| Coal is the most abundant fossil energy in the world. Integrated gasification combined cycle (IGCC) power generation process is an attractive option for using coal for electricity generation with a high efficiency and a low environmental pollution, and is regarded to be the most promising technology in this century. In IGCC system, the removal of sulfur specics (mainly H2S) is crucial for the efficient and economic coal utilization. Up to now, the main process of high temperature coal gas desulfurization technology are the regeneration of desulfurization sorbents and recovery of sulfur resource from regeneration gases, which were to drive industrial development for high temperature desulfurizer. In order to solve these problems, it is very necessary to master the behaviors of regeneration of the sorbents in the different regeneration gas atmospheres, and the effects of temperature, space velocity, gas concentration.Iron oxide is reckoned as a benign sorbent for its low cost, rich in resource, high sulfur capacity, fast reaction rate, and recovery of sulfur when it regenerated with H2O-O2 mixtures atmosphere. Fe2O3-based high temperature coal gas desulfurizer was prepared by red mud from steel factory. The influences of regeneration temperature, space velocity and regeneration gas concentration on regeneration performances of prepared Fe2O3-based high temperature coal gas desulfurizer were tested in fixed bed reactor under O2, H2O and H2O-O2 atmosphere. The changes of phase and composition of Fe2O3-based high temperature coal gas desulfurizer before and after regeneration were characterized by XRD and XPS. The changes of surface and pore structure were characterized by SEM and mercury intrusion method.Firstly, the influences of experimental conditions, such as regeneration temperature, space velocity and oxygen concentration on the regeneration behavior of Fe2O3 desulfuizer were studied in oxygen-containing atmosphere. The results shown that 600℃, 4000h-1 and 6% (vol) O2 is the best regeneration condition for Fe2O3-based high temperature coal gas desulfurizer in the atmosphere with oxygen. FeS reacted with oxygen to produce Fe2O3, SO2 and few sulfur. As the temperature, space velocity and oxygen concentration raise, the time of regeneration become shorter and the sulfur content of tail gas increase. The formation of sulfric salt in regeneration process was reasons of the addition of regenerated sorbent weight and the decrease of regeneration conversion and in sulfidation activity in second cycle sufidation. The increase of space velocity and the decreae of O2 concentration can reduce the formation of sulfuric acid. Secondly, the regeneration behavior was investigated in H2O-containing atmosphere. The mainly components of tail gas is H2S, and the mainly components of desulfurizer of regenerated are Fe3O4 and few FeO. The results shown that in H2O-containing atmosphere the regeneration conversion of desulfurizer can be reached 95%, but the time of regeneration is too long. After regeneration, the number of macropore increased. In several severalsulfidation/regeneration cycles, no the change of sulfidation property for regenerated is found and the sulfidation activity is stable in the whole sulfidation/regeneration. As the temperature and water vapour concentration raise, the time of regeneration become shorter , the sulfur content of tail gas and the regeneration conversion increase. The best regeneration condition for Fe2O3-based high temperature coal gas desulfurizer in H2O-containing atmosphere is 700℃,4000h-1 and 60% (vol) H2O(g).Last, the regeneration behavior was also investigated in H2O-O2 mixtures atmosphere. Oxygen reacts rapidly with FeS to produce SO2 and Fe2O3, steam reacts to give Fe3O4 and H2S, and elemental sulfur is formed by the reaction between H2S and SO2. Addition O2 is consumed in converting Fe3O4 to Fe2O3. The results shown that the effect of H2O/O2 ratio and regeneration temperature on the formed sulfur ratio or regeneration conversion is remarkable. Within range of 400℃～700℃, 600℃is the best temperature for regeneration conversion and the formed sulfur ritao. By comparison to regenerated with individual atmosphere, the surface pore structure of desulfurizer changed remarkably and total pore area remain same, but the porosity and the pore diameter changed remarkably when it regenerated with H2O-O2 mixed atmosphere. The faster space velocity is propitious to regeneration conversion, and the lower space velocity is propitious to the selectivity of elemental sulfur. The maximum yield of element sulfur, approximately 50% of total sulfur contents of tail gas, was achieved using a large H2O/O2 ratio (80) at 3000h-1, 600℃.The article investigated Fe2O3-based high temperature coal gas desulfurizer with the O2 atomsphere, H2O atmosphere and H2O-O2 mixed atmosphere deeply and systematically for the first time, meantime it showed whole regeneration mechanism with tracking changes in phase component of desulfurizers in every stage of regeneration by XRD and XPS.
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