Hydrogen production from methanol steam reforming in a microwave reactor

Nikazar, Sohrab
Today’s world is facing crucial environmental issues, such as climate change and greenhouse gas emission, mainly attributed to the overusing fossil fuels. An environmentally friendly and sustainable replacement is proton exchange membrane fuel cell system which is a promising technology fed by hydrogen. However, fuel cell’s anode catalyst is sensitive to amount of CO in the feed stream. Steam reforming of methanol is an appropriate method for hydrogen production. Nevertheless, endothermic nature of this reaction brings its economic feasibility into question. In this study, hydrogen was produced from methanol steam reforming (MSR) reaction. For this purpose, metal-loaded mesoporous carbon catalysts were synthesized and characterized. The catalyst activity was tested in the MSR reaction heated by a conventional heating method. Effect of catalyst calcination temperature, Cu/Zn ratio, total metal loading amount, and reaction temperature was investigated on the reaction product distribution, methanol conversion, and hydrogen yield. Furthermore, microwave was used as an alternative heat source which is more efficient than conventional heating method. CMK-3 with the surface area of 1120 m2/g, pore volume of 3.7 cm3/g, and pore size of 3.7 nm was synthesized as the support material. Both support material and metal loaded catalyst exhibited Type IV isotherm with H2 hysteresis. It was observed that the catalyst activity increases with increasing Cu/Zn ratio and total metal loading amount, while increasing the catalyst calcination temperature declines the catalyst activity. CO-free hydrogen was produced from the 18.75Cu6.25Zn/CMK-3/300 catalyst at 250oC in the conventionally-heated reactor system with methanol conversion of 93.0% and hydrogen yield of 94%. A higher methanol conversion was obtained in the microwave-focused heated reactor system compared to the conventionally-heated reactor system in addition to a higher energy efficiency. 97.5% methanol conversion and 95.6% hydrogen yield were achieved in this system at 300oC.