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Asprey, Steven Peter. "Theory and application of the temperature-scanning plug-flow reactor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq22442.pdf.
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Marr, Joseph Allen. "PAH chemistry in a jet-stirred/plug-flow reactor system." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12662.
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Grenier, Bernard. "A treatment of catalyst decay using a temperature-scanning plug flow reactor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq22315.pdf.
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PERERA, UPULI. "Investigation of Operating Conditions for Optimum Biogas Production in Plug Flow Type Reactor." Thesis, KTH, Kraft- och värmeteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-79429.
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Lam, Frederick Warren. "The formation of polycyclic aromatic hydrocarbons and soot in a jet-stirred/plug-flow reactor." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/14310.
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Touitou, Jamal. "Development of an in-situ spatially resolved technique to investigate catalysts in a plug flow reactor." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.677844.
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This thesis presents, in detail, all the steps of the development of a new in-situ spatially resolved method to probe gas phase concentrations and temperature with minimum invasiveness. From the literature review, it was noted that no techniques developed to date were designed to investigate packed powdered catalyst beds which simultaneously obtain the gas concentrations and the temperature profile. Within this thesis, details of the development of a prototype and further optimisation of a spatial resolution technique for packed powdered catalyst beds were disclosed. The technique was designed to have negligible impact on the packed powdered catalyst bed with the use of the smallest equipment available. Significantly, a number of validation tests of the spatially resolved technique were conducted and the results proved that the technique was working under different experimental conditions. The results of these validation tests highlighted the improvements of the optimised spatial resolution system, which provided twice as many sampling points as the prototype, as well as the additional benefit of simultaneous temperature recording. Additionally, the invasiveness of the spatially resolved technique was investigated using Computational Fluid Dynamics (CFD); more precisely the sampling capillary was found to have negligible impact on the packed catalyst bed during the experiment. Furthermore, the results obtained experimentally have been compared with simulations using a micro kinetic model. The results obtained showed that a hybrid model (simulated concentrations and experimental temperature) allowed a more accurate picture of the phenomena occurring in the packed catalyst bed which was one of the initial aims of the development of the spatially resolved technique.
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Celani, Andrea. "Oxidation and pyrolysis of methane and methyl formate in a plug flow reactor: computational and experimenal studies." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5932/.
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Biodiesel represents a possible substitute to the fossil fuels; for this reason a good comprehension of the kinetics involved is important. Due to the complexity of the biodiesel mixture a common practice is the use of surrogate molecules to study its reactivity.
In this work are presented the experimental and computational results obtained for the oxidation and pyrolysis of methane and methyl formate conducted in a plug flow reactor. The work was divided into two parts: the first one was the setup assembly whilst, in the second one, was realized a comparison between the experimental and model results; these last was obtained using models available in literature.
It was started studying the methane since, a validate model was available, in this way was possible to verify the reliability of the experimental results. After this first study the attention was focused on the methyl formate investigation. All the analysis were conducted at different temperatures, pressures and, for the oxidation, at different equivalence ratios.
The results shown that, a good comprehension of the kinetics is reach but efforts are necessary to better evaluate kinetics parameters such as activation energy. The results even point out that the realized setup is adapt to study the oxidation and pyrolysis and, for this reason, it will be employed to study a longer chain esters with the aim to better understand the kinetic of the molecules that are part of the biodiesel mixture.
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Jing, Yin. "Computer Simulation of a Plug Flow Reactor for Cobalt Catalyzed Fischer Tropsch Synthesis Using a Microkinetic Model." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1349306005.
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YANG, JUN. "Thermal Decomposition and Growth of Short Alkylated Naphthalenes." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1172807217.
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McIntyre, Christopher. "CPFD Modeling of a Novel Internally Circulating Bubbling Fluidized Bed for Chemical Looping Combustion." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42054.
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Pressurized chemical looping combustion (PCLC) is a promising next generation carbon capture technology which operates on the fundamentals of oxyfuel combustion to concentrate carbon dioxide in the flue gas stream. Oxygen is supplied through cyclic oxidation and reduction of a solid metal oxide between an air reactor and fuel reactor to prevent the direct contact of fuel and air. CanmetENERGY-Ottawa, in collaboration with Hatch Ltd., is designing a pilot scale PCLC system which uses ilmenite as the oxygen carrier and a novel fluidized bed design called the Plug Flow Internally-recirculating Reactor (PFIR). The PFIR consists of an annular bubbling fluidized region in which particles are circulated by angle jets through two reactive zones separated by baffles. The overall objective of this thesis was to provide key design parameters and insight for the construction of the pilot facility.
Experimental work was first conducted investigating the minimum fluidization velocity (Umf), gas bubble size, and tube-to-bed heat transfer coefficients of different ilmenite particle size distributions (PSDs) at varying pressures up to 2000 kPa. The data was compared to a variety of literature correlations. The Saxena & Vogel (1977) constants for the Wen-Yu type correlations (Remf=√C12+C2Ar-C1) resulted in the best fit for predicting the Umf of the PSDs with Sauter mean diameters (SMD) less than 109 μm, while the Chitester et al. (1984) constants resulted in better predictions for the larger particle size distributions (SMD greater than 236 μm). Gas bubble size was found to be marginally impacted by pressure, with the Mori & Wen (1975) correlation best fitting the data. The heat transfer coefficient was found to also be marginally increased by pressure with the the Molerus et al. (1995) correlation matching the atmospheric data. A computational particle fluid dynamic (CPFD) model of the experimental unit was then created and validated using the obtained data for minimum fluidization velocity and bubble size. The accuracy of the model was found to be dependent on the particle close packing factor input variable, with a value of 0.58 resulting in the best results for each of the ilmenite PSDs modeled. Finally, a CPFD model was created for a cold flow design of the PFIR to investigate the impacts of different operating parameters on the solids circulation rate and gas infiltration rate between the two reactor zones. This model used the validated parameters of the previous CPFD model to add confidence to the results. The impacts of increasing superficial gas velocity, fluidizing gas jet velocity, bed height, and pressure were all found to increase the solids circulation rate through their respective impacts on the momentum rate of the fluidizing gas. A polynomial function was fit between these two variables resulting in a method to predict the solids circulation rate. Similarly, the rate of gas infiltration between sections was found to be dependent on the solids circulation rate, allowing for a function to be made to predict the gas infiltration at different operating conditions.
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Possani, Germano 1986. "Modelagem e simulação de um reator catalítico de membrana inerte permseletiva a hidrogênio com transferência de calor e massa." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266922.
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Orientador: Teresa Massako Kakuta RavagnaniDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Dentre os termoplásticos mais utilizados atualmente na indústria, pode-se mencionar o estireno, principal responsável pela produção de plásticos e borrachas. No processo de fabricação de estireno, a principal rota química é por meio da desidrogenação de etilbenzeno, com o hidrogênio como subproduto. A conversão de etilbenzeno nesta reação é em torno de 50,0 %, devido ao equilíbrio termodinâmico. Para deslocar esse equilíbrio e aumentar a produtividade de estireno,foram desenvolvidas novas configurações de reatores, tal como os reatores com membrana. eatores equipados com membranas de paládio fornecem uma seletividade maisalta ao estireno uando comparados com reatores equipados apenas com membranas porosas. Para explorar o otencial desse tipo de reator, modelagens matemáticas foram desenvolvidas a fim de determinar os parâmetros cruciais que regem esses processos. O objetivo deste trabalho foi modelar e simular um reator de leito fixo catalítico, envolto por uma membrana inerte permseletiva ao hidrogênio com transferência de calor e massa, sendo composta por uma camada de aço inoxidável de 1,6 mm de espessura, a qual serviu de suporte para a deposição de um filme de 20 µm de paládio. Para essa modelagem foram utilizados os métodos de Runge-Kutta-Gill para o cálculo das variáveis no sentido axial, tanto no retentato quanto no permeado, considerando no retentato um leito fixo catalítico descrito pelo modelo Pseudo-homogêneo, e para os cálculos das equações não lineares das frações molares das espécies e do fluxo mássico de hidrogênio na direção radial do reator foi utilizado o método de Newton-Raphson. Foram analisados os perfis de temperatura, pressão e concentração dos componentes da reação axialmente, considerando a transferência de massa e energia através da membrana, além dos valores para a conversão do etilbenzeno e produtividade em relação ao estireno. Como resultados das simulações foram obtidos valores para a conversão e produtividade de 50,3 % e 35,2 %, respectivamente, para o reator na condição de reator de leito fixo catalítico convencional, e 71,2 % e 60,2 %, para o reator na condição de reator de leito fixo catalítico envolto por uma membrana permseletiva ao hidrogênio, sendo estes valores 41,6 % maiores para a conversão do etilbenzeno e 71,0 % maiores para a produtividade em relação ao estireno. Concluiu-se que com a implementação da membrana no reator em estudo, considerando também a troca térmica na membrana, esta é uma boa opção como nova alternativa para o processo de fabricação do estireno
Abstract: Among the most widely used thermoplastics in the industry, styrene can be mentioned, the main responsible for the production of plastics and rubbers. In the manufacturing process of styrene, the principal chemical route is by means of dehydrogenation of ethylbenzene, with hydrogen as a byproduct. The conversion of ethylbenzene in this reaction is around 50,0 % due to thermodynamic equilibrium. To overcome this equilibrium and increase the productivity of styrene, new reactor configurations were developed such as membrane reactors. Membrane reactors equipped with a palladium membrane provide a higher selectivity compared with reactors that are equipped only with a porous membrane. To explore the potential of this type of reactor, mathematical models were developed to determine the crucial parameters governing these processes. The aim of this study was to model and simulate a fixed bed catalytic reactor, surrounded by a permselective to hydrogen inert membrane with heat and mass transfer, composed by a layer of stainless steel of 1,6 mm thickness, which served as support for deposition of a 20 µm film of palladium. For this modeling the Runge-Kutta-Gill method was used to calculate the variables in the axial direction, both in tube side and in permeate side, considering in tube side a catalytic fixed bed described by Pseudo-homogeneous model, and for the calculations of nonlinear equations of the mole fractions of species and the mass flow of hydrogen in the radial direction it was used the method of Newton-Raphson. Profiles of temperature, pressure and concentration of reaction components on axial toward were analyzed considering the heat and mass transfer across the membrane, besides the values for ethylbenzene conversion, selectivity and productivity in relation to styrene. As the simulation results, values were obtained for the conversion and productivity of 50,3 % and 35,2 %, respectively, putting the reactor on condition of conventional catalytic fixed bed reactor, and 71,2 % and 60,2 % for the reactor on condition of catalytic fixed bed reactor surrounded by a permselective membrane to hydrogen, then , the obtained values were 41,6 % higher for the conversion of ethylbenzene and 71,0 % higher for the productivity of styrene. It was concluded that with the implementation of a membrane in reactor under study, also considering the heat transfer in the membrane, this technology is a good option as new alternative to the styrene manufacturing process
Mestrado
Sistemas de Processos Quimicos e Informatica
Mestre em Engenharia Química
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Olughu, Williams C. "The systematic consideration of the large-scale fed-batch fermentation inhomogeneities using a genetically modified C. glutamicum strain as a model organism." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/34284.
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The loss of efficiency and performance of bioprocesses on scale-up is well known, but not fully understood. This work addresses this problem, by studying the effect of some fermentation gradients (pH, glucose and oxygen) at a larger scale in a bench-scale two compartment reactor (PFR + STR) using the cadaverine-producing recombinant bacterium, Corynebacterium glutamicum DM1945 Δact3 Ptuf-ldcC_OPT. The initial scale down strategy increased the magnitude of these gradients by only increasing the mean cell residence time in the plug flow reactor (τ_PFR). The cell growth and product related rate constants were compared as the τ_PFR was increased; differences were significant in some cases, but only up to 2 min residence time. For example, losses in cadaverine productivity when compared to the control fed-batch fermentation on average for the τ_PFR of 1 min, 2 min and 5 min were 25 %, 42 % and 46 % respectively. This indicated that the increasing the τ_PFR alone does not necessarily increase the magnitude of fermentation gradients. The new scale-down strategy developed here, increased the magnitude of fermentation gradients by not only increasing the τ_PFR, but also considering the mean frequency at which the bacterial cells entered the PFR section (f_m). The f_m was kept constant by reducing the broth volume in the STR. Hence, the bacterial cells also spent shorter times in the well mixed STR, as the τ_PFR was increased (hypothesised as giving the bacterial cells less time to recover the non-ideal PFR section of the SDR). On adoption of this strategy cadaverine productivity decreases for the τ_PFR of 1 min, 2 min and 5 min were 25 %, 32 % and 53 % respectively. Thus, highlighting that loss in performance is most likely to occur as the magnitude of heterogeneity within the fermentation environment increases. However, Corynebacterium glutamicum DM1945 Δact3 Ptuf-ldcC_OPT did show some resilience in its biomass productivity. It was only marginally affected in the harshest of conditions simulated here.
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Rincon, Guillermo. "Kinetics of the electrocoagulation of oil and grease." ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/131.
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Research on the electrocoagulation (EC) of hexane extractable materials (HEM) has been conducted at the University of New Orleans using a proprietary bench-scale EC reactor. The original reactor configuration forced the fluid to follow a vertical upward-downward path. An alternate electrode arrangement was introduced so that the path of flow became horizontal. Both configurations were evaluated by comparing the residence time distribution (RTD) data generated in each case. These data produced indication of internal recirculation and stagnant water when the fluid followed a vertical path. These anomalies were attenuated when the fluid flowed horizontally and at a velocity higher than 0.032 m s-1 . A series of EC experiments were performed using a synthetic emulsion with a HEM concentration of approximately 700 mg l-1. It was confirmed that EC of HEM follows first-order kinetics, and kinetic constants of 0.0441 s-1 and 0.0443 s-1 were obtained from applying both the dispersion and tanks-in-series (TIS) models, respectively. In both cases R2 was 0.97. Also, the TIS model indicated that each cell of the EC behaves as an independent continuous-stirred-tank reactor.
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Bennadji, Hayat. "Biodiesel : combustion des esthers éthyliques d'huiles végétales comme additifs au pétrodiesel." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL044N/document.
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Le biodiesel est un biocarburant, composé d'un mélange de mono-esters d'acide gras saturés et insaturés avec une longue chaîne carbonée. Ce travail de thèse présente les données de la littérature sur l'origine du biodiesel et son procédé de fabrication ; sont présentées aussi les performances et les émissions des moteurs diesel fonctionnant au biodiesel et la cinétique d'oxydation du biodiesel. Des efforts ont été faits pour mettre en évidence les principales différences entre les esters méthyliques et éthyliques tout en montrant que d'autres recherches sont encore à développer. Pour ces raisons, les délais d'auto-inflammation de cinq esters méthyliques et éthyliques ont été mesurés dans un tube à onde de choc : l'acrylate d'éthyle, l'acrylate de méthyle, le crotonate d'éthyle, le crotonate de méthyle et le butanoate d'éthyle. Les mécanismes cinétiques détaillés d'oxydation des cinq esters étudiés ont été générés automatiquement en utilisant le logiciel EXGAS. L'oxydation du butanoate d'éthyle, molécule modèle d'esters éthyliques d'huiles végétales (EEHV) a été étudiée dans un réacteur piston à pression atmosphérique pour une gamme de température allant de 500 à 1200 K. Les résultats représentent les profils de concentration des réactifs, les intermédiaires stables et les produits finaux. Le modèle cinétique a été validé de façon satisfaisante par une comparaison entre les résultats simulés et expérimentauxAn increasingly popular biofuel is biodiesel, composed of a mixture of saturated and unsaturated fatty acid methyl or ethyl esters, with a long aliphatic main chain. This PhD dissertation provides a literature review concerning the origin of biodiesel, its manufacturing process, performance and emissions of diesel engines fueled with biodiesel, and the kinetics of oxidation of biodiesel. Efforts were made to highlight the main differences between methyl and ethyl esters while showing where further research needs to be developed or pursued. For these reasons, the autoignition of five esters were measured behind reflected shock tube: ethyl acrylate, methyl acrylate, ethyl crotonate, methyl crotonate, and ethyl butanoate. Detailed mechanisms for the oxidation of the five studied esters were automatically generated using the version of EXGAS software. In addition, the oxidation of ethyl butanoate as a model compound for Fatty Acid Ethyl Esters (FAEE) has been investigated in tubular plug flow reactor at atmospheric pressure over wide range of temperature (500-1200 K). The results consist of concentration profiles of the reactants, stable intermediates, and final products. The model was again validated satisfactorily by comparison between computed results and the generated experimental data
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Jennesson, Didier. "Étude de l'influence des phénomènes de couche limite sur le fonctionnement de photoréacteurs." Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL114N.
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Certains problèmes spécifiques de la conduite industrielle d'une réaction photochimique concernent l'influence des conditions hydrodynamiques au voisinage des parois d'irradiation sur la sélectivité et sur la rentabilité de la fabrication. En effet, le traitement de solutions photoréactives fortement concentrées en régime turbulent confine souvent le lieu de la réaction à proximité directe de la paroi, dans les zones d'amortissement de la turbulence où l'accumulation des espèces photoproduites peut s'accompagner d'effets d'absorption et de dégradation généralement désignés par l'expression phénomènes de couche limite. La finalité du travail réalisé repose sur la mise au point d'un support expérimental fiable se prêtant à l'étude quantitative de ces phénomènes, et permettant de préciser le rôle du critère adimensionnel utilisé pour caractériser les tendances d'un tel système. D'autre part, l'examen des processus de transport de traceurs fluorescents à proximité d'une paroi en régime turbulent a permis d'estimer un ordre de grandeur correct de l'épaisseur limitant le transfert de matière. Enfin, plusieurs solutions sont envisagées pour prévenir les effets liés à l'irradiation dans les couches limites ; la mise en œuvre expérimentale d'un réacteur à film tombant se révèle efficace pour le traitement de solutions concentrées, et la simulation numérique d'une irradiation distribuée en créneau à travers une paroi laisse présager de nouvelles possibilités de gain
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Carey, Elizabeth A. "Using plug-flow reactors to determine the role of soluble Fe(III) in the cycling of iron and sulfur in salt marsh sediments." Thesis, Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-03292004-141819/unrestricted/carey%5Felizabeth%5Fa%5F200312%5Fms.pdf.
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Campos, Danuza Costa. "STRIPPING DE AMÔNIA DE LIXIVIADO DE ATERRO SANITÁRIO EM REATORES DE FLUXO PISTONADO." Universidade Estadual da Paraíba, 2009. http://tede.bc.uepb.edu.br/tede/jspui/handle/tede/2168.
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Previous issue date: 2009-07-09By the population growth, the production of municipal solid residues is enhancing, and consequently the final disposal of such residues has been one of the major environmental problems faced in large urban centers. Lately the most used form of arrangement is the sanitary landfill, and when the residues are biodegraded inside the landfill cells they produce leachate and biogas. The leachate is a highly liquid pollutant, besides having high concentrations of ammonia nitrogen. Treating leachate is a very difficult task once its composition is very complex. A kind of treatment that is being developed is the stripping of ammonia where this chemical will be removed from the leachate by the mass transfer of the liquid phase to gas. Therefore, this paper addressed to study the ammonia stripping process in leachate liquids using plug-flow reactors in series. In order to accomplish the experimental part four plugflow reactors in series were built, with average height of 50 centimeters, without forced air supplier and without the leachate pH adjustment. The leachate samples used was from the metropolitan landfill of João Pessoa city, Paraiba, which was collected and transported to the EXTRABES laboratory and made the physicalchemical caracterization. The experimental monitoring system consisted of four distinct phases, with applied superficial loads of 450, 500, 600 and 700 kg NH4 +. ha 1.dia 1, hydraulic detention time equal to 65, 60, 50 and 38 days, and it was obtained an average efficiency of ammonia nitrogen removal around 96.1%, 99.7%, 99.5% and 98.5% respectively. At the end of monitoring, the reactor was discharged and made microscopic examinations of the remaining sludge reactor and each can observe the presence of bacteria fototróficas anoxigênicas, cocci, bacilli and algae. Can be found in this study that the higher the applied superficial load, was greater efficiency of removal of ammonia nitrogen, which may be load tested to verify the larger surface of contaminant removal.
Com o aumento populacional, a geração de resíduos sólidos urbanos vem aumentando, e com isso a disposição final desses resíduos vem sendo um dos graves problemas ambientais enfrentados nos grandes centros urbanos. A forma de disposição mais utilizada ultimamente é o aterro sanitário, e quando os resíduos são biodegradados dentro das células dos aterros, esses geram lixiviado e biogás. O lixiviado é um líquido altamente poluidor, haja vista, possuir altas concentrações de nitrogênio amoniacal. Tratar lixiviado é uma tarefa muito difícil devido a sua composição ser muito complexa. Um tratamento que vem sendo desenvolvido é o stripping de amônia, no qual a amônia vai ser removida do lixiviado por transferência de massa da fase líquida para a fase gasosa. Com isso, o presente trabalho tem como objetivo estudar o processo de stripping de amônia em líquidos lixiviados, utilizando reatores em série de fluxo pistonado. Para a realização da parte experimental foram construídos quatro reatores em série de fluxo pistonados, com altura média de 50 centímetros, sem alimentação forçada de ar e sem correção do pH do lixiviado. O lixiviado utilizado foi proveniente do aterro metropolitano de João Pessoa, onde foi coletado e transportado até as dependências físicas do laboratório da Estação Experimental de Tratamento Biológico de Esgoto Sanitário EXTRABES e feito a caracterização físico-química. O monitoramento do sistema experimental constou de quatro fases distintas, com cargas superficiais aplicadas de 450, 500, 600 e 700 kg NH4 +.ha 1.dia 1, tempo de detenção hidráulica igual a 65, 60, 50 e 38 dias, e obteve-se uma eficiência média de remoção de nitrogênio amoniacal em torno de 96,1%, 99,7%, 99,5% e 98,5%, respectivamente. Ao final do monitoramento, os reatores foram descarregados e feitos exames microscópicos no lodo remanescente de cada reator e pode-se observar a presença de bactérias fototróficas anoxigênicas, cocos, bacilos e algas. Pode ser constatado nesta pesquisa que quanto maior a carga superficial aplicada aos reatores, maior foi eficiência de remoção de nitrogênio amoniacal, podendo ainda ser testadas cargas superficiais maiores para verificar a remoção desse contaminante.
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Jiu-Wang, Chiou, and 邱居旺. "Treatment of the Wasetwater of Papermaking Industry by Completely Mixed Reactor and Dispersed Plug-Flow Reactor." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/54565526627131376103.
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Lin, Chien-An, and 林建安. "Studies on electrochemical production of chlorine dioxide by modified plug flow reactor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/08560771670637832336.
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碩士國立高雄師範大學
化學系
99
The advantages of chlorine dioxide are nontoxic, pollution and long efficiency.The preparation method of chlorine dioxide can be categorized in chemical and electrolysis methods. Chemical method has not only synthesized chlorine dioxide but also produce by-products (ClO2- and ClO3-). Therefore, this method is unsuited to disinfect the food. Chlorine dioxide produced by electrochemistry technology is simple dosing and continuous operating on-site processing, and the product can be applied to food disinfection which uses sodium chloride to be the main reactant will produce excess chlorine. Hence, we design a new reactor by Plug Flow Reactor (PFR) as the main model cell, while taking sodium chlorite as the main reactants. We conferred the current, flow rate into reactor, polar distance, electrolyte concentration and pH with the electrolytic preparation of chlorine dioxide yield, residual chlorine, purity and other effects by E. Marco Aieta method. The purity of chlorine dioxide is promoted by sodium chlorite method and reduces the generation of by-product.
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Chen, Jiun-Fu, and 陳俊甫. "Homogeneous and Heterogeneous Catalytic Reactions of Nitric Oxide in a Plug-Flow Reactor." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/23669661661990071613.
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碩士中原大學
化學工程研究所
89
The chemical reactions in the system NO/N2/O2 have been studied in a plug-flow reactor (PFR) to simulate the reaction within the freeboard of the fluidized-bed combustor. Experiments were carried out over wide ranges of temperature (600~1000 ℃), residence time (1.56~3.76 sec) and concentration of oxygen (0~9.58 vol %). The homogeneous reactions were performed in a quartz-glass reactor. The heterogeneous catalytic reactions on stainless steel were performed in a 316 stainless-steel reactor and a quartz glass reactor with stainless-steel meshes. The major homogeneous reaction of the NO/N2/O2 systems is NO+O+M=NO2+M. The rate constant of this reaction decreased with temperature and the conversion of NO decreased as the temperature increased. On the other hand, the conversion of NO increased with residence time and the concentration of oxygen. It is suggested that the free radicals of oxygen that formed during thermal homolysis played an important role in this homogeneous reaction. NO can be reduced by the heterogeneous catalytic reaction of the mixture of NO/N2 on the stainless steel. This reaction started at 700℃ and NO was almost reduced entirely at 1000℃. In this situation, the reduction rate of NO increased with increasing residence time. In the presence of oxygen, the conversion of NO decreased with the concentration of oxygen. The conversion of NO in the stainless-steel reactor is higher than that in the quartz-glass reactor in the same operating condition. It is showed that the conversion of NO increased with surface area of stainless steel.
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Yang, Tsung-Hong, and 楊聰宏. "In various condition, Plug-flow and Non-mixing reactor hydrogen-productivity compare and bio-reaction kinetic simulate." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/94107055155971095428.
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碩士臺中師範學院
環境教育研究所
91
Abstract The conventional anaerobic wastewater treatments are able to reco- very biogas, which is mainly methane. The methane’s greenhouse effect is more 21times than CO2. Based on the regulation of the Framework Convention On Climate Change, methane is the next item to be put under control due to its greenhouse effect. Hydrogen produced by anaerobic fermentation can be used as an energy source with no greenhouse effect and therefore become a more market-potential technique and energy. The research of the anaerobic fermentation hydrogen productivity is the basic study in the world. The experiments are more in the batch types about anaerobic fermentation hydrogen productivity. The more using reactor’s types are CSTR (Continuous flow Stirred Tank Reactor). It is less about in the optimal controlling condition and feasibility in the con- tinuous reaction. This research is based on the wastewater anaerobic bio- logical treatment experiments, considering physiological characteristics and the required growth environment of anaerobic hydrogen-fermentative bacteria. The study will compare the hydrogen-productivity in the diffe- rent temperature and pH about Non-mixing conventional reactor and Plug flow reactor. There are two main purposes in research: The first purpose include various operational conditions, that is pH and temperature of Non-mixing conventional reactor and Plug flow reactor, in order to estab- lish the pattern control model and compare hydrogen productivity. The second purposes include Plug Flow reactors establish the kinetics, process control and model simulation of anaerobic hydrogen-fermentative process, and hydrogen productivity. As the result shown, while the temperature being 43℃, the hydrogen productivity is the best. The Non-mixing conventional reactor can get the 2.36 mmole-H2 /g-CODre and the Plug Flow reactors is 1.46 mmole-H2 /g-CODre . The next is 35℃,28℃and the worst is 20℃.In the hydrogen productivity of per unit reactor is the best while the temperature is 43℃. The Non-mixing conventional reactor can get the 21.12 mole-H2/m3˙day and the Plug Flow reactors is 37.09 mole-H2/m3˙day. The both tempera- ture correlation factors,θ of hydrogen productivity of per unit biomass and per unit volume in Non-mixing conventional reactor are 1.039 and 1.064. And in Plug Flow reactors, the both temperature correlation factors,θ of hydrogen productivity of per unit biomass and per unit volume are 1.001 and 1.080. The hydrogen productivity of each reactors was increa- sed with the increased temperature. While the pH being 4.5, the hydrogen productivity is the best, but the biogas productivity is the best in the pH 6.5. The Non-mixing conventional reactor can get the 3.68 mmole-H2 /g-CODre and the Plug Flow reactors is 1.31 mmole-H2 /g-CODre . The next is pH 5.0, pH 5.5, pH 6.0 and the worst is pH 6.5. In the hydrogen productivity of per unit reactor is the best while the pH is 5.0. The Non-mixing conventional reactor can get the 24.36 mole-H2/m3˙day and the Plug Flow reactors is 33.88 mole-H2/m3˙day in the pH 4.5. The both pH correlation factors,θ of hydrogen productivity of per unit biomass and per unit volume in Non- mixing conventional reactor are 0.578 and 0.625. And in Plug Flow rea- ctors, the both pH correlation factors,θof hydrogen productivity of per unit biomass and per unit volume are 0.314 and 0.424. The hydrogen pro- ductivity of both reactors were increased with the decreased pH, but the biogas productivity were increased with the increased pH. As the result shown, we can get the more hydrogen productivity in the shorter term when the pH is 6.5. But the reactors will be highly methanation for a short time. When the pH is 4.5, we can get the long term and stable hydrogen productivity. Plug Flow reactors is best in COD removal than Non-mixing conventional reactor. The biogas productivity is the same trend in the different temperature and pH value. From the observation under the fluorescent microscope and electron microscope, it was found that yellow-orange fluorescence was emitted by a sludge sample it was found that the anaerobic fermentation hydrogene- sis be good. However, blue fluorescence, which indicated a highly metha- nation, was emitted while the anaerobic fermentation hydrogenesis was poor. These results may be helpful in determining the efficiency of anae- robic fermentation hydrogensis from the color of the reactor sludge and observation under the fluorescent microscope and electron microscope. Because of the main ingredients of the synthetic organic wastewater are glucose and beef extract. The flow pattern is Plug Flow reactors conti- nuous feed system. So Gompertz equation , that used in batch experiment, is not adopted. The regression result performed the Monod equation is fit for this study. From the result of simulation and experiment, the formula of the hydrogen productivity and process control model of Non-mixing conventional reactor was : hydrogen productivity of Non-mixing conventional reactor（mole-H2/m3˙day）=（0.324˙loading+0.245）˙1.064（T-35）˙0.625（pH-5.5） The formula of the hydrogen productivity and process control model of Plug Flow reactor was : hydrogen productivity of Plug Flow reactor（mole-H2/m3˙day）=（0.251˙loading+0.917）˙1.080（T-35）˙0.424（pH-5.5）, while the rage of loading is 2 to 60 kg-COD/m3˙day, temperature is 20 to 43℃ and the pH value is pH 4.5 to 6.5.
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Fayemiwo, Oluwademilade Martha. "Microbial enhanced oil recovery from oily sludge using a novel plug flow reactor system." Diss., 2014. http://hdl.handle.net/2263/43335.
Full textAbstract:
The refining and transportation of crude oil often results in an inevitable accumulation of recalcitrant waste products such as oily sludge. Remediation processes such as landfarming and anaerobic landfilling have been recently ruled as inappropriate disposal methods, due to the length of time it takes for remediation to reach completion, as well as the uncontrollable release of harmful organics into the soil, atmosphere and potentially groundwater. This study focused on a biological treatment method for oily sludge using a plug flow reactor system.
Biosurfactant-producing bacteria, Bacillus cereus, Klebsiella oxytoca and Cronobacter dublinensis were isolated from petroleum-contaminated and uncontaminated soil samples. Optimal growth of the bacteria was observed when incubated at ±30°C and biosurfactant activity was confirmed using the drop-collapse test. Oily sludge was simulated in the laboratory using fumed silica as intermediate compound to form Pickering emulsions. The recovery of oil involved the comparison of a plug flow system and a batch system. The plug flow system achieved up to 85% oil recovery from oily sludge while the batch system only achieved a maximum of 30% elution of the aqueous phase. The effect of waterflooding, in conjunction with biosurfactant-producing bacteria on the batch system had negligible effect while on the plug flow system, an increase of ±10% in percentage recovery was observed. GC-MS analysis of oil before and after the recovery process showed a reduction of concentration of certain compounds, suggesting possible degradation by bacteria or loss due to volatilization. TOC analysis showed a reduction in TOC of residual sludge, after completion of recovery process, suggesting degradation activity by bacteria trapped in the sludge matrix after the completion of the recovery process. Fifteen days after completion of recovery process, residual sludge from the plug flow system had a low TOC value of 1.03mg/L while sludge from the batch system had a much higher value of 7.119mg/L. The high percentage recovery of oil, coupled with the reduction of sludge TOC to negligible values suggest that MEOR is a feasible method for treatment of oily sludge and can be further investigated as a waste treatment procedure in the petroleum industry.Dissertation (MSc)--University of Pretoria, 2014.
lk2014
Chemical Engineering
MSc
Unrestricted
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"Analysis and LQ-optimal control of infinite-dimensional semilinear systems : application to a plug flow reactor." Université catholique de Louvain, 2005. http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-11302005-154241/.
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Chien, Chang Ju, and 簡昌儒. "The Studies of Photocatalytic Degradation of Toluene Vapor Using B/V-codoped TiO2 Photocatalysts in Plug-Flow Reactor." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/49accv.
Full textAbstract:
碩士長庚大學
化工與材料工程學系
104
In this study, 0.05%B-0.05% V-P25 of the modified photocatalyst is prepared, and photodegradation of toluene gas in the plug flow reactor. The photocatalyst powder characteristic is determind by uv-vis spectrophotometer、photoluminescence、scanning electron microscopy. By changing the feed concentration, relative humidity, residence time, catalyst particle size and two-component degradation of toluene and methyl ethyl ketone, explore different operating parameters on toluene removal efficiency. Then experimental data into the Langmuir-Hinshelwood kinetic equation to obtain the reaction kinetic model. The results show that the relative humidity increased from 25% to 75% in favor of the removal of toluene. Different locations within the reactor was observed removal of toluene, found the reaction belong to the pseudo-first-order reaction. In two-component degradation experiments, since toluene and methyl ethyl ketone compete with each other for the position of the active catalyst surface, resulting in a decline removal. The energy need to damage toluene molecules bond is higher than the methyl ethyl ketone. Therefore, methyl ethyl ketone the removal will be higher than the removal of toluene.
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Gao, Jia Yu, and 高嘉妤. "The Studies of Photocatalytic Degradation of Isopropyl Alcohol Vapor Using B/V-codoped TiO2 Photocatalysts in Plug-Flow Reactor." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8264hh.
Full textAbstract:
碩士長庚大學
化工與材料工程學系
105
In this study, B,V co-doped TiO2 which was coated in plug flow reactor, was used as photocatalyst to degrade isopropanol. The study focused on how the initial concentration, residence time, relative humidity and light source effect on the removal efficiency of isopropanol . The experimental results were used to analyze consecutive reaction and Langmuir-Hinshelwood. The removal efficiency of isopropanol decreased with the initial concentration increased. When the residence time was 3.665 min, the removal rate of 100ppmv-isopropanol achived to 99%. Under the relative humidity at 20% and 65%, the removal rate of 100ppmv-isopropanol was both achived to 99% when the residence time was 3.665 min. The result means that the relative humidity did not affect the photocatalytic degradation of isopropanol. Under UV light, the removal rate of 500 ppmv-isopropanol achived to 99% at the residence time was 2.199 min. The results of kinetic analysis showed that the low initial concentration of isopropanol was in accordance with the consecutive reaction. Whether high initial concentrations or low initial concentrations of isopropanol both match Langmuir-Hinshelwood Model.
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Lien, Wei-Ling, and 連瑋翎. "Study of the kinetics for penicillin G acylase on immobilized metal affinity membrane for batch and plug flow reactor." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/35113196498539980924.
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Hua, Chi Yu, and 紀又華. "The Study of Hydrogen Productivity of Anaerobic Photohydrogenesis by Plug-Flow Reactors in Various Organic Loadings and Operational Conditions." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/76484455315421486582.
Full textAbstract:
碩士國立臺中教育大學
環境教育研究所
94
The main purpose of this study was that photohydrogenic bacteria —Rhodopsedo-monas palustris (purple nonsulfur bacteria, strain WP3-5), which screened out from NCHU laboratory of professor Li, was used in the tests by opened-system and conti-nuous-input plug-flow reactors for hydrogen productivity in various organic loadings (influent COD concentration, HRT) and operational conditions (pH, Temp.). In tests of various organic loading, the main ingredients of influent were beef extract and glucose, the range of organic loadings were between 3.0~19.2 kg-COD/m3•day. The results were shown below: The test of highest organic loading (19.2 kg-COD/ m3•day) was the best operation. The hydrogen productivity of per unit reactor volume was 45.82 mol-H2/m3•day, the hydrogen content of biogas was 55.23% and the hydro-gen productivity of per gram influent COD was 2.45 mmol-H2/g-CODin. Therefore the operational condition (the highest organic loading: 19.2 kg-COD/m3•day) was used in tests of various operational conditions (pH and Temp.). The formula of linear regression and correlations is: The hydrogen productivity of per unit reactor volume (mol-H2/m3•day) =2.738(organic loading) - 8.087. In tests of various operational conditions(pH, Temp.), the influent COD concentra-tion was 8,000 mg/L with HRT of 10 h, the illumination was 11,000 lux, the pHs were 4.5, 5.0, 5.5, 6.0, the Temp. were 21, 28, 35, 43℃. In tests of various pHs, the results were shown below: The test of pH 5.0 was the best. The hydrogen productivity of per unit reactor volume was 45.72 mol-H2/m3•day, the hydrogen content of biogas was 54.90% and the hydrogen productivity of per gram influent COD was 2.48 mmol-H2/g-CODin. This was the best operational condition of pH. And the second one was the test of pH 4.5. The test of pH 5.5 was the third. The θpH (correction coefficient of pH tests) is 0.776. In tests of various temperatures, the results were shown below: The test of Temp. 35℃ was the best one. The hydrogen productivity of per unit reactor volume is 45.72 mol-H2/m3•day, the hydrogen content of biogas was 54.90% and the hydrogen productivity of per gram influent COD was 2.48 mmol-H2/g-CODin. This was the best operational condition of Temp. tests. And the second one was the test of Temp. 28℃. The test of Temp. 43℃ was the third. The θT (correction coefficient of Temp. tests) is 0.975. The formula of linear regression and correlations for all is: The hydrogen productivity of per unit reactor volume (mol-H2/m3•day) =〔2.738(organic loading)-8.087〕× , which was tested in 3.0~19.2 kg-COD/ m3•day, pH=4.5~ 6.0, Temp. 21~43℃. The results of this study can be provided as a reference of control and operation for anaerobic photohydrogenic reactors.
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(6588797), Joseph A. Oliva. "Process Intensification Techniques for Continuous Spherical Crystallization in an Oscillatory Baffled Crystallizer with Online Process Monitoring." Thesis, 2019.
Find full textAbstract:
Guided by the continuous manufacturing paradigm shift in the pharmaceutical industry, the proposed thesis focuses on the implementation of an integrated continuous crystallization platform, the oscillatory baffled crystallizer (OBC), with real time process monitoring. First, by defining an appropriate operating regime with residence time distribution (RTD) measurements, a system can be defined that allows for plug flow operation while also maintaining solid suspension in a two-phase system. The aim of modern crystallization processes, narrow crystal size distributions (CSDs), is a direct result of narrow RTDs. Using a USB microscope camera and principal component analysis (PCA) in pulse tracer experiments, a novel non-contact RTD measurement method was developed using methylene blue. After defining an operating region, this work focuses on a specific process intensification technique, namely spherical crystallization.
Used mainly to tailor the size of a final dosage form, spherical crystallization removes the need for downstream size-control based unit operations (grinding, milling, and granulation), while maintaining drug efficacy by tailoring the size of the primary crystals in the agglomerate. The approach for generating spherical agglomerates is evaluated for both small and large molecules, as there are major distinctions in process kinetics and mechanisms. To monitor the spherical agglomeration process, a variety of Process Analytical Technology (PAT) tools were used and the data was implemented for scale-up applications.
Lastly, a compartmental model was designed based on the experimental RTD data with the intention of predicting OBC mixing and scale-up dynamics. Together, with validation from both the DN6 and DN15 systems, a scale independent equation was developed to predict system dispersion at different mixing conditions. Although it accurately predicts the behavior of these two OBC systems, additional OBC systems of different scale, but similar geometry should be tested for validation purposes.
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(5930285), Karen N. Son. "Improved Prediction of Adsorption-Based Life Support for Deep Space Exploration." Thesis, 2019.
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Adsorbent technology is widely used in many industrial applications including waste heat recovery, water purification, and atmospheric revitalization in confined habitations. Astronauts depend on adsorbent-based systems to remove metabolic carbon dioxide (CO2) from the cabin atmosphere; as NASA prepares for the journey to Mars, engineers are redesigning the adsorbent-based system for reduced weight and optimal efficiency. These efforts hinge upon the development of accurate, predictive models, as simulations are increasingly relied upon to save cost and time over the traditional design-build-test approach. Engineers rely on simplified models to reduce computational cost and enable parametric optimizations. Amongst these simplified models is the axially dispersed plug-flow model for predicting the adsorbate concentration during flow through an adsorbent bed. This model is ubiquitously used in designing fixed-bed adsorption systems. The current work aims to improve the accuracy of the axially dispersed plug-flow model because of its wide-spread use. This dissertation identifies the critical model inputs that drive the overall uncertainty in important output quantities then systematically improves the measurement and prediction of these input parameters. Limitations of the axially dispersed plug-flow model are also discussed, and recommendations made for identifying failure of the plug-flow assumption.
An uncertainty and sensitivity analysis of an axially disperse plug-flow model is first presented. Upper and lower uncertainty bounds for each of the model inputs are found by comparing empirical correlations against experimental data from the literature. Model uncertainty is then investigated by independently varying each model input between its individual upper and lower uncertainty bounds then observing the relative change in predicted effluent concentration and temperature (e.g., breakthrough time, bed capacity, and effluent temperature). This analysis showed that the LDF mass transfer coefficient is the largest source of uncertainty. Furthermore, the uncertainty analysis reveals that ignoring the effect of wall-channeling on apparent axial dispersion can cause significant error in the predicted breakthrough times of small-diameter beds.
In addition to LDF mass transfer coefficient and axial-dispersion, equilibrium isotherms are known to be strong lever arms and a potentially dominant source of model error. As such, detailed analysis of the equilibrium adsorption isotherms for zeolite 13X was conducted to improve the fidelity of CO2 and H2O on equilibrium isotherms compared to extant data. These two adsorbent/adsorbate pairs are of great interest as NASA plans to use zeolite 13X in the next generation atmospheric revitalization system. Equilibrium isotherms describe a sorbent’s maximum capacity at a given temperature and adsorbate (e.g., CO2 or H2O) partial pressure. New isotherm data from NASA Ames Research Center and NASA Marshall Space Flight Center for CO2 and H2O adsorption on zeolite 13X are presented. These measurements were carefully collected to eliminate sources of bias in previous data from the literature, where incomplete activation resulted in a reduced capacity. Several models are fit to the new equilibrium isotherm data and recommendations of the best model fit are made. The best-fit isotherm models from this analysis are used in all subsequent modeling efforts discussed in this dissertation.
The last two chapters examine the limitations of the axially disperse plug-flow model for predicting breakthrough in confined geometries. When a bed of pellets is confined in a rigid container, packing heterogeneities near the wall lead to faster flow around the periphery of the bed (i.e., wall channeling). Wall-channeling effects have long been considered negligible for beds which hold more than 20 pellets across; however, the present work shows that neglecting wall-channeling effects on dispersion can yield significant errors in model predictions. There is a fundamental gap in understanding the mechanisms which control wall-channeling driven dispersion. Furthermore, there is currently no way to predict wall channeling effects a priori or even to identify what systems will be impacted by it. This dissertation aims to fill this gap using both experimental measurements and simulations to identify mechanisms which cause the plug-flow assumption to fail.
First, experimental evidence of wall-channeling in beds, even at large bed-to-pellet diameter ratios (dbed/dp=48) is presented. These experiments are then used to validate a method for accurately extracting mass transfer coefficients from data affected by significant wall channeling. The relative magnitudes of wall-channeling effects are shown to be a function of the adsorption/adsorbate pair and geometric confinement (i.e., bed size). Ultimately, the axially disperse plug-flow model fails to capture the physics of breakthrough when nonplug-flow conditions prevail in the bed.
The final chapter of this dissertation develops a two-dimensional (2-D) adsorption model to examine the interplay of wall-channeling and adsorption kinetics and the adsorbent equilibrium capacity on breakthrough in confined geometries. The 2-D model incorporates the effect of radial variations in porosity on the velocity profile and is shown to accurately capture the effect of wall-channeling on adsorption behavior. The 2-D model is validated against experimental data, and then used to investigate whether capacity or adsorption kinetics cause certain adsorbates to exhibit more significant radial variations in concentration compared than others. This work explains channeling effects can vary for different adsorbate and/or adsorbent pairs—even under otherwise identical conditions—and highlights the importance of considering adsorption kinetics in addition to the traditional dbed/dp criteria.
This dissertation investigates key gaps in our understanding of fixed-bed adsorption. It will deliver insight into how these missing pieces impact the accuracy of predictive models and provide a means for reconciling these errors. The culmination of this work will be an accurate, predictive model that assists in the simulation-based design of the next-generation atmospheric revitalization system for humans’ journey to Mars.