Effect of air depletion in the preferential oxidation reactor and fuel depletion in a proton exchange membrane fuel cell system fueled by natural gas

Abstract

This study estimates the steady-state performance of a proton exchange membrane fuel cell (PEMFC) under conditions of air depletion in the preferential oxidation reactor (PrOx) and fuel depletion at the anode, which has not been previously studied. Considering the detailed chemical reactions of the reforming process, the composition of the reformed gas at the anode inlet is determined using the temperature and pressure data measured at various state points in the PEMFC system. To calculate the voltage loss at the anode due to the air depletion in PrOx or reformate gas depletion before the anode, the electrochemical reaction of the reformed gas in the anode catalyst layer is studied. The calculations show that when the fuel entering the anode or air entering the PrOx decreases, the amount of CO at the anode increases depending on the reduction, resulting in activation loss at the anode, and thereby leading to power loss. This analysis of the power loss in a PEMFC due to a lack of air or fuel can serve as an auxiliary diagnostic tool to identify faulty parts in the Balance of Plant (BOP).