Hydrogen from the high temperature water gas shift reaction with an industrial Fe/Cr catalyst using biomass gasification tar rich synthesis gas

Abstract

The high temperature water gas shift reaction (HTS) over an iron/chromium (Fe/Cr) industrial catalyst was investigated in a pilot scale plant consisting of two fixed-bed reactors arranged in series and a biomass-derived tar-rich synthesis gas was used as a feed-stream. CO conversion and selectivity for the water gas shift reaction were evaluated through parameter variation. Four dry gas hourly space velocities (GHSVd) and two steam to dry synthesis gas ratios (H2O/SGd) equal to 52% v/v and 60% v/v were investigated at temperatures (T) of 350–450°C. CO conversion was investigated by varying H2S concentration 180–540 ppmv (dry basis) at a temperature of 425°C, considering two GHSVd. The highest CO conversion (~83%) was observed in the basis case at 60% v/v H2O/SGd, and 450°C. The catalyst appeared to be resistant to sulfur poisoning deactivation, and achieved 48% CO conversion at the maximum H2S concentration used.