Iron Oxide Based High Temperature Desulfurization Sorbent

Sheng Ju ,Fang Shen,Maoqian Miao,Huiling Fan,Litong Liang,Yanli Zhu ,Peng-Fei Hou

doi:10.1109/icbbe.2009.5162987

Abstract

Iron oxide sorbent is used as high temperature desulfurization sorbent due to high sulfur capacity, easy regeneration and recovery elemental sulfur. In this paper, the iron oxide based high-temperature sorbent was obtained by mixing iron oxide with calcium oxide, extrudating and calcinating. The sulfidation, reduction and regeneration performance for the prepared iron oxide based desulfurization sorbent were conducted. The phases of fresh iron oxide based sorbents, sulfided sorbent and regenerated sorbent were characterized by XRD and SEM. There are three reduced peaks corresponding Fe 3 O 4 , FeO and Fe for iron oxide based sorbent in temperature-programmed reduction. The breakthrough curve of iron oxide based sorbent in present of H 2 and H 2 S at 500degC and 3600 h -1 shows that outlet concentration of H 2 S exhibits a peak at early stage, and then approaches a stable until breakthrough. This phenomenon shows that Fe 2 O 3 -H 2 reaction rate is more rapidly than Fe 2 O 3 -H 2 S reaction. The Fe 2 O 3 reacts rapidly with H 2 to form FeO and FeO reacts with H 2 S to form FeS. This work examined the sulfur compound concentration change during regeneration as a function of temperature. The regeneration reaction is given by 2FeS + 7/2O 2 = Fe 2 O 3 + 2SO 2 when O 2 take as the only reactive component in the feed gas, 3FeS + 4H 2 O = Fe 3 O 4 +3H 2 S +H 2 when H 2 O take as the only reactive component in the feed gas. The regeneration rate in O 2 is more rapid than that in H 2 O, and there are big pore on the surface of the regeneration sorbent in oxygen agent compared with the regeneration sorbent in steam agent.

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