The Solid Oxide Fuel Cell (SOFC) is a promising technology for electricity generation. It converts the chemical energy of the fuel gas directly to electricity energy and therefore, very high electrical efficiencies can be achieved. The high operating temperature of the SOFC also provides excellent possibilities for cogeneration applications. In addition to producing power very efficiently, the SOFC has the potential to concentrate CO₂ with a minimum of an overall efficiency loss. Concentration of CO₂ is a desirable feature of a power generation process so that the CO₂ may be subsequently sequestered thus preventing its contribution to global warming. The primary purpose of this research project was to investigate the role of the SOFC technology in power generation processes and explore its potential for CO₂ capture in power plants. <br /><br /> This thesis introduces an AspenPlus^TM SOFC stack model based on the natural gas feed tubular internal reforming SOFC technology. It was developed utilizing existing AspenPlus^TM functions and unit operation models. This SOFC model is able to provide detailed thermodynamic and parametric analysis of the SOFC operation and can easily be extended to study the entire process consisting of the SOFC stack and balance of plant. <br /><br /> Various SOFC-based power generation cycles were studied in this thesis. Various options for concentrating CO₂ in these power generation systems were also investigated and discussed in detail. All the processes simulations were implemented in AspenPlus^TM extending from the developed natural gas feed tubular SOFC stack model. The study shows that the SOFC technology has a promising future not only in generating electricity in high efficiency but also in facilitating CO₂ concentration, but the cost of the proposed processes still need be reduced so SOFCs can become a technical as well as economic feasible solution for power generation.

A solid oxide fuel cell (SOFC) is an energy conversion device that has the potential to efficiently generate electricity in an environmentally-friendly manner. In general, a SOFC operates between 750&deg;C and 1000&deg;C utilizing hydrogen or hydrocarbons as fuel and air as an oxidant. The three major components comprising a fuel cell are the electrolyte, the cathode, and the anode. At present, the state-of-the-art SOFC is made from a dense yttria-stabilized zirconia (YSZ) electrolyte, a porous lanthanum manganite cathode, and a porous nickel/YSZ composite anode. With the advent of the anode-supported SOFC and the increased interest in using a wider range of fuels, such as those containing sulphur, knowledge of the anode properties is becoming more important. <br /> The properties of the current anodes are limited due to the narrow range of nickel loadings imposed by the minimum nickel content for electrical conductivity and the maximum allowable nickel loading to avoid thermal mismatch with the YSZ electrolyte. In addition, there is little research presented in the literature regarding the use of nickel metal as a starting anode material, rather than the traditional nickel oxide powder, and how porosity may affect the anode properties. <br /> The purpose of this investigation is to determine the influence nickel morphology and porosity distribution have on the processing and properties of tape cast Ni/YSZ composites. Specifically, the sintering characteristics, electrical conductivity, and thermal expansion behaviour of tape cast composites created from YSZ, nickel, nickel oxide (NiO), nickel coated graphite (NiGr), and/or graphite (Gr) powders are investigated. In addition to samples made from 100% YSZ, 100% Ni, and 100% NiO powders, five composite types were created for this investigation: NiO/YSZ, NiO&Gr/YSZ, Ni/YSZ, NiGr/YSZ, and Ni&Gr/YSZ each with nickel loadings varying between 4 vol% Ni of total solids and 77 vol% Ni of total solids. Another set of composites with a fixed nickel loading of 27 vol% Ni and 47 vol% Ni of total solids and varying graphite loadings were also created. <br /> During the burnout stage, the composites made from nickel oxide powder shrink slightly while the composites made from nickel metal expand due to nickel oxidation. Graphite additions below 20 vol% of the green volume do not alter the dimensional changes of the composites during burnout, but graphite loadings greater than 25 vol% of the green volume cause significant expansion in the thickness of the composites. <br /> After sintering, the amount of volumetric sintering shrinkage decreases with higher nickel loadings and is greater for the composites made with nickel oxide compared to the composites made from nickel metal. The porosity generated in the composites containing graphite is slightly higher than the volume of graphite added to the composite and is much greater than the porosity contained in the graphite-free composites. <br /> Dimensional changes of the porous Ni/YSZ and NiO/YSZ composites during both burnout and sintering were analysed based on concepts of constrained sintering of composite powder mixtures. In some cases constrained sintering was evident, while in others, a more simple rule of mixtures behaviour for shrinkage as a function of YSZ content was observed. <br /> When nickel oxide is reduced to nickel metal during the reduction stage there is essentially no change in the composite volume for the composites containing YSZ because the YSZ prevents the composites from shrinking. After reduction the additional porosity generated in the composites is equivalent to the change in volume due to the reduction of nickel oxide to nickel metal. <br /> When measuring the electrical conductivity, each composite type demonstrated classic percolation behaviour. The NiGr/YSZ composites had the lowest percolation threshold, followed by the Ni/YSZ and NiO/YSZ composites. When graphite was added with a nickel coating, the added porosity did not disrupt the nickel percolation network and allowed the nickel to occupy a larger effective volume compared to a composite made with similar sized solid nickel particles. When graphite was added to the composites, the electrical conductivity was reduced and the percolation threshold increased. <br /> Generally, the coefficient of thermal expansion (CTE) for Ni/YSZ composites are expected to follow the rule of mixtures prediction since the elastic properties for nickel and YSZ are similar. However when porosity is distributed unevenly between the YSZ and nickel phases, the CTE prediction will deviate from the rule of mixtures. When cornstarch was added to the NiGr/YSZ composites, the CTE increased as the amount of porosity in the YSZ phase increased. The CTE of the NiGr/YSZ composites followed the rule of mixtures indicating that the porosity was evenly distributed between the nickel and YSZ phases. For the other composite types, the measured CTE was higher than the rule of mixtures prediction suggesting that more porosity was contained within the YSZ phase.

There has always been a desire to develop industrial processes that minimize the resources they use, and the wastes they generate. The problem is when new guidelines are forced upon long established processes, such as solvent based coating operations. This means instead of integrating an emission reduction technology into the original design of the process, it is added on after the fact. This significantly increases the costs associated with treating emissions. In this work the ultimate goal is the design of an “add-on” abatement system to treat emissions from solvent based coating processes with high destruction efficiency, and lower costs than systems in current use. Since emissions from processes that utilize solvent based coatings are primarily comprised of volatile organic compounds (VOCs), the treatment of these compounds will be the focus. VOCs themselves contain a significant amount of energy. If these compounds could be destroyed by simultaneously extracting the energy they release, operational costs could be substantially reduced. This thesis examines the use of model-based design to develop and optimize a VOC abatement technology that uses a Solid Oxide Fuel Cell (SOFC) for energy recovery. The model was built using existing HYSYS unit operation models, and was able to provide a detailed thermodynamic and parametric analysis of this technology. The model was validated by comparison to published literature results and through the use of several Design of Experiment factorial analyses. The model itself illustrated that this type of system could achieve 95% destruction efficiency with performance that was superior to that of Thermal Oxidation, Biological Oxidation, or Adsorption VOC abatement technologies. This was based upon design criteria that included ten year lifecycle costs and operational flexibility, as well as the constraint of meeting (or exceeding) current regulatory thresholds.

The Solid Oxide Fuel Cell (SOFC) is a promising technology for electricity generation. It converts the chemical energy of the fuel gas directly to electricity energy and therefore, very high electrical efficiencies can be achieved. The high operating temperature of the SOFC also provides excellent possibilities for cogeneration applications. In addition to producing power very efficiently, the SOFC has the potential to concentrate CO₂ with a minimum of an overall efficiency loss. Concentration of CO₂ is a desirable feature of a power generation process so that the CO₂ may be subsequently sequestered thus preventing its contribution to global warming. The primary purpose of this research project was to investigate the role of the SOFC technology in power generation processes and explore its potential for CO₂ capture in power plants. <br /><br /> This thesis introduces an AspenPlus^TM SOFC stack model based on the natural gas feed tubular internal reforming SOFC technology. It was developed utilizing existing AspenPlus^TM functions and unit operation models. This SOFC model is able to provide detailed thermodynamic and parametric analysis of the SOFC operation and can easily be extended to study the entire process consisting of the SOFC stack and balance of plant. <br /><br /> Various SOFC-based power generation cycles were studied in this thesis. Various options for concentrating CO₂ in these power generation systems were also investigated and discussed in detail. All the processes simulations were implemented in AspenPlus^TM extending from the developed natural gas feed tubular SOFC stack model. The study shows that the SOFC technology has a promising future not only in generating electricity in high efficiency but also in facilitating CO₂ concentration, but the cost of the proposed processes still need be reduced so SOFCs can become a technical as well as economic feasible solution for power generation.

A solid oxide fuel cell (SOFC) is an energy conversion device that has the potential to efficiently generate electricity in an environmentally-friendly manner. In general, a SOFC operates between 750&deg;C and 1000&deg;C utilizing hydrogen or hydrocarbons as fuel and air as an oxidant. The three major components comprising a fuel cell are the electrolyte, the cathode, and the anode. At present, the state-of-the-art SOFC is made from a dense yttria-stabilized zirconia (YSZ) electrolyte, a porous lanthanum manganite cathode, and a porous nickel/YSZ composite anode. With the advent of the anode-supported SOFC and the increased interest in using a wider range of fuels, such as those containing sulphur, knowledge of the anode properties is becoming more important. <br /> The properties of the current anodes are limited due to the narrow range of nickel loadings imposed by the minimum nickel content for electrical conductivity and the maximum allowable nickel loading to avoid thermal mismatch with the YSZ electrolyte. In addition, there is little research presented in the literature regarding the use of nickel metal as a starting anode material, rather than the traditional nickel oxide powder, and how porosity may affect the anode properties. <br /> The purpose of this investigation is to determine the influence nickel morphology and porosity distribution have on the processing and properties of tape cast Ni/YSZ composites. Specifically, the sintering characteristics, electrical conductivity, and thermal expansion behaviour of tape cast composites created from YSZ, nickel, nickel oxide (NiO), nickel coated graphite (NiGr), and/or graphite (Gr) powders are investigated. In addition to samples made from 100% YSZ, 100% Ni, and 100% NiO powders, five composite types were created for this investigation: NiO/YSZ, NiO&Gr/YSZ, Ni/YSZ, NiGr/YSZ, and Ni&Gr/YSZ each with nickel loadings varying between 4 vol% Ni of total solids and 77 vol% Ni of total solids. Another set of composites with a fixed nickel loading of 27 vol% Ni and 47 vol% Ni of total solids and varying graphite loadings were also created. <br /> During the burnout stage, the composites made from nickel oxide powder shrink slightly while the composites made from nickel metal expand due to nickel oxidation. Graphite additions below 20 vol% of the green volume do not alter the dimensional changes of the composites during burnout, but graphite loadings greater than 25 vol% of the green volume cause significant expansion in the thickness of the composites. <br /> After sintering, the amount of volumetric sintering shrinkage decreases with higher nickel loadings and is greater for the composites made with nickel oxide compared to the composites made from nickel metal. The porosity generated in the composites containing graphite is slightly higher than the volume of graphite added to the composite and is much greater than the porosity contained in the graphite-free composites. <br /> Dimensional changes of the porous Ni/YSZ and NiO/YSZ composites during both burnout and sintering were analysed based on concepts of constrained sintering of composite powder mixtures. In some cases constrained sintering was evident, while in others, a more simple rule of mixtures behaviour for shrinkage as a function of YSZ content was observed. <br /> When nickel oxide is reduced to nickel metal during the reduction stage there is essentially no change in the composite volume for the composites containing YSZ because the YSZ prevents the composites from shrinking. After reduction the additional porosity generated in the composites is equivalent to the change in volume due to the reduction of nickel oxide to nickel metal. <br /> When measuring the electrical conductivity, each composite type demonstrated classic percolation behaviour. The NiGr/YSZ composites had the lowest percolation threshold, followed by the Ni/YSZ and NiO/YSZ composites. When graphite was added with a nickel coating, the added porosity did not disrupt the nickel percolation network and allowed the nickel to occupy a larger effective volume compared to a composite made with similar sized solid nickel particles. When graphite was added to the composites, the electrical conductivity was reduced and the percolation threshold increased. <br /> Generally, the coefficient of thermal expansion (CTE) for Ni/YSZ composites are expected to follow the rule of mixtures prediction since the elastic properties for nickel and YSZ are similar. However when porosity is distributed unevenly between the YSZ and nickel phases, the CTE prediction will deviate from the rule of mixtures. When cornstarch was added to the NiGr/YSZ composites, the CTE increased as the amount of porosity in the YSZ phase increased. The CTE of the NiGr/YSZ composites followed the rule of mixtures indicating that the porosity was evenly distributed between the nickel and YSZ phases. For the other composite types, the measured CTE was higher than the rule of mixtures prediction suggesting that more porosity was contained within the YSZ phase.

There has always been a desire to develop industrial processes that minimize the resources they use, and the wastes they generate. The problem is when new guidelines are forced upon long established processes, such as solvent based coating operations. This means instead of integrating an emission reduction technology into the original design of the process, it is added on after the fact. This significantly increases the costs associated with treating emissions. In this work the ultimate goal is the design of an “add-on” abatement system to treat emissions from solvent based coating processes with high destruction efficiency, and lower costs than systems in current use. Since emissions from processes that utilize solvent based coatings are primarily comprised of volatile organic compounds (VOCs), the treatment of these compounds will be the focus. VOCs themselves contain a significant amount of energy. If these compounds could be destroyed by simultaneously extracting the energy they release, operational costs could be substantially reduced. This thesis examines the use of model-based design to develop and optimize a VOC abatement technology that uses a Solid Oxide Fuel Cell (SOFC) for energy recovery. The model was built using existing HYSYS unit operation models, and was able to provide a detailed thermodynamic and parametric analysis of this technology. The model was validated by comparison to published literature results and through the use of several Design of Experiment factorial analyses. The model itself illustrated that this type of system could achieve 95% destruction efficiency with performance that was superior to that of Thermal Oxidation, Biological Oxidation, or Adsorption VOC abatement technologies. This was based upon design criteria that included ten year lifecycle costs and operational flexibility, as well as the constraint of meeting (or exceeding) current regulatory thresholds.

Solid oxide fuel cells (SOFCs) conventionally operate between 800 and 1000°C. The barriers for full-scale commercialization of SOFCs are the high cost and relatively poor long-term stability due to the high temperatures used in current state-of-the-art SOFCs. One solution is to decrease the operating temperature, e.g. to 550-750°C but this requires developing new electrolytes and electrode materials. Also, to increase efficiency and practicality, the anode should be able to internally reform hydrocarbon fuels especially methane because it is the most common hydrocarbon in natural gas. The overall goal of this research is to develop a coke-tolerant Ni1-x-yCuxMgyO-SDC anode for methane fuelled IT-SOFCs. The Ni-Cu-Mg-O-SDC anode has been chosen based on the premises that doped-ceria is suitable for intermediate operating temperatures (550-800°C), Ni is known as an active metal and good electronic conductor, Cu increases resistance to coking, MgO helps prevent agglomeration of Ni during reduction, and finally SDC improves oxide ion transport to the cell at this intermediate temperature range. In this work, these materials were characterized in three primary ways: material physical and chemical properties, methane steam reforming activity and electrochemical performance. Two different methods have been used to add Cu to Ni1-yMgyO: a one-step co-precipitation method and a two-step co-precipitation/impregnation method. For the first method, Ni1-x-yCuxMgyO was synthesized via co-precipitation of Ni, Mg and Cu. In the two-step method, Ni0.9Mg0.1O was first prepared by co-precipitation, followed by addition of copper to Ni0.9Mg0.1O by impregnation. However, co-precipitation of all metal in one step limits the sintering temperature of the anode in the cell fabrication due to the low boiling point of CuO. Therefore, co-precipitation of Cu is not a practical method and only Cu impregnation should be considered for practical SOFC applications. It was found that the addition of Mg (Ni0.9Mg0.1O) lowers the reducibility of NiO. Addition of Cu to Ni0.9Mg0.1O up to 5% shows similar reducibility as Ni0.9Mg0.1O. The reducibility of Ni1-x-yCuxMgyO becomes lower when the Cu content is increased to 10%. Nonetheless, all materials are fully reduced at 750ºC. The XRD patterns of pure NiO, Ni0.9Mg0.1O, and the Cu-containing material when Cu is less than 10 mol% are similar. The lower reducibility of Ni-Mg-O and Ni-Cu-Mg-O compared to NiO indicates that they form a solid solution with NiO as the matrix. Solid oxide fuel cells (SOFCs) conventionally operate between 800 and 1000°C. The barriers for full-scale commercialization of SOFCs are the high cost and relatively poor long-term stability due to the high temperatures used in current state-of-the-art SOFCs. One solution is to decrease the operating temperature, e.g. to 550-750°C but this requires developing new electrolytes and electrode materials. Also, to increase efficiency and practicality, the anode should be able to internally reform hydrocarbon fuels especially methane because it is the most common hydrocarbon in natural gas. The overall goal of this research is to develop a coke-tolerant Ni1-x-yCuxMgyO-SDC anode for methane fuelled IT-SOFCs. The Ni-Cu-Mg-O-SDC anode has been chosen based on the premises that doped-ceria is suitable for intermediate operating temperatures (550-800°C), Ni is known as an active metal and good electronic conductor, Cu increases resistance to coking, MgO helps prevent agglomeration of Ni during reduction, and finally SDC improves oxide ion transport to the cell at this intermediate temperature range. In this work, these materials were characterized in three primary ways: material physical and chemical properties, methane steam reforming activity and electrochemical performance. Two different methods have been used to add Cu to Ni1-yMgyO: a one-step co-precipitation method and a two-step co-precipitation/impregnation method. For the first method, Ni1-x-yCuxMgyO was synthesized via co-precipitation of Ni, Mg and Cu. In the two-step method, Ni0.9Mg0.1O was first prepared by co-precipitation, followed by addition of copper to Ni0.9Mg0.1O by impregnation. However, co-precipitation of all metal in one step limits the sintering temperature of the anode in the cell fabrication due to the low boiling point of CuO. Therefore, co-precipitation of Cu is not a practical method and only Cu impregnation should be considered for practical SOFC applications. It was found that the addition of Mg (Ni0.9Mg0.1O) lowers the reducibility of NiO. Addition of Cu to Ni0.9Mg0.1O up to 5% shows similar reducibility as Ni0.9Mg0.1O. The reducibility of Ni1-x-yCuxMgyO becomes lower when the Cu content is increased to 10%. Nonetheless, all materials are fully reduced at 750ºC. The XRD patterns of pure NiO, Ni0.9Mg0.1O, and the Cu-containing material when Cu is less than 10 mol% are similar. The lower reducibility of Ni-Mg-O and Ni-Cu-Mg-O compared to NiO indicates that they form a solid solution with NiO as the matrix. Addition of Mg also lowers the BET specific surface area from 11.5 m2/g for NiO:SDC to 10.4 m2/g for Ni0.9Mg0.1O. The surface area is further reduced when Cu is added; for example, at 10% Cu, the surface area is 8.2 m2/g. The activity of 50wt% Ni1-x-yCuxMgyO/50wt% SDC samples for methane steam reforming (SMR) and water-gas-shift reaction (WGS) was evaluated in a fully automated catalytic fixed-bed reactor where the exiting gases were analyzed online by a gas chromatograph (GC). The tests were performed at steam-to-carbon ratios (S/C) of 3, 2 and 1, and at temperatures of 750°C and 650°C for twenty hours. Higher methane conversions were obtained at the higher temperature and higher S/C ratio. Higher methane conversion are obtained using NiO:SDC and Ni0.9Mg0.1O:SDC than Ni-Cu-Mg-O. The conversion decreases with increasing Cu content. Over NiO:SDC and Ni0.9Mg0.1O:SDC the methane conversions are the same; for example 85% at 750°C for S/C of 3. At the same conditions, impregnation of 5%Cu and 10%Cu yields lower conversions: 62% and 48%, respectively. The activity for the WGS reaction was determined by mornitoring CO2/(CO+CO2) ratio. As expected because WGS is a moderately exothermic reaction, this ratio decreases when increasing the temperature. However, the CO2/(CO+CO2) ratio increases with higher S/C. The results indicate that adding Mg does not affect the WGS activity of NiO. The WGS activity of Ni0.9Mg0.1O:SDC is higher when Cu is added. The effect of additional Cu is more pronounced at 650ºC. At 750°C, changing the amount of Cu does not change the WGS activity because the WGS reaction rapidly reaches equilibrium at this high temperature. At 750°C for S/C of 1, carbon filaments were found in all samples. At 650ºC, different types of deposited carbon were observed: carbon fibers and thin graphite layers. Spent NiO:SDC had the longest carbon fibers. Addition of Mg significantly reduced the formation of carbon fibers. Impregnating 5% Cu on Ni0.9Mg0.1O:SDC did not change the type of deposited carbon. Monitoring the amount of deposited carbon on Ni0.9Mg0.1O:SDC, 3%Cu and 5%Cu impregnated on Ni0.9Mg0.1O:SDC for S/C of 0 at 750ºC showed that Cu addition deactivated methane cracking causing a reduction in the amount of carbon deposited. Electrochemical performance in the presence of dry and humidified hydrogen was determined at 600, 650, 700 and 750ºC. Electrolyte-supported cells constructed with four different anodes were tested using polarization curve and electrochemical impedance spectra. The four anodes were NiO:SDC, Ni0.9Mg0.1O:SDC, 3%Cu and 5%Cu on Ni0.9Mg0.1O:SDC. Adding Mg improved the maximum power density from 356 mW.cm-2 with NiO:SDC to 369 mW.cm-2 with Ni0.9Mg0.1O:SDC at 750ºC in dry hydrogen. Addition of Cu, on the other hand, lowered the maximum power density to 325 mW.cm-2 with 3%Cu impregnated and to 303 mW.cm-2 with 5% Cu impregnated. The cell with Ni0.9Mg0.1O:SDC was also tested under dry methane. To minimize methane cracking under this extreme condition, a current density of 0.10 A.cm-2 was always drawn when methane was present in the feed. The voltage decreased during the first hour from 0.8 to 0.5 V, then remained stable for 10 hours, and then started to drop again. Many small cracks were observed on the anode after completion of the electrochemical test, but there was no evidence of much carbon being deposited. In addition to dry methane, tests were also carried out, using the same material, with a H2O/CH4 mixture of 1/6 in order to generate a polarization curve at 750°C. Under these conditions, the maximum power density was 226 mW.cm-2. This is lower than the maximum power density obtained with humidified hydrogen, which was 362 mW.cm-2.

This research characterizes the thermal stress resulting from temperature gradients in hybrid solid oxide fuel cells that are processed using a novel oxide powder slurry technology developed at Georgia Tech. The hybrid solid oxide fuel cell is composed of metallic interconnect and ceramic electrolyte constituents with integral mechanical bonds formed during high temperature processing steps. A combined thermo-mechanical analysis approach must be implemented to evaluate a range of designs for power output and structural integrity. As an alternative to costly CFD analysis, approximate finite difference techniques that are more useful in preliminary design are developed to analyze the temperature distributions resulting from a range of fuel cell geometries and materials. The corresponding thermal stresses are then calculated from the temperature fields using ABAQUS. This model analyzes the manufacturing, start-up, and steady state operating conditions of the hybrid solid oxide fuel cell.

Interfacial polarization resistances limit the performance of many thin film solid-state devices, especially at low temperatures. To improve performance, a fundamental understanding of the electrode kinetics that govern interfacial reaction rates must be developed. The goal of this work is to determine site-specific reaction mechanisms and the relative significance of various reactions in order to quantify optimum structural parameters within the cathode microstructure. Key parameters include the length of triple phase boundary (TPB), the quantity of exposed electrolyte/electrode surface, and the ratio of electrolyte to electrode material. These parameters, when studied in a specific system, can be incorporated into broader models, which will encompass the specific conductivity of each component to develop an optimized three-dimensional network. The emphasis of this work is the systematic control and manipulation of potential cathodic reaction sites in order to develop an understanding of the relative importance of specific reaction sites. Since the physical dimensions of reaction sites are relatively small, an approach has been developed that utilizes micro-fabrication (similar to that used in integrated-circuit fabrication) to produce small and highly controlled microstructures. Investigations were made into the nature and reactivity of Triple Phase Boundaries (hereafter TPB) through the use of patterned platinum electrodes since only the TPBs are active in these electrodes. After the processing details of micro-fabrication were established for the platinum electrodes, patterned Mixed-Ionic/Electronic Conducting (MIEC) electrodes were fabricated and studied using impedance spectroscopy to determine the contributions from the MIEC surface versus the TPB. Systematically changing the geometry of the MIEC electrodes (thickness and line width) allowed for the determination of the effect of ambipolar transport within the MIEC on the activity of MIEC surfaces versus the TPB. This information is critical to rational design of functionally graded electrodes (with optimal particle size, shape, porosity and conductivity). In addition to experimental studies, representative patterned electrode samples were made available for collaborative studies with surface scientists at other institutions to provide additional techniques (such as Raman Spectroscopy) on the carefully designed and controlled cathode surfaces.

In order to facilitate the application of solid oxide fuel cells, in conjunction with reduced research and development costs, there is a need for accurate performance models to aid scientists and engineers in component and process design. To this end, an enhanced transient performance model has been developed. The present thesis enhances transient modeling and simulation via characterization of two important transient phenomena. They are bimodal stimuli (i.e., simultaneous changes in reactant supply and load demand) electrical transients, inclusive of the simulation of electrolysis, and the electrochemical light off phenomenon. One key result of the electrochemical light off simulations was that the realization that electrochemical parameters such as cell potential may be used as dynamic control variables during transitional heating of the cell. Reflective of the state-of-the-art in controls and dynamic simulation development, the modeling efforts are completed in the MATLAB computing environment. There is then a tangible software development that accompanies the modeling and simulation exercises and transient insights resolved.