The production of clean fuel faces the challenges of high production cost and complying with stricter environmental regulations. In this research, the ability of using a novel technology of upgrading heavy oil to treat Light Gas Oil (LGO) will be investigated. The target of this project is to produce cleaner transportation fuel with much lower cost of production. Recently, a novel process for upgrading of heavy oil has been developed at University of Waterloo. It is combining the two essential processes in bitumen upgrading; emulsion breaking and hydroprocessing into one process. The water in the emulsion is used to generate in situ hydrogen from the Water Gas Shift Reaction (WGSR). This hydrogen can be used for the hydrogenation and hydrotreating reaction which includes sulfur removal instead of the expensive molecular hydrogen. This process can be carried out for the upgrading of the bitumen emulsion which would improve its quality. In this study, the hydrodesulphurization (HDS) of LGO was conducted using in situ hydrogen produced via the Water Gas Shift Reaction (WGSR). The main objective of this experimental study is to evaluate the possibility of producing clean LGO over dispersed molybdenum sulphide catalyst and to evaluate the effect of different promoters and syn-gas on the activity of the dispersed Mo catalyst. Experiments were carried out in a 300 ml Autoclave batch reactor under 600 psi (initially) at 391oC for 1 to 3 hours and different amounts of water. After the hydrotreating reaction, the gas samples were collected and the conversion of carbon monoxide to hydrogen via WGSR was determined using a refinery gas analyzer. The sulphur content in liquid sample was analyzed via X-Ray Fluorescence. Experimental results showed that using more water will enhance WGSR but at the same time inhibits the HDS reaction. It was also shown that the amount of sulfur removed depends on the reaction time. The plan is to investigate the effect of synthesis gas (syngas) molar ratio by varying CO to H2 ratio. It is also planned to use different catalysts promoters and compare them with the un-promoted Mo based catalysts to achieve the optimum reaction conditions for treating LGO. The results of this study showed that Ni and Co have a promoting effect over un-promoted Mo catalysts for both HDS and WGSR. Ni was found to be the best promoter for both reactions. Fe showed no significant effect for both WGSR and HDS. V and K have a good promoting effect in WGSR but they inhibited the HDS reaction. Potassium was found to be the strongest inhibitor for the HDS reaction since no sulfur was removed during the reaction

Catalytic naphthalene hydrogenation to tetralin in water/hydrocarbon emulsions with simultaneous water gas shift as the hydrogen source was performed in a 300 ml batch autoclave as a model for aromatic hydrogenation in water/bitumen emulsions. The catalyst utilized was an unsupported and dispersed type based on molybdenum sulfide (MoS2). Distinguishing the fate of hydrogen from water as opposed to molecular hydrogen in hydrogenation and water gas shift was accomplished by utilizing deuterium oxide (D2O) with NMR spectroscopy. The use of D2O allowed determination of isotope effects when compared with H2O. Diffuse Reflectance Infrared Fourier Transform Spectroscopy was performed to observe CO adsorption on the MoS2 sulfide surface. Ruthenium was tested as a potential candidate to enhance the activity of the Mo catalyst. Iron, nickel and vanadium were utilized in combination with molybdenum to test promotional/inhibitive activity during naphthalene hydrogenation and water gas shift since Ni and V are found in significant quantities in real bitumen feed. Finally, a multifactorial experiment was performed to test the hydrogenation and water gas shift activity of a binary VNiMo-sulfide catalyst towards H2S partial pressure, temperature and H2 versus CO atmospheres. Deuterium from D2O was incorporated into both saturated and aromatic hydrogen positions in tetralin products. Calculation of a Hydrogenation Index and Exchange Index indicated the extent of H-exchange is greater than hydrogenation. Exchange between D2O and organic products was enhanced with the MoS2 catalyst under H2 or CO compared to N2. A kinetically measured isotope effect of 1.58 was in agreement with a quasi-equilibrium thermodynamic isotope effect for O-H dissociations measured in the literature. A true kinetic isotope effect may be masked by transient surface concentrations occurring under batch conditions. Two strong vibrational bands associated with adsorbed CO were observed over MoS2 above 160 °C. Activation of the MoS2 surface with CO produces COS, suggesting an analgous mechanism to the production of H2S during reduction in H2. In the presence of H2S, Ru displayed low catalytic activity for both water gas shift and naphthalene hydrogenation, attributed to incomplete sulfidation to active RuS2. FeMo and VMo exhibited lower hydrogenation activity than Mo, but the water gas shift activity of VMo was high. A ternary VNiMo displayed lower hydrogenation activity than NiMo and Mo but was higher than VMo, implying Ni could offset the inhibition caused by V. Recycle of V and Ni rich asphaltene residues in catalytic slurry upgrading may therefore be feasible. An analysis of the effect of H2S pressure, temperature and type of reduction gas (CO vs. H¬2) concluded that temperature had the greatest positive effect on rate, followed by a small interaction effect of temperature/gas type and PH2S/gas type. The proximity to equilibrium conversions in WGS limited the analysis, while equilibrium limited the conversion of naphthalene at 380 °C in the batch reactor.

The production of clean fuel faces the challenges of high production cost and complying with stricter environmental regulations. In this research, the ability of using a novel technology of upgrading heavy oil to treat Light Gas Oil (LGO) will be investigated. The target of this project is to produce cleaner transportation fuel with much lower cost of production. Recently, a novel process for upgrading of heavy oil has been developed at University of Waterloo. It is combining the two essential processes in bitumen upgrading; emulsion breaking and hydroprocessing into one process. The water in the emulsion is used to generate in situ hydrogen from the Water Gas Shift Reaction (WGSR). This hydrogen can be used for the hydrogenation and hydrotreating reaction which includes sulfur removal instead of the expensive molecular hydrogen. This process can be carried out for the upgrading of the bitumen emulsion which would improve its quality. In this study, the hydrodesulphurization (HDS) of LGO was conducted using in situ hydrogen produced via the Water Gas Shift Reaction (WGSR). The main objective of this experimental study is to evaluate the possibility of producing clean LGO over dispersed molybdenum sulphide catalyst and to evaluate the effect of different promoters and syn-gas on the activity of the dispersed Mo catalyst. Experiments were carried out in a 300 ml Autoclave batch reactor under 600 psi (initially) at 391oC for 1 to 3 hours and different amounts of water. After the hydrotreating reaction, the gas samples were collected and the conversion of carbon monoxide to hydrogen via WGSR was determined using a refinery gas analyzer. The sulphur content in liquid sample was analyzed via X-Ray Fluorescence. Experimental results showed that using more water will enhance WGSR but at the same time inhibits the HDS reaction. It was also shown that the amount of sulfur removed depends on the reaction time. The plan is to investigate the effect of synthesis gas (syngas) molar ratio by varying CO to H2 ratio. It is also planned to use different catalysts promoters and compare them with the un-promoted Mo based catalysts to achieve the optimum reaction conditions for treating LGO. The results of this study showed that Ni and Co have a promoting effect over un-promoted Mo catalysts for both HDS and WGSR. Ni was found to be the best promoter for both reactions. Fe showed no significant effect for both WGSR and HDS. V and K have a good promoting effect in WGSR but they inhibited the HDS reaction. Potassium was found to be the strongest inhibitor for the HDS reaction since no sulfur was removed during the reaction

Catalytic naphthalene hydrogenation to tetralin in water/hydrocarbon emulsions with simultaneous water gas shift as the hydrogen source was performed in a 300 ml batch autoclave as a model for aromatic hydrogenation in water/bitumen emulsions. The catalyst utilized was an unsupported and dispersed type based on molybdenum sulfide (MoS2). Distinguishing the fate of hydrogen from water as opposed to molecular hydrogen in hydrogenation and water gas shift was accomplished by utilizing deuterium oxide (D2O) with NMR spectroscopy. The use of D2O allowed determination of isotope effects when compared with H2O. Diffuse Reflectance Infrared Fourier Transform Spectroscopy was performed to observe CO adsorption on the MoS2 sulfide surface. Ruthenium was tested as a potential candidate to enhance the activity of the Mo catalyst. Iron, nickel and vanadium were utilized in combination with molybdenum to test promotional/inhibitive activity during naphthalene hydrogenation and water gas shift since Ni and V are found in significant quantities in real bitumen feed. Finally, a multifactorial experiment was performed to test the hydrogenation and water gas shift activity of a binary VNiMo-sulfide catalyst towards H2S partial pressure, temperature and H2 versus CO atmospheres. Deuterium from D2O was incorporated into both saturated and aromatic hydrogen positions in tetralin products. Calculation of a Hydrogenation Index and Exchange Index indicated the extent of H-exchange is greater than hydrogenation. Exchange between D2O and organic products was enhanced with the MoS2 catalyst under H2 or CO compared to N2. A kinetically measured isotope effect of 1.58 was in agreement with a quasi-equilibrium thermodynamic isotope effect for O-H dissociations measured in the literature. A true kinetic isotope effect may be masked by transient surface concentrations occurring under batch conditions. Two strong vibrational bands associated with adsorbed CO were observed over MoS2 above 160 °C. Activation of the MoS2 surface with CO produces COS, suggesting an analgous mechanism to the production of H2S during reduction in H2. In the presence of H2S, Ru displayed low catalytic activity for both water gas shift and naphthalene hydrogenation, attributed to incomplete sulfidation to active RuS2. FeMo and VMo exhibited lower hydrogenation activity than Mo, but the water gas shift activity of VMo was high. A ternary VNiMo displayed lower hydrogenation activity than NiMo and Mo but was higher than VMo, implying Ni could offset the inhibition caused by V. Recycle of V and Ni rich asphaltene residues in catalytic slurry upgrading may therefore be feasible. An analysis of the effect of H2S pressure, temperature and type of reduction gas (CO vs. H¬2) concluded that temperature had the greatest positive effect on rate, followed by a small interaction effect of temperature/gas type and PH2S/gas type. The proximity to equilibrium conversions in WGS limited the analysis, while equilibrium limited the conversion of naphthalene at 380 °C in the batch reactor.

Heavy oil derived from oil sands is becoming an important resource of energy and transportation fuels due to the depletion of conventional oil resources. However, bitumen and heavy oils have a low hydrogen/carbon ratio and contain a large percentage of sulfur and nitrogen heterocyclic compounds. At the level of deep desulfurization, aromatic poly-nuclear molecules, especially nitrogen-containing heterocyclic compounds, exhibit strong inhibitive effect on hydrodesulfurization (HDS) due to competitive adsorption on catalytically active sites with sulfur-containing molecules. Therefore, it is necessary to study the HDS of refractory sulfur-containing compounds and also the effect of nitrogen-containing species on the deep HDS for achieving the ultra low sulfur specifications for transportation fuels. Additionally, the cost of H2 increased in recent years and a bitumen emulsion upgrading technique using an alternative in-situ H2 generated via the water gas shift (WGS) reaction during the hydro-treating was developed in our group. In the present study, a kind of nano-dispersed unsupported MoSx based catalyst was developed and used for hydrodesulfurization, hydrodenitrogenation (HDN) and upgrading bitumen emulsions. Objectives of this thesis were to (1) improve the catalytic activity of the nano-dispersed Mo based catalysts towards the HDS and HDN reactions of refractory sulfur-/nitrogen-containing compounds; and (2) compare the reactivity of in-situ hydrogen generated via the WGS reaction versus externally provided molecular hydrogen in HDS and HDN reactions to improve the efficiency of the bitumen emulsion upgrading technology developed by our group. In the present study, to stimulate the reaction system of bitumen emulsion, water was added into the organic reaction system, so there are different phases in this reaction system. To investigate the activity of the catalyst, the catalyst particles dispersed in different phases were characterized separatedly via HRTEM-EDX. After HRTEM-EDX study, all phases were mixed up and dried for further characterizations, BET, SEM, and XRD. The catalyst prepared in in-situ hydrogen was found to have higher surface area and smaller particle size than the one made in molecular hydrogen. The presence of sulfur-/nitrogen-containing compounds in the preparation system caused significant changes in the morphology of dispersed Mo sulfide catalyst according to HRTEM observations. Refractory sulfur-containing compounds of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) were used as model compounds in HDS studies. The simultaneous HDS of both model compounds was performed at different reaction temperatures from 330??C to 400??C. The effect of the reaction temperature on the WGS reaction in the presence of sulfur-containing model compounds was reported. A kinetic model for HDS reactions was proposed and used in discussing experiment results. The relative HDS reactivity of 4,6-DMDBT to DBT using dispersed Mo sulfide catalyst in in-situ hydrogen was found to be higher than the reported results which were obtained over supported catalysts. Nickel and potassium were introduced into Mo sulfide catalysts as promoters and their effect on the WGS reaction and the HDS reaction were discussed. The simultaneous HDS was carried out in the two different hydrogen sources. The in-situ hydrogen reaction system showed higher conversion and desulfurization results of both sulfur model compounds. This observation has been found to be mainly contributed by the higher activity of the Mo sulfide catalyst prepared in in-situ H2. Strong inhibitive effect of nitrogen-containing compounds, basic quinoline or non-basic carbazole, on the HDS of refractory sulfur model compounds was observed and discussed. Basic quinoline was a much stronger inhibitor than non-basic carbazole. The two HDS reaction pathways were affected by nitrogen-containing compounds to different extents. The HDN of quinoline over the dispersed Mo sulfide catalyst using in-situ hydrogen had been studied extensively by a previous member in our group. In this thesis, the HDN of carbazole was studied. From the identification of HDN products of carbazole, a HDN reaction network was proposed. The HDN of carbazole was processed at different reaction temperatures. The WGS reaction was not inhibited in the presence of carbazole. Comparable reactivity of the two hydrogen sources towards the HDN of carbazole was observed. The presence of 4,6-DMDBT caused significant effect on the HDN of carbazole due to the competitive adsorption on the catalyst surface.

In this research project, adsorption is considered in conjunction with the reverse water gas shift reaction in order to convert CO2 to CO for synthetic fuel production. If the CO2 for this process can be captured from high emitting industries it can be a very good alternative for reduced fossil fuel consumption and GHG emission mitigation. CO as an active gas could be used in Fischer-Tropsch process to produce conventional fuels. Literature review and process simulation were carried out in order to determine the best operating conditions for reverse water gas shift (RWGS) reaction. Increasing CO2 conversion to CO requires CO2/CO separation downstream of the reactor and recycling unreacted CO2 and H2 back into the reactor. Adsorption as a viable and cost effective process for gas separation was chosen for the CO2/CO separation. This was started by a series of adsorbent screening experiments to select the best adsorbent for the application. Screening study was performed by comparing pure gas isotherms for CO2 and CO at different temperatures and pressures. Then experimental isotherm data were modeled by the Temperature-Dependent Toth isotherm model which provided satisfactory fits for these isotherms. Henry law’s constant, isosteric heat of adsorption and binary mixture prediction were determined as well as selectivity for each adsorbent. Finally, the expected working capacity was calculated in order to find the best candidate in terms of adsorption and desorption. Zeolite NaY was selected as the best candidate for CO2/CO separation in adsorption process for this project. In the last step breakthrough experiments were performed to evaluate operating condition and adsorption capacity for real multi component mixture of CO2, CO, H2 in both cases of saturated with water and dry gas basis. In multi components experiments zeolite NaY has shown very good performance to separate CO2/CO at low adsorption pressure and ambient temperature. Also desorption experiment was carried out in order to evaluate the working capacity of the adsorbent for using in industrial scale and eventually temperature swing adsorption (TSA) process worked very well for the regeneration step. Integrated adsorption system downstream of RWGS reactor can enhance the conversion of CO2 to CO in this process significantly resulting to provide synthetic gas for synthetic fuel production as well as GHG emission mitigation.

Thesis (Ph.D.)--Tufts University, 2004. / Submitted to the Dept. of Chemical and Biological Engineering. Includes bibliographical references.

Thesis (Ph.D.)--Mississippi State University. Department of Agricultural and Biological Engineering. / Title from title screen. Includes bibliographical references.

Extracts from Thesis (Ph. D.)--University of Michigan, 1934. / Part 2 has title: Evaluation of oils from the manufacture of carburetted water gas by their available hydrogen content. Bibliography at end of each part.

86 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-11T16:26:04Z No. of bitstreams: 1 HilmaFonseca_dissertação_ 2011.pdf: 2091220 bytes, checksum: ab1c531b8b0822721d83a6c9c22c4001 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-05-10T16:56:08Z (GMT) No. of bitstreams: 1 HilmaFonseca_dissertação_ 2011.pdf: 2091220 bytes, checksum: ab1c531b8b0822721d83a6c9c22c4001 (MD5) / Made available in DSpace on 2013-05-10T16:56:08Z (GMT). No. of bitstreams: 1 HilmaFonseca_dissertação_ 2011.pdf: 2091220 bytes, checksum: ab1c531b8b0822721d83a6c9c22c4001 (MD5) Previous issue date: 2011 / CNPq / A reação de deslocamento de monóxido de carbono com vapor d‟água (water gas shift reaction, WGSR) é um processo industrial amplamente utilizado, sendo uma etapa fundamental para a produção comercial de hidrogênio de alta pureza. A reação também é importante para a remoção de monóxido de carbono, a partir de vapores ricos em hidrogênio, uma vez que ele envenena a maioria dos catalisadores metálicos. O catalisador clássico da WGSR, conduzida na faixa de 350-420 °C, é a hematita dopada com oxido de cromo, que é toxico e perde área superficial específica, durante os processos industriais. Portanto, um esforço considerável tem sido feito nos últimos anos, a fim de obter catalisadores alternativos para a reação. Os catalisadores do tipo perovskita têm atraído muita atenção nos últimos tempos devido à alta flexibilidade da sua estrutura, às suas propriedades redox e à possibilidade de controlar as propriedades ácido-base. Desta forma foram estudados, neste trabalho, óxidos tipo perovskitas LaFe1-xCoxO3 (0 ≥ x ≤ 1), que foram empregados como precursores de catalisadores alternativos da WGSR. As amostras foram preparadas por decomposição térmica dos precursores, obtidos pelo método do citrato amorfo, seguida de calcinação a 600 ° C, por 4 h. As amostras foram caracterizadas por espectroscopia no infravermelho com transformada de Fourier, difração de raios X, fluorescência de raios X, medidas de área de superfície específica, redução à temperatura programada, espectroscopia de refletância difusa no ultravioleta e visível e microscopia eletrônica de varredura. Os catalisadores foram avaliados em WGSR, conduzida a 1 atm e distintas temperaturas, na faixa de 250 a 600 °C. Antes da reação, as amostras foram reduzidos sob fluxo de hidrogênio a 600 °C, por 1 h. Todas as amostras exibiram uma única fase de perovskita. A amostra isenta de ferro mostrou uma baixa área superficial específica (3,5 m2g-1), que aumentou com a introdução de ferro, sendo alcançados valores na faixa de 12 a 17 m2.g-1. A redução da perovskita LaCoO3 ocorreu em duas etapas, a primeira em torno de 300 °C, atribuída à redução da espécies Co3+ para Co2+ e a segundo em cerca de 500 °C, relacionada à redução de espécies Co2+ para Co0. Em todas as amostras, a adição de ferro dificultou a produção de espécies Co0 e este efeito aumentou com a quantidade de ferro em sólidos. Todos os catalisadores levaram a valores similares de conversão de monóxido de carbono em temperaturas até 300 °C. O catalisador LaCoO3 foi o mais ativo na faixa de 250-450 °C e a adição de ferro diminuiu a atividade neste intervalo de temperatura. Em temperaturas superiores a 450 °C, o efeito do ferro sobre a atividade catalítica foi dependente da sua quantidade nos sólidos. Em quantidades baixas (x= 0,1), altas (x= 0,9) ou iguais (x= 0,5) a atividade diminuiu, enquanto em quantidades intermediárias (x= 0,3) e (x= 0,7), houve um aumento. Estes resultados podem ser explicados pelo fato de que o cobalto ser facilmente reduzido na estrutura perovskita garantindo alta atividade na WGSR. A adição de quantidades elevadas de ferro (x = 0,9) gera um sólido com alta resistência à redução e, portanto, menos ativos na WGSR. Por outro lado, a adição de uma quantidade intermediária (x = 0,3) leva a um sólido capaz de ser reduzido em temperaturas superiores a 450 °C, aumentando a atividade catalítica. A partir desses resultados, pode-se concluir que óxidos com estrutura perovskita do tipo LaFe1-xCoxO3 são precursores promissores para catalisadores da WGSR em altas temperaturas (>350 °C); a adição de ferro é benéfica em quantidade suficiente para produzir uma perovskita tipo LaFe0,7Co0,3O3, obtém-se o catalisador mais ativo em altas temperaturas / Salvador