MICROPOROUS AND MESOPOROUS MATERIALS
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2019
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IF 4.182
Meng Chen,Haoming Wu,Zhentao Li,Keke Wu,Yanpeng Jiao,Changren Zhou
In this study, the effect of the hydrophobicity of reduced graphene oxide (rGO) on the activity of candida rugose lipase (CRL) was investigated firstly. It was observed that the increasing hydrophobicity of rGO surface could increase CRL activity, while excessive hydrophobicity acted to depress its activity. Then, reduced graphene oxide beads (rGOB) had been fabricated through a facile self-assembly method. The morphology, specific surface area, and mechanical properties of the rGOB were investigated by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and static mechanics properties test, respectively. The results revealed that the rGOB showed a three-dimensional micro-nano porous structure and surface hydrophobicity, which played an important role in improving their adsorption properties and catalytic activity of CRL. CRL was directly immobilized onto the beads by physical adsorption with the maximum adsorption capacity of 117.67 mg/g under the optimized condition. The immobilized lipase (rGOB@CRL) exhibited good temperature, thermal, and reuse stability in comparison to free CRL. In the glycerolysis reaction of olive oil, the conversion rate of triglycerides (TG) in free enzyme reaction system was 67.83%, while the conversion rate of TG in rGOB 4 @CRL reaction system could reach 74.87%, which was higher than that of the former. Moreover, rGOB@CRL was further used to adsorb emulsified oil due to the excellent oil-absorbing ability of rGOB, and then producing monoglyceride (MG) and diglyceride (DG) in situ by catalyzing the glycerolysis reaction. When the oil concentration was 4 mg/mL, the conversion rate of triglyceride (TG) could reach 89.70%.
研究领域:
生物化学
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材料科学
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催化工程
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2022
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IF 9.224
Zishuai Wang,Yu Jin,Yaoqiang Wang,Zequn Tang,Shaojie Wang,Gang Xiao,Haijia Su
Due to the antibiodegradable properties, numerous plastics have been accumulated in the ecosystem and aggravate ecological pollution. Poly (ethylene terephthalate) (PET) is among the most used plastics. Glycolysis of PET is a useful approach to solve the waste PET pollution and obtain bis(2-hydroxyethyl) terephthalate (BHET). In this paper, waste PET was efficiently depolymerized through glycolysis catalyzed by cyanamide. In particular, compared with the previously reported catalyst, cyanamide is more readily available and can be used directly in catalysis without a complex preparation process. Under optimal conditions, PET was completely depolymerized with up to nearly 100% BHET yield. Even at a temperature as low as 150 °C, a good BHET yield can be obtained. The application potential of this glycolysis procedure was demonstrated by its excellent performance in the glycolysis of various real PET wastes like transparent and opaque PET samples and polyester foam and by the high quality of the obtained BHET products. The mechanism was studied by 1H NMR analysis, and DFT calculations showed that the higher activity of cyanamide than its trimer, melamine, is due to the stronger hydrogen bonds formed between cyanamide and PET or ethylene glycol.
研究领域:
环境科学
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材料化学
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催化反应
✓ 已验证
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2024
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IF 3.7
Yufan Pan,Zixin Qi,Shengping You,Yingtong Gao,Yu Zhou,Nan Jiang,Mengfan Wang,Rongxin Su,Wei Qi
The current society has an increasing demand for poly(ethylene terephthalate) (PET). Due to its high crystallinity and hydrophobicity , PET could be hardly degraded for high-value utilization. Besides, the escalating accumulation of waste PET has also led to significant environmental issues. In this study, a convenient and cost-efficient industrial strategy featuring the integration of glycolysis and enzymatic catalysis has been developed for the selective conversion of PET into terephthalic acid (TPA), which provides a method for colored waste PET degradation. Without the need for complex purifying processes, the products of glycolysis directly initiate the next round of the enzymatic system. Through this system, a total yield of 72.47 % of bis-2-(hydroxyethyl) terephthalate(BHET) and mono-(2-hydroxyethyl) terephthalate(MHET) was produced by glycolysis loading sodium bicarbonate (NaHCO 3 ) catalyst, and the enzyme system almost completely converted a substrate concentration of 100 g/L within 48 h, producing 50.36 g/L TPA. Besides, the product problem of pink color in the air after acidification caused by cobalt ions was solved by resin adsorption. In general, the glycolysis and enzymatic catalysis system in this study has prospects for commercial application due to its value for colored waste PET recycling, which reduces the environmental burden caused by waste PET.
研究领域:
环境科学
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生物化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
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2018
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IF 5.651
Shangde Sun,Gaoshang Wang,Ping Wang
Monoricinolein (MRO) and diricinolein (DRO) were renewable and biodegradable lubricants . In this paper, MRO and DRO were prepared by the novel cleaner enzymatic glycerolysis of castor oil (CO) in solvent-free system. Three commercial immobilized lipases (Novozym 435, Lipozyme RM IM and Lipozyme TL IM) were screened and compared, and Novozym 435 showed the best catalysis performance among the tested lipases. Effects of reaction variables (reaction pressure, reaction time, temperature, enzyme load, substrate ratio and water content) on the enzymatic glycerolysis of CO were investigated. High conversion of CO (92.48 ± 1.02%) and the maximum bio lubricants yields (54.47 ± 0.58% MRO and 38.01 ± 0.50% DRO) were achieved under the following conditions: enzyme load 5% (w/w, based on the total mass), CO/glycerol ratio at 1:6, 90 °C, and 3 h. The activation energies (Ea) for CO conversion and the formation of MRO and DRO were calculated as 33.75 kJ/mol, 22.26 kJ/mol and 24.37 kJ/mol, respectively, and the process showed high selectivity toward the formation of MRO. Reaction kinetic agreed with the ping-pong Bi-Bi mechanism with the inhibition of CO, and the kinetic values ( V max , K m ′ and K IA ) were 0.0946 mol/(L·min), 1.6704 mol/L, and 0.89 mol/L, respectively.
研究领域:
生物化学
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可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Oleo Science
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2022
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IF 1.628
Lihong He,Jiawei Zheng,Siting Feng,Li Xu,Nanjing Zhong
In this study, lipase A from Candida antarctica (CALA) was immobilized onto the macroporous resin NKA-9. Immobilization conditions (pH, time and CALA concentration) were studied, enzymatic activity and immobilization efficiency (IE) up to 968.89 U/g and 53.19% were respectively obtained under optimal conditions (immobilization pH 5.0, time 5 h and CALA concentration at 30 mg/mL). Then, the NKA-9 supported CALA (CALA@NKA-9) samples were used to catalyze glycerolysis in solvent-free system. With 0.25 g of the present CALA@NKA-9 (soybean oil 3.52 g and glycerol 0.184 g) and after 12 h reaction at 50 °C, diacylglycerols (DAG) content up to 64.37% and triacylglycerols (TAG) conversion at 83.33% were obtained. The relationship between temperature and TAG conversion was LnV 0 = 13.9310-6.4212/T for CALA@NKA-9. Meanwhile, the activation energy (Ea) of CALA@NKA-9 was calculated to be 53.39 kJ/mol. In addition, reusability in the glycerolysis reaction was also evaluated, and 57.82% of the initial glycerolysis activity was retained after 9 consecutive applications. Furthermore, the CALA@NKA-9 was also used to catalyze the esterification (esterification of fatty acids with glycerol), however, the present CALA@NKA-9 cannot initiate the esterification. Therefore, the present CALA@NKA-9 is shown to be potential for DAG production through glycerolysis reaction.
研究领域:
生物技术
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酶工程
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化学工程
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）