NiY分子筛选择性吸附脱硫性能及作用机理  

Selective Adsorption Desulfurization Performance and Adsorptive Mechanisms of NiY Zeolites

作　　者：宋丽娟[1] 潘明雪[1] 秦玉才[1] 鞠秀芳[1] 段林海[1] 陈晓陆[1] 

机构地区：[1]辽宁石油化工大学辽宁省石油化工重点实验室,抚顺113001

出　　处：《高等学校化学学报》2011年第3期787-792,共6页Chemical Journal of Chinese Universities

基　　金：国家"九七三"计划项目(批准号:2007CB216403);国家自然科学基金(批准号:20976077;21076100)资助

摘　　要：用液相离子交换法制备了NiY分子筛,并用XRD,TEM,ICP,N2吸附和吡啶吸附原位红外技术等手段对其进行了表征.利用固定床、气相色谱-硫发光检测器联用(GC-SCD)及傅里叶变换红外光谱(FTIR)等方法研究了NiY分子筛对噻吩、2-甲基噻吩、3-甲基噻吩、四氢噻吩、苯并噻吩、二苯并噻吩、4-甲基二苯并噻吩及4,6-二甲基二苯并噻吩等8种有机硫化物的选择性吸附脱硫性能及其吸附机理.结果表明,NiY分子筛对硫化物的穿透吸附硫容量顺序为四氢噻吩>苯并噻吩≈二苯并噻吩≈4,6-二甲基二苯并噻吩>4-甲基二苯并噻吩>2-甲基噻吩≈3-甲基噻吩>噻吩,说明有机硫化物的空间位阻效应不是其在NiY分子筛上吸附的决定因素.红外光谱分析结果表明,不同硫化物与NiY分子筛的作用机理并不相同,但主要以硫原子与金属离子配位作用(S-M作用)为主.噻吩及其烷基取代物在NiY吸附剂上且在表面酸性作用下发生催化反应,噻吩环的共轭体系遭到破坏,形成硫化物大分子或聚合物,导致分子筛孔道堵塞,严重影响吸附剂的吸附脱硫能力.NiY的选择性吸附脱硫是硫化物与吸附中心的相互作用及吸附剂表面酸性综合作用的结果.NiY zeolites were prepared by liquid phase ion exchange method and the adsorbents were characterized by XRD,TEM,ICP,nitrogen adsorption and Py-IR.The adsorptive behavior of thiophene（T）,2-methylthiophene（2-MT）,3-methylthiophene（3-MT）,tetrahydrothiophene（THT）,benzothiophene（BT）,dibenzothiophene（DBT）,4-methyldibenzothiophene（4-MDBT） and 4,6-dimethyldiben-zothiophene（4,6-DMDBT） on NiY zeolites were investigated by a fixed bed,gas chromatography-sulfur chemiluminescence detector（GC-SCD） and Fourier transform infrared（FTIR）.The results show that the breakthrough adsorption capacities of different sulfur compounds are in the order of THTBT≈DBT≈4,6-DMDBT4-MDBT3-MT≈2-MTT,indicating that the steric hindrance of sulfur compounds is not the crucial factor for their adsorptive properties on NiY zeolites.The mechanisms of thiophene and thiophene derivatives interacting with NiY zeolites are different,but the direct S-M interaction is the domain process.Thiophene and thiophene alkyl complex adsorbed on the surface acidic sites of the sorbents can subsequently undergo the opening of the heterocyclic rings and then to form some larger sulfur compounds.These polymer molecules will plug the pore of zeolite,resulting in the decreasing of the desulfurization capacity of the NiY.Adsorption mechanisms and surface acidity of NiY zeolites are the key factors for the selective adsorption desulfurization.

关 键 词：液相离子交换 NiY分子筛 吸附脱硫 表面酸性 

分 类 号：O643[理学—物理化学]