Investigation of hydrogen sulphide removal from simulated producer gas of biomass gasification by titanomagnetite

This work investigated removal of H2S from simulated producer gas by using iron-based sand, named titanomagnetite (Fe2.9Ti0.1O4), in a fluidised bed quartz reactor. The aims of this study were to determine the effectiveness of titanomagnetite and the most effective operation temperatures, and to examine the effect of steam and CO in the producer gas. In the experiments, H2S concentration in the gases was controlled at 240 ± 20 ppmv and the test gases were, respectively, (1) Ar gas, (2) simulated producer gas from biomass steam gasification (CO, CO2, CH4 and H2), (3) mixture of Ar and steam, and 4) mixture of Ar and CO. Unprocessed and H2-reduced titanomagnetites were used as sorbents and operation temperatures were varied from 350 to 750 °C. Results from the experiments show that both of the unprocessed and the H2-reduced titanomagnetites were effective to remove H2S in Ar gas at 600 °C. However, at the same temperature, the H2S removal efficiency was reduced in the simulated gas for which the unprocessed titanomagnetite was more effective than the H2-reduced titanomagnetite. For the unprocessed titanomagnetite, the temperature range for most effective H2S removal was found to be 400-450 °C. It was also observed that both steam and CO in the gas mixture reduced the removal efficiency significantly although steam in the gas had more significant impacts.