A 10 kW Class Natural Gas-PEMFC Distributed Heat and Power Cogeneration System

Abstract

A 10kW 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 10kW class prototype was developed with design dimensions of 1600mm (L) × 1700mm (H) × 600mm (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% H2, 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 8kW AC power and about 10kW heat. During increasing DC power output from 0.8kW to 8kW, 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.