5A分子筛吸附分离C_(5)/C_(6)正构烷烃  

Adsorption and separation of C_(5)/C_(6) normal alkanes through 5A molecular sieves

作　　者：王红超[1] 李伦西 杨彦强[1] 王德华[1] 王辉国[1] Wang Hongchao;Li Lunxi;Yang Yanqiang;Wang Dehua;Wang Huiguo(Sinopec Research Institute of Petroleum Processing,Beijing 100083,China)

机构地区：[1]中国石化石油化工科学研究院,北京100083

出　　处：《石油化工》2022年第8期887-894,共8页Petrochemical Technology

摘　　要：以水玻璃、NaOH和偏铝酸钠为原料,采用水热晶化法合成4A分子筛,再经成型、焙烧、黏结剂转晶和离子交换制备得到无黏结剂的5A分子筛小球吸附剂。采用XRD、SEM、XRF、N_(2)吸附-脱附、正己烷吸附量等方法对所制备吸附剂试样进行表征;通过液相脉冲实验考察了吸附温度和解吸剂对C_(5)/C_(6)正构烷烃吸附分离的影响;通过小型模拟移动床实验评价了无黏结剂5A分子筛吸附剂对某炼厂C_(5)/C_(6)异构化油的分离效果。表征结果显示,成型用黏结剂基本全部转变为5A分子筛。实验结果表明,对于C_(5)/C_(6)包括C_(7)正构烷烃,较适宜的吸附温度为90~150℃;与正壬烷和正癸烷相比,正辛烷作为解吸剂时,C_(5)/C_(6)正构烷烃的净保留体积更大,更利于吸附分离;正壬烷作为解吸剂时,抽出油中正构烷烃纯度可达99.3%,抽余油中非正构烷烃纯度可达97.5%,抽余油的研究法辛烷值达到88.8。4A molecular sieve was synthesized by hydrothermal crystallization from sodium silicate,sodium hydroxide and sodium metaaluminate,and then the binderless 5A molecular sieve pellet adsorbents were prepared through molding,calcination,binder crystallization and Ca^(2+)ion exchange procedures.The achieved samples were characterized by XRD,SEM,XRF,N_(2)adsorption-desorption and n-hexane adsorption techniques.The effects of adsorption temperature and desorbent on the adsorption and separation of C_(5)/C_(6)n-alkanes were investigated by liquid phase pulse experiment.The separation performance of binderless 5A molecular sieve adsorbent for C_(5)/C_(6)isomerized oil from a refinery was evaluated by a small-scale simulated moving bed experiment.The characterization results showed that the binder for molding was basically transformed into 5A molecular sieves.The experimental results showed that the suitable adsorption temperature for C_(5)/C_(6),and C_(7) n-alkanes,is in the range of 90-150℃.Compared with n-nonane and n-decane,when n-octane is used as desorbent,the net retention volume of C_(5)/C_(6)n-alkanes will be larger,which is more conducive to adsorption and separation.When n-nonane is used as desorbent,the purity of n-alkanes in the extracted oil could reach up to 99.3%,the purity of non-n-alkanes in the raffinate oil could be 97.5%,and the research octane number of the raffinate oil will be 88.8.

关 键 词：5A分子筛 吸附剂 正构烷烃 模拟移动床 

分 类 号：TQ426[化学工程]