Re-Use of the anode exhaust gas of a PEM fuel cell to improve the efficiency and lower the running cost

This paper presents a method of recycling hydrogen gas from the anode exhaust in small (200 W) proton exchange membrane fuel cells (PEMFC´s). The aim is to decrease the wastage of the hydrogen fuel and increase the overall efficiency of the cell. A gas chromatographer (GC) was used to analyse the exhaust gas. The result of the analysed exhaust gas was used to determine and implement appropriate measures to clean the exhaust gas to a level acceptable to be re-used at the input. A microprocessor control circuit was designed to control the re-use of the exhaust gases. A 15 % increase in the usage of the available hydrogen was achieved by re-using the exhaust gases.