Cold start-up study of methanol reformer based on chemical-looping combustion

Abstract

It is critical to shorten the cold start-up time of methanol reformers for onboard methanol reforming for hydrogen fuel cell vehicles (HFCVs), in which methanol is used as a hydrogen carrier. In this paper, based on chemical-looping combustion of methanol over copper-based catalysts, a cold start-up method for methanol reformers was first proposed. For the cold start-up process, air was used to raise the temperature to 200 °C under the exothermic reaction between air and reduced catalysts; then, methanol was used to continue heating the reformer under the exothermic reaction between methanol and oxidized catalysts. The two reactions were separately studied on a vertical tubular reactor to simulate the cold start-up of the reformer. The results show that the catalytic layer temperature rising to 200 °C from ambient temperature was 69 s with an air hourly space velocity of 4000 h−1 after 100 cycles. The catalytic layer temperature increases to 300 °C from 200 °C in 120 s with 550 ml/min methanol. A rapid cold start-up of methanol reformers can be achieved with almost no external electric or thermal energy.