Combination of preferential CO oxidation and methanation in hybrid MCR (micro-channel reactor) for CO clean-up

CO in the hydrogen stream must be reduced to extremely low levels, under 10 ppm, because the Pt electrode is detrimentally affected by residual CO in the H2 stream. Therefore removal of carbon monoxide from the H2-rich stream during fuel generation from hydrocarbons is a critical challenge, especially for PEMFC (proton exchange membrane fuel cell) applications. Herein, CO an initial concentration of 1.0 vol.% was successfully removed from a H2-rich stream to a residual level below 10 ppm, within the wide operating temperature range from 92 to 235 °C by utilizing a hybrid channel reactor comprising a micro-channel heat exchanger and mini-packed bed reactor. The mini-packed bed reactor contained two kinds of catalysts that promote preferential oxidation and methanation of CO in series. The HMCR (hybrid micro- and mini- channel reactor) offers not only ultimately safe operation but also easy scale-up and is adaptable to mass production of CO clean-up units.