CHEMICAL ENGINEERING RESEARCH & DESIGN
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2020
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IF 3.35
Shaojian Hu,Jianhua Zhu,Bencheng Wu,Rui Ma,Xiaohui Li
As an eco-friendly lubricant base oil, ester base oil is receiving increasing attention. However, studies on synthetic reaction kinetics of high viscosity complex ester have been rarely reported. In this work, based on the principle of equal reactivity of all functional groups and simplified kinetics models, synthetic reaction kinetics for high viscosity complex ester was investigated in two steps. As for the esterification of trimethylolpropane with glutaric acid, the activation energies of the first and second stage were 55.3 and 73.5 kJ/mol, respectively. As for the esterification of the first step products with 2-ethylhexanoic acid, the activation energies of the first and second stage were 60.6 and 98.2 kJ/mol, respectively. As for the esterification of the first step products with n -heptanoic acid, its activation energy was 68.9 kJ/mol. A mutation phenomenon on reaction order from zero to second order was discovered, which could be explained by the strong adsorption of organic acid on catalyst surface. The conversion rate of carboxyl of synthetic reaction for mixed acid ester was estimated by simulation, and average relative error was less than 3.0%. The synthetic process of high viscosity complex ester was considered to consist of a series of parallel–consecutive reactions with addition–elimination mechanism.
研究领域:
化学工程
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环境科学
✓ 已验证
DOI
高影响因子
FUEL
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2020
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IF 5.578
Shaojian Hu,Jianhua Zhu,Bencheng Wu,Rui Ma,Yuechun Chang,Xiaohui Li,Yuqing Wei,Liujie Yu
High viscosity ester base oil, as an eco-friendly lubricant base oil with high performance, can significantly reduce the friction, wear, and energy consumption of large machinery. However, there is less research on the preparation of heterogeneous catalysts for synthesis of high viscosity ester oil. In this work, Sn/Zr mixed oxide catalysts were prepared for the green synthesis of ester base oil with high viscosity. This approach gets rid of additional template, surfactant, organic solvent, sulfur, nitrogen, phosphorus, and halogen, thereby avoiding the potential environmental pollution. A superior powdered catalyst MO-Sn 8 Zr-9.0-160-18 was developed with optimized Sn/Zr molar ratio, pH, hydrothermal temperature, and hydrothermal time of 8:1, 9.0, 160 °C, and 18 h, respectively. Results of catalyst characterization indicated that the developed catalysts were mesoporous materials with hydrophobic properties, allowing for free diffusion of macromolecules, adsorption of reactants, and desorption of water. Additionally, the specific surface area, pore volume, pore diameter, and surface hydrophobicity of catalyst were enhanced by doping Zr, so the catalysts with higher [Sn/Zr] ICP /[Sn/Zr] XPS exhibited better catalytic activity. Preformed catalyst was prepared by simple mechanical mixing method to achieve better catalyst separation. The specific surface area, acid amount, and acid strength of catalyst were indeed improved significantly after catalyst molding. By programmed heating, the preformed catalyst achieved a maximum carboxyl conversion of 97.2%. Moreover, spent catalyst could be reactivated via solvent washing, drying, calcination, and hydrogen reduction, exhibiting good reusability.
研究领域:
化学工程
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材料科学
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催化
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）