process-optimization of modular synthetic enzyme cascades towards diols and hydroxy ketones meeting industrial demands / Reinhard Oeggl ; Dörte Rother, Lars Mathias Blank." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1192218019/34.
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Oeggl, Reinhard [Verfasser], Dörte Akademischer Betreuer] Rother, and Lars Mathias [Akademischer Betreuer] [Blank. "Reaction and process-optimization of modular synthetic enzyme cascades towards diols and hydroxy ketones meeting industrial demands / Reinhard Oeggl ; Dörte Rother, Lars Mathias Blank." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1192218019/34.
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Alsalim, Rana. "Contribution à la synthèse totale de la céphalotaxine." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA114811/document.
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Depuis plus de 40 ans des chimistes se sont intéressés à l’extraction, à l’activité biologique et à la synthèse de l’homoharringtonine, un ester naturel de la céphalotaxine, qui est un puissant antileucémique, en vue de son utilisation thérapeutique, en particulier contre les leucémies résistantes aux inhibiteurs de tyrosine kinase. Ces alcaloïdes sont extraits de Cephalotaxus, des conifères originaires du sud de la Chine à croissance extrêmement lente et menacés d’extinction, la synthèse de ces alcaloïdes est nécessaire pour une utilisation thérapeutique.L’objectif de ce travail consiste à développer une synthèse concise de la (-)-céphalotaxine 1, afin de palier notamment le problème de sa pureté énantiomérique variable lorsqu’elle est issue de la matière première végétale. La stratégie développée dans ce travail nécessite d’effectuer un couplage de Heck avec des substrats désactivés et encombrés. Les résultats préliminaires ayant été décevants, le première objectif à consisté à développer l’utilisation de la méthode des plans d’expérience en synthèse totale, car l’efficacité de chaque étape a une répercussion importante sur le rendement en produit final. Dans une première partie, l’application d’un plan d’expériences a permis de pallier ce problème par une étude modèle pour déterminer les paramètres importants pour effectuer une telle réaction efficacement. Dans une deuxième partie, nous avons synthétisé les précurseurs et réalisé le couplage de Heck en vue de l’accès à un précurseur AC comportant tous les atomes de carbone du squelette de la céphalotaxine et les fonctionnalités requises pour sa cyclisation ultérieure en tétracycle ABCD. Enfin, nous avons fonctionnalisé les produits de Heck en position C3 par différents méthodes. Ces résultats ont permis de valider notre stratégie de synthèseFor more than 40 years the chemists were interested in the extraction, in the biological activity and in the synthesis of the homoharringtonine, a natural ester of cephalotaxine, which is a powerful antileukemic compound of therapeutic use, in particular against the leukaemia resistant to tyrosine kinase inhibitors. These alkaloids are extracted from Cephalotaxus, conifers native of the South of China with extremely slow growth. The objective of this work thus consisted in developing a concise synthesis of the cephalotaxine, to limit the recourse to the endangered vegetable resource The developed strategy requires an intermolecular Heck-coupling of electronically and sterically deactivated demanding substrates. The preliminary results having been disappointing, the first objective consisted in developing the use of the model of the experimental design in total synthesis because the classic methodology of variation of a single parameter at the same time said of "one by one" was ineffective. The application of a complete factorial design overcomes this problem by a model study, allowing to determine the optimized parameters to make this coupling reaction effective. We then synthesized the precursors from naturally abundant safrol and 2,3-butanedione then realized the Heck coupling with the aim of the access to the precursor AC containing all the atoms of carbon of cephalotaxine and the features required for its later cyclization in pyrrolobenzazepine ABC fragment. The o-iodized homopiperonylic alcohol led in certain conditions to an isochromane through a tandem Heck-oxa-Michael reaction. Finally, we have functionalized the Heck and hydro-arylation products obtained with 69-70 % yield in position C3 by different methods allowing us to validate our strategy to access these alkaloids
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Paci, Benjamin. "Synthèse et caractérisation de polyimides semi-aromatiques obtenus par polymérisation à l'état solide de sel." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0137.
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Les polyimides sont des polymères a hautes performances souvent utilisés dans des environnements dits hostiles (hautes températures et hautes pressions, forts frottement, …). Ils sont connus pour leur forte résistance thermique et chimique mais aussi pour leur faible processabilité. La technique de synthèse la plus utilisée industriellement est celle utilisant les poly(acides amiques) comme intermédiaires, ce qui nécessite des solvants couteux et dangereux pour l’homme et l’environnement comme le crésol ou la N-methyl-2-pyrrolidone. Les polyimides semi-aromatiques ont eux des températures caractéristiques (fusion, transition vitreuse) plus basses que les polyimides aromatiques, ce qui permet d’augmenter leur processabilité (extrusion, injection). Une nouvelle technique de synthèse basée sur la polymérisation de sels précurseurs permet de synthétiser des polyimides (aromatiques ou non) en utilisant des solvants moins coûteux et moins dangereux. De nombreuses recherches ont été menées sur ce thème ces cinquante dernières années. À notre connaissance, cette technique n’est pas être utilisée industriellement. L’objectif de ces travaux de thèse consiste en la synthèse de polyimides semi aromatiques via la polymérisation à l’état solide de sels précurseur. Une étude préliminaire sur des molécules de faible masse molaire a permis de mettre en avant les paramètres critiques de l’étape de salification et le comportement thermique lors de l’imidification. Un protocole de salification et de polymérisation à l’état solide a été mis au point puis utilisé pour synthétiser trois polyimides semi-aromatiques présentant une solubilité accrue. Cette solubilité a permis une caractérisation complète des polymères, nous conduisant à un meilleur contrôle la synthèse. Des éléments de réponse au sujet des mécanismes réactionnels ont été proposés. Deux techniques visant le contrôle de la masse molaire des polymères synthétisés ont été testées puis comparées en termes d’efficacité et sur leur caractère industrialisable. Enfin, deux polymères synthétisés ont étés mis en œuvre puis caractérisés mécaniquementPolyimides are known as high performance polymers, they are used in harsh environments (high temperatures, high pressure, …). They also have low processibility. The most used industrial synthesis process is using poly(amic acid) as reaction intermediate. This process requires high prices solvents that are harmful for human being and environment such as n-methyl-2-pyrrolidone and cresol. Semi-aromatic polyimides have lower characteristic temperatures and can thus be processed easily. A new way of synthesis based on salt polymerisation can be used to synthesize polyimides (aromatic or not), this process only needs simple solvents such as water or ethanol. Numerous researches have been made on this subject in the past 50 years. To our knowledge, this technique is not used at industrial scale. The goal of this work is to synthetize semi-aromatic polyimides using solid-state salt polymerisation. A preliminary examination on low weight molecules allowed us to highlight critical parameters on every step of reactions and thermal behaviour. Both salification and polymerization protocols are been made with the view to synthetize 3 soluble polyimides. This solubility allowed us to characterize our polymers and to enhance polymerization control. Those characterizations provided us answers on salification and polymerization mechanisms. Two molar mass control techniques have then been compared in terms of industrialization and efficiency. At the end, polymers have been synthetized, processed and then characterized in physic-chemical and mechanical ways
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Quteishat, Laith. "Contribution à la synthèse totale de la céphalotaxine." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA114846/document.
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Depuis plus de 40 ans des chimistes se sont intéressés à l’extraction, à l’activité biologique et à la synthèse de l’homoharringtonine (HHT), un ester naturel de la céphalotaxine, qui est un puissant antileucémique utilisé pour le traitement des leucémies résistantes aux inhibiteurs de tyrosine kinase. Ces alcaloïdes sont extraits de Cephalotaxus, des conifères originaires du sud de la Chine à croissance extrêmement lente et menacés d’extinction. Leur synthèse est donc nécessaire. L’homoharringtonine utilisée en thérapeutique est obtenue à partir de (-)-céphalotaxine d’origine naturelle, par greffage d’une chaîne latérale acide suivie de purifications longues et coûteuses. L’objectif de ce travail consiste à développer une synthèse concise de la (-)-céphalotaxine, afin de s’affranchir de la ressource naturelle, de ce fait de garantir un approvisionnement d’HHT de qualité constante et de développer des analogues de seconde génération.Les stratégies développées dans ce travail ont consisté à développer une synthèse très concise de la céphalotaxine, d’une part en valorisant un synthon ABC nitrile pour y introduire les deux atomes de carbone manquant au squelette de la céphalotaxine, et d’autre part à améliorer l’accès à une synthon analogue ABC ester pour en étudier la réactivité. Ces travaux ont conduit à décrire un nouveau complexe arène chrome pentacarbonyle analogue de céphalotaxine, une méthode originale et efficace de cyclisation anionique d’imide formant un squelette 3-benzazépine à l’aide d’une nouvelle combinaison de bases, le tert-butylate de potassium et le carbonate de potassium agissant en synergie, et une nouvelle méthode de solvolyse de nitrile aliphatiques ou aromatiques sous micro-ondes qui a été exemplifiéeFor over 40 years, chemists are interested in the extraction, biological activity and synthesis Homoharringtonine (HHT ), a natural cephalotaxine ester, which is a potent antileukemic used therapeutically, especially leukemias resistant against tyrosine kinase inhibitors. These alkaloids are extracted from Cephalotaxus, evergreen trees from southern China having extremely slow growth and are in extinction. Their synthesis is thus necessary. Homoharringtonine used therapeutically is obtained from (-)-cephalotaxine of natural origin, by grafting an acidic side chain followed by lengthy and expensive purifications. The objective of this work is to develop a concise synthesis of (-)-cephalotaxine to get rid of the natural resource, thereby ensuring a supply of constant quality and develop similar second generation of HHT.The strategies developed in this work has been to develop a very concise synthesis of cephalotaxine , firstly by enhancing an ABC nitrile synthon to introduce the two carbon atoms missing to the backbone of cephalotaxine , and secondly to improve access to similar ABC ester synthon to investigate its reactivity. This work led to describe a new arena complex chromium pentacarbonyle cephalotaxine analog, an original and efficient method of anionic cyclization of imide forming a 3-benzazepine skeleton using a new combination of bases , potassium tert -butoxide and potassium carbonate acting synergistically, and a new method of aliphatic or aromatic nitrile solvolysis under microwave which was exemplified
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Quezada, Maxwell Josias. "Hydrogénation catalytique de CO₂ en méthanol en lit fixe sous chauffage conventionnel et sous plasma à DBD ZSM-5 surface modification by plasma for catalytic activity improvement in the gas phase methanol-to-dimethylether reaction." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR12.
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L’objectif de cette thèse est de contribuer à l’optimisation de la production de méthanol par hydrogénation de CO₂ en synthétisant des nouveaux catalyseurs sous forme d’extrudés pour un usage industriel. Six catalyseurs à base de Cu et ZnO supportés sur de l’alumine et des ZSM-5 ont été préparés et testés. A 36 bar et sous chauffage conventionnel, le CuZnO/Al₂O₃ a montré le meilleur rendement en méthanol. Un procédé industriel basé sur ce catalyseur a été proposé et optimisé. L’influence de l’extraction de l’eau et du méthanol du milieu réactionnel en utilisant deux réacteurs en série au lieu d’un a été étudié et il a été trouvé que cela augmente le rendement en méthanol considérablement. Sous plasma à DBD et à 1 bar, le Cu/Al₂O₃ donne des meilleures conversions de CO₂, alors que le CuZnO/ZSM-5 montre des meilleurs rendements en méthanol. Cela a été attribuée à la conductivité ionique et à la constante diélectrique des matériauxThe objective of this thesis is to contribute to the optimisation of the production of methanol by hydrogenation of CO₂ by synthesising new catalysts in the form of extrudates for industrial use. In this regard, six Cu-ZnO based catalysts supported on alumina and ZSM-5 were prepared and tested. At 36 bar and under conventional heating, the CuZnO/Al₂O₃ showed the best methanol yield. An industrial process based on this catalyst has been proposed and optimised. The influence of extracting water and methanol from the reaction medium using two reactors in series instead of one was investigated and it was found to increase methanol yield considerably. Tests at atmospheric pressure and under DBD plasma showed that the Cu/Al₂O₃ gives better CO₂ conversions, while the CuZnO/ZSM-5 showed better methanol yields. This was attributed to the ionic conductivity and the dielectric constant of the catalysts
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Safadi, Rami Bassam. "Reactor system synthesis and design based on process economics." 1990. https://scholarworks.umass.edu/dissertations/AAI9100536.
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The problem of finding the best reactor system configuration has been considered in the chemical engineering literature since the 1940's. The problem was attacked, invariably, by isolating the reactor system and maximizing an objective function which usually was the yield or some linear combination of the reactor inlet and outlet compositions. However, there are numerous cases where it is not possible to uncouple the reactor problem from the rest of the process. The reason for this is that the optimum values of the reactor design variables (e.g., the reactor temperature, the limiting reactant conversion, the molar ratio of the reactants, etc.) are determined by the economic tradeoffs between raw materials costs and recycle costs, where the recycle costs depend on the structure of the flowsheet (i.e., the distillation sequence, the heat exchanger network, etc.). However, in order to design the heat exchanger network and the separation system, one needs to know the reactor exit flows. Thus, there is normally a coupling between the best reactor design and the design of the equipment in the recycle loop. This thesis presents the results of our efforts in providing solutions to the reactor synthesis and design problem considered in the context of the complete chemical process.
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Seodigeng, Tumisang Gerald. "Numerical Formulations For Attainable Region Analysis." Thesis, 2006. http://hdl.handle.net/10539/1664.
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Student Number : 9611112G -
PhD thesis -
School of Chemical and Metallurgical Engineering -
Faculty of Engineering and the Built EnvironmentAttainable Region analysis is a chemical process synthesis technique that enables a design engineer to find process unit configurations that can be used to identify all possible outputs, by considering only the given feed specifications and permitted fundamental processes. The mathematical complexity of the attainable regions theory has so far been a major drawback in the implementation of this powerful technique into standard process design tools. In the past five years researchers focused on developing systematic methods to automate the procedure of identifying the set of all possible outputs termed the Attainable Regions. This work contributes to the development of systematic numerical formulations for attainable region analysis. By considering combinations of fundamental processes of chemical reaction, bulk mixing and heat transfer, two numerical formulations are proposed as systematic techniques for automation of identifying optimal process units networks using the attainable region analysis. The first formulation named the recursive convex control policy (RCC) algorithm uses the necessary requirement for convexity to approximate optimal combinations of fundamental processes that outline the shape of the boundary of the attainable regions. The recursive convex control policy forms the major content of this work and several case studies including those of industrial significance are used to demonstrate the efficiency of this technique. The ease of application and fast computational run-time are shown by assembling the RCC into a user interfaced computer application contained in a compact disk accompanying this thesis. The RCC algorithm enables identifying solutions for higher dimensional and complex industrial case studies that were previously perceived impractical to solve. The second numerical formulation uses singular optimal control techniques to identify optimal combinations of fundamental processes. This formulation also serves as a guarantee that the attainable region analysis conforms to Pontryagin’s maximum principle. This was shown by the solutions obtained using the RCC algorithm being consistent with those obtained by singular optimal control techniques.
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Patel, Rajnikant, K. Dawson, R. Butterfield, Amir Khan, B. Ahada, and Harvey Arellano-Garcia. "Process for Synthesis of Biodiesel from Used Cooking Oil: Feasibility and Experimental Studies." 2014. http://hdl.handle.net/10454/10764.
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NoBiodiesel has turned out to be an integral part of the discussion of renewable energy sources and has diverse advantages in terms of its flexibility and applicability. Considering the characteristics of the transesterification reaction, a laboratory-scale system has been developed in this work. Waste Vegetable Oil (WVO), mainly sunflower oil, from local sources has been used and the transesterification carried out using methanol in the presence of sodium hydroxide catalyst. Characterisation of the biodiesel produced has been carried out using a number of different techniques including rheology, calorimetry, and gas liquid chromatography. The main factors affecting the % yield of biodiesel are temperature, catalyst, and alcohol to triglyceride ratio. Thus, experimental work has been carried out so as to study the rate and yield of the reaction as a function of those factors. A model has also been developed to validate the experimental data and this should help in increasing the efficiency of these processes and reducing the energy input. Moreover, the novel use of ultrasound as a method of measuring progression of the reaction is correlated with in-situ pH monitoring of the reaction process.
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Snell, Douglas C. "A study of a diffusionally controlled reactive synthesis process using a multi-tube diffusion flame burner." Thesis, 1994. http://hdl.handle.net/1957/34979.
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A continuous process for the production of ceramic materials has been studied.
This method reacted metal and oxidizer in a diffusionally controlled process,
demonstrated by reacting a magnesium particle stream and hot water vapor. Many small
rich hydrogen/air diffusion flames provide an atmosphere of hot water vapor, hydrogen,
and nitrogen for oxidizing the magnesium, which reacts with the water vapor in the form
of a diffusion flame. The burner that provides the hot atmosphere has been characterized
thermally using thermocouple measurements and a model that gives the true temperature
from the measured values. A model was developed that gives the flame profile for the
parallel flow geometry of particle stream combustion used in this study as defined in the
cartesian coordinate system.Graduation date: 1995
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陳建宇. "Synthesis of the Indolyl-Nitroalcohols via the Friedel-Crafts Alkylation–Henry Reaction Process." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/djsup3.
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碩士國立中正大學
化學暨生物化學研究所
106
In this thesis, we have synthesized a series of indole derived nitro alcohols containing multiple chiral centers by using Friedel-Crafts alkylation of indoles with nitroolefins followed by Henry reaction with different aldehydes. In addition, the structure of nitro alcohols, e.g. compound 37b, was confirmed by X-ray crystallographic analysis of the single crystal.
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Nawaf, A. T., S. A. Gheni, Aysar Talib Jarullah, and Iqbal M. Mujtaba. "Improvement of fuel quality by oxidative desulfurization: Design of synthetic catalyst for the process." 2015. http://hdl.handle.net/10454/7926.
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YesThe present study explored a novel oxidative desulfurization (ODS) method of light gas oil fuel, which combines a catalytic oxidation step of the dibenzothiophene compound directly in the presence of molecular air as oxidant to obtain high quality fuel for light gas oil. In chemical industries and industrial research, catalysis play a significant role. Heightened concerns for cleaner air together with stricter environmental legislations on sulphur content in addition to fulfill economic have created a driving force for the improvement of more efficient technologies and motivating an intensive research on new oxidative catalysts. As the lower quality fuel becomes more abundant, additional challenges arise such as more severe operation conditions leading to higher corrosion of the refinery installations, catalyst deactivation and poisoning. Therefore, among the technologies to face these challenges is to develop catalysts that can be applied economically under moderate conditions. The objective of this work is to design a suitable synthetic catalyst for oxidative desulfurization (ODS) of light gas oil (LGO) containing model sulphur compound (dibenzothiophene (DBT)) using air as oxidant and operating under different but moderate operating conditions. The impregnation method is used to characterize two homemade catalysts, cobalt oxide (Co3O4/γ-Al2O3) and manganese oxide (MnO2/γ-Al2O3). The prepared catalysts showed that the manganese oxide has a good impregnation (MnO2=13%), good pore size distribution and larger surface area. A set of experiments related to ODS of dibenzothiophene has been carried out in a continuous flow isothermal trickle bed reactor using light gas oil as a feedstock utilizing both catalysts prepared in-house. At constant pressure of 2 bar and with different initial concentration of sulphur within dibenzothiophene, the temperature of the process was varied from 403K to 473K and the liquid hourly space velocity from(LHSV) was varied from 1 to 3 hr-1. The results showed that an increase in reaction temperature and decreasing in LHSV, higher conversion was obtained. Although both catalysts showed excellent catalytic performance on the removal of molecule sulphur compound from light gas oil, the catalyst MnO2 catalyst exhibited higher conversion than Co3O4 catalyst at the same process operating conditions.
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Rosa, Marta Filipa Calvinho. "Liquid-Phase Peptide Synthesis Optimisation: Selection of Quenching Reagents and Peptide Solubility Estimation." Master's thesis, 2021. http://hdl.handle.net/10362/112039.
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With the increasing demand on peptides market, the peptide synthesis process must be kept upgraded. Therefore, the focus of this project is the optimisation of liquid-phase peptide synthesis. During peptide synthesis, the by-products and the amino acid excess must be kept controlled to not interfere with the main reactions and, consequentially, with the final product yield and purity. In order to achieve this, a quenching reagent is added to inactivate the amino acid in excess.
An optimisation study was performed for the quenching reaction, where it was found that 2 or 3 amino acids equivalents reacting with 2.1 quenching reagent equivalents allowed the best conditions for a controlled reaction. From there, with the conditions established, three reagents – piperidine, aniline, thiomalic acid – were used in the quenching reaction, where the quenching efficiency was evaluated by the quenching rate constant (kq). The kq values for piperidine, thi-omalic acid and aniline we deduced to 2.962, 1.849, and 0.020 min-1 respectively. Piperidine was then determined as the best quenching reagent, followed by thiomalic acid and aniline, respec-tively.
The second problem of peptide synthesis that this project approached, was the determina-tion of the peptide solubility. Currently, the solubility of peptides is measured experimentally, which is a time-consuming and wasteful process once it needs to be measured in different sol-vents, thus increasing the process cost.
The second part of the project investigated two theoretical approaches – Solubility Param-eters and COSMO-RS – to predict the best and worst solvents for free peptides and peptides attached to a hub (wang and rink amide nanostar). DMSO was found the best solvent for most of the peptides, followed by NFM, which also presented itself as the best green solvent. The valida-tion of the COSMO-RS method was tested and exhibited a RMSE of between 1.10 – 0.74 loga-rithmic units. Therefore, this model is presented as a tool to be implemented in determining the solubility of the amino acids.O aumento da procura de mercado por peptídeos obriga a constante otimização do seu processo de síntese. Assim, o foco deste projeto é a otimização da síntese de peptídeos em fase líquida. Durante o processo, os by-products e os aminoácidos em excesso devem ser controlados, de forma a não afetar o rendimento e a pureza do produto final. Para tal, é necessário proceder à sua inativação com a adição de um reagente. A primeira parte deste projeto apresenta um estudo das condições ótimas para a reação de inativação, que determinou-se sendo 2 ou 3 equivalentes de aminoácido a reagir com 2.1 equivalentes de reagente. Com base nas condições estabelecidas, três reagentes – piperidina, anilina e ácido tiomálico - foram testados e avaliados pelas constante de inativação (kq). Os valores de kq obtidos foram 2.962, 1.849, e 0.020 min-1 respetivamente à piperidina, ácido tiomálico e anilina. Visto que a piperidina apresentou os melhores resultados, a mesma foi reconhecida como o melhor reagente para a inativação dos aminoácidos. O segundo e principal problema da síntese de peptídeos abordado neste projeto é a determinação da solubilidade dos peptídeos. Atualmente, a solubilidade dos peptídeos é determinada experimentalmente, sendo um processo demorado e com elevado desperdício, uma vez que os peptídeos precisam de ser avaliados em diferentes solventes, tendo por consequência o aumento do custo do processo. Este projeto apresenta duas abordagens teóricas – Parâmetros de Solubilidade e COSMO-RS – que preveem quais os melhores e piores solventes para os peptídeos e para os peptídeos ligados à âncora, quer por ligantes wang ou rink amide. No geral, o DMSO mostrou-se como o melhor solvente, seguido pelo NFM, que também se apresentou como o melhor solvente verde. A validade do método COSMO-RS foi testada e exibiu um erro médio quadrático de entre 1.10 – 0.74 unidades logarítmicas. Deste modo, este modelo apresenta-se como uma ferramenta a implementar na determinação da solubilidade dos aminoácidos
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Constantino, Dânia Sofia Martins. "Process Intensification for Butyl Acrylate Synthesis based on Sorption-Enhanced Reaction and Pervaporation-based Hybrid Processes." Tese, 2019. https://hdl.handle.net/10216/123266.
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Constantino, Dânia Sofia Martins. "Process Intensification for Butyl Acrylate Synthesis based on Sorption-Enhanced Reaction and Pervaporation-based Hybrid Processes." Doctoral thesis, 2019. https://hdl.handle.net/10216/123266.
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Rosa, Marta Filipa Calvinho. "Liquid-Phase Peptide Synthesis Optimisation: Selection of Quenching Reagents and Peptide Solubility Estimation." Master's thesis, 2020. http://hdl.handle.net/10362/112891.
Full textAbstract:
With the increasing demand on peptides market, the peptide synthesis process must be kept upgraded. Therefore, the focus of this project is the optimisation of liquid-phase peptide synthesis. During peptide synthesis, the by-products and the amino acid excess must be kept controlled to not interfere with the main reactions and, consequentially, with the final product yield and purity. In order to achieve this, a quenching reagent is added to inactivate the amino acid in excess.
An optimisation study was performed for the quenching reaction, where it was found that 2 or 3 amino acids equivalents reacting with 2.1 quenching reagent equivalents allowed the best conditions for a controlled reaction. From there, with the conditions established, three reagents – piperidine, aniline, thiomalic acid – were used in the quenching reaction, where the quenching efficiency was evaluated by the quenching rate constant (kq). The kq values for piperidine, thiomalic acid and aniline we deduced to 2.962, 1.849, and 0.020 min-1 respectively. Piperidine was then determined as the best quenching reagent, followed by thiomalic acid and aniline, respectively.
The second problem of peptide synthesis that this project approached, was the determination of the peptide solubility. Currently, the solubility of peptides is measured experimentally, which is a time-consuming and wasteful process once it needs to be measured in different solvents, thus increasing the process cost.
The second part of the project investigated two theoretical approaches – Solubility Parameters and COSMO-RS – to predict the best and worst solvents for free peptides and peptides attached to a hub (wang and rink amide nanostar). DMSO was found the best solvent for most of the peptides, followed by NFM, which also presented itself as the best green solvent. The validation of the COSMO-RS method was tested and exhibited a RMSE of between 1.10 – 0.74 logarithmic units. Therefore, this model is presented as a tool to be implemented in determining the solubility of the amino acids.
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Lin, Wei-De, and 林瑋德. "A novel synthetic process for (R)-phenylephrine production using enantioselective enzymatic catalysis and Walden inversion reaction." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/26977867347156618326.
Full textAbstract:
博士國立中興大學
分子生物學研究所
98
(R)-phenylephrine [(R)-PE] is an α-1-adrenergic receptor agonist that is widely used in over-the-counter drugs to treat the common cold. In this study, three bacteria strains were able to convert 1-(3-hydroxyphenyl)-2-(methylamino) ethanone (HPMAE) to (S)-PE. And the other two yeast strains can convert 2-[benzyl-(methyl)amino]- 1-(3-hydroxyphenyl)ethanone (BMAHPE) to BMA-PE. We found that Rhodococcus erythropolis BCRC10909 can convert detectable level of HPMAE to (S)-PE by high performance liquid chromatography tandem mass spectrometry analysis. An amino alcohol dehydrogenase gene (RE_AADH) which possesses the ability to convert HPMAE to (S)-PE was then isolated from R. erythropolis BCRC10909 and expressed in Escherichia coli NovaBlue. The purified RE_AADH, tagged with 6′His, had a molecular mass of approximately 30 kDa and exhibited a specific activity of 0.19 mU/mg to HPMAE in the presence of NADPH, indicating this enzyme could be categorized as NADP+-dependent short-chain dehydrogenase reductase. E. coli NovaBlue cell expressing the RE_AADH gene was able to convert HPMAE to (S)-PE with more than 99% enantiomeric excess (ee), 78% yield and a productivity of 3.9 mmol (S)-PE/L h in 12 h at 30°C and pH 7. The (S)-PE, recovered from reaction mixture by precipitation at pH 11.3, could be converted to (R)-PE (ee > 99%) by Walden inversion reaction. This is the first reported biocatalytic process for the production of (S)-PE from HPMAE.
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Huan-YuChen and 陳煥煜. "Process Development for Combustion Synthesis of Aluminum Nitride Using Aluminum Powders with Different Morphology and Study on the Reaction Mechanism." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/28335033192727534081.
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Chamni, Supakarn. "New Diazo Reagents and Applications of β-Lactones for Synthesis and Biological Evaluation of Natural Products." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10413.
Full textAbstract:
Natural products are essential tools for basic cellular studies leading to the identification of medically relevant protein targets and the discovery of potential therapeutic agents. We have developed a set of second generation diazo reagents with small steric footprints, namely an alpha-trifluoroethyl (HTFB) diazo reagent, for simultaneous arming and SAR studies of bioactive natural products. The Rh(II)-catalyzed O-H insertions of several alcohol-containing natural products, including the potent translation inhibitor lactimidomycin, are investigated and useful reactivity and both chemo- and site- (chemosite) selectivities are observed. The alpha-trifluoroethyl diazo reagents (HTFB) shows clear differences in the IL-2 reporter assay with FK506
derivatives and provides greater retention of biological activity in a hMetAP2 proliferation assay of fumagillol derivatives compared to the first generation pbromophenyl
diazo reagent (HBPA). The synthetic utilities of the new alpha-trifluoroethyl diazo reagent (HTFB) provide a great new tool for basic cellular studies facilitating the
discovery of new drug candidates for human disease.
Furthermore, we are interested in methodologies for beta-lactone synthesis and transformations. In this study, we demonstrated synthetic versatilities of beta-lactones for the synthesis of beta-lactam congeners of orlistat as fatty acid synthase inhibitors via SnCl4- promoted tandem Mukaiyama aldol-lactonization (TMAL) reaction and a one-pot, mild conversion of beta-lactones to beta-lactams. The inhibitory activities of the derived beta-lactam derivatives are determined in a biochemical fluorogenic assay using recombinant FASTE, and the micro-molar range FAS-TE inhibitory activities were observed.
Additionally, we pursued synthetic studies toward the total synthesis of spongiolactone, which is a unique beta-lactone-containing marine diterpenoid, isolated from the marine sponge Spongionella gracilis. This natural product bears a unique tricyclic beta-lactone core possessing four contiguous stereogenic centers and an additional stereogenic quaternary carbon on a cyclohexyl appendage. We completed the total synthesis of 6,15-bis-epi-spongiolactone by employing an intramolecular nucleophilecatalyzed aldol-lactonization (NCAL) process as the key step to construct the fused tricyclic beta-lactone core. Importantly, we developed a double diastereoselective and, for the first time, a kinetic resolution via the NCAL process that enables an enantioselective strategy to the tricyclic beta-lactone core of (+)-spongiolactone.