Exhaust gas from bright heat treatment furnaces can be used as a fuel for fuel cells because it is rich in hydrogen. However, it contains carbon monoxide (CO); when a CO-containing gas is used as a fuel gas in a proton-exchange membrane fuel cell (PEMFC), cell performance decreases. Therefore, it is necessary to remove contaminants from hydrogen-rich exhaust gas. In this study, the effect of CO contaminants in hydrogen gas on the PEMFC stack performance was firstly evaluated. The experimental results showed a correlation between CO concentration and fuel cell stack performance, wherein performance degraded quickly because of CO poisoning. Furthermore, for improving the performance of the PEMFC stack using the CO-containing hydrogen gas, three methods were evaluated: molecular sieve adsorption, methanation reaction, and air bleeding. These methods were effective against CO poisoning and delayed performance deterioration. In particular, methanation refining was observed to be the most effective method for reducing CO poisoning.
Keywords PEM fuel cell, carbon monoxide, bright heat treatment furnace, refining process