Micro-tubular flame-assisted fuel cells

Abstract

Micro-tubular solid oxide fuel cells operating in fuel-rich combustion exhaust are explored in this work and their benefits in reducing the balance of plant in fuel cell systems is discussed. The current state of performance of these micro-tubular flame-assisted fuel cells operating with methane fuel is described and the benefits of operating in propane fuel are explored. An experimental investigation of propane combustion at different fuel/air equivalence ratios is conducted. Temperature measurements of the propane combustion are recorded with thermocouples while the gas species present in the exhaust are measured with a gas chromatograph. Propane is found to have advantages over methane due to a higher upper flammability limit and higher percentages of hydrogen and carbon monoxide, i.e. syngas, generated in the combustion exhaust. A micro-tubular flame-assisted fuel cell is tested using the four probe technique in model propane combustion exhaust at different equivalence ratios and temperatures. A method for comparing the performance of the fuel cell in the combustion exhaust to a hydrogen fuel baseline is developed and comparisons are made. The benefits of operating in propane compared to methane are explored with the potential for fuels like propane and butane being distinguished by their higher upper flammability limits and potential for higher concentrations of syngas in the combustion exhaust.

Keywords

• micro-tubular flame-assisted fuel cell
• solid oxide fuel cell
• fuel-rich combustion
• upper flammability limit
• fuel cell stack
• micro combined heat and power