The Regeneration Performance on Novel Hot Gas Sulfur Removal Sorbents

摘要

Integrated Gasification Combined Cycle (IGCC) technology is receivingincreased attention because of its promise of higher thermal efficiency and reducedenvironmental impact compared to today’s coal fired plants. Current IGCC plantsoperate with an efficiency of about 43%, compared to 35% for a conventional coalplant. A number of metal oxide sorbents which will react with H_2S to form thecorresponding metal sulfide and which, according to thermodynamics, have the abilityto reduce the H_2S concentration to the required level have been identified. In addition,the sorbent must be stable in the coal gas atmosphere, have acceptable sulfur capacity,be regenerable, and maintain activity through a large number ofsulfidation/regeneration cycles. Compromises are necessary since none of the metaloxides satisfy all requirements. Much of the recent research has focused uponzinc-based sorbent. However, in strongly reducing atmosphere at high temperatures,ZnO is slowly reduced to volatile metallic zinc. And also the price for ZnO is a littlehigher than other metal oxides, for example, Fe_2O_3.In this paper, the novel sorbents we used for the removal of H2S is the red mudwith different argillaceous minerals. There are six different sorbents which is mixedthe red mud with Kaolinite, Clay, Bentonite, Refractory Clay, Casting Clay, andDiatomite. The number of cycle for sulfidaiton/regeneration is 5. From the result, wecan compare above mentioned mixtures by their sulfur capacity, desulpharizationefficiency and other factors. The result is that the sorbent which is red mud mixingwith clay (NTKW2) has the highest sulfur capacity and desulpharizaiton. And itsmechanical strength is also high. It belongs to the structure of Clay. From theregeneration result, NTKW2 has a high regenrability. So the best sorbent is NTKW2.From th e experiment, we also find that the optimum sulfidaiton temperature is 550.The Bench-scale studies have the same law as the lab experiment.