Journal of Chemical Engineering of Japan, Vol.35, No.1, 15-21, 2002
Investigation of hydrogen sulfide removal and sulfur recovery from low sulfur containing gases with aqueous solution of heteropoly compound
Hydrogen sulfide, as a highly undesirable contaminant, is most widely emitted from factories and waste treatment facilities. An innovative approach to low sulfur containing gas desulfurization and sulfur recovery involving the use of heteropoly compounds is presented in this paper. The favorable redox potential of heteropoly compounds makes it thermodynamically feasible for them to oxidate H2S to elemental sulfur and to be regenerated by air. The presence of Na2CO3 in the absorbent system can improve the absorption rate of H2S, and NaCl can accelerate the absorbent regeneration. The regeneration time decreases with the increase in the absorbent concentration, temperature and the regeneration air flow rate, and it increases with the increase in the feed gas H2S concentration. With the aid of TGA (thermogravimetric analysis) and ES (electron spectrum), the principal component of the sedimentation product from the process of desulfurization was confirmed to be elemental sulfur.