nHEP/MCH在多级孔UiO-66上吸附热力学及动力学研究  

Thermodynamics and kinetics of n-heptane and methyl cyclohexane adsorption by UiO-66 with hierarchical pores

作　　者：张昭 陈思伽 张林 钱刚 刘宗健[1] 孙智聪 崔群[1] 王海燕[1] ZHANG Zhao;CHEN Si-jia;ZHANG Lin;QIAN Gang;LIU Zong-jian;SUN Zhi-cong;CUI Qun;WANG Hai-yan(College of Chemical Engineering,Nanjing Tech University,Nanjing 210009,China)

机构地区：[1]南京工业大学化工学院

出　　处：《高校化学工程学报》2019年第4期942-950,共9页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(51476074);中国石油化工集团有限公司(416039)

摘　　要：采用模板法合成了多级孔UiO-66 (H-UiO-66)和普通微孔UiO-66;在50~150℃下,测定正庚烷(n HEP)、甲基环己烷(MCH)在H-UiO-66、UiO-66上吸附/脱附等温线及速率曲线,研究引入介孔的UiO-66对n HEP、MCH吸附热力学及动力学参数影响。结果表明:n HEP、MCH在H-UiO-66、UiO-66上吸附等温线均为I型等温线,其优惠程度随着吸附温度提高而降低;在较高吸附温度下,H-UiO-66对MCH与n HEP平衡吸附量之比为2.93,明显高于UiO-66(1.32);H-UiO-66对n HEP的特征吸附功比UiO-66降低约20%;n HEP、MCH在H-UiO-66上等量吸附热相对于UiO-66均降低20%;n HEP、MCH在H-UiO-66上有效吸附、脱附扩散系数均为UiO-66的10倍左右。介孔的引入削弱UiO-66表面与n HEP、MCH吸附作用,强化其孔道内传质过程,有利于n HEP、MCH在UiO-66上脱附,提高了从120号溶剂油中反择形吸附提纯正庚烷的效率。UiO-66 with hierarchical pores was synthesized through a soft template method. Adsorption/desorption isotherms and rates of n-heptane (nHEP) and methyl cyclohexane (MCH) on UiO-66 with hierarchical pores and UiO-66 were measured at 50~150 ℃. Effects of mesoporous structure on equilibrium adsorption/desorption performance of n-HEP and MCH were studied. The results show that adsorption isotherms of n-HEP and MCH on UiO-66 and UiO-66 with hierarchical pores are of type I, and the adsorption isotherm degree reduces gradually with the increase of adsorption temperature. The ratio of equilibrium adsorption capacity between MCH and nHEP on UiO-66 with hierarchical pores is 2.93, which is higher than that of UiO-66 (1.32). Characteristic adsorption energy of nHEP on UiO-66 hierarchical pores is about 20% lower than that of UiO-66. Isosteric adsorption heats of nHEP and MCH on UiO-66 with hierarchical pores are about 20% lower than that of UiO-66. Effective adsorption/desorption diffusion coefficients of nHEP and MCH on UiO-66 with hierarchical pores are 10 times larger than that of UiO-66. The introduction of hierarchical structure reduces adsorption forces between UiO-66 surface and nHEP/MCH, and dramatically strengthens mass transfer process, which is beneficial for the desorption of nHEP/MCH on UiO-66. Efficiency of adsorption separation of nHEP from No.120 solvent oil is improved.

关 键 词：多级孔UiO-66 正庚烷 甲基环己烷 吸附热 扩散系数 

分 类 号：TQ244.2[化学工程—有机化工]