Bench‐scale testing of high‐temperature desulfurization sorbents

Extrudates of regenerable mixed-metal oxide sorbents including zinc ferrite, copper-modified zinc ferrite, and zinc titanate were prepared and tested for their potential to remove hydrogen sulfide (H2S) from coal gasifier gas in a high-temperature high-pressure (HTHP) fixed-bed reactor. Reductions in H2S concentration from > 10,000 parts per million by volume (ppmv) to < 1 to 50 ppmv were achieved depending on sorbent, reactor temperature, and steam concentration. Zinc ferrite showed no apparent loss in capacity over 15 sulfidation-regeneration cycles, but underwent significant strength reduction at 5% steam due to soot formation. Zinc titanate exhibited excellent strength and capacity retention at 5% steam and temperatures up to 735°C.