应用化学 ›› 2023, Vol. 40 ›› Issue (9): 1302-1311.DOI: 10.19894/j.issn.1000-0518.230087

• 研究论文 • 上一篇    下一篇

基于甲苯模板合成的ZIF-93及其对1,3-丙二醇和2,3-丁二醇的吸附分离性能

王梦瑶, 高美珍, 石琪(), 董晋湘   

  1. 太原理工大学化学工程与技术学院,太原 030024
  • 收稿日期:2023-04-03 接受日期:2023-07-19 出版日期:2023-09-01 发布日期:2023-09-14
  • 通讯作者: 石琪
  • 基金资助:
    国家自然科学基金(22278289)

Toluene-Templated Synthesis of ZIF-93 and Its Adsorptive Separation of 1,3-Propanediol and 2,3-Butanediol

Meng-Yao WANG, Mei-Zhen GAO, Qi SHI(), Jin-Xiang DONG   

  1. College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China
  • Received:2023-04-03 Accepted:2023-07-19 Published:2023-09-01 Online:2023-09-14
  • Contact: Qi SHI
  • About author:shiqi594@163.com
  • Supported by:
    the National Natural Science Foundation of China(22278289)

摘要:

生物基1,3-丙二醇原液预处理后主要是由低浓度水溶液、1,3-丙二醇和2,3-丁二醇组成。1,3-丙二醇和2,3-丁二醇均是二元醇,含有2个羟基能与水形成强的氢键,增加了分离的难度。然而仅具有范德华作用的传统疏水吸附剂通过动态柱吸附无法实现有效分离二元醇。因此,选择具有范德华作用基团—CH3和氢键作用基团—CHO的ZIF-93研究其对低浓度2,3-丁二醇/1,3-丙二醇的静态和动态柱吸附分离性能。首先,在ZIF-93合成中引入甲苯作为溶剂和模板剂,利用甲苯与咪唑基配体以及甲苯分子之间的π-π相互作用模板支撑ZIF-93的结构单元lta笼,有效提高ZIF-93的BET比表面积和微孔孔容。结果表明, ZIF-93对2,3-丁二醇(50 g/L)/1,3-丙二醇(50 g/L)的动态柱吸附量为69.9和17.3 mg/g,对2,3-丁二醇/1,3-丙二醇的选择性为4.0。相对于传统疏水吸附剂,具有氢键作用基团的ZIF-93穿透曲线斜率增大,传质区间缩短,穿透时间提高,从而提高吸附床层的有效利用率,利于工业上连续分离操作。通过模拟揭示了ZIF-93的-CHO与2,3-丁二醇的―OH和―CH3之间形成氢键相互作用,高于与1,3-丙二醇之间形成的氢键相互作用,从而实现了低浓度2,3-丁二醇/1,3-丙二醇的有效分离。经过3次吸附-解析循环实验,ZIF-93对2,3-丁二醇的吸附能力保持不变,仍能保持良好的稳定性。因此,ZIF-93是水溶液中分离二元醇的高效吸附剂。

关键词: 沸石咪唑酯骨架结构材料, ZIF-93, 模板剂, 吸附分离, 二元醇

Abstract:

The bio-based 1,3-propanediol (1,3-PDO) stock solution after pretreatment is mainly composed of low concentration of 1,3-PDO and 2,3-butanediol (2,3-BDO). 1,3-PDO and 2,3-BDO are diols and contain two hydroxyl groups that can form strong hydrogen bonds with the large amount of water present, increasing the difficulty of separation. However, conventional hydrophobic adsorbents with only van der Waals cannot achieve effective separation of diols by dynamic column adsorption. Therefore, ZIF-93 with van der Waals group —CH3 and hydrogen bonding group —CHO is selected to investigate its batch and dynamic column adsorption capacity on low concentration of 2,3-BDO/1,3-PDO. Firstly, toluene is introduced as solvent and template agent in the synthesis of ZIF-93, and the structural unit lta cage of ZIF-93 is supported by π?-?π interaction between toluene and imidazole-based ligands as well as toluene molecules, which effectively increases the BET surface area and microporous pore volume of ZIF-93. The results show that the dynamic column adsorption capacity of ZIF-93 for 2,3-BDO/1,3-PDO (50/50 g/L) is 69.9 mg/g/17.3 mg/g, and the selectivity for 2,3-BDO/1,3-PDO is 4.0. Compared with the conventional hydrophobic adsorbent, ZIF-93 with hydrogen-bonding groups has an increased slope of the breakthrough curve, a shorter mass transfer interval, and an increased breakthrough time, thus improving the effective utilization of the adsorption bed and facilitating the continuous separation operation in industry. The simulation results show that the hydrogen bonding interaction formed between —CHO of ZIF-93 and —OH/—CH3 of 2,3-BDO is higher than that with 1,3-PDO, thus achieving effective separation of low concentration of 2,?3-BDO/1,?3-PDO. After three adsorption-resolution cycle experiments, the adsorption capacity of ZIF-93 on 2,3-BDO does not change, and ZIF-93 still maintains good stability. Therefore, ZIF-93 is an efficient adsorbent for the separation of diols in aqueous solution.

Key words: Zeolitic imidazolate frameworks, ZIF-93, Template agent, Adsorptive separation, Bio-diols

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