Hydrogen-rich gas with low-level CO produced with autothermal methanol reforming providing a real-time supply used to drive a kW-scale PEMFC system

Abstract

An integrated system was developed to produce hydrogen-rich gas with low-level CO via autothermal reforming (ATR) of methanol for the purpose of real-time use in a kW-scale proton exchange membrane fuel cell (PEMFC) system. Methanol was converted into a hydrogen-rich gas through ATR in conjunction with water gas shifting (WGS) and preferential oxidation (PrOX) reactors to reduce the CO concentration. A 29.5% hydrogen-rich gas with a CO concentration of approximately 20 ppm was achieved under the optimal parameter settings (i.e., an H2O/CH3OH ratio = 0.5 and an O2/CH3OH ratio = 0.55 for the ATR reaction, an H2O/CO ratio = 5.6 for the WGS reaction, and an O2/CO ratio = 1.08 for the PrOX reaction). Specifically, the reformer system steadily produced low CO, hydrogen-rich gas after 4 h of durability testing. This system was then combined with 40-cell fuel cell stacks with air bleeding and tested for its durability over a period of 6 h. It was verified that the hydrogen-rich gas produced by the reformer system enabled the fuel cell to steadily generate 1040 W of power. Notably, the hydrogen-rich gas (the actual reformate gas) produced herein could generate better performance than the simulated reformate gas reported in the literature.