Investigation of the effect of H2S on the performance of an iron/chromium-based high-temperature water–gas shift catalyst using simulated coal-derived syngas

The effects of H2S concentrations on the performance of an iron/chromium-based high-temperature water–gas shift catalyst were investigated using simulated dry-feed coal-derived syngas. The experiments were performed in a differential reactor at a constant temperature of 450 °C and at approximately atmospheric pressure. Low concentrations of H2S in the syngas (<50 ppm) were found to have a minor effect on the water–gas shift activity of the catalyst. At a higher range of H2S concentration (168–250 ppm), the catalyst lost approximately half of its activity. The reaction orders with respect to H2S concentration in the feed gas were calculated to be −0.24 ± 0.09 for a lower range of H2S concentration (17–70 ppm) and −0.55 ± 0.05 for a higher range of H2S concentration (120–1100 ppm).