Singaravelu Elangovan

Fuel cell column heat exchanger mated module

A fuel cell module (10) with a fuel cell column (18), having at least one fuel cell stack, mated with the planar wall of a heat exchanger (60), wherein the fuel cell column and heat exchanger are mounted to a support structure (30), and which define an air plenum between the fuel cell column and planar wall of the heat exchanger, thereby eliminating the ductwork and insulation requirements associated with heat exchange systems while increasing the efficiency of the heat exchanger.

High-performance ceramic interconnect for SOFC applications

An improved ceramic interconnect component for a solid oxide fuel cell having good electrical conductivity thermodynamic stability in the presence of fuel and a coefficient of thermal expansion matching closely that of zirconia electrolytes is disclosed. The interconnect is a lanthanum strontium chromate material containing minor quantities of calcia, and iron and, optionally, very minor quantities of cobalt, as dopants.

Diffusion and Gas Conversion Analysis of Solid Oxide Fuel Cells at Loads via AC Impedance

Impedance measurements were conducted under practical load conditions in solid oxide fuel cells of differing sizes. For a 2 cm2 button cell, impedance spectra data were separately measured for the anode, cathode, and total cell. Improved equivalent circuit models are proposed and applied to simulate each of measured impedance data. Circuit elements related to the chemical and physical processes have been added to the total-cell model to account for an extra relaxation process in the spectra not measured at either electrode. The processes to which elements are attributed have been deduced by varying cell temperature, load current, and hydrogen concentration. Spectra data were also obtained for a planar stack of five 61 cm2 cells and the individual cells therein, which were fitted to a simplified equivalent circuit model of the total button cell. Similar to the button cell, the planar cells and stack exhibit a pronounced low-frequency relaxation process, which has been attributed to concentration losses, that is, the combined effects of diffusion and gas conversion. The simplified total-cell model approximates well the dynamic behavior of the SOFC cells and the whole stack.

Formation of Synthesis Gas Using Solar Concentrator Photovoltaics (SCPV) and High Temperature Co-electrolysis (HTCE) of CO2 and H2O

Carbon dioxide is considered a greenhouse gas (GHG) that reflects solar radiation and consequently increases the temperature of the earth. Many countries are now considering putting a tax on CO2 emissions that will increase the cost of products that are associated with those emissions. The most common method currently considered for dealing with CO2 emissions is the capture of the gas, pressurization, and then sequestration in either rock formations or saline aquifers. This is relatively costly in both capital investment and operation of the equipment. Also, there is the possibility that this CO2 will escape at some point in the future subjecting the company in question to an uncertain risk. Ceramatec has been investigating an alternative approach that converts the CO2 into a useful product that can then be sold. Using solid oxide fuel cell materials in conjunction with a non-carbon source of energy it is possible to generate synthesis gas (CO and H2) and oxygen from CO2 and H2O. SCPV (Solar Concentrator Photovoltaic) systems are the most efficient generators of solar electricity and generate high quality heat at the same time. HTCE (High Temperature Co-electrolysis) uses both the solar electricity and the heat to electrolyze the CO2 and H2O at double the total cycle efficiency of traditional electrolysis. The synthesis gas that is produced can be used to produce synthetic fuels such as synthetic natural gas or Fischer Tropsch liquid fuels, or chemicals. This paper will discuss this alternative approach to the disposal of CO2. This approach has the following advantages: permanent disposal, usable product, storage of solar energy in fuel, reduction of GHG, reduction in solar radiation, and no additional GHG.