Molecular Catalysis
·
2024
·
IF 3.9
Xiangsheng Zheng,Xiaohong Hao,Yan Wang,Siyu Gao,Dantong Wen,Jinchuan Wang
The development of novel biocatalysts is essential to promote the commercialization of biodiesel production by transesterification reaction. In this paper, Rhizopus oryzae lipase (ROL) was immobilized on an amino-functionalized zirconium-based metal organoskeleton by interfacial adsorption. The immobilization conditions were optimized and the enzymatic properties were tested, and the resulting novel biocatalysts exhibited higher stability and heat resistance. SEM, XRD and BET analyses were used to characterize the biocatalysts and carrier materials. The catalytic performance of ROL@UiO-66-NH 2 in the production of biodiesel by transesterification reaction was explored, and the production process was optimized by response surface method. The results showed that the conversion rate of FAEE reached 82.05% at molar ratio of ethanol/oil of 15.43:1, reaction temperature of 50.28°C, reaction time of 120.9 min, DES addition of 48.08 wt%, biocatalyst addition of 3 wt%, and ultrasonic power of 90 W. In addition, ROL@UiO-66-NH 2 demonstrated good recyclability, with the catalytic efficiency remaining at 71.87% after five cycles.
研究领域:
生物化学
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催化材料
·
可再生能源
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2026
·Vol. 65
·期 34
·18145-18158
·
IF 3.9
He Yiruo,Su Weiyi,Song Jianheng,Liu Qidong,Wang Na,Yu Xiong,Wang Honghai
The
combination of immobilized enzymes and microreactors offers
great advantages in green biomanufacturing. However, improving the
catalytic loading and reusability of immobilized enzymes remains a
challenge. This study developed a magnetically separable immobilized
enzyme system for continuous-flow biocatalysis. Candida antarctica lipase B (CALB) was covalently immobilized onto polydopamine-modified
Fe 3 O 4 nanoparticles to prepare a magnetic nanoimmobilized
enzyme (CALB@PNMNs). Compared to free enzymes, CALB@PNMNs exhibited
enhanced stability in organic solvents and storage stability. CALB@PNMNs
microreactor was constructed, with CALB@PNMNs immobilized on its inner
walls by an external magnetic field. This layer of magnetic particles
allows for the convenient recovery and reuse of the catalyst by removing
the applied magnetic field. After optimizing the immobilization process,
the actual CALB loading per unit area was 0.30 mg/cm 2 ,
and the adsorption yield reached 86.89%. The microreactor was applied
to the transesterification of n -butanol and ethyl
acetate, with the optimal conditions identified as an alcohol–ester
ratio of 1:3, a total flow rate of 10 μL/min, and a reaction
temperature of 60 ° C, yielding an n -butanol
conversion of 63.72%. After short-term continuous operation for 6
h, the microreactor retained 87.63% of the enzyme adsorption capacity
and CALB@PNMNs maintained a n -butanol conversion
above 50% after 8 reuse cycles. This work has established a stable
magnetically controlled immobilized enzyme microreactor (IMER) platform,
offering application potential for continuous-flow bioprocesses.
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Qi Fu,Qiming Yan,Xiang Jiang,Heqing Fu
Dynamic combinatorial chemistry (DCC) involves reversible reactions which can be controlled by thermodynamics method . Transesterification is one of the most widely explored DCC reactions. In this paper, transesterification was used to synthesize self-healing network. First, a three-arm star -shaped hydroxyl-terminated polyglycolide (HTPG) was fabricated though the ring-opening polymerization (ROP) of glycolide by using triethanolamine (TEA) as initiator and tetrabutyl titanate (TBT) as catalyst. Then the self-healing network i.e. isocyanate-based crosslinked star -shaped polyglycolide (ICSPG) was prepared through the crosslink between hexamethylene diisocyanate trimer (HDIT) and HTPG. In order to explore the mechanism of the self-healing, a polyurethane based on a tri-functional polyether polyol (PPPU)was synthesized. The structures of HTPG, ICSPG and PPPU were characterized by fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy ( 1 H NMR). The mechanical properties and self-healing properties were characterized by dynamic mechanical thermal analysis (DMTA) and polarizing optical microscopy (POM). And the welding test was used to further characterize the self-healing properties of ICSPG. It was found that mechanical recovery is about 70%. The POM results showed that ICSPG exhibited self-healing properties at high temperature.
研究领域:
材料科学
·
聚合物化学
·
自愈合材料
·
动态组合化学
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DOI
高影响因子
CHEMICAL ENGINEERING & TECHNOLOGY
·
2020
·Vol. 43
·期 12
·2359-2364
·
IF 1.543
Weihua Shen,Qing Ge,Kaijie Gu,Yingying Nie,Linyu Jiao,Zhiqing Zhu,Yunjin Fang
The transesterification of dimethyl carbonate with phenol to methyl phenyl carbonate (MPC) was investigated on novel catalysts such as titanium diisopropoxide bis(ethyl acetoacetate) and titanium dibutoxide bis(ethyl acetoacetate) in a closed batch reactor at 185–206 °C under high pressure. The produced methanol could be removed efficiently by reactive distillation in order to overcome the equilibrium. The prepared catalysts have higher resistance to water than titanium alkoxides. Phenol conversion as high as 86.4 % with an MPC selectivity of 99.4 % was achieved under optimal reaction conditions within 9 h. Most of the catalytic activity was retained after repeated use for ten times.
研究领域:
化学工程
·
催化化学
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DOI
高影响因子
INORGANICA CHIMICA ACTA
·
2018
·
IF 2.264
Ningmeng Hu,Zhaoni Kong,Liang He,Ping Ning,Junjie Gu,Rongrong Miao,Xiangqian Sun,Qingqing Guan,Peigao Duan
Different morphologies of ZrO 2 were produced by different templates: ZrO 2 (CaCO 3 ), ZrO 2 (C 12 H 25 SO 3 Na), ZrO 2 (C 12 H 25 SO 4 Na), ZrO 2 (CTAB), and solid superacids, such as ZrO 2 /SBA-15, SO 4 2- /ZrO 2 , SO 4 2- /ZrO 2 /SBA-15, and SBA-15-SO 3 H. The catalytic transesterification activities of these catalysts were tested. The more highly acidic catalysts and higher surface areas led to higher catalytic activity. In particular, the conversion yield of triglyceride reached 90.1% and was maintained for 90 min at 200 °C with 5.0 wt% SBA-15-SO 3 H, indicating this material to be one of most effective acid catalysts for the transesterification process. The mechanism indicated that the most important process was the abstraction of hydrogen from alcohols and α-substituted carboxylic glycerides. In the initial transesterification, the alcohol hydrogen atoms could be attracted onto the surface. Then, the nucleophilic attack of the alcohol led to the α-substituted carboxylic glyceride. Finally, monoglycerides, diglycerides or glycerine were released from the surface by proton (H + ) replacement.
研究领域:
化学工程
·
催化
·
材料科学
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DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Ye Tian,Feng Wang,Long-Fei Xie,Yu-Ping Xu,Pei-Gao Duan
Lewis acid-catalyzed in situ transesterification/esterification of tigernut ( Cyperus esculentus ) was conducted in sub/supercritical ethanol. An L 16 (4 4 ) orthogonal design with four factors at four levels was employed to investigate the influence of the process variables on the product distribution and the composition of crude biodiesel (CBD). The four factors were temperature (230–290 °C), time (0–90 min), ethanol to feedstock ratio (E/F) (4/3–16/3 mL/g), and catalyst type (ZnCl 2 , FeCl 3 , SnCl 2 , and H 3 PO 4 ). The results showed that the catalyst type and E/F ratio were the two most influential variables affecting the yield and composition of the CBD. Of the Lewis acids tested, SnCl 2 showed the highest performance in terms of the CBD yield and its esters content. Increasing the E/F ratio essentially led to a higher CBD yield and higher ester content of the CBD. A higher temperature and longer reaction time resulted in an obvious increase in the gas yield but had no significant effect on the yield and quality of the CBD. The produced CBDs had extremely low N and S contents (0.2–0.6 wt% and less than 0.1 wt%, respectively) and were abundant in fatty acid esters (∼70%), mainly ethyl oleate and ethyl palmitate, making it more suitable for subsequent biofuel production.
研究领域:
生物能源
·
化学工程
·
植物学
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DOI
高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Bin Jiang,Yumei Wang,Luhong Zhang,Yongli Sun,Huawei Yang,Baoyu Wang,Na Yang
In this work, the preparation and catalytic application of novel superhydrophobic porous poly(ionic liquid) (PIL) solid base catalyst have been reported. The PIL was synthesized by radical polymerization with subsequent anion exchange providing alkali catalysis. The as-prepared catalyst possesses favorable wetting properties in the reaction of biodiesel production. Various characterization techniques were utilized to characterize the as-prepared PIL catalyst, including nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), nitrogen adsorption–desorption isotherms, thermogravimetric analyses (TG), and static water contact angle measurement. In addition, the catalytic performance of the PIL catalyst was evaluated by the transesterification of soybean oil with methanol to produce biodiesel. The effects of various reaction parameters on the oil conversion ratio were systemically investigated by three-level and three-factorial central composite design of response surface methodology to obtain the optimum reaction conditions. The catalyst was reused for five cycles without a significant decrease in activity, and the activity could be recovered by anion exchange. Moreover, the properties of the prepared biodiesel were within the standards of EN14214 and ASTM D6751.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Xiaoda Wang,Qinglian Wang,Changshen Ye,Xiaolian Dong,Ting Qiu
This paper aims to present the feasibility of conducting the transesterification of propylene glycol ether (PM) with methyl acetate (MeAc) in a reactive distillation (RD) column to improve the reaction conversion. The essential thermodynamic and reaction kinetic data of the reaction system were measured for the feasibility study. There is only one azeotrope, MeAc–MeOH, in the reaction system, and the NRTL model could describe well the thermodynamic behavior of this system. The transesterification of PM with MeAc is an endothermic reaction with activation energy E = 55.704 kJ·mol–1. The feasibility was analyzed by residue curve maps (RCM), showing that full conversion of PM could be realized by RD with a mole ratio of MeAc–PM larger than 2.882. The intensification effect was experimentally verified in a batch RD column. Finally, some important parameters are given through the conceptual design to develop a continuous RD column for the transesterification of PM with MeAc.
研究领域:
化学工程
·
反应动力学
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DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2017
·
IF 5.589
Heng Zhang,Hu Li,Hu Pan,Anping Wang,Chunbao (Charles) Xu,Song Yang
Biodiesel, typically derived from non-edible vegetable oils via heterogeneous catalysts, is being deemed as a promising alternative to fossil fuels. Herein, basic polymeric ionic liquids (PILs) immobilized on magnetic mesoporous carrier (Fe 3 O 4 @SiO 2 @SBA-15), FnmS-PILs, were synthesized through the facile radical polymerization and anion exchange methods, and were further utilized to catalyze transesterification of non-food feedstock-crude Firmiana platanifolia L.f. oil (CFPO, acid value of 1.20 mg KOH/g) into biodiesel directly. The characterization results demonstrated that FnmS-PILs with uniform core–shell structure, moderate surface area (153.2 m 2 /g), pore size (4.1 nm), strong magnetism (13.6 emu/g) and relative higher basicity (2.3 mmol/g) exhibited high catalytic performance, giving a high biodiesel yield of 92.8 wt% under mild reaction conditions (9/1 methanol/oil molar ratio, 4 wt% catalyst dosage at 85 °C for 5 h). Furthermore, kinetic study was also investigated accordingly, wherein the activation energy was found to be 51.6 kJ/mol along with a determined pseudo first order model. More importantly, the catalyst could be recovered easily by means of magnetic force and remained sufficiently active in five consecutive cycles.
研究领域:
能源化学
·
材料科学
·
催化化学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Tian Ma,Zhensheng Shen,Huan Li,An Li,Qian Feng,Yingqiang Sun,Shuguang Deng
Brønsted acid ionic liquids (BAILs) are effective to biodiesel production of in situ transesterification of wet algae due to their dual role as both solvents of cellulose and catalysts of transesterification. The cellulose solubilities of BAILs are depending on H-bonding of BAILs-cellulose in varied solvent conditions, which subsequently affect the biodiesel productions. For this reason, the effects of H-bonding between BAILs including [Bmim][H2PO4], [Bmim]2[HPO4], [Bmim][HSO4], and cellulose under different methanol and water conditions on cellulose extractions are experimentally and theoretically investigated. The cellulose extractions in BAILs are decreasing as [Bmim][H2PO4] > [Bmim]2[HPO4] > [Bmim][HSO4], contrary to the variation of their thermal stabilities and crystallinities caused by varied H-bonding of BAILs-cellulose. Increasing methanol is positive to cellulose extractions in [Bmim][HSO4], while negative to those in [Bmim][H2PO4] and [Bmim]2[HPO4], due to the solvent effect of methanol confirmed by cyclic voltammetry (CV) measurements. The effect of water on H-bonding of BAILs-cellobiose is contrary to the effect of methanol. It is confirmed via the bonding interaction of BAILs-cellobiose through the density functional theory (DFT) computational method. However, the biodiesel yields are varied differently due to the competition of H-bonding of BAILs-cellobiose and deprotonation of BAILs under different methanol and water conditions. This study might pave the way to neutralize the negative effect of water on in situ transesterification via enhancing the cellulose extractions of BAILs.
研究领域:
生物化学
·
能源科学
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DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Zheng Cui,Yu Chen,Dan Meng,Shuheng Wang,Tongbing Sun,Jun Sun,Hongfei Li,Xiaoyu Gu,Sheng Zhang
The reactive type flame retardants have been applied in rigid polyurethane foams (RPUF) owing to their excellent durability and minimal negative effect on the physical properties, however, their flame retardant efficiency cannot meet the requirements in many practical application scenarios. In this work, two reactive-type flame retardants with several hydroxyl groups were synthesized by a solvent-free transesterification between erythritol and dimethyl methyl phosphonate (DMMP), and they were then introduced into RPUF by reacting with isocyanate respectively. The flammability of the as-prepared RPUF samples was evaluated by limiting oxygen index (LOI) and cone calorimeter tests. With the presence of 10 phr as prepared flame retardant, the LOI value of RPUF was improved from 18.3% to 29.8%, and the peak heat release rate (pHRR) and total heat release (THR) were reduced by 31.4% and 47.8% respectively in contrast to that of control RPUF. Furthermore, the compressive strength and thermal conductivity of RPUF containing reactive flame retardants were similar to those of control RPUF. This study provides an innovative method for the clean production of commercial RPUF with fire safety by using a modified phosphorus ester.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 12
·2636-2649
·
IF 5.2
Chunrui Han,Rui Wang,Chang Shu,Xingang Li,Hong Li,Xin Gao
Reactive distillation is an effective technique for separating azeotropic systems, especially ethylene glycol (EG) and 1,2-butanediol (1,2-BDO), and mastering the reaction network and competitive kinetics is vital for the successful design of a reactive distillation process. Herein, a reactive distillation process using dimethyl carbonate (DMC) as a reactant to recover EG and the high-value-added byproduct 1,2-BC was developed. The reaction systems EG–DMC, 1,2-BDO–DMC, and EC–1,2-BDO were investigated through experiments in the presence of the catalyst KIP321p and the kinetic parameters were subjected to regression analysis; a unified power-law model describes the kinetics of transesterification reactions very well. The heat absorption values of the EG–DMC and 1,2-BDO–DMC systems are 7.18 kJ mol−1 and 9.56 kJ mol−1, respectively; as EG has fewer ethyl groups in its molecular structure than 1,2-BDO, this lower spatial resistance resulted in a faster reaction rate under the same conditions. The enthalpy change of the EC–1,2-BDO system is 1.53 kJ mol−1, and the small positive value indicates that BC is more thermodynamically stable than EC. The transesterification of EG/1,2-BDO with DMC was also investigated experimentally, and the experimental data were compared with the predicted results from the reaction kinetic models obtained in this work. These kinetic parameters can be employed to design reactive distillation methods for the implementation of transesterification reactions of mixed glycols with DMC.
研究领域:
化学工程
·
反应动力学
·
过程设计
·
热力学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）