Modeling of a catalytic membrane reactor for CO removal from hydrogen streams – A theoretical study

Typical industrial hydrogen streams arising from reforming processes contain about 1% of carbon monoxide (CO). For fuel cell applications hydrogen should contain less than 10 ppm of CO, since it poisons the platinum catalysts in the electrodes. Traditionally, this is carried out through a selective oxidation reactor – PROX reactor. However, the parallel oxidation of hydrogen to water should be avoided. This work proposes the use of a catalytic membrane reactor (MR) whose design is based on a CO permselective membrane containing the selective catalyst loaded in the permeate side. It is considered plug-flow pattern and segregated feed of CO and oxygen. This strategy should improve the selective oxidation, as the permselective membrane enhances the CO/H2 ratio at the catalyst surface. mbined process is analyzed using a mathematical model. The performances of the MR and of the PROX reactor at 393 K are compared in terms of selectivity towards CO oxidation and catalytic requirements to achieve the desired output CO concentration. The proposed MR is a promising alternative in performing the required purification.