华南理工大学学报(自然科学版) ›› 2025, Vol. 53 ›› Issue (11): 150-156.doi: 10.12141/j.issn.1000-565X.240368

• 化学化工 • 上一篇    

煤制乙二醇悬浮结晶精制实验研究

薛雨源, 赵淼, 赵志仝, 袁栋勇, 李钢   

  1. 太原理工大学 化学与化工学院,山西 太原 030024
  • 收稿日期:2024-07-16 出版日期:2025-11-25 发布日期:2025-01-17
  • 作者简介:薛雨源(1992—),男,博士,副教授,主要从事低值植物资源利用和结晶分离研究。E-mail: xueyuyuan@tyut.edu.cn
  • 基金资助:
    山西省自然科学基金青年科学基金项目(20210302124465);山西浙大新材料与化工研究院项目(2021SX-TD004)

Experimental Investigation into Suspension Crystallization Refining of Coal-to-Ethylene Glycol

XUE Yuyuan, ZHAO Miao, ZHAO Zhitong, YUAN Dongyong, LI Gang   

  1. College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China
  • Received:2024-07-16 Online:2025-11-25 Published:2025-01-17
  • About author:薛雨源(1992—),男,博士,副教授,主要从事低值植物资源利用和结晶分离研究。E-mail: xueyuyuan@tyut.edu.cn
  • Supported by:
    the Natural Science Foundation of Shanxi Province for Young Scholars(20210302124465)

摘要:

悬浮结晶耦合离心分离可精制得到聚酯级煤制乙二醇。与传统精馏纯化相比,悬浮结晶具有低能耗、无需溶剂、对环境友好等优点,对煤制乙二醇生产过程中杂质与乙二醇形成的窄沸、共沸以及热敏体系能起到节能减排的效果。为优化煤制乙二醇悬浮结晶的操作工艺,为相关耦合离心分离技术的开发提供参考,该文研究了晶种添加量、滤饼厚度、搅拌强度、程序降温和母液循环操作工艺对纯化效果的影响。结果显示:晶种添加量对晶体的粒径分布有影响,增大添加量可提高产品纯度,有效分配系数降幅达15.8%;降低滤饼厚度可使晶体与发汗气体更充分地接触,增强发汗效果,有效分配系数最大降幅达56.8%;搅拌强度直接影响传质传热,搅拌强度越大,产品纯度越高,但收率随之下降,有效分配系数和收率最大降幅分别为39.4%和30.8%;程序降温直接影响结晶时间,降温速率越小则结晶时间越长,产品纯度反而降低;母液循环使用会导致体系水含量增加,降低过冷度,从而提高产品纯度,与新鲜母液相比,母液循环7次时有效分配系数降低了72.0%。

关键词: 煤制乙二醇, 悬浮结晶, 工艺优化, 实验研究

Abstract:

Suspension crystallization coupled with centrifugal separation can be used to refine polyester-grade coal-to-ethylene glycol. Compared with the traditional distillation purification, suspension crystallization has the advantages of low energy consumption, no need for solvents and environmental friendliness. It is particularly effective in reducing energy consumption and emissions when purifying the narrow-boiling, azeotropic and heat-sensitive systems formed by impurities and ethylene glycol during the coal-to-ethylene glycol production process. To optimize the operation process of suspension crystallization for coal-to-ethylene glycol and provide a reference for the deve-lopment of coupled centrifugal separation technology, this paper investigated the effects of seed dosage, filter cake thickness, stirring intensity, programmed cooling and mother liquid circulation operation process on the purification efficiency. The results show that seed dosage affects crystal size distribution, and that increasing the dosage may improve the product purity, with the effective distribution coefficient decreasing by 15.8%. Reducing the filter cake thickness allows for more sufficient contact between crystals and sweating gas, thus enhancing the sweating effect and resulting in a maximum reduction of 56.8% in the effective distribution coefficient. Stirring intensity directly affects mass and heat transfer. Higher stirring intensity leads to higher product purity but lower yield, with maximum decreases in the effective distribution coefficient and the yield of 39.4% and 30.8%, respectively. Programmed cooling directly affects crystallization time. A slower cooling rate prolongs the crystallization time but reduces product purity. Mother liquid recycling increases the water content in the system, reduces the degree of supercooling, and thereby improves product purity. Compared with fresh mother liquid, the mother liquid cycled for 7 times leads to an effective distribution coefficient decrease by 72.0%.

Key words: coal-to-ethylene glycol, suspension crystallization, process optimization, experimental investigation

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