Investigation of the performance of high-temperature electrochemical hydrogen purification from reformate gases

Abstract

In the present work, the purification of hydrogen from a hydrogen/carbon dioxide/carbon monoxide (H-2:CO2:CO) mixture by a high-temperature electrochemical purification (HT-ECHP) system is examined. Electrochemical H-2 purification experiments were carried out in the temperature range of 140-180 degrees C. The effects of the molar ratio of the gases in the mixture (H-2:CO2:CO-75:25:0, H-2:CO2:CO-72:26:2,0 H-2:CO2:CO-75:22:3, H-2:CO2:CO-75:20:5, H-2:CO2:CO-97:0:3, H-2:CO2:CO-95:0:5) and the operating temperature on the electrochemical H-2 separation were investigated. As a result of the electrochemical H-2 purification experiments, it was determined that the operating temperature is the most important parameter affecting the performance. According to the results obtained, H-2 purity of 99.999% was achieved at 160 degrees C with the reformate gas mixture containing 72% H-2, 26% CO2, and 2% CO by volume. According to the polarization curves of the gas mixtures containing CO, high current densities at low voltage were reached at 180 degrees C, and it was observed that the performance increased as the temperature increased, whereas the gas mixture without CO gave the best performance at 160 degrees C.