INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2017
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IF 2.843
Weiting Ma,Yufeng Hu,Jianguang Qi,Lihu Wei,Xianming Zhang,Zhenyu Yang,Siqi Jiang
The effects of solvent, acid specificity, acid concentration, added salt, and reaction temperature on the yields of trioxane and formic acid (byproduct) in paraformaldehyde + acid (or acid + salt) + aprotic solvent were investigated. The mechanism that underlies the yield of paraformaldehyde and the selectivity of trioxane was determined. A highly practical and efficient synthesis of trioxane by a salt-mediated and acid-catalyzed yield of paraformaldehyde in sulfolane media was developed. The method increased the yield of paraformaldehyde by more than 5 times and decreased the formic acid concentration by 10 times compared to the commercial synthesis of trioxane in an aqueous reaction system (formaldehyde + H2SO4 + H2O).
研究领域:
有机化学
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工业化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2017
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IF 3.648
Jie Li,Xinwei Zhang,Quanjie Liu,Zequn Yin
The solubilities of 1,3,5-trioxane were measured by a dynamic method in binary solvents (methanol-water, ethanol-water, isopropanol-water and dimethoxymethane-water) at the temperature range (288.15 to 328.15) K at atmosphere pressure. The solubility increased with increasing of temperature in all case, indicating that the dissolution process of 1,3,5-trioxane was endothermic. In addition, the experimental solubility of 1,3,5-trioxane in binary solvents at different temperatures were correlated by the (CNIBS)/Redlich–Kister model, the modified Apelblat model, Wilson model and NRTL equation. The calculated values were in good agreement with the measured experimental data. The (CNIBS)/Redlich–Kister model and modified Apelblat model were in agreement with the experimental solubility in all the binary solvents. The Wilson model was suitable for the binary solvent of methanol-water and dimethoxymethane-water. NRTL equation was suitable for the all in agreement with the experimental solubility in the binary solvent except the isopropanol–water.
研究领域:
化学工程
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 29
·13993-14001
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IF 3.3
Wenhui Wu,Conger Deng,Qian Lei,Honglin Chen
ZSM-5 could be a good candidate for the catalysis of formaldehyde to trioxane (TOX) because of its appropriate and adjustable acid properties. However, the space-time yield (STYTOX) and selectivity of the TOX catalyzed by ZSM-5 zeolites are relatively low at present. [Ga, Al]-MFI zeolites containing different Ga/Al atomic ratios were used as catalysts for reaction of synthetic TOX. The structural information of the materials was illustrated by characterization through XRD, ICP-OES, XPS, SEM, BET analysis, and MAS NMR spectroscopy. And the acid properties of the materials were tested by NH3-TPD and Py-IR. The catalytic performance test showed that the STYTOX of [Ga, Al]-MFI-50 is about twice that of ZSM-50 or [Ga]-MFI-50. And the selectivity of TOX is also significantly improved compared to that with [Al]-MFI-50 and Ga-MFI-50. This is because the introduction of Ga atoms into ZSM-5 causes the Brønsted acid content to rise, resulting in STYTOX. It is worth noting that adjusting the Ga/Al atom ratio in the framework affects the B/L value of the zeolite, which leads to the optimization of the selectivity.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
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IF 7.1
Zhiyuan Wang,Zhiyong Su,Yuan Xu,Jianguang Qi,Baohui Qi,Xueyang Wei,Xingjian Chen,Yufeng Hu,Zhichang Liu,Xin Guo
With the increasing emphasis on sustainable development, people have realized that energy transformation is the key to solving the global energy and climate crisis. 1,3,5-Trioxane (TOX), as a crucial chemical raw material, is an important substitute for anhydrous formaldehyde, and the production of bulk industrial products through TOX is a significant way to extend the C1 industry chain. However, in the industrial synthesis process of TOX, coexisting water (H2O) and TOX form an azeotrope. This paper proposes for the first time a novel method of using green and environmentally friendly 1,3-dimethylimidazolium dimethyl phosphate ([MMIM][DMP]) ionic liquid as an entrainer to separate TOX and H2O through extractive distillation. Based on the COSMO-RS model, [MMIM][DMP] was screened and understood to be the most promising entrainer. Vapor–liquid equilibrium (VLE) experiments demonstrated that [MMIM][DMP] can obviously break the azeotropic point of the (TOX + H2O) system, the critical concentration for breaking the azeotropic point is about 1 mol/kg. The TOX + H2O + [MMIM][DMP] ternary VLE data were regressed by the NRTL model, e-NRTL model, Wilson model, and UNIQUAC model, and the results showed that the NRTL model achieved the best regression accuracy. In addition, the separation mechanism of [MMIM][DMP] breaking the azeotropic point of the TOX + H2O system was evidenced by the density functional theory and the COSMO-RS model. Finally, by conducting experiments on the extractive distillation pilot device, it was further verified that under the conditions of solvent ratio 2 and reflux ratio 1, TOX could be completely separated from H2O by using [MMIM][DMP] as an entrainer, and the TOX product with a mass fraction greater than 99.5% was obtained. Compared with the traditional use of organic solvents as extractants to separate TOX, this method can avoid the challenges of volatility and toxicity, demonstrating its enormous potential in promoting sustainable development.
研究领域:
化学工程
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可持续发展
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过程工业
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
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IF 2.514
Xianming Zhang,Yufeng Hu,Weiting Ma,Jianguang Qi,Shuqin Mo
The salt effect on vapor–liquid phase equilibrium (VLE) has potential applications in industrial production of 1,3,5-trioxane. Optimizing reactive distillation process and developing new catalysts for industrial production of 1,3,5-trioxane require a reliable model for VLE of the reaction mixtures. Here an extended UNIFAC model combined a Debye–Hückel type is developed to describe the vapor–liquid and chemical equilibria of the multi-solvent salt-containing reactive mixtures associated with the 1,3,5-trioxane synthesis. New experimental data for the VLE of the quinary systems (formaldehyde + 1,3,5-trioxane + methanol + salt + water) and their ternary subsystems (1,3,5-trioxane + salt + water), (methanol + salt + water), and (formaldehyde + salt + water) are systematically measured at atmospheric pressure. The salts considered include LiCl, NaCl, KCl, NaBr, MgSO 4 , MgCl 2 , and Na 2 SO 4 . The model parameters, which are either obtained from the literature or determined from the VLE data of the above-mentioned ternary systems , are used to provide predictions for the quinary systems (formaldehyde + 1,3,5-trioxane + methanol + salt + water). The agreements between measured and predicted results are accurate. Furthermore, the model is used to uncover the effects of the salts considered on the VLE of these chemical reactive systems. The results show that MgSO 4 is a potential additive that can be used to improve the vapor–liquid phase separation during the reactive distillation process of 1,3,5-trioxane production.
研究领域:
化学工程
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物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2025
·
IF 5.2
Yusen Chen,Jie Li,Chunshan Li,Yinglong Wang,Jianguang Qi,Zhaoyou Zhu
Trioxane (Tox) is an important source of anhydrous formaldehyde, which is used in large quantities in industrial production resulting in large quantities of low concentration Tox wastewater. Liquid-liquid extraction is one of the commonly used methods for wastewater resource recycling. This study presents a method on the separation of Tox from wastewater using hydrophobic deep eutectic solvents (HDES). Firstly, Thy-BA and Thy-DA were screened from 12 HDES by extraction performance and solubility in water. The effects of different molar ratios of HDES, extraction temperature and addition of acetic acid as impurity on the extraction performance were further investigated. For the measured ternary phase data of HDES-Tox-water, the reliability of the data was verified using the Othmer-Tobias and Hand equations, and the data were fitted using the NRTL model. Quantum chemistry was used to calculate the interaction energy of HDES with Tox and to establish a correlation with the extraction efficiency. Hydrogen bonding was found to be the main force for separating Tox by electrostatic potential and interaction region indicator analysis. Molecular dynamics computing found that Thy was a substance that plays a major role in Thy-BA and Thy-DA. Ultimately, it was discovered that the chosen HDES has great recycling and thermal stability characteristics. This work explores three aspects of phase equilibrium, thermodynamics and microscopic separation mechanism revelation to support the systematic recovery of Tox wastewater.
研究领域:
环境科学
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化学工程
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量子化学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2020
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IF 2.627
Xiaofei Qin,Sen Lei,Xubin Zhang,Chen Cao,Feng Xin,Honglin Chen,Xiaoming Zhang,Yachen Yin,Guilian Wu
Polyoxymethylene dimethyl ethers (CH 3 -O-(CH 2 O) n -CH 3 , PODE n , n > 1) can be added to diesel to reduce air pollution caused by incomplete combustion. Driven by this need, a cost-effective and efficient synthetic route is presented and investigated by this work for the production of PODE n , which are formed from methylal and trioxane with low water content (< 10 %(mass)) over HZSM-5 catalyst in a batch slurry autoclave at the temperature from 353.15 K to 393.15 K. The reaction rate laws including the PODE n and byproducts of polyoxymethylene hemiformals (HF n ), polyoxymethylene glycols (MG), methanol (MeOH) and methyl formate (MF) are developed. The rate constants of propagation step ( k 6 ) and depolymerization step ( k − 6 ) are assumed independent on polymerization degree of PODE n . The rate of reaction is proportional to the content of the catalyst ( W cat ) for the catalytic reaction within the scope of the study. All kinetic parameters were estimated by combining genetic algorithm and least square regression to fit experimental data well. This work is valuable for process optimization and reactor design.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
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