Journal of the Taiwan Institute of Chemical Engineers
·
2018
·
IF 3.849
Yafei Guo,Chang Tan,Peng Wang,Jian Sun,Junjie Yan,Weiling Li,Chuanwen Zhao,Ping Lu
Coal and biomass fly ash was impregnated with tetraethylenepentamine (TEPA) to prepare solid CO 2 sorbent. Experimental CO 2 adsorption capacities of the sorbent in fixed-bed column were fitted to several kinetic equations. The modified Avrami fractional kinetic model could accurately predict the CO 2 adsorption kinetic behaviors of the sorbent under different conditions. CO 2 adsorption rate increases with the increase in temperature, initial CO 2 concentration and gas flow rate, as a result of the decreased CO 2 diffusion resistance. A mathematical model was proposed and demonstrated to well predict the CO 2 adsorption breakthrough curves in the fixed-bed column. Effects of temperature, initial CO 2 concentration and gas flow rate on the mass transfer kinetic behaviors of the desired sorbent were investigated. The positive effect of these factors on promoting the overall mass transfer coefficient and the internal mass transfer coefficient is not significant. The external mass transfer coefficient will be remarkably reinforced with the increase in these operating parameters, due to the change in viscosity and density of the gas phase and the reduced external mass transfer resistance. Internal mass transfer process is determined as the rate-limiting step for CO 2 adsorption. The results will lay the groundwork for future scale-up application of the sorbent in post-combustion CO 2 capture.
研究领域:
环境科学
·
化学工程
·
能源工程
·
大气污染控制
·
碳捕集与封存
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DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2016
·
IF 2.189
Chen Chen,Xue-yan Zhu,Qiao-ling Gao,Fei Fang,Li-wei Wang,Xiao-jun Huang
Functional polyphosphazene cyclomatrix microspheres (PMS) containing glucose and dodecyl moieties were utilized for physical adsorption of lipase. In this regard, Candia Rugosa lipase was immobilized onto the above microspheres through physical adsorption, which exhibited catalytic hydrolysis of glycerol triacetate as the model reaction. As observed under transmission electron microscope (TEM) and scanning electron microscope (SEM), the size of all the microspheres ranged from 400 nm to 1 μm with a mean diameter of 680 nm. Zeta potential analysis demonstrated that the microspheres were negatively charged. The influences of buffer pH, substrate concentration and temperature were also studied along with reusability. The obtained results demonstrated that the immobilized lipase on deprotected glycosylated PMS (D-GPMS) showed the best performance and possessed the highest enzymatic loading activity around 1.0884 mmol L −1 min −1 g −1 , and retained nearly 50% of its initial activity even after 10 cycles of application. Moreover, the lipase-microsphere complex displayed high pH adaptability from 7 to 9 and temperature stability above 40 °C. From the viewpoint of biocompatible PMS support, the GPMS-lipase conjugate have potential applications in field such as food, medicine and environment.
研究领域:
生物材料
·
酶工程
·
纳米医学
·
分子生物学
·
环境生物技术
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DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 3.371
Liya Zhou,Xucong Luo,Jiaojiao Li,Li Ma,Ying He,Yanjun Jiang,Luyan Yin,Liya Gao
The meso-molding three-dimensionally ordered macroporous alumina (3DOM/m-Al) was synthesized via a dual-templating approach (polystyrene (PS) colloidal crystals as hard template and triblock copolymer P123 as soft template) with hydrous aluminum isopropoxide as precursor. The obtained 3DOM/m-Al was characterized, and the results showed that 3DOM/m-Al had ordered macropores ( ca. 300 nm in diameter) with wormhole-like mesopores, relatively high surface areas (338.1 m 2 /g), large pore volumes (0.4030 cm 3 /g) and tunable pore sizes. The amino functionalized 3DOM/m-Al by aminopropyltriethoxysilane (APTES) was activated by glutaraldehyde and used as support for the immobilization of three different commercial enzymes (Lipase B from Candida antarctica (CALB), penicillin G acylase (PGA) and nitrile hydratase (NHase)). The result of confocal laser scanning microscopy (CLSM) indicated that the enzyme was successfully immobilized onto glutaraldehyde-activated NH 2 -3DOM/m-Al. The effect of the immobilized conditions on the specific activity of enzymes was investigated. Compared with free enzymes, the immobilized enzymes exhibited enhanced thermal stability. The three immobilized enzymes (CALB@NH 2 -3DOM/m-Al, PGA@NH 2 -3DOM/m-Al and NHase@NH 2 -3DOM/m-Al) were applied for the synthesis of palmitic acid, 6-aminopenicillanic acid (6-APA) and acrylamide, respectively. After recycling 10 times, CALB@NH 2 -3DOM/m-Al, PGA@NH 2 -3DOM/m-Al and NHase@NH 2 -3DOM/m-Al retained approximately 76%, 87% and 52% of their initial activities, respectively, indicating that the immobilized enzymes had good operational stability. Therefore, this work documented herein provides a versatile platform for enzyme immobilization with several inherent advantages.
研究领域:
材料科学
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生物催化
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纳米材料
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酶工程
·
多孔材料
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DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Bingyang Li,Meiqian Chen
Massive spent ion exchange resins (SIERs) containing radionuclides are produced in nuclear power plants , which need to be treated reasonably. The migration mechanism of nuclides in SIER in both pyrolysis and gasification was evaluated from the chemical equilibrium analysis based on the Gibbs free energy minimization. The maximum volatility degrees of Co, Sr and Cs at 400–600 °C and 0.1 MPa were 0.01%, 0% and 0.1% in the pyrolysis . The maximum volatility degrees of Co, Sr and Cs were 0.015%, 0% and 100% at 600–1300 °C and 0.1 MPa in the gasification, and the steam concentration should be set mainly how to limit the volatilization of radionuclides . To reduce the volatility of nuclides as much as possible, the temperatures should be kept below 600 °C and 870 °C in the pyrolysis and gasification, respectively. The volatilization of Cs was greatly inhibited with lifting the pressure from 0.1 MPa to 1.5 MPa, which decreased from 0.103% to 0.007% in the pyrolysis (600 °C) and from 4.80% to 0.30% in the gasification (715 °C), respectively. Based on preventing the nuclides leakage, the negative pressure in the gasification should be controlled between 0.097 and 0.099 MPa. The volatilization of radionuclides was effectively weakened by adding a fixative, Zr(HPO 4 ) 2 ·H 2 O, since it could be helpful to reduce the gaseous cesium-based products in the pyrolysis and gasification. The volatility degree of Cs was close to 0 if Zr/Cs was great than or equal to 0.5. This study could provide basic data for the pyrolysis and gasification treatment of SIER.
研究领域:
核化学
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环境工程
·
放射化学
·
废物处理
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热力学分析
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Huaxia Zhang,Tianshu Liu,Yawei Zhu,Li Hong,Tianfeng Li,Xiqing Wang,Yujie Fu
In the present study, modified polyporous magnetic cellulose beads (PMCBs) were synthesized by several organic amines (EDA, DETA, TETA and AST) grafting PMCBs and then utilized as a new kind of support to immobilize Candida antarctica lipase B (CALB) for biodiesel production. The immobilized lipase catalysts based on PMCBs were characterized by Fourier transform infrared and scanning electron microscopy. The results showed that PMCBs-DETA was a more suitable immobilization support and the catalytic activity of immobilized lipases could reach 1.0 U/mg. Then the synthesized catalyst of CALB-PMCBs-DETA was used to produce biodiesel from Yellow horn seed oil via transesterification reaction. A high biodiesel yield (92.3%) was obtained under the optimal reaction conditions and the main compositions of the prepared biodiesel were tested by GC-MS. Moreover, the catalyst of CALB-PMCBs-DETA could be removed easily by a magnet and recycled at least 5 times. As a new kind of support, the modified PMCBs could be a promising alternative for the carriers of immobilizing enzymes used for the green and efficient production of biodiesel.
研究领域:
生物催化
·
可再生能源
·
酶工程
·
绿色化学
·
生物质转化
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DOI
高影响因子
CHIRALITY
·
2012
·Vol. 24
·期 5
·391-399
·
IF 2.35
Hui Yu,Chenghua Yin,Cunyu Jia,Yu Jin,Yanxiong Ke,Xinmiao Liang
Two “click” binaphthyl chiral stationary phases were synthesized and evaluated by liquid chromatography. Their structures incorporate S-(−)-1,1'-binaphthyl moiety as the chiral selector and 1,2,3-triazole ring as the spacer. These chiral stationary phases (CSPs) allowed the efficient resolution for a wide range of racemic BINOL derivatives, particularly for nonpolar diether derivatives and 3-phenyl indolin-2-one analogs. The chromatographic data showed that the π–π interaction was crucial for enantiorecognition of these CSPs. Loss of enantioselectivity observed on CSP3 , which are lacking the triazole ring linkage, indicated that the triazole ring linkage took part in the enantioseparation process, although it was remote from the chiral selector of the CSP. The substitution of the phenyl group at 6 and 6' positions can significantly improve the separation ability of the CSP. The chiral recognition mechanism was also investigated by tracking the elution orders and studying the thermodynamic parameters. Chirality 24:391–399, 2012 . Copyright © 2012 Wiley Periodicals, Inc.
研究领域:
分析化学
·
药物化学
·
色谱学
·
手性分离
·
有机合成
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DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2014
·
IF 2.745
Teng Zhang,Xiao-Ling Xu,Yi-Ning Jin,Jian Wu,Zhi-Kang Xu
Carbon nanotubes are widely applied in electronics, which offers great potential for enhancing the activity of redox enzyme. In this work, polyimide (PI) was blended with multiwalled carbon nanotubes (MWCNTs) and then electrospun into nanofibers for the immobilization of horseradish peroxidase (HRP), a redox enzyme. SEM and TEM were used to characterize the surface morphology of the PI/MWCNTs nanofibers and to analyze the protruding parts induced by the blending of MWCNT. The results indicate that, compared to the virgin PI nanofibers, the blending of MWCNTs increases the retention activity of immobilized HRP from 2.38% to 12.50%. Circular dichroism and UV–vis molecular absorption spectrometry were used to explore the interactions between HRP and MWCNTs . It seems that MWCNTs increase the enzyme activity by the facilitation of electron transfer among the catalytic intermediates “HRP I”, “HRP II” and MWCNTs.
研究领域:
生物化学
·
纳米生物技术
·
酶工程
·
生物材料
·
分析化学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Hao Dong,Huan Tang,Xinxing Shi,Wenlan Yang,Wenjing Chen,Han Li,Yu Zhao,Zhengyong Zhang,Ming Hua
Efficient elimination of fluoride from wastewater is an urgent need for ensuring water safety. In the present study, a stable and reusable nanocomposite (NCO@PAE) was synthesized by impregnating nanosized cerium oxides (NCO) inside a porous polystyrene anion exchanger (PAE) host for efficient fluoride removal from wastewater. The newly fabricated NCO@PAE exhibited excellent resistance to acid and alkali environment, allowing it to be utilized in a wide pH range (2–12). Fluoride uptake onto NCO@PAE was a pH-dependent process, which could reach the maximum capacity at pH 3.0. Compared with its host PAE , NCO@PAE showed conspicuous adsorption affinity towards fluoride in the coexistence of other competing anions at high concentrations. Adsorption kinetics confirmed its high efficiency for achieving equilibrium within 120 min. Fixed-bed adsorption runs demonstrated that the effective processing capacity of NCO@PAE for synthetic fluoride-containing wastewater (initial fluoride 2.5 mg/L) was about ~330 BV (bed volume), while only 22 BV for the host PAE . The exhausted NCO@PAE could be effectively revived by a simple in-situ desorption method for long-term cycle operation without conspicuous capacity loss. All the results indicated that NCO@PAE is a reliable and promising adsorbent for water defluoridation.
研究领域:
环境科学
·
水处理技术
·
材料科学
·
吸附化学
·
环境功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jing Zhou,Dapeng Li,Shutong Chen,Yao Xu,Xue Geng,Chaoran Guo,Yong Huang
The immobilization of sedimentary phosphorus (P) by capping sediments with amended calcium peroxide material (ACPM) and CaO 2 was investigated, the sediments and overlying water from a black-odor river. Under the capping with ACPM and CaO 2 , the pH and dissolved oxygen (DO) in the overlying water were higher than in the control. This contributed to the more loss of external P under the ACPM (the phosphate sorption was fitted well by the Langmuir equation, the maximum P sorption capacity up to 29.28 mg P g −1 ). Additionally, ACPM improves the decrease of the reduction materials (e.g., NH 4 + -N, Fe 2+ ) in the pore water compared to that associated with CaO 2 , resulting in a less obvious dissolved inorganic P (DIP) in the pore water, but the accumulation of DIP in the pore water with CaO 2 suggested an explosive release once the micro-environment conditions encounters adverse conditions. The sharp reduction of Fe/Al-P and Res-P contributes to the increase of DIP in the pore water, with a release of up to 390.60 mg P kg −1 DW (dry weight), whereas the value is only 62.55 mg P kg −1 DW when capped with ACPM. Correspondingly, the percentage of the bioavailable P to Tot-P decreases rapidly from 17.27% (control, 0–2 cm) to 7.21% (ACPM, 0–2 cm) and 10.57% (CaO 2 , 0–2 cm), indicating the obvious P immobilization. The implication is that the application of CaO 2 is not suitable for direct use, while the combination with other materials (e.g., WPS) is a better choice.
研究领域:
环境科学
·
水体修复
·
环境化学
·
污染控制
·
沉积物管理
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Xia Hua,Zhihong Gao,Qianqian Wang,Wenming Hao,Xiaoliang Yan,Ruifeng Li
The accumulation of heavy metal on catalysts during petrochemical process produces deactivated catalysts that cannot be directly disposed in nature, due to the high toxicity. The elimination of the detrimental effect of heavy metal ions can be achieved by immobilizing these ions in the form of spinel structure, yet this requires high-temperature calcination . Herein, Ni 2+ ions are stabilized and confined within the surface NiAl 2 O 4 on Al 2 O 3 through hydrothermal process and subsequent low-temperature thermal treatment. The formation of nickel aluminum layered double hydroxide (NiAl-LDH) as intermediate favors the generation of surface aluminate spinel at the temperature as low as 450 °C. The formation of surface spinel is beneficial to restricting the mobility of Ni 2+ ions. The growth and immobilization mechanisms of the surface spinel structure were proposed, which contributes to alternative and promising route for the low-temperature approach of the retention of the heavy metal ions mobility.
研究领域:
环境催化
·
材料化学
·
工业化学
·
固体化学
·
污染控制
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2011
·Vol. 212
·期 21
·2378-2388
·
IF 2.437
Bin Yuan,Xiaohui He,Yiwang Chen,Kaiti Wang
Covalently immobilized silica-supported acetylacetonate dichloride palladium(II) precatalyst is prepared by the reaction of silica particles grafted acetylacetonate ligand further exchange with [Et 4 N] 2 PdCl 4 . The silica-supported catalyst is used in slurry polymerizations of norbornene (NB) to afford a highly productive NB addition polymerization system in combination with B(C 6 F 5 ) 3 cocatalyst. It exhibits productivity of 84 kg of PNB (mol Pd) −1 h −1 at the initial activity, and the catalyst deactivation kinetics in the early stage of polymerization are fitted well by the first-order deactivation kinetics. The obtained vinyl-type polynorbornene is confirmed to be nanosilica hybrid PNB nanocomposite by SEM, TEM with an energy dispersive spectrometer, TGA, and XRD.
研究领域:
高分子化学
·
纳米复合材料
·
催化化学
·
有机金属化学
·
材料科学
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2012
·Vol. 50
·期 24
·5177-5184
·
IF 3.919
Yonggang Gao,Lin Gu,Yusheng Qin,Xianhong Wang,Fosong Wang
Low-molecular weight oligo(carbonate-ether) diols are important raw materials for polyurethane formation, which with tunable carbonate unit content (CU) may endow new thermal and mechanical performances to polyurethane. Herein, facile synthesis of oligo(carbonate-ether) diols with number average molecular weight ( M n ) below 2000 g mol −1 and CU tunable between 40% and 75% are realized in high activity by immortal copolymerization of CO 2 /propylene oxide (PO) using zinc-cobalt double metal cyanide complex (Zn-Co-DMCC) in the presence of sebacic acid (SA). M n of the oligomer is in good linear relationship to the mole ratio of PO and SA (PO/SA) and hence can be precisely controlled by adjusting PO/SA. Besides, the molecular weight distribution is quite narrow due to the rapid reversible chain transfer in the immortal copolymerization. High pressure and low temperature are favorable for raising CU. In all the reactions, the weight fraction of propylene carbonate ( W PC ) can even be controlled as low as 2.0 wt %, and the catalytic activity of Zn-Co-DMCC is above 1.0 kgg −1 cat. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
研究领域:
高分子化学
·
催化化学
·
绿色化学
·
功能材料
·
聚合物合成
·
二氧化碳利用
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）