化工学报 ›› 2014, Vol. 65 ›› Issue (10): 3946-3952.DOI: 10.3969/j.issn.0438-1157.2014.10.027

• 分离工程 • 上一篇    下一篇

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

张闯, 张波, 尉明全   

  1. 浙江工业大学化学工程与材料学院, 浙江 杭州 310014
  • 收稿日期:2013-11-27 修回日期:2014-06-26 出版日期:2014-10-05 发布日期:2014-10-05
  • 通讯作者: 张波
  • 基金资助:

    浙江省绿色化工重大专项(2007C11043)。

Adsorptive separation of 1,1,1,2-tetrafluoroethane/1,1-difluoro-2-chloroethylene over ion-exchanged Y zeolites

ZHANG Chuang, ZHANG Bo, WEI Mingquan   

  1. College of Chemical Engineer & Materials, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
  • Received:2013-11-27 Revised:2014-06-26 Online:2014-10-05 Published:2014-10-05
  • Supported by:

    supported by the Major Special Project in the Green Chemical Industry of Zhejiang Province (2007C11043).

摘要: 用CaCl2、La(NO33和Ce(NO3 3溶液对NaY分子筛进行离子改性制备出CaY、LaY和CeY分子筛。将其及NaY为吸附剂,利用动态吸附法评价其吸附分离1,1,1,2-四氟乙烷(HFC-134a)产品中微量1,1-二氟-2-氯乙烯(HCFC-1122)的性能。同时采用X射线衍射(XRD)、吡啶红外(FTIR)和氨-程序升温脱附(NH3-TPD)等手段对新鲜及再生后的吸附剂进行结构和表面性质表征。结果表明:CaY、LaY与CeY分子筛上的Brønsted酸中心可与HCFC-1122形成p-吸附配合物,从而将吸附流出气中HCFC-1122的残余率降低至1.0%以下;Brønsted酸强度越高,p-吸附配合物越容易形成,最低吸附温度越低(CeY

关键词: 离子交换, Y型分子筛, 吸附, 脱附, 分离

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 zeolites via the formation of p-adsorption complexes between HCFC-1122 and Brønsted acid sites. The increase of intensity of Brønsted acid favors the formation of p-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 by p-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.

Key words: ion-exchange, Y-type zeolite, adsorption, desorption, separation

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