Hydrogen Production through CO_2 Absorption Enhanced Diesel Steam Reforming for PEMFC Systems

摘要

CO_2 absorption enhanced diesel steam reforming was investigated for hydrogen production in this paper. The utilization of CO_2 absorbent in the reforming reactor sharply decreases the CO_2 level in the reacting gas and shifts the equilibrium towards hydrogen formation. This increases the diesel conversion and reforming rate of hydrocarbon at relatively low temperature. At the temperature of 600°C, reforming rate of hydrocarbon reached 95%, and that is 30 percent higher than that in traditional steam reforming reaction without absorbent. In an optimal temperature range of 545-625°C, diesel conversion could reach near 100%. Hydrogen concentration reached 95% when using CO_2 absorbent, correspondingly concentrations of CO, CH_4, and CO_2 decreased obviously, while hydrogen concentration was about 70% in conventional diesel steam reforming process. Further, a novel PEMFC system for hydrogen production was proposed by combining CO_2 absorption enhanced diesel steam reforming (AEDSR) with chemical-looping combustion (CLC) process, which could continuously produce hydrogen and regenerate absorbent at the same time, heat balance of steam reforming and CO_2 absorption reaction could also be obtained by adjusting the amount of reforming catalyst and CaO.