The system and engineering modifications will allow the stationary power plant to generate base-load electricity when conventional fuel supplies are threatened due to natural disaster or security issues.
The project is sponsored by the US Federal Government to give Direct FuelCell (DFC) power plants a "dual-fuel" capacity that allows rapid switching to back-up fuel in case of emergency. CTC is a primary contractor to the US Army Corps of Engineers, and the security of energy supplies is a primary military objective.
"The military is always looking for multiple options, whether on the battlefield or in connection with critical stationary facilities here at home," said Franklin Holcomb, Army Engineer Construction Engineering Research Laboratory fuel cell team project leader.
"The ability to switch fuels on the fly, from the standpoint of security, is highly desirable."
DFC units can use any hydrocarbon fuel that has been desulphurised, including natural gas, diesel, jet fuel, coal gas, digester gas, coal mine methane, gasified biomass and coke oven gas while producing virtually no nitrogen oxide or sulphur oxide emissions.
"The dual-fuel capability of our DFC power plants demonstrates that our products can be an important part of the enhancement of our nation's homeland security efforts," said Dan Brdar, FuelCell Energy chief executive officer.
"If events disrupt the natural gas pipeline or the electricity grid, our fuel cells can immediately switch to on-site propane and provide the necessary power for essential government and other mission-critical facilities."
Engineering changes required include accommodating the higher steam-to-carbon ratio required for HD-5 propane, installing flow measurement and control instruments for propane rather than natural gas, adjusting the humihex fuel humidifier for a higher steam to carbon ratio, altering the control system software and installing additional control valves for switching fuels.
Initial development of the new design will take place at FuelCell Energy's research and development facilities in Connecticut and an existing DFC 300A power plant at CTC's Department of Defense Fuel Cell Test & Evaluation Center in Pennsylvania will be used for field trials.
