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
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材料科学
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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
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分离技术
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DOI
高影响因子
VACUUM
·
2024
·
IF 3.8
Kaile Shi,Haodong Zheng,Yuze Sun,Honghai Wang,Jing Fang,Chunli Li,Jiapeng Liu
The utilization of 1,4-butanediol (BDO) spans across numerous sectors, underscoring its significance as a pivotal chemical. However, the separation of crude BDO still presents great challenges. Ethylene glycol (EG) and 3-methyl-1,5-pentanediol (MPD) are classical impurities in BDO crude products. In this paper, the pressure and temperature data of MPD components under high vacuum pressure were measured, and Antoine constant was obtained by fitting to supplement the basic data. The isobaric vapor-liquid equilibrium (VLE) data for the EG-BDO and BDO-MPD mixtures were experimentally measured at pressures of 1.0, 10.0, and 50.0 kPa. Meanwhile, the thermodynamic consistency of the experimental binary data was examined using the Herington area test. The experimental VLE data for binary systems were analyzed using the nonrandom two-liquid (NRTL) universal quasichemical (UNIQUAC) and Wilson activity coefficient models, demonstrating that the predicted outcomes showed excellent agreement with the measured data. Finally, the interaction energy between the components was calculated by molecular simulation to explain the gas-liquid equilibrium behavior. Therefore, this work provided guidance and basis for the separation of EG-BDO and BDO-MPD in high vacuum separation.
研究领域:
化学工程
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物理化学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Bin Xiao,Mingyuan Zheng,Jifeng Pang,Yu Jiang,Hua Wang,Ruiyan Sun,Aiqin Wang,Xiaodong Wang,Tao Zhang
Using biomass-derived ethylene glycol (bio-EG) to synthesize poly(ethylene terephthalate) (PET) is of notable significance for alleviating the dependence on fossil energy resources. Bio-EG readily contains a small amount of miscellaneous diols, which derive from the side reactions in the catalytic conversion of biomass. To disclose the effects of miscellaneous diols on the synthesis and properties of PET, EG feedstock containing four 1,2-diols, i.e., 1,2-propylene glycol, 1,2-butanediol, 1,2-pentanediol, and 1,2-hexanediol at 0–10% concentrations was used for the synthesis of PET. The molecular weights, intrinsic viscosities, and thermal and mechanical properties of obtained PET materials were measured. It was found that when the overall content of miscellaneous diols in EG was lower than 5%, the molecular weights and thermal properties of the prepared PET materials were very similar to that of PET synthesized from pure EG. The miscellaneous diols were less likely to be incorporated into PET resin because of the steric hindrance of the alkyl group in diols to the esterification and polycondensation reactions. Instead, they preferred to undergo dehydration reactions to form low-boiling-point aldehydes and hemiacetals, which could be removed from the reaction system during the reactions. Three bio-EG samples at purities of 99.9, 98.5, and 95.8 wt % were used for the bio-PET synthesis. Transparent and colorless bio-PET samples were obtained, demonstrating that the presence of miscellaneous diols does not have negative effects on the color quality of PET. The physical properties of bio-PET prepared with bio-EG at a purity of higher than 98 wt % were nearly the same as those of PET derived from pure EG. At a lower bio-EG purity of 95.8 wt %, the tensile strength of the obtained bio-PET sample was slightly decreased. The comprehensive results of property characterization show that bio-PET materials prepared with bio-EG at purity higher than 95 wt % could be used as widely as the conventional petro-PET resin without notable deterioration in their performance.
研究领域:
材料科学
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化学工程
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可再生资源利用
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2024
·Vol. 31
·期 10
·1-11
·
IF 2.6
Chen Yueqing,Huang Zhenhong,Chen Haijian,Ai Jiaoyan,Song Lina,Liu Baohua
Waterborne polyurethanes emulsions (WPU) based on polyethylene carbonate diol (PECD) were synthesized, characterized and modified by polypropylene carbonate diol (PPCD) and organosilicon KH-792. The mechanical, thermal and hydrolysis resistance properties of waterborne polyurethanes were comprehensively investigated. The results show that PECD based WPU has very excellent mechanical properties. The tensile strength and the elongation at break the PU was up to 73 MPa and 1040%, which was much higher than that reported for similar types of PPCD-based WPU. It was found that water absorption of PECD based WPU can be decreased dramatically, from 40.9% to 21.1%, after 50% PECD was replaced by PPCD, while tensile strength only decreased from 73.0 MPa to 63.4 MPa. The addition of KH-792 has great influence on PECD based WPU, when 1% KH-792 was added, the water absorption rate decreased from 21.1% to 11.88%, the mechanical strength remained at 63.3 MPa, the WPU film remained transparent after soaking in 80 ℃ hot water for 4 h.
研究领域:
材料科学
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化学工程
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产品关联
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
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工业化学
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产品关联
DOI
高影响因子
Polymers
·
2018
·Vol. 10
·期 1
·90
·
IF 2.935
Zhenhui Bai,Yun Liu,Tingting Su,Zhanyong Wang
Poly(ethylene succinate) (PES), poly(butylene succinate) (PBS), and poly(hexylene succinate) (PHS), were synthesized using succinic acid and different dihydric alcohols as materials. Enzymatic degradability by cutinase of the three kinds of polyesters was studied, as well as their solid-state properties. The biodegradation behavior relied heavily on the distance between ester groups, crystallinity, and the hydrophilicity-hydrophobicity balance of polyester surfaces. The weight loss through degradation of the three kinds of polyesters with different hydroxyl monomers took place in the order PHS > PBS > PES. The degradation behavior of the polyesters before and after degradation was analyzed by scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The decrease in relative intensity at 1800–1650 estedpolyesters were degraded simultaneously. The frequencies of the crystalline and amorphous bands were almost identical before and after degradation. Thus, enzymatic degradation did not change the crystalline structure but destroyed it, and the degree of crystallinity markedly decreased. The molecular weight and polydispersity index only changed slightly. The thermal stability of the three kinds of polyesters decreased during enzymatic degradation.Keywords:poly(ethylene succinate);poly(butylene succinate);poly(hexylene succinate);cutinase;biodegradability
研究领域:
材料科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
BIOTECHNOLOGY LETTERS
·
2014
·Vol. 37
·期 1
·183-188
·
IF 1.736
He Yu-Cai,Tao Zhi-Cheng,Zhang Dan-Ping,Yang Zhen-Xing,Gao Shan,Ma Cui-Luan
Rhodococcus sp. CGMCC 4911 transformed 1,3-propanediol cyclic sulfate (1,3-PDS) and its derivatives into corresponding diols. Ethylene sulfate, glycol sulfide, 1,3-PDS, and 1,2-propanediol cyclic sulfate were effectively hydrolyzed with growing cells. ( R )-1,2-Propanediol (>99 % e.e. ) was obtained at 44 % yield with growing cells. Glycol sulfide, ethylene sulfate, and 1,3-PDS were converted into the corresponding diols at 94.6, 96.3, and 98.3 %, respectively. Optimal reaction conditions with lyophilized resting cells were 30 °C, pH 7.5, and cell dosage 17.9 mg cell dry wt/ml. 1,3-Propanediol was obtained from 50 mM 1,3-PDS at 97.2 % yield by lyophilized cells after 16 h. Lyophilized cells were entrapped in calcium alginate with a half-life of 263 h at 30 °C, and the total operational time of the immobilized biocatalysts could reach over 192 h with a high conversion rate.
研究领域:
微生物学
·
生物催化
✓ 已验证
DOI
PubMed
高影响因子
ACS Catalysis
·
2015
·
IF 9.312
Ruiyan Sun,Tingting Wang,Mingyuan Zheng,Weiqiao Deng,Jifeng Pang,Aiqin Wang,Xiaodong Wang,Tao Zhang
Using cellulosic biomass to synthesize bulk quantities of high-value chemicals is of great interest for developing a sustainable biobased society. Especially, direct catalytic conversion of cellulose to glycols, important building blocks for polymers, remains a grand challenge. Herein, we report the development of a versatile binary nickel–lanthanum(III) catalyst for the conversion of cellulose to both ethylene glycol (EG) and propylene glycol (1,2-PG) in a yield of 63.7%, which is one of the best performances reported for this catalytic reaction. Especially, lanthanum(III) exhibited a high level of activity toward the degradation of cellulose (TON = 339) at a very low concentration (0.2 mmol/L). On the basis of density functional theory calculations and experimental analyses, we addressed a dual route for this catalytic mechanism: a major route involving the selective cracking of sugars into C2 molecules and a minor route involving the hydrogenolysis of sugar alcohols. Lanthanum(III) catalyzes the cleavage of the C2–C3 bond in glucose via sequential epimerization and 2,3-hydride shift reactions to form glycolaldehyde, the precursor of EG.
研究领域:
化学工程
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催化科学
·
生物质能
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产品关联
DOI
高影响因子
COLD REGIONS SCIENCE AND TECHNOLOGY
·
2022
·
IF 4.427
Haoxia Ma,Haiyan Ma,Hongfa Yu,Bo Da,Wei Gong,Na Zhang
Ethylene glycol (EG) deicer and propylene glycol (PG) deicer were frequently used as the aircraft de-icing fluids in cold region. In this paper, the icing pressure ( I p ), icing volume expansion rate (Δ V P ), freezing point ( T 0 ) and under-cooling ( △T ) of aircraft deicers with different concentrations were investigated, and the above indicators of aircraft deicers were also compared with that of water and NaCl deicers. The results showed that the icing volume expansion of deicers was the direct cause of icing pressure. During the cooling process, values of I p and Δ V P firstly increased sharply, then slowly, and finally became stable. The stabilized values of I p and Δ V P decreased with concentration. The stabilized I p value of EG deicer was slightly higher than that of 3.5% NaCl deicer and far greater than 3.5% PG deicer. Of all the tested deicers, the stabilized Δ V P value of NaCl deicer was the highest and that value of EG deicer was close to that of PG deicer. The results further confirmed the feasibility of using impulse of icing pressure as the indicator to evaluate the freeze-thaw deterioration to concrete.
研究领域:
材料科学
·
航空工程
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产品关联
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Chao Zheng,Xiaoyan Yu,Xiaoyi Chen,Mingming Chang
Poly(ethylene oxide)- b -poly(propylene oxide)- b -poly(ethylene oxide) (PEO-PPO-PEO) and acrylamide are both commercially available and widely used water-soluble substances. There are many situations that PEO-PPO-PEO coexist with acrylamide in industry applications, while little is known about the influence of acrylamide on cloud point of PEO-PPO-PEO aqueous solution. In this work, it reveals a universal solubilization of PEO-PPO-PEO by acrylamide. There is always an increase in cloud point with addition of acrylamide no matter what the molecular structure and concentration of PEO-PPO-PEO is. It is found the solubilization is more pronounced when PEO-PPO-PEO is with lower molecular weight or lower weight fraction of PPO segments. On the other hand, the cloud point of systems at lower concentration is more sensitive to addition of acrylamide. On the contrary, polyacrylamide exhibits an opposite impact on cloud point of PEO-PPO-PEO. Acrylamide/PEO-PPO-PEO solution changes from clear to cloudy after polymerization of acrylamide.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2015
·
IF 9.312
Ruiyan Sun,Mingyuan Zheng,Jifeng Pang,Xin Liu,Junhu Wang,Xiaoli Pan,Aiqin Wang,Xiaodong Wang,Tao Zhang
The direct hydrogenolysis of cellulose represents an attractive and promising route for green polyol production. Designing a catalyst system that could control the selectivity of polyols of this process is highly desirable. In this work, we realized the selectivity-switchable production of ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG) by using Sn species with different valences in combination with Ni catalysts. The combination of Ni/AC and metallic Sn powders exhibited a superior activity toward EG (57.6%) with up to 86.6% total polyol yield, while the combination of Ni/AC and SnO favored the formation of 1,2-PG (32.2%) with a 22.9% yield of EG. The Sn species in NiSn alloy in situ formed from metallic Ni and Sn powders was found to be the active sites for the high selectivity of EG as evidenced by control experiments and characterizations including X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, energy dispersive X-ray mapping, and 119Sn Mössbauer spectroscopy. The effects of Sn loading, reaction temperature, reaction time, and the concentration of cellulose were investigated for Ni/AC + Sn powders. Because of the formation of NiSn alloy, the Ni–Sn catalyst showed good stability during repeated use. Experimental results disclosed that the Sn species with different valence possessed distinct catalytic functions. Both SnO and the alloyed Sn species could catalyze the retro-aldol condensation of glucose to glycolaldehyde, and meanwhile, SnO was also active for the isomerization of glucose to fructose. Therefore, controlling the glycol products distribution could be realized using SnO or the alloyed Sn species as catalysts.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）