Removal of sulfur at high temperatures using iron-based sorbents supported on fine coal ash

This paper deals with the simultaneous removal of H2S and COS in the temperature range of 400–650 °C at 1 bar by using iron-based sorbents. The iron-based sorbents were prepared using iron oxide and cerium oxide with coal fine ash as the support. Simulated coal gas was used in the sulfidation experiments and 5% O2 in N2 gas was used for regeneration of sorbents. Both sulfidation and regeneration experiments have been carried out using a fixed-bed quartz reactor. The product gases were analyzed using a GC equipped with a TCD and a FPD. The results demonstrated that both H2S and COS can be effectively reduced using the iron-based sorbents supported on fine coal ash. XRD analysis shows that Fe1−xS phase has formed during sulfidation indicating a high sulfur capacity of the sorbent. The mechanism of the removal of COS simultaneously with H2S is also discussed.