A 10 kW class natural gas-PEMFC distributed heat and power cogeneration system

A 10 kW class prototype of natural gas-PEMFC distributed heat and power cogeneration system has been developed and demonstrated for the first time in China. In this system, fuel processing - including steps of natural gas desulfurisation, steam reforming, CO water gas shift, and CO preferential methanation for CO deep removal - has been applied. The 10 kW class prototype was developed with design dimensions of 1600 mm (L) x 1700 mm (H) x 600 mm (W). It mainly comprises natural gas reformer, reformate gas moisturiser, PEMFC stack, heat recovery unit, DC/AC inverter, and controlling computer. At a steady state, the reformate gas obtained through the fuel processor has a composition of higher than 75% H-2, about 21% CO2, less than 4% CH4, less than 10 ppm(V/V) CO, and less than 10 ppb(g/V) sulfur in dry base. The prototype could supply about 8 kW AC power and about 10 kW heat. During increasing DC power output from 0.8 kW to 8 kW, DC and AC efficiency were higher than 40% and 35%, respectively, and the reformer efficiency higher than 75% (LHV). The efficiency of heat recovery reached 45%, so the total efficiency for cogeneration was higher than 80%. The efficiency of the inverter was basically higher than 90%. The PEMFC cogeneration system is suitable to be applied in small-scale hotels, community buildings etc. for supplying clean and high-efficiency electricity and hot water at the same time.(C) 2012 Published by Elsevier Ltd.