化工学报Issue(10)：3946-3952,7.DOI:10.3969/j.issn.0438-1157.2014.10.027
离子改性Y分子筛吸附分离1,1,1,2-四氟乙烷/1,1-二氟-2-氯乙烯
Adsorptive separation of 1,1,1,2-tetrafluoroethane/1,1-difluoro-2-chloroethylene over ion-exchanged Y zeolites
摘要
Abstract
Using CaCl2, La(NO3)3 and Ce(NO3) 3 solutions, NaY was ion-exchanged to prepare CaY, LaY and CeY zeolites. Adsorptive removal of trace amount of 1,1-difluoro-2-chloroethylene (HCFC-1122) from 1,1,1,2-tetrafluoroethane product over NaY, CaY, LaY, and CeY zeolites were investigated. The structure and surface properties of fresh and regenerated adsorbents were characterized by X-ray diffraction, pyridine infrared spectra techniques and temperature programmed desorption of ammonia. Results show that the residual ratio of HCFC-1122 impurity in the eluate can be decreased to 1.0% over CaY,LaY and CeY zeolitesvia the formation ofπ-adsorption complexes between HCFC-1122 and Brønsted acid sites. The increase of intensity of Brønsted acid favors the formation ofπ-adsorption complexes, consequently decreasing adsorption temperature for complete removal of HCFC-1122 (CeY < LaY < CaY). Breakthrough adsorption capacity of HCFC-1122 at 220℃ increases in the order of CaY < LaY < CeY, since lower density of strong Brønsted and weak Lewis acid sites are favorable to lower degree polymerization initiated byπ-adsorption complexes. The thermal regeneration of adsorbents is unsatisfactory, attributed to hardly removal of contaminant on the acid sites of saturated adsorbents during the thermal regeneration process.关键词
离子交换/Y型分子筛/吸附/脱附/分离Key words
ion-exchange/Y-type zeolite/adsorption/desorption/separation分类
化学化工引用本文复制引用
张闯,张波,尉明全..离子改性Y分子筛吸附分离1,1,1,2-四氟乙烷/1,1-二氟-2-氯乙烯[J].化工学报,2014,(10):3946-3952,7.基金项目
浙江省绿色化工重大专项（2007C11043）。 （）
