JOURNAL OF MEMBRANE SCIENCE
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2017
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IF 6.035
Weihua Qing,Jiaqian Wu,Yajun Deng,Lele Liu,Weidong Zhang
A composite catalytically active membrane was prepared focusing on the reduction of membrane mass transfer resistance to achieve a better esterification-pervaporation coupling performance. The effect of membrane preparation conditions on the membrane morphology was first evaluated. Under an optimized membrane preparation conditions, a “sandwich-like” composite membrane with a highly inter-connected sponge-like catalytic layer on a polyvinyl alcohol / polyethersulfone bilayer was obtained. The porosity of the membrane was found to be as high as 81.6%. A simple resistance-in-series model was developed to analyze the mass transfer resistance distribution in a traditional inert membrane reactor (IMR), a catalytically active membrane reactor (CAMR) with dense catalytic layer and a catalytically active membrane reactor with porous catalytic layer, respectively. Results showed that the preparation of a highly porous catalytic layer decreased the resistance of catalytic layer from 48.5% to 20.6% of overall resistances, leading to an enhanced water removal ability for the composite membrane. Finally, reaction-separation coupling experiments in IMR, CAMR with porous catalytic layer and CAMR with dense catalytic layer showed that, with a faster reaction kinetics and water removal rate, CAMR with porous catalytic layer exhibited a best coupling performance.
研究领域:
化学工程
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材料科学
✓ 已验证
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
Xiaoda Wang,Wenkai Li,Shiwei Wang,Qinglian Wang,Ling Li,Hongxing Wang,Ting Qiu
Producing 2-ethyl-1-hexyl thioglycolate (ETE) via esterification reaction with thioglycolic acid (TGA) aqueous solution as raw material by reactive-separation coupling technology is a promising process intensification method. To choose suitable reactive-separation coupling strategy, the kinetic studies of the esterification of TGA with 2-ethyl-1-hexanol (EHL) were carried out in a batch system. The commercial ion exchange resin was employed as an eco-friendly catalyst. The effects of temperature, catalyst concentration and molar ratio were determined. It was interesting to observe that the equilibrium conversion of TGA increased with the increase of catalyst mass fraction due to the adsorption of product water onto resin surface. The activity-based pseudo-homogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW) models were used to fit the kinetics data of the resin-catalyzed reaction. The models of ER and LHHW performed better than the PH model. The kinetics of the TGA-self-catalyzed reaction was also determined. An activity-based homogeneous kinetics model could well describe this self-catalyzed reaction. These results would be meaningful to the selection and design of an appropriate reaction-separation strategy for the production of ETE, to realize the process intensification.
研究领域:
化学工程
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反应动力学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2025
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IF 4.3
Rongzhen Zhang,Ting Wang,Gan Li,Bo Xue,Dahuan Liu
Lithium (Li) stands as a pivotal resource in the 21st century and is mainly stored in the brines of salt lakes. However, the high Mg content and Mg/Li ratio in brines pose a challenge to the recovery of Li resources. This work introduces a reactive separation strategy for Mg/Li separation from brine characterized by a high Mg/Li ratio. By using gallic acid as an organic ligand to react with Mg in solution, a high-valued metal–organic framework of Mg-gallate can be obtained. At the same time, Li remains unaffected in the mixture of Mg/Li reaction residue. Through optimization of reaction parameters, an excellent Mg 2+ removal rate of 98 % and a Li + retention rate nearing 100 % can be achieved. Also, equally excellent separation performances can be achieved in scaled-up reactions and high Mg 2+ concentration brines. Experimental characterization confirms that the obtained Mg-gallate has the same topological structure as that of the simulated one. In addition, the obtained material has outstanding chemical and thermal stability and exhibits a CO 2 adsorption capacity of 81.6 cm 3 /g and CO 2 /CH 4 selectivity of 1807, which is expected to be used for carbon capture and natural gas purification. Therefore, this work not only successfully segregated Li + and Mg 2+ from salt lake brine but also yielded a valuable metal–organic framework, providing an efficient means of resource recovery and utilization.
研究领域:
化学工程
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材料科学
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环境科学
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无机化学
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分离技术
✓ 已验证
产品关联
DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
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2025
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IF 3.6
Xiong Neng,Chen Jia-Yu,Lei Pei-Qi,Fu Teng-Teng,Xu Rui,Xue Ya-Ping,Zheng Yu-Guo
Immobilized enzyme bioreactors provide a controlled reaction environment and integrated reaction-separation processes for biocatalysis. In this study, a biocatalytic process based on resin-immobilized nitrilase and a partial-mixed recirculating bed bioreactor was developed for the synthesis of 1-cyanocyclohexaneacetic acid, a gabapentin intermediate. The resin catalyst prepared by immobilizing the regioselective nitrilase AcN-S on the activated amino resin LX-1000EPHA achieved 99.12% immobilization yield, 73.40 U/g specific activity, and 95.42% activity recovery when loaded with 10 mg/g crude enzyme. The resin catalyst (100 g/L) could convert 1 M (148.2 g/L) substrate 1-cyanocyclohexaneacetonitrile to 1-cyanocyclohexaneacetic acid within 18 h, achieving a conversion of 95.40%. At a substrate concentration of 0.5 M, > 85% conversion could still be achieved after 15 batches. In a partial-mixed recirculating bed reactor, the resin catalyst (100 g/L) could completely convert 500 mM substrate within 10 h, and achieve > 90% conversion after 20 batches, with residual activity of 93.23%. Resin activation and cross-linking treatment after immobilization were found to improve operational stability, reduce protein leakage, and ensure high immobilization yield and activity recovery. The reactor provided a low-shear environment and recirculating flow, which together improve catalyst reusability and reduce product inhibition. The constructed reaction system provides a solution for the efficient conversion of slightly soluble/insoluble substrates and the integration of reaction and separation.
研究领域:
生物催化
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酶固定化
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化学反应工程
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反应器设计
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有机合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2022
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IF 9.224
Su Liu,Mingqiang Tang,Jun Pang,Jintao Hu,Weijie Chen,Jie Cheng,Zewei Liu,Haihong Zhao,Rong Tan
Water-soluble single-chain polymeric nanoparticles (SCPNs), which isolated catalytic sites within a hydrophobic interior, made water-incompatible organometallic catalysis highly efficient in water. However, it is still a great challenge to conveniently control their hydrophilicity, so as to combine reactivity and recovery of the catalytic SCPNs in aqueous systems. Herein, we have developed a series of catalytic SCPNs, which possessed CO2-switchable hydrophilic/hydrophobic behavior, to realize the gas-controlled reaction and separation for asymmetric sulfa-Michael addition (SMA) in water. A novel series of CO2-switchable random copolymers were thus synthesized by copolymerization of CO2-responsive amidine derivatives with hydrophobic chiral salen FeIII monomers via reversible addition-fragmentation chain transfer polymerization. Characterization suggested their CO2-controlled self-collapse behavior in water due to CO2-switched change in hydrophilicity/hydrophobicity of the amidine moiety. The resultant CO2-switchable SCPNs provided hydrophobic, catalytic compartments for asymmetric SMA in water upon CO2 addition, giving various chiral β-keto sulfides with almost quantitative yields (90–98%) and high enantioselectivities (93–99%). When CO2 is removed by N2 bubbling, they were collapsed and spontaneously precipitated from the aqueous system for steady reuse. The gas-controlled reaction-separation approach provides an energy-efficient way to combine reactivity and recovery of catalytic SCPNs in aqueous systems, which should be quite practical in large-scale industrial applications.
研究领域:
材料科学
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化学工程
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催化
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聚合物化学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2020
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IF 3.871
Hui Zhao,Jie Li,Lei Wang,Chunshan Li,Suojiang Zhang
A reaction/separation system composed of water-in-oil Pickering emulsion was constructed for the synthesis of methacrolein. The catalyst (diethanolamine acetate) aqueous solution was encapsulated in numerous emulsion droplets which were stabilized by dual stabilizer system and could be recycled and separated from product by filtration. The dual stabilizer system consisted of methyl–modified silica nanoparticles and monoglyceride. The effect of stabilizer system and dispersed phase on the Pickering emulsion properties were investigated, such as stability, rheological property, interfacial property and droplet size. The effect of emulsion properties on the catalytic performance was also studied. The strong stability, large interface area and proper particle layers of Pickering emulsion stabilized by dual stabilizer determined its excellent reactivity and catalyst efficiency. The Pickering emulsion showed good reaction stability in 8 cycles and could be used to produce methacrolein continuously for at least 72 h by filling in a column reactor.
研究领域:
化学工程
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催化
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材料科学
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化学
✓ 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）