Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Xiaowei Fang,Ze Wang,Wenli Song,Songgeng Li,Weigang Lin
The preparation of furans from catalytic conversion of corn stover is investigated in H 2 O–THF (tetrahydrofuran) co-solvent system, and the effects of Bronsted acids (H 2 SO 4 , HCl, HNO 3 ) combined with alkali metal cations (Li + , Na + , K + ) are studied systematically. It is found that the effect of individual acid in promoting the summary yield of 5-hydroxymethylfurfural (HMF) and furfural (FF) can be ordered as Cl − > SO 4 2− > NO 3 − . When combined with a salt, the anion effect can be ranked in SO 4 2− > Cl − > NO 3 − , both for the HMF yield and the summary yield of furans. Based on the best anion of SO 4 2− , the impacts of the combined cations can be finely ranked as Na + > K + > Li + . For the system with Cl − , it ranks in K + > Li + > Na + for the HMF yield or the summary yield of furans. The performance of NO 3 − is so poor that no liquid product can be detected when any alkali metal cations is combined with HNO 3 . The performance of H 2 SO 4 /Na 2 SO 4 is the best among 9 tested combined catalysts, and the yield of HMF and FF from corn stover conversion under optimized conditions are 76% and 81% respectively.
研究领域:
生物化学
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可再生资源转化
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DOI
高影响因子
POLYMER COMPOSITES
·
2014
·Vol. 35
·期 10
·2056-2066
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IF 1.455
Xiangming Hu,Yanyun Zhao,Weimin Cheng,Deming Wang,Wen Nie
In this study, phenol, urea, and paraformaldehyde were used as the monomers for the one-step synthesis of phenol-urea-formaldehyde (PUF) foaming resin that was used to block air leakage in mining. An orthogonal test was used to study the effects of urea amount, catalyst amount, reaction temperature, and reaction time on the foaming property of the resin. The results showed that the optimum parameters for synthesizing PUF resin are as follows: 1 mol phenol, 0.5 mol urea, 3 mol formaldehyde equivalents of paraformaldehyde, and 0.05 mol catalyst at 75°C for 3 h. The infrared and 13 C nuclear magnetic resonance spectra of the PUF resin showed that the chemical structure of the PUF resin was significantly different from that of phenol-formaldehyde resin, indicating that a copolymerization reaction has occurred among the three components, that is, phenol, urea, and paraformaldehyde. In this study, PUF foam was prepared from catalysts and PUF resin. The results showed that the foaming capacity and oxygen index of the PUF foam were significantly improved by using urea, whereas the shrinking percentage decreased with no change in compression strength. POLYM. COMPOS., 35:2056–2066, 2014. © 2014 Society of Plastics Engineers
研究领域:
材料科学
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矿业工程
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DOI
高影响因子
Fermentation-Basel
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2023
·Vol. 9
·期 3
·286
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IF 3.7
Hongsen Zhang,Jiahui Jiang,Conghui Quan,Guizhong Zhao,Guotao Mao,Hui Xie,Fengqin Wang,Zhimin Wang,Jian Zhang,Pingping Zhou,Andong Song
Inhibitors from lignocellulosic biomass have become the bottleneck of biorefinery development.Gluconobacter oxydansDSM2003 showed a high performance of inhibitors degradation, which had a short lag time in non-detoxified corn stover hydrolysate and could convert 90% of aldehyde inhibitors to weaker toxic acids. In this study, an aldehyde dehydrogenase geneW826-RS0111485, which plays an important function in the conversion of aldehyde inhibitors inGluconobacter oxydansDSM2003, was identified.W826-RS0111485was found by protein profiling, then a series of enzymatic properties were determined and were heterologously expressed inE. coli. The results indicated that NADP is the most suitable cofactor of the enzyme when aldehyde inhibitor is the substrate, and it had the highest oxidation activity to furfural among several aldehyde inhibitors. Under the optimal reaction conditions (50 °C, pH 7.5), theKmandVmaxof the enzyme under furfural stress were 2.45 and 80.97, respectively, and theKcatwas 232.22 min−1. The biodetoxification performance experiments showed that the recombinantE. colicontaining the target gene completely converted 1 g/L furfural to furoic acid within 8 h, while the controlE. colionly converted 18% furfural within 8 h. It was further demonstrated thatW826-RS0111485played an important role in the detoxification of furfural. The mining of this inhibitor degradation gene could provide a theoretical basis for rational modification of industrial strains to enhance its capacity of inhibitor degradation in the future.Keywords:inhibitors degradation;Gluconobacter oxydans;protein profiling;aldehyde dehydrogenase;furfural
研究领域:
生物技术
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酶学
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微生物学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2023
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IF 8.4
Li Bai,Mei Wu,Huazhong Yu,Shima Liu,Ke Song,Xianwu Zhou,Jie Guo,Jian He
Acetalization is a promising method for upgrading biomass-derived molecules into valuable chemicals, and acetal products are considered excellent oxygenated fuel additives. Herein, a catalyst-free, facile, and effective protocol for the acetalization of furfural and ethylene glycol is established, affording a 78.6% yield of 2-(furan-2-yl)-1,3-dioxolane with a furfural/ethylene glycol molar ratio of 1:15 in cyclohexane at 160 °C after 2 h. Moreover, the lower activation energy (15.8 kJ/mol) corroborates that the established system is efficient, and the thermodynamic studies demonstrate that catalyst-free acetalization is an endothermic, nonspontaneous, and endergonic reaction. A plausible mechanism including two pathways for catalyst-free acetalization of furfural and ethylene glycol is proposed, wherein the formed water from the acetalization process can render the ethylene glycol to be hydrolyzed, which plays a positive role in facilitating the acetalization of furfural and ethylene glycol. In addition, the excess ethylene glycol in the reaction mixture can be easily recovered and almost shows the same activity as fresh ethylene glycol in catalyst-free acetalization. Furthermore, the established catalyst-free protocol is viable for various biobased furanic compounds and alcohols, enabling broad access to various acetals. Finally, catalyst-free acetalization of furfural and ethylene glycol can be magnified to 10 times, showing the promising potential of large-scale production.
研究领域:
生物化学
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可再生资源
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绿色化学
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DOI
高影响因子
ChemCatChem
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2020
·Vol. 12
·期 12
·3257-3264
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IF 4.853
Xue-Ying Zhang,Xin Wang,Nan-Wei Li,Ze-Wang Guo,Min-Hua Zong,Ning Li
Graphical Whole-cell biocatalysis : Cofactor-engineered E. coli cells proved to be versatile catalysts to produce furan carboxylic acids from toxic biobased furans with high productivities. The introduction of NADH oxidase (NOX) into E. coli harboring aldehyde dehydrogenases (ALDHs) significantly promoted intracellular NAD + regeneration, thus enhancing ALDH-catalyzed aldehyde oxidation. A group of aromatic aldehydes was efficiently oxidized to target carboxylic acids. More importantly, these engineered whole-cell biocatalysts displayed high substrate tolerance toward toxic furans. Furan carboxylic acids are useful chemicals in various industries. In this work, biocatalytic production of furan carboxylic acids was reported with high productivities by cofactor-engineered Escherichia coli cells. NADH oxidase (NOX) was introduced into E. coli harboring aldehyde dehydrogenases (ALDHs) to promote intracellular NAD + regeneration, thus significantly enhancing ALDH-catalyzed oxidation. These engineered biocatalysts were capable of efficient aerobic oxidation of a variety of aromatic aldehydes. More importantly, they exhibited high substrate tolerance toward toxic furans. E. coli co-expressing vanillin dehydrogenase and NOX ( E. coli_ CtVDH1_NOX) enabled efficient oxidation of 250 mM of 5-hydroxymethylfurfural (HMF) to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), providing a productivity of 3.7 g/L h. With E. coli_ CtVDH2_NOX as catalyst, up to 240 mM of furfural and 5-methoxymethylfurfural (MMF) could be smoothly oxidized. 2-Furoic acid (FCA, 227 mM) and 5-methoxymethyl-2-furancarboxylic acid (MMFCA, 287 mM) were produced in fed-batch synthesis, providing the productivities of 2.0 and 5.6 g/L h, respectively.
研究领域:
生物技术
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生物化学工程
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代谢工程
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DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
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2024
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IF 6.3
Tengfei Han,Benzhi Ju,Shufen Zhang
Despite covalent adaptable networks (CANs) imparting the reprocessing performance of crosslinked polymers, due to reversible bond exchange of the dynamic covalent bonds ; it is still a huge challenge to design catalyst-free, fast reprocessing, controlled degradation and raw material recycling biomass base CANs. Here, for the first time, we prepared cellulose CANs base on hemiacetal and acetal bonds (ACCs) via aldehyde and hydroxyl reaction of the dialdehyde crosslinker with hydroxypropyl cellulose (HPC). By regulating the crosslink density and chemical structure of the crosslinked network, ACCs exhibit tunable thermal and mechanical properties. The crosslinked network structure of the ACCs benefits from the rapid bond exchange of the hemiacetal and acetal bonds at elevated temperatures, which allows for rapid stress relaxation and thus, superior reprocessing properties. In addition, it was found that the dynamic exchange of acetals in the ACCs is influenced by the chain length and flexibility of the crosslinker. Moreover, ACCs possess good degradation and cellulose feedstock recycling properties due to the acid sensitivity of the acetal bonds. This work provides an effective solution to the problems of resource waste caused by petroleum-based thermoset plastics.
研究领域:
材料科学
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化学工程
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生物化学
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DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
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2024
·Vol. 160
·期 23
·
IF 3.1
Li Meiyue,Tian Xiao,Du Weiping,Wang Xiujuan,Lei Juncheng,Gao Tianyue,Zou Siyu,Xu Xuefang,Wang Hao,Chen Junhua,Gou Qian
The rotational spectrum of an acrolein–formaldehyde complex has been characterized using pulsed jet Fourier transform microwave spectroscopy complemented with quantum chemical calculations. One isomer has been observed in pulsed jets, which is stabilized by a dominant O=C⋯O tetrel bond (n → π* interaction) and a secondary C–H⋯O hydrogen bond. Splittings arising from the internal rotation of formaldehyde around its C 2v axis were also observed, from which its V 2 barrier was evaluated. It seems that when V 2 equals or exceeds 4.61 kJ mol −1 , no splitting of the spectral lines of the rotational spectrum was observed. The nature of the non-covalent interactions of the target complex is elucidated through natural bond orbital analysis. These findings contribute to a deeper understanding on the non-covalent interactions within the dimeric complex formed by two aldehydes.
研究领域:
物理化学
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量子化学
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分子光谱学
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DOI
PubMed
高影响因子
ATMOSPHERIC ENVIRONMENT
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2024
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IF 4.2
Cici Fan,Huijie Yan,Weigang Wang,Zheng Sun,Maofa Ge
Aldehydes are one of the most important oxygenated volatile organic compounds in the atmosphere, contributing to atmospheric radicals such as HO 2 and RO 2 , which play a pivotal role in atmospheric chemistry and the oxidative capacity of the atmosphere. The kinetics, gas-phase products, and SOA formation of pentanal and n-hexanal initiated by Br atoms were studied in this work. The reaction rate constants of n-pentanal and n-hexanal reacting with Br atoms were determined to be (1.77 ± 0.25) × 10 −11 cm 3 molecule −1 s −1 and (2.07 ± 0.29) × 10 −11 cm 3 molecule −1 s −1 at 298 K and 760 Torr, respectively. Key gas-phase products, including smaller aldehydes, carboxylic acids, and alcohols, are known to contribute to atmospheric reactivity and have potential implications for air quality by promoting the formation of secondary pollutants and influencing the oxidative capacity of the atmosphere. The SOA yields were (5.24 ± 0.10)% and (6.00 ± 1.20)% for n-pentanal and n-hexanal, respectively, higher than the SOA yields of the aldehydes reaction initiated by OH radicals. The higher SOA yields observed from Br atoms oxidation compared to OH radical oxidation highlight the necessity to re-evaluate the role of halogen chemistry in atmospheric processes, particularly in regions where halogen compounds are prevalent. This research enhances our understanding of the atmospheric fate of aldehydes and highlights the importance of considering halogen-driven oxidation pathways in atmospheric models.
研究领域:
环境科学
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大气化学
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 97
·94976-94988
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IF 3.289
Longfei Liao,Ying Liu,Zengyong Li,Junping Zhuang,Yanbin Zhou,Size Chen
Amino modified Fe3O4@SiO2 (Fe3O4@SiO2–NH2) was used to immobilize Cu2+ and VO2+ for preparing Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalysts. Various technologies had been used for the characteristics of catalysts, such as XRD, XPS, FT-IR, SEM, TEM and VSM. The catalytic performance of Fe3O4@SiO2–NH2–VO2+ in HMF oxidation could be significantly enhanced by the use of Fe3O4@SiO2–NH2–Cu2+ as the co-catalysts. The type of reaction solvents showed a great influence on the oxidation of HMF. The highest HMF conversion reached up to 98.7% at 110 °C in toluene with an optimal 2,5-diformylfuran yield of 85.5%. Moreover, the Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalyst exhibited great stability and could be readily applied in the next recycle after magnetic separation.
研究领域:
化学工程
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催化材料
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
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2017
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IF 4.95
Yao Sun,Zhaobing Guan,Hongwei Cai,Yiyong Huang,Yawei Lin,Xiaosong Hu
A pre-column fluorescent derivatization method based on nitrone formation has been applied to determine furfurals (e.g. furfural (F), 5-methyfurfural (5-MF) and 5-hydroxymethylfurfural (5-HMF)) in food samples for the first time. An N-substituted hydroxylamine reagent 4-((hydroxyamino)butyl)-7-hydroxycoumarin (HAHC) was used to react with the aldehyde group of furfurals to form stable nitrone derivatives with high fluorescence intensities . The reactions proceeded under mild conditions in 30 min with high derivatization yields (>93%). A baseline-separation of three furfurals derivatives was subsequently achieved within 25 min on a reversed-phase column. The detection limits were at the low femtomol level (S/N = 3, 20 μL per injection). The linear range of the calibration curve was 0.4–4000 nM with good correlation coefficients (R 2 ≥ 0.9991). The proposed method was further applied for food sample analysis, such as bovine milk powder and raisin. Satisfactory recoveries were obtained in the range of 94.7%–103.5%. Above all, this pre-column derivatization method is simple, fast and highly sensitive, providing an effective and promising way for future studies of aldehydes in different matrices.
研究领域:
分析化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2014
·Vol. 36
·期 8
·1531-1540
·
IF 1.455
Xiang-Ming Hu,Yan-Yun Zhao,Wei-Min Cheng
Six types of phenolic foaming resins were synthesized at room temperature with different formaldehyde/phenol (F/P) ratios in this study. The effects of F/P ratios on physicochemical characteristics and foaming properties of the resulting resins were analyzed based on viscosity, solids content, hydroxymethyl index, residual monomer content, molecular structure of the foaming resin, flame retardancy, and foam compression strength measurements. The results of the present study indicated that viscosity and solids content of the foaming resins increased with an increase in F/P; the hydroxymethyl index of the resin first increased and then decreased with an increase in F/P, reaching its maximum at F/P = 1.6; the trimer, tetramer, and pentamer contents of the resins increased with an increase in F/P. Nuclear magnetic resonance ( 13 C NMR) spectral analysis indicated that the presence of para / para -methylene, para -hydroxymethyl, and ortho -hydroxymethyl groups in the resin gradually increased with an increase in F/P; the proportions of ortho/ortho - and ortho / para -methylene bonds of the resin increased as F/P was increased. The increase in F/P was demonstrated to be conducive to improving the compression strength, thermal stability, and flame retardancy of the phenolic foam and reducing its peak heat release rate and total smoke release. The morphology of phenolic foams show that the closed cell content in the PF foam increases with the F/P ratio until it reaches a ratio of 1.6. Furthermore, the cell size becomes more uniform. POLYM. COMPOS., 36:1531–1540, 2015. © 2014 Society of Plastics Engineers
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
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2022
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IF 5.204
Juxiang Chen,Ke Zhang,Kuiyuan Zhang,Bo Jiang,Yudong Huang
Phenolic resins with irreversible cross-links structure make them difficult to degrade and recycle. It is an emerging trend for phenolic resins thermoset to develop a rapid and facile closed-loop recycling approach. Herein, the degradable and reprocessable phenolic thermosets (PRTs) based on reversible acetal bonds were synthesized by tri(ethylene glycol) divinyl ether (TEGDVE) and linear phenolic resin through one-step “click” addition reaction. By employing the chain mobility induced by dynamic weak acetal motifs and linear TEGDVE in PRTs, the mechanical strengths could be rationally adjusted, and more moderate reprocessing and degradation conditions were achieved. Accordingly, the flexible structure units containing weak reversible acetal linkages were expected to accelerate the mobility of the chain segments and decrease the reprocessing temperature, while the linear phenolic structure afforded the high mechanical strength. Remarkedly, a champion degradation rate of 121.8 mg·mL −1 ·h −1 was achieved under acid condition by adjusting the ratio of flexible chains consisting of dynamic acetal bonds. In addition, compared with pristine PRTs, regenerative one maintained 93.41% of elongation at break. This work may shed a light for realizing degradable and reprocessable dynamic network materials with high efficiency.
研究领域:
材料科学
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化学工程
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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）