INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Tiefeng Wang,Xu Li,Jinxiang Dong
Ethylene glycol (EG), synthesized from coal-based syngas, is frequently contaminated with refractory impurities 1,2-butanediol (BDO) and 1,2-propanediol (PDO), which affect the quality of EG for polyester production. Distillation, one of the existing methods employed, is still difficult for separation and purification due to the close boiling points. Melt crystallization is an effective technology to obtain high-purity organic compounds based on the difference in the melting points of each component in the mixture. Thus, in this work, we have explored the feasibility of the static melt crystallization on the separation of these two binary systems, EG/BDO and EG/PDO, respectively. For this purpose, a jacketed crystallization tube was adopted and the process was divided into three stages: seed generation, crystallization, and sweating. The crystallization parameters were investigated and fractal porous media theory was used to describe the state of the crude crystals. Furthermore, sweating was applied as a finishing treatment. The purity of ethylene glycol was recorded using gas chromatography, and its corresponding UV transmittance spectrum was studied. The results showed that the purity of ethylene glycol could reach ≥99.8% from the two binary systems studied and its UV transmittance at 220 nm was significantly improved by the tertiary separation process. Overall, melt crystallization has been proved as an effective way to solve the difficulty of separating these short-chain glycols.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Rui Wang,Jian Na,Xingang Li,Hong Li,Sai Gu,Xin Gao
Ethylene glycol (EG) is a widely used industrial chemical material, and integrated chemical-looping separation technology (CLS) was verified effective to remove 1,2-butanediol (1,2-BDO) and recover EG produced via the syngas to EG route. Thermodynamic experiments were carried out and employed to analyze the vapor–liquid and liquid–liquid behaviors of the system. Propyl aldehyde, apart from as the reactant, also shows excellent performance in water removal and acetals extraction. Based on the results of the thermodynamic analysis, a reactive extraction process was proposed to intensify the acetalization of EG and 1,2-BDO mixture with propyl aldehyde. The reactive extraction model was established on Aspen Plus v11, and the effects of flow mode (co-current and counter-current), number of stages, the feed-in mole ratio of aldehyde to DIOL on the conversions of EG and 1,2-BDO, the recovery of 2-ethyl-1,3-dioxolane (2ED), and the purity of acetals were investigated. Results show that co-current flow mode performs better than counter-current flow mode and an aldehyde to DIOL feed-in mole ratio of 1.35 to 1 is sufficient. The whole flowsheet, which consists of a seven-stage reactive extraction column and two distillation columns, was designed and optimized. Remarkably, the conversions of EG and 1,2-BDO are over 0.95 and the recovery of 2ED is 0.999 with the aldehyde to DIOL stoichiometric coefficient, which indicates the effectiveness of this process and provides fundamental data and guidance for industrial application.
研究领域:
化学工程
·
工业化学
✓ 已验证
产品关联
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 101
·期 7
·4217-4229
·
IF 2.5
Jia Wang,Rongchun Shen,Yueqiang Cao,Wei Li,Jinghong Zhou
1,2-butanediol (1,2-BDO) and 1,2-propanediol (1,2-PDO) are inevitably side produced in the ethylene glycol (EG) production processes from non-petroleum routes, but are very difficult to separate by the ordinary distillation method because of the closeness of their boiling temperatures to EG, thus compromise the economy of these processes. The azeotropic distillation process using 1-octanol (CPO) as an entrainer to separate EG and 1,2-BDO mixture with or without 1,2-PDO was studied in this paper. Four binary vapour–liquid equilibrium data of EG-1,2-BDO, EG-CPO, 1,2-BDO-CPO, and 1,2-PDO-CPO were measured using an Ellis equilibrium kettle and regressed with the thermodynamic model of non-random two liquid to obtain the corresponding binary interaction parameters. On this basis, azeotropic distillations with CPO as an entrainer were designed to separate EG and 1,2-BDO with or without 1,2-PDO. The complete separation processes, including the azeotropic distillation and CPO recovery process consisting of extraction with H 2 O and subsequent distillation, were simulated and optimized with Aspen Plus for both the EG-1,2-BDO binary mixture and the EG-1,2-BDO-1,2-PDO ternary mixture. The simulation results show that the azeotropic distillation method with CPO as an entrainer can effectively separate the mixture of EG-1,2-BDO and EG-1,2-BDO-1,2-PDO, achieving EG of 99.90% purity with 99.98% recovery and 1,2-BDO of 99.30% purity with 99.45% recovery for the binary mixture, and achieving EG of 99.90% purity with 99.80% recovery, 1,2-BDO of 99.35% purity with 99.35% recovery, and 1,2-PDO of 90.59% purity with 94.38% recovery for the ternary mixture. These processes are promising for industrial application and can significantly improve the economy of non-petroleum EG production.
研究领域:
化学工程
·
分离技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）