酸/碱处理对HZSM-5分子筛结构及性能的影响  

Effect of acid/alkali treatment on structure and performance of HZSM-5 zeolite

作　　者：何志伟[1,2] 袁程远 杜晓辉[3] 刘宏海 高雄厚 

机构地区：[1]兰州交通大学化学与生物工程学院,甘肃兰州730070 [2]中国石油兰州化工研究中心,甘肃兰州730060 [3]西北师范大学化学化工学院,甘肃兰州730070

出　　处：《石化技术与应用》2015年第2期103-107,112,共6页Petrochemical Technology & Application

基　　金："十二五"国家科技支撑计划(项目编号:2012 BAE 05 BO 2)

摘　　要：采用乙二酸/Na OH溶液对HZSM-5分子筛进行改性研究,利用SEM,XRD,XRF,NH3-TPD和N2等温吸脱附分析技术对改性前后的分子筛样品进行表征,并在催化裂化微反装置上评价其反应活性。结果表明,乙二酸溶液具有清除无定形物种,疏通孔道,提高分子筛结晶度的作用;Na OH溶液可以脱除分子筛骨架结构中的硅物种,适度调节酸强度和强、弱酸量分布,产生二次介孔-大孔结构;HZSM-5分子筛样品经乙二酸/Na OH溶液2步复合改性后,比表面积由335.0 m2/g增至430.4 m2/g,其中外比表面积比例由32%增至54%,介孔体积由0.118 cm3/g扩大至0.392 cm3/g,微反活性指数由43%增大至63%,较Na OH溶液单独改性显示出更加规整的晶体骨架结构和较好的微反活性。HZSM -5 zeolites were modified with C2H2O4 or/and NaOH solution,and the zeolite samples before and after modification were characterized by means of scanning electron microscope,X - ray diffraction, X - ray fluorescence, NH3 temperatureprogrammed desorption and N2 isothermal adsorption - desorption analysis, also the reaction activities of the samples were evaluated in a catalytic cracking micro - reactor. The results showed that G2H2O4 solution could clear the amorphous species, dredge the pores and improve the crystallinity of zeolite. NaOH solution could remove framework silicon of zeolite and reasonably regulated the intensity and acidity distribution of strong and weak acid sites and form the second mesomacropores. And C2H2O4 and NaOH twostep modification could increase the specific surface of the zeolite from 335.0 m2/g to 430.4 m2/g,in which the external specific surface area from 32% to 54% ,the mesopore volume from 0. 118 mL/g ＇to 0. 392 mL/g and the micro - activity index from 43% to 63% ,indicating more regular crystal structure and better micro - activity compared with the sample treated by NaOH solution alone.

关 键 词：分子筛 HZSM-5分子筛 乙二酸溶液 NAOH溶液 酸性 孔结构 微反活性 

分 类 号：TE624.99[石油与天然气工程—油气加工工程]