MHPS launches new integrated fuel cell and gas turbine

Last month, Mitsubishi Hitachi Power Systems, Ltd. launched a new, pressurized, hybrid power-generation system (photo) that integrates solid-oxide fuel cell (SOFC) stacks with micro gas turbines (MGT). The hybrid system (diagram) has a broad range of commercial and industrial applications, and is especially suitable for distributed or cogeneration power systems, says the company.

SOFCs are ceramic fuel cells that operate at a high temperature of 900°C. In a pressurized hybrid system, power is generated directly by chemical reaction between O2 in the air and H2 and CO extracted from reformed city gas; residual fuel is then used to drive an MGT. This two-stage system achieves significantly higher power generation efficiency and, as a result, saves substantial energy. Air pressurized in the MGT’s compressor is supplied to the SOFCs for use in generating power, and then high-temperature exhaust is fed to the MGT and the heat and pressure, together with the residual fuel, are used to generate power. The pressurized SOFCs, having substantially increased voltage as a result of pressurization, lead to enhanced power generation efficiency, says the company.

The demonstration system is in the 250-kW class, and delivers generation efficiency of 55%. It is a follow-up to the prototype (Model 15) system that has been undergoing demonstration testing at Kyushu University since spring 2015. The system was developed with support of the New Energy and Industrial Technology Development Organization.