同时脱硫脱硝过程中钙基吸收剂表面孔隙结构变化规律  

Evolution of Pore Structure of Ca-based Sorbent in Simultaneous Removal of SO_2 and NO_x

作　　者：陈国庆[1] 高继慧[1] 尹伊郡[1] 贾利峰[1] 吴少华[1] 秦裕琨[1] 

机构地区：[1]哈尔滨工业大学能源科学与工程学院,黑龙江省哈尔滨市150001

出　　处：《中国电机工程学报》2011年第20期60-66,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50806019);国家863高技术基金项目(2007AA05Z307)~~

摘　　要：低温潮湿环境下,吸收剂表面孔隙结构对其表面气固反应过程有着重要的影响。采用等温氮气吸附法对同时吸收SO2/NO2过程中Ca(OH)2颗粒表面孔隙结构的变化特性进行了测量分析。结合SO2和NO2在Ca(OH)2颗粒表面的吸收机制,该文探讨了吸收剂表面孔隙结构的变化机制。研究结果表明,反应产物的形成改变了吸收剂表面孔隙的孔形特征,但对比表面积和孔容的影响并不明显。在反应过程中,孔径大于30nm和小于7nm的孔逐渐减少,而孔径位于两者之间的孔隙数量逐渐增多。吸收剂颗粒表面新孔的出现一方面弥补了由于反应导致的比表面和孔容的降低,另一方面也改变了吸收剂表面的分形特征。孔隙表面的膨胀和产物的堆积是导致吸收剂表面孔隙收缩,孔形变化的主要原因。ABSTRACT： The pore structure of the sorbent plays a significant role in gas-solid surface reaction under low temperature and humid conditions. By using the nitrogen adsorption method, the pore structure of Ca（OH）2 particles subjected to SO2 and NO2 for different reaction times were analyzed. The evolution mechanism of the absorbent surface structure was discussed in combination with the absorption mechanisms of SO2 and NO2 on the surface of Ca（OH）2 particle. The results show that the presence of the surface reactions products changes the pore shape, but has a negligible effect on the BET surface area and pore volume. The amount of the pores 〈7 nm and 〉30 nm decrease with the increase of reaction time, while the pores from 7 nm to 30 nm show an opposite trend. The presence of the pores （7 nm〈d〈30 nm） can not only account for the unchanged of BET surface area and pore volume during reactions, but also affect the fractal characteristics of the absorbent. The expansion and depositing of the reaction products result in the shrinking of the pores, and the change of pore shape structure.

关 键 词：燃煤烟气 同时脱硫脱硝 孔结构 钙基吸收剂 

分 类 号：TK223[动力工程及工程热物理—动力机械及工程]