A mathematical modeling framework for the methane steam reforming reaction operating in steady state has been developed. Performances are compared between the classic catalytic packed bed reactor and a Pd-based catalytic membrane reactor. Isothermal simulations on MATLAB © has first been conducted and show a higher performance of the membrane reactor over the packed bed reactor. Methane conversion of 1 can be reached for lower temperatures than used with industrial PBR, and better performances are shown for an increase in the operating pressure. Optimum conditions were defined for Temperature (500-600 Celsius), reaction side pressure (16-40 bars), membrane thickness (1-7 micrometers), steam/methane ratio (3-4), reactor length (5-10 meters) and permeate sweep ratio (20 or more). This model was validated by multiple recognized sources. Adiabatic simulations were conducted in order to develop a mathematical model base for non-isothermal simulations. The membrane reactor is again showing a higher conversion of methane compared to the packed bed reactor, however the heat loss due to the membrane and the hydrogen leaving through the tube is decreasing the performances of the MR over the PBR compared to the isothermal case. Results show also that most of the reaction occurs at the very beginning of the reactor.

The search for an alternative clean and renewable energy source has become an urgent matter. One such energy-saving technology is a fuel cell; it uses fuel as the source of energy to produce electricity directly and the byproducts formed are not as voluminous and environmentally harmful. The conventional low temperature fuel cells use hydrogen as the fuel which is produced from conventional fuels via reforming. However, developing reformers for hydrocarbon fuels requires AN understanding of the fundamental mechanisms and kinetics studies. In this study, simple hydrocarbon fuel, namely methane, in external reforming or internal reforming within a solid oxide fuel cell has been studied because of its importance and with the hope that it will ultimately lead to an understanding of reforming of higher hydrocarbons, such as logistic fuels like JP-8. For this purpose, methane was used the starting point and building block for the progressive understanding of reforming of complex hydrocarbons. Methane steam reforming (MSR), CH4 + 2H2O = CO2 + 4H2 is, in fact, the most common method of producing commercial bulk hydrogen along with the hydrogen used in ammonia plants. United States alone produces 9 million tons of hydrogen per year. The overall MSR reaction CH4 + 2H2O = CO2 + 4H2 is in fact composed of two reactions, the water gas shift reaction, CO + H2O = CO2 + H2, which has recently been investigated by a former Ph.D. student in our group, Caitlin Callaghan. Here, the first reaction CH4 + H2O = CO + 3H2, i.e., methane reforming, is analyzed using a reaction route network approach to obtain the overall methane steam reforming network and kinetics. Kinetics providing detailed information of elementary reaction steps for this system, namely micro-kinetics, has not yet been fully addressed. Employing the theory of Reaction Route Network Theory, recently developed by Fishtik and Datta, and using the Unity Bond Index-Quadratic Exponential Potential (UBI-QEP) method of Shustorovich to predict elementary step kinetics coupled with transition-state theory, a detailed microkinetic model of steam and dry reforming of methane has been developed for Rh(111) and Ni(111) in this thesis. While there is extensive literature on it, the standard reference on the mechanism and kinetics of MSR is that of Xu and Froment, who proposed a 13 step mechanism. Based on the assumption of rate limiting steps for these overall reactions, Xu and Froment derived rate expressions for overall kinetics with fitted parameters. Here a more detailed micro-kinetic model of steam reforming of methane has been developed by adding 3 steps pertinent to carbon formation on the catalyst to Xu and Froment's mechanism. The complete set as well as the dominant reaction routes has been identified. This was accomplished first by enumerating the list of reaction routes and drawing this network. A program was written in Maple and was used to assist in creating the list of full routes, empty routes and intermediate nodes. This program reduces the amount of repetitive work that was needed in an earlier Matlab program when computing the list. After drawing the complete reaction network it was than converted into an equivalent electrical circuit and Multisim analysis was performed. Further, the resistances of various reaction steps were compared. From the reduced graph, it was determined that reaction steps pertaining to desorption of carbon dioxide, i.e., step s4, and intermediate methylene forming intermediate methylidyne, s11, are the rate limiting steps. Further, through simulation with Multisim, it was determined that in fact only 2 overall reactions are needed. Adding a third overall reaction results in a nodal balance error. A rate expression was developed based on assuming the above two rate determining steps, with remaining steps at pseudo equilibrium along with the quasi-steady state approximation. The rate expression however produced a substantial error in conversion when compared to the overall microkinetic model. In addition to computing the micro-kinetic model, experimental work for methane steam reforming was conducted. A steam to carbon ratio of 2:1 was fed to the packed bed reactor, where experimental conversion data were obtained. These data points for Ni and Rh catalyst were plotted against the model to see how well the simulation predicted the experimental results. Reasonable agreement was obtained.

With the increase in production of biodiesel, a glut of glycerol has resulted in the world market. Glycerol, once a valuable chemical, has become a recalcitrant byproduct. It is also a potential renewable feedstock for hydrogen production. This study is focused on hydrogen production from glycerol steam reforming. During the initial stage, effect of process variables, such as system pressure (1-5 atm), temperature (327 – 727 oC), and water/glycerol molar ratio of (1:1-9:1) on hydrogen yield was investigated using a thermodynamic analysis. The equilibrium concentrations of different compounds were calculated by the method of Gibbs free energy minimization. The study revealed that the best conditions for producing hydrogen is at temperature > 627 oC, atmospheric pressure, and water/glycerol molar ratio (WGMR) 9:1. As a part of catalysts screening, 14 catalysts were prepared on monoliths and tested for their activity. Effects of those catalysts on hydrogen selectivity and glycerol conversion in temperatures ranging from 600-900 oC were discussed. Ni/Al2O3 and Rh/CeO2/Al2O3 were found to be the best performing catalysts based on hydrogen selectivity and glycerol conversion under the conditions investigated in this study. Also, the effect of WGMR, metal loading, and feed flow rate (FFR) were analyzed for the two best performing catalysts. Subsequently, effect of CeO2, MgO, and TiO2 supported Ni catalysts on hydrogen production from glycerol was studied. Effects of reaction temperature, FFR, and WGMR on hydrogen selectivity and glycerol conversion were also analyzed. Ni/CeO2 was found to be the best performing catalyst when compared to Ni/MgO and Ni/TiO2 under the experimental conditions investigated. The activation energy of glycerol reforming reaction was found to be 103 kJ/mol, and the reaction order with respect to glycerol was 0.23 over Ni/CeO2 catalysts based on the power law.

Fuel processing is one of the essential parts for development of intermediate solid oxide fuel cells (IT-SOFC). Natural gas (methane) is considered as the most abundant and cost effective fuel for the production of hydrogen for IT-SOFC. The primary aim of this thesis is to use a novel precursor material—layered double hydroxide (LDH) – for developing a new type of cost effective, highly active and long lasting catalyst which can reform natural gas in IT-SOFC anode environment. Small amount of noble metals Pd, Rh and Pt are used as promoters to enhance the catalyst’s performance as while maintaining the cost relatively low. The research objectives are achieved by a series of studies including catalysts synthesis, characterisation and the catalytic activities. The thesis initially gives a comprehensive review on fuel cell and SOFC technology, steam methane reforming and reforming catalyst to provide better understanding of the research. Experimental studies include the effects of the synthetic conditions of the LDH precursors and thermal treatments on the physical, chemical behaviours and catalytic activities of the catalysts and promotional effects by noble metals. The LDH derived catalysts compositions, promoter quantities and operating conditions are optimised for the best performance in the IT-SOFC anode environment. A new method for the development of precursor sol for easy coating of the anode is developed and studied. The sol preparation is achieved by acid attack. The sol developed is found to produce better coating and has very high catalytic properties after activation. The catalysts developed were tested for their stability and self-activation ability to ensure its use in the commercial cells. The findings of the present study indicate that the catalysts developed show excellent catalytic performance and these catalysts have very high potential for further commercialisation in IT-SOFC.

<p>Biomass derived oil (BDO) reforming with CO2 was carried out at 800oC under atmospheric pressure in a tubular fixed bed vertical reactor packed with quartz particles. The feed gas was a mixture of CO2 and N2 at various compositions with a flow rate of 30 to 60 cm3/min. The BDO flow rate was 5 g/h. The product gas consisted mostly of H2, CO, CO2, CH4 and C2H4.</p><p>The maximum production of synthesis gas (~76 mol%) was observed at a total carrier gas flow rate of 60 cm3/min and a mole fraction of CO2 in carrier gas of 0.1. Maximum hydrogen (42 mol%) and H2 to CO molar ratio (1.44) were obtained while using only N2 as the carrier gas at a flow rate of 50 cm3/min. In the range of residence time considered, CO2 was not consumed in BDO gasification at 800oC but helped to increase gas production at the expense of the char.</p><p>Pyrolysis of lard was performed to produce a diesel-like liquid and a high heating value gaseous fuel. Lard was fed into the reactor at 5 g/h using N2 (10-70 cm3/min) as carrier gas. Two particle size ranges of quartz particles (0.7-1.4 and 1.7-2.4 mm) were used as reactor packing material. The liquid product essentially consisted of linear and cyclic alkanes and alkenes, aromatics, ketones, aldehydes and carboxylic acids. The maximum yield for diesel-like liquid product (37g/100g lard) was obtained at 600oC, residence time of 1.5 s and packing particle size of 1.7- 2.4 mm. The liquid product obtained at 600oC, carrier gas flow rate of 50 cm3/min and quartz packing particle size of 0.7-1.4 mm has a cetane index of 46, specific gravity of 0.86, a heating value of 40 MJ/kg and cloud and pour points of 10 and -18 respectively. The heating value of the product gas ranged between 68 and 165 MJ/m3. This study shows that there is a potential for producing diesel-like liquid from pyrolysis of lard. It also identifies the pyrolysis of animal fats as a source of high heating value gaseous fuel.</p><p>Steam reforming of lard was performed at 500, 550, 600 and 800oC and at steam to lard mass ratios of 0.5 to 2.0. The maximum diesel-like liquid yield from the steam reforming process (39 g/100g of lard) was obtained at a steam to lard ratio of 1.5 and a temperature of 600oC. Higher cetane index (52) and lower viscosity (4.0 mPa.s at 40oC) were obtained by addition of steam. The net energy recovered from pyrolysis and steam reforming processes were 21.7and 21.9 kJ/g of lard respectively. Thus, the processes are energy efficient.</p><p>In comparison, lard is a better feedstock for the production of hydrogen, char, high heating value gas and high H2/CO ratio than BDO. On the other hand, BDO is the preferred feedstock for the production of synthesis gas with H2/CO in the vicinity of 1.</p>

La energía se ha convertido en una necesidad vital para garantizar el desarrollo de las sociedades modernas. Entre las diferentes posibles alternativas para producir energía, el hidrogeno presenta varias características que lo convierten en un atractivo vector energético: primero, se trata de una tecnología más eficiente para transformar la energía química en electricidad -por ejemplo, utilizando pilas de-combustible, las cuales también reducen de manera significativa los niveles de emisión de CO2 -; en segundo lugar, el hidrogeno puede ser producido a partir de una amplia variedad de materias primas, incluyendo recursos renovables y no renovables. Sin embargo, las tecnologías para producir hidrogeno para applicaciones con pilas de combustible aun requieren de un esfuerzo en investigación y desarrollo.El objetivo principal de esta tesis fue de evaluar técnicamente las opciones para preparar y utilizar catalizadores en placas insertados en un reactor de pared catalítica para producir hidrogeno mediante el reformado por vapor de etanol bajo condiciones de alta eficiencia térmica. Para completar el objetivo general y los objetivos específicos, se diseño un plan experimental sistemático, compuesto de tres partes: documentación, experimentación y simulación numérica. La información utilizada se puede clasificar en tres ramas: primero, una revisión detallada de las características generales que presentan las técnicas de reformado, seguido por una revisión descriptiva del reformado por vapor de etanol, enfocado en los principales aspectos de la preparación de catalizadores y la realización de la reacción química. A continuación en segundo lugar, se presenta una descripción acerca de reactores estructurados y los métodos para preparar catalizadores. Por último, en tercer lugar, se expone una explicación centrada en los materiales, equipos y métodos empleados para explorar el rendimiento de los catalizadores. Esta parte incluye la descripción de: algunas de las técnicas analíticas más comunes para caracterizar y evaluar tanto catalizadores como compuestos químicos y la descripción de las herramientas utilizadas en la simulación numérica.El primer bloque de simulación numérica tiene como fin evaluar las posibles restricciones termodinámicas por medio de análisis específicos basados en el equilibrio termodinámico, tanto del reactor como del proceso integrado. Luego, se ejecuta un mapeo del conjunto de condiciones operacionales, compuesto por cuatro variables principales: (temperatura, relación vapor carbón, presión y factor de recobro de hidrogeno en el separador de membrana). Ello con el fin de garantizar una operación auto-térmica del procesador de combustible. Se compara la habilidad y la ventaja entre los diferentes tipos de catalizadores publicados en trabajos previos en base a las condiciones termodinámicas ideales determinadas en el análisis termodinámico.Para los catalizadores en polvo, se realizo experimentos de caracterización y reacción mediante el empleo de un reactor de lecho fijo. Se ha efectuado un estudio sistematico para comparar la actividad y la selectividad de dos tipos de catalizadores, bajo condiciones moderadas de temperatura y relación vapor carbón. Los catalizadores basados en níquel (Ni/La2O3-Al2O3) y cobalto (Co-Fe/ZnO y Co-Mn/ZnO) han sido preparados y probados a las siguientes condiciones: temperatura en el rango de 400-500°C, relación vapor carbono entre 2 y 4, tiempo de contacto desde 4.3 hasta 1100 min·gcat molEtOH-1, cubriendo un rango de conversión de etanol desde 20 hasta 100%. Se ha efectuado un diseño de análisis multifactorial para establecer la influencia de las variables (temperatura, relación vapor carbón, tiempo de contacto y formulación del catalizador) en términos de la conversión de etanol y la selectividad hacia los diferentes productos.Por último, se ha efectuado la caracterización, simulación y experimentación utilizando una configuración de reactor de pared catalítica. Primero, se emplea un modelo en 2D para analizar las características principales del reactor de pared catalítica diseñado y construido para realizar la reacción sobre las placas con catalizador previamente preparadas. En segundo lugar, se expone de manera detallada el método seguido para preparar dos tipos diferentes de placas catalíticas. Estas placas con catalizador son caracterizadas de manera similar al método empleado con los catalizadores en polvo. Luego, se ha realizado un estudio sistemático para comparar la actividad y la selectividad de los dos tipos de placas catalíticas. Por último, mediante un modelo 1D se revelan aspectos fundamentales de la configuración del reactor de pared catalítica utilizando una configuración con dos canales paralelos, en los cuales se ejecutan una reacción endotérmica y otra exotérmica respectivamente.La principal conclusión de este trabajo es que el reformado por vapor de etanol puede ser realizado bajo condiciones de alta eficiencia térmica si se emplea un diseño basado en un reactor de pared catalítica con recobro de calor integrado a una unidad de separación para la purificación del hidrogeno. Las placas catalíticas han demostrado ser un elemento fundamental en este tipo de reactor porque incrementan de manera significativa el transporte de calor que se requiere para sostener las reacciones endotérmicas. / Energy has become a fundamental necessity to guarantee modern society development. Among different alternatives possible to produce energy, hydrogen presents several characteristics which make it an attractive energy vector: first, more efficient processes to transform chemical energy into electricity -such as Fuel Cells that, in addition, will help to reduce significantly CO2 emission levels-; and second, hydrogen can be produced from a large variety of feed stocks, including fossil and renewable resources. However, as hydrogen production technologies for Fuel Cell applications are not available commercially yet, it still requires additional R&D efforts.The principal objective of this thesis was to evaluate technical feasibility for preparing and using catalytic plates in a Catalytic Wall Reactor configuration to produce hydrogen by Steam Reforming of Ethanol under conditions of high thermal efficiency. To fulfill the overall and specific objectives, a systematic experimental plan was designed and executed. It was composed of three main parts: documentation, experimentation and numerical simulation. Background information is divided into three branches, first a detailed overview of technical features for reforming technology, followed by a descriptive review of Steam Reforming of Ethanol key aspects for catalysts preparation and reaction performance. Third is presented a comprehensive examination on structured reactor and catalyst preparation methods. In this part is exposed a detailed explanation of materials, equipments, and methods employed for screening catalyst and evaluating catalytic reactor performance. Also, is presented employed techniques for catalyst characterization and fluid analysis. Finally are described tools for numerical simulation.First component of numerical simulations evaluates possible thermodynamic constrains through specific analyses based on thermodynamic equilibrium of reactor and integrated fuel processor. Then, is performed a mapping for the set of four operational variables (temperature, steam to carbon ratio, pressure, and hydrogen recovery in the membrane separator), that allow an auto-thermal operation of the fuel processor. The suitability and advantages of the different catalysts preparations that are known from recent publications are discussed on the basis of the operation conditions determined on the thermodynamic analysis.Experimental work is performed for powder catalyst characterization and catalytic experimentation using a Packed Bed Reactor (PBR). It has conducted a systematic study to compare the activity and selectivity of two types of catalyst at moderate temperature and steam to carbon (SC) ratios. Nickel-based catalysts (Ni/La2O3-Al2O3) and novel Co-based catalysts (Co-Fe/ZnO and Co-Mn/ZnO) have been prepared and tested at temperatures of 400 and 500 °C, Steam to Carbon (SC) molar ratios of 2 and 4, and contact times from 4.3 to 1100 min·gcat molEtOH-1, covering a range of ethanol conversion from 20 to 100%. A multifactorial design analysis has been conducted to establish the significance of temperature, SC ratio, contact time and catalyst formulation on ethanol conversion and selectivity towards the different reaction products.At last, it is carried out the catalytic plate characterization, simulation and experimentation using a Catalytic Wall Reactor configuration. First, is used a 2D modeling to analyze main characteristics of the Catalytic Wall Reactor designed and constructed to perform reactions on the prepared catalytic plates. Prepared catalytic plates are characterize in a similar way to that employed for the powder catalysts. After that, it was conducted a systematic study to compare the activity and selectivity of two types of catalytic plates. 1D model reveals main aspects on thermal performance for a theoretical Catalytic Wall Reactor using two co-current channels with endothermic and exothermic reactions respectively.Main conclusion from this work is that Steam Reforming of Ethanol can be performed at high thermal efficiency if the design of the fuel processor is based on structured catalytic wall reactors with integrated heat recovery coupled to a separation unit for hydrogen purification. Catalytic plates have proven to be a key component on CWR because improves significantly the heat transfer which is required to sustain endothermic reactions.

The conversion of ethanol to hydrogen or syngas can be achieved by reacting ethanol with water via steam reforming, CH3CH2OH + (1-x)H2O = (4-x)H2 + (2-x)CO + xCO2 (R.1) CH3CH2OH + H2O = 4H2 + 2CO (R.2) CO + H2O = H2 + CO2 (R.3) Ideally, the ethanol steam reforming reaction can achieve a hydrogen yield of 6 moles of hydrogen per mole of ethanol when the value of x in (R.1) equals 2. High theoretical H2 yield makes ethanol steam reforming a very attractive route for H2 production. Thermodynamic equilibrium studies have shown that ethanol steam reforming produces mixtures of H2, CO, CO2, and CH4 below 950 K, while above 950 K the ethanol steam reforming reaction (R.1) adequately describes the product composition In this study a series of 10wt% Ni loaded Mg-Al mixed oxide supported catalysts were evaluated for the production of hydrogen via the steam reforming of ethanol. Mg-Al mixed oxide supported nickel catalysts were found to give superior activity, steam reforming product selectivity (H2 and COx), and improved catalyst stability than the pure oxide supported nickel catalyst at both temperatures investigated. Activity, product selectivity, and catalyst stability were dependent upon the Al and Mg content of the support. At 923 K, the Mg-Al mixed oxide supported nickel catalysts were the best performing catalysts exhibiting the highest steam reforming product yield and were highly stable, showing no signs of deactivation after 20 h of operation. The improved performance of the Mg-Al mixed oxide supported catalysts was related to the incorporation of the pure oxides, MgO and Al2O3, into MgAl2O4. The formation of MgAl2O4 reduced nickel incorporation with the support material since MgAl2O4 does not react with Ni; therefore, nickel was retained in its active form. In addition, incorporation of Mg and Al in to MgAl2O4, a slight basic material, modified the acid-base properties resulting in a catalyst that exhibited moderate acidic and basic site strength and density compared to the pure oxide supported catalysts. Moderation of the acid-base properties improved the activity, selectivity, and stability of the catalysts by reducing activity for by-product reactions producing ethylene and acetaldehyde. At lower reaction temperatures, below 823 K, Mg-Al mixed oxide supported nickel catalysts experienced substantial deactivation resulting in reduced ethanol conversion but interestingly, the H2 and CO2 yields increased, exceeding equilibrium expectations with time on stream while CH4 yield decreased far below equilibrium expectations, suggesting a direct ethanol steam reforming reaction pathway. Over stabilized Mg-Al mixed oxide supported nickel catalysts, direct ethanol steam reforming was activated by a reduction in the catalyst’s activity for the production and desorption of CH4 from the surface. The effect of pressure on the direct ethanol steam reforming reaction pathway over stabilized Mg-Al mixed oxide supported nickel catalysts was investigated at 673 and 823 K. At 823 K, increasing the total pressure resulted in a product distribution that closely matched the thermodynamic expectations. However, at 673 K, the product distribution deviated from thermodynamic expectations, giving substantially greater yields for the steam reforming products, H2, CO, and CO2, while CH4 yield was consistently less than equilibrium expectations. The identification of an alternative direct ethanol steam reforming reaction pathway at relatively low temperatures (below 823 K) that could be operated at elevated pressures will result in an energy efficient process for the production of hydrogen from bio-ethanol.

The conversion of ethanol to hydrogen or syngas can be achieved by reacting ethanol with water via steam reforming, CH3CH2OH + (1-x)H2O = (4-x)H2 + (2-x)CO + xCO2 (R.1) CH3CH2OH + H2O = 4H2 + 2CO (R.2) CO + H2O = H2 + CO2 (R.3) Ideally, the ethanol steam reforming reaction can achieve a hydrogen yield of 6 moles of hydrogen per mole of ethanol when the value of x in (R.1) equals 2. High theoretical H2 yield makes ethanol steam reforming a very attractive route for H2 production. Thermodynamic equilibrium studies have shown that ethanol steam reforming produces mixtures of H2, CO, CO2, and CH4 below 950 K, while above 950 K the ethanol steam reforming reaction (R.1) adequately describes the product composition In this study a series of 10wt% Ni loaded Mg-Al mixed oxide supported catalysts were evaluated for the production of hydrogen via the steam reforming of ethanol. Mg-Al mixed oxide supported nickel catalysts were found to give superior activity, steam reforming product selectivity (H2 and COx), and improved catalyst stability than the pure oxide supported nickel catalyst at both temperatures investigated. Activity, product selectivity, and catalyst stability were dependent upon the Al and Mg content of the support. At 923 K, the Mg-Al mixed oxide supported nickel catalysts were the best performing catalysts exhibiting the highest steam reforming product yield and were highly stable, showing no signs of deactivation after 20 h of operation. The improved performance of the Mg-Al mixed oxide supported catalysts was related to the incorporation of the pure oxides, MgO and Al2O3, into MgAl2O4. The formation of MgAl2O4 reduced nickel incorporation with the support material since MgAl2O4 does not react with Ni; therefore, nickel was retained in its active form. In addition, incorporation of Mg and Al in to MgAl2O4, a slight basic material, modified the acid-base properties resulting in a catalyst that exhibited moderate acidic and basic site strength and density compared to the pure oxide supported catalysts. Moderation of the acid-base properties improved the activity, selectivity, and stability of the catalysts by reducing activity for by-product reactions producing ethylene and acetaldehyde. At lower reaction temperatures, below 823 K, Mg-Al mixed oxide supported nickel catalysts experienced substantial deactivation resulting in reduced ethanol conversion but interestingly, the H2 and CO2 yields increased, exceeding equilibrium expectations with time on stream while CH4 yield decreased far below equilibrium expectations, suggesting a direct ethanol steam reforming reaction pathway. Over stabilized Mg-Al mixed oxide supported nickel catalysts, direct ethanol steam reforming was activated by a reduction in the catalyst’s activity for the production and desorption of CH4 from the surface. The effect of pressure on the direct ethanol steam reforming reaction pathway over stabilized Mg-Al mixed oxide supported nickel catalysts was investigated at 673 and 823 K. At 823 K, increasing the total pressure resulted in a product distribution that closely matched the thermodynamic expectations. However, at 673 K, the product distribution deviated from thermodynamic expectations, giving substantially greater yields for the steam reforming products, H2, CO, and CO2, while CH4 yield was consistently less than equilibrium expectations. The identification of an alternative direct ethanol steam reforming reaction pathway at relatively low temperatures (below 823 K) that could be operated at elevated pressures will result in an energy efficient process for the production of hydrogen from bio-ethanol.

<p>Biomass derived oil (BDO) reforming with CO2 was carried out at 800oC under atmospheric pressure in a tubular fixed bed vertical reactor packed with quartz particles. The feed gas was a mixture of CO2 and N2 at various compositions with a flow rate of 30 to 60 cm3/min. The BDO flow rate was 5 g/h. The product gas consisted mostly of H2, CO, CO2, CH4 and C2H4.</p><p>The maximum production of synthesis gas (~76 mol%) was observed at a total carrier gas flow rate of 60 cm3/min and a mole fraction of CO2 in carrier gas of 0.1. Maximum hydrogen (42 mol%) and H2 to CO molar ratio (1.44) were obtained while using only N2 as the carrier gas at a flow rate of 50 cm3/min. In the range of residence time considered, CO2 was not consumed in BDO gasification at 800oC but helped to increase gas production at the expense of the char.</p><p>Pyrolysis of lard was performed to produce a diesel-like liquid and a high heating value gaseous fuel. Lard was fed into the reactor at 5 g/h using N2 (10-70 cm3/min) as carrier gas. Two particle size ranges of quartz particles (0.7-1.4 and 1.7-2.4 mm) were used as reactor packing material. The liquid product essentially consisted of linear and cyclic alkanes and alkenes, aromatics, ketones, aldehydes and carboxylic acids. The maximum yield for diesel-like liquid product (37g/100g lard) was obtained at 600oC, residence time of 1.5 s and packing particle size of 1.7- 2.4 mm. The liquid product obtained at 600oC, carrier gas flow rate of 50 cm3/min and quartz packing particle size of 0.7-1.4 mm has a cetane index of 46, specific gravity of 0.86, a heating value of 40 MJ/kg and cloud and pour points of 10 and -18 respectively. The heating value of the product gas ranged between 68 and 165 MJ/m3. This study shows that there is a potential for producing diesel-like liquid from pyrolysis of lard. It also identifies the pyrolysis of animal fats as a source of high heating value gaseous fuel.</p><p>Steam reforming of lard was performed at 500, 550, 600 and 800oC and at steam to lard mass ratios of 0.5 to 2.0. The maximum diesel-like liquid yield from the steam reforming process (39 g/100g of lard) was obtained at a steam to lard ratio of 1.5 and a temperature of 600oC. Higher cetane index (52) and lower viscosity (4.0 mPa.s at 40oC) were obtained by addition of steam. The net energy recovered from pyrolysis and steam reforming processes were 21.7and 21.9 kJ/g of lard respectively. Thus, the processes are energy efficient.</p><p>In comparison, lard is a better feedstock for the production of hydrogen, char, high heating value gas and high H2/CO ratio than BDO. On the other hand, BDO is the preferred feedstock for the production of synthesis gas with H2/CO in the vicinity of 1.</p>

Steam reforming of methanol and hydrocarbon are currently the processes of choice to produce hydrogen. Due to the endothermic nature of these reactions, zones of low temperature are commonly found in reformers. These zones can potentially damage the reformer through thermal stresses. Moreover, the response time and size of a reformer are controlled by the heat available to the reaction. The objective of this thesis is to demonstrate the feasibility of using fiber Bragg gratings as an alternative solution for temperature monitoring in methanol and methane steam reformers. To meet this objective, a sensor array containing seven gratings is placed in a metal-plate test reformer. First, temperature monitoring during methanol steam reforming is conducted in 12 different sets of conditions. The resulting profile of the temperature change along the length of the catalyst captures the zones of low temperature caused by the endothermic nature of the reaction. Several small changes in the temperature profile caused by increasing temperature and/or flow rates were captured, demonstrating the ability to use these gratings in methanol steam reforming. Similar experimental work was conducted to validate the possibility of using fiber Bragg gratings as temperature sensors in methane reforming. Using a regenerated grating array, data was collected for 13 operating conditions. The conclusions arising from this work are similar to those drawn from the methanol steam reforming work. The regenerated FBGs exhibited a behaviour that has not been reported in the literature which is referred to in this thesis as secondary erasure. This behaviour caused some instability in the grating signal and erroneous readings for some operating conditions. Despite this, the grating measurements captured the zones of low temperatures in the reformer and the small changes brought about by increasing the reforming temperature and lowering the steam to carbon ratio. / Graduate