High temperature hydrogen sulfide adsorption on activated carbon II. Effects of gas temperature, gas pressure and sorbent regeneration

Several types of activated carbon sorbents were evaluated for removal of H2 S at high temperatures (400-600 degrees C) in an integrated gasification co mbined cycle (IGCC) power generation process. Part I of this series of pape rs discussed the effects of gas composition and metal addition. Here we exa mine the effects of gas temperature, gas pressure and sorbent regeneration. Adsorption experiments with a zinc-impregnated activated carbon sample pro duced almost identical breakthrough times at varied temperatures (400-600 d egrees C). High pressure (10 atm) adsorption experiments showed significant ly longer breakthrough times at 10 atm compared to 1 atm. Gaseous H-2 sampl e regeneration was found to be the most effective regeneration method of th e variety of methods analyzed, with all previously H2S adsorbed sulfur bein g removed in a H-2 regeneration experiment. While additional research is ne cessary to further evaluate sample regeneration and multi-cycle adsorption/ regeneration, results of temperature and pressure effect experiments are en couraging for IGCC applications. (C) 2000 Elsevier Science Ltd. All rights reserved.