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Stability analysis of alkaline nitrobenzene-containing wastewater by a catalyzed Fe-Cu treatment process

FAN Jinhong, XU Wenying, GAO Tingyao, MA Luming

《环境科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 504-508 doi: 10.1007/s11783-007-0081-6

摘要: Iron and copper bimetallic system (catalyzed Fe-Cu process) is a promising technology for alkaline nitrobenzene-containing wastewater treatment. However, little is currently known about the changes of treatment efficiency with time

关键词: technology     bimetallic     catalyzed     nitrobenzene-containing wastewater     efficiency    

Octane compositions in sulfuric acid catalyzed isobutane/butene alkylation products: experimental and

Lina Liang, Youzhi Liu, Weizhou Jiao, Qiaoling Zhang, Chao Zhang

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1229-1242 doi: 10.1007/s11705-020-2030-x

摘要: Octanes in alkylation products obtained from industrial alkylation were studied by batch experiments. More than eight octane isomers were identified and quantified by gas chromatography-mass spectrometry. Based on a classic carbenium ion mechanism, the carbocation transition states in concentrated sulfuric acid catalyzed alkylation were investigated using quantum-chemical simulations and predicted the concentration and octane isomerization products including trimethylpentane and dimethylhexane as well as the formation of heavier compounds that resulted from the oligomerization of octane and butene. The agreement between model calculations and experimental data was quite satisfactory. Calculation results indicated that composition and content of trimethylpentanes in the alkylation products were 2,2,4-trimethylpentane>2,3,3-trimethylpentane>2,3,4-trimethylpentane>2,2,3-trimethylpentane whether the 2-butene or -butene acts as olefin. Heavier compounds in the alkylate were primarily formed by the oligomerization of dimethylhexane with 1-butene. Hopefully, the carbocation transition state models developed in this work will be useful for understanding the product distributions of octane in alkylation products.

关键词: sulfuric acid catalyzed alkylation     carbocation reaction     transition state     octane compositions    

Alkylation of benzene with propylene catalyzed by FeCl3-chloropyridine ionic liquid

SUN Xuewen, ZHAO Suoqi, LI Hui

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 292-295 doi: 10.1007/s11705-007-0053-1

摘要: Alkylation of benzene with propylene was carried out with FeCl3-chloro-butyl-pyridine (FeCl-[bpc]) ionic liquid as catalyst to obtain cumene. Significant improvements in propylene conversion and cumene selectivity under mild reaction conditions were attained by modification of the catalyst with HCl. Under 20ºC, 0.1 MPa, reaction time 5 min, mole ratio of benzene to propylene 10:1 and mass ratio of FeCl-[bpc] to benzene 1:100, conversion of propylene can increase from 83.60% to 100.00% and selectivity of cumene can increase from 90.86% to 98.47%. If reaction is carried out in following two stages, the result will be very good. At the initial stage of the reaction, alkylation is the main reaction and a higher conversion of propylene is obtained at a lower temperature. At the later stage of the reaction, transalkylation is the main reaction and selectivity to cumene can be increased by appropriately raising the reaction temperature.

Study of ultrasound-promoted, lipase-catalyzed synthesis of fructose ester

Kai ZHU, Hui LIU, Pingfang HAN, Ping WEI,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 367-371 doi: 10.1007/s11705-009-0312-4

摘要: The effect of low energy ultrasound in biochemistry and biotechnology has attracted great attention in recent years. It can enhance substrate dissolution and improve mass transfer within and outside of a cell, both of which are beneficial to the synthesis of fructose ester. Here we describe the experimental study of the effect of ultrasounds of different intensity on the lipase-catalyzed synthesis of fructose ester in the solvent butanone. The results were compared with control reactions performed with no ultrasound. High performance liquid chromatography (HPLC) and thin layer chromatography (TLC) were used for qualitative and quantitative analyses. The results show the following: 1) the concentration of mono-ester and diester increased with the reaction time, either with or without ultrasonic irradiation. Low energy ultrasound accelerated the reaction due to the effect of ultrasonic steady cavitations, and high energy ultrasound was not beneficial to the reaction. 2) The application of ultrasound played an important role in our lipase-catalyzed reaction. It decreased reaction time as compared to a reaction without ultrasound that resulted in the same yield, increased reaction rate, and enhanced the amount of fructose ester produced. When the frequency was 10 kHz and sound intensity was 0.16 W·m, the concentration of ester was twofold more than without ultrasonic irradiation after a reaction time of up to 12 h. With the proper ultrasonic parameters, the overall concentration of production appeared to increase exponentially with the reaction time. 3) Ultrasound had little effect on the initial reaction rate, and continuous ultrasonic irradiation was favorable for the reaction. The longer the reaction continued, the more obvious the effects of the ultrasound became in our experiments.

Mild and highly regioselective synthesis of biaryl acids via Rh(I)-catalyzed cross-dehydrogenative coupling

Yun Liu, Youquan Zhu, Chaojun Li

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 3-8 doi: 10.1007/s11705-017-1693-4

摘要: A mild and efficient synthesis for the biaryl acids via rhodium-catalyzed cross-dehydrogenative coupling reaction has been developed. This novel protocol with sodium chlorite as an oxidant featured many advantages such as mild reaction conditions, high regioselectivity, tolerance of various functional groups, and good to excellent yields.

关键词: biaryl acids     cross-dehydrogenative coupling     rhodium-catalyzed    

Chemical reactions of oily sludge catalyzed by iron oxide under supercritical water gasification condition

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 886-896 doi: 10.1007/s11705-021-2125-z

摘要: Supercritical water gasification is a promising technology in dealing with the degradation of hazardous waste, such as oily sludge, accompanied by the production of fuel gases. To evaluate the mechanism of Fe2O3 catalyst and the migration pathways of heteroatoms and to investigate the systems during the process, reactive force field molecular dynamics simulations are adopted. In terms of the catalytic mechanisms of Fe2O3, the surface lattice oxygen is consumed by small carbon fragments to produce CO and CO2, improving the catalytic performance of the cluster due to more unsaturated coordination Fe sites exposed. Lattice oxygen combines with •H radicals to form water molecules, improving the catalytic performance. Furthermore, the pathway of asphaltene degradation was revealed at an atomic level, as well as products. Moreover, the adsorption of hydroxyl radical on the S atom caused breakage of the two C–S bonds in turn, forming •HSO intermediate, so that the organic S element was fixed into the inorganic liquid phase. The heteroatom O was removed under the effects of supercritical water. Heavy metal particles presented in the oily sludge, such as iron in association with Fe2O3 catalyst, helped accelerate the degradation of asphaltenes.

关键词: oily sludge     SCWG     ReaxFF     Fe2O3     heteroatoms    

Benzene alkylation with long chain olefins catalyzed by ionic liquids: a review

QIAO Congzhen, CAI Yonghong, GUO Quanhui

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 346-352 doi: 10.1007/s11705-008-0045-9

摘要: The introduction of ionic liquids to alkylation process gives a choice for “green production” in the petrochemical and detergent industry. A lot of papers and patents have been published using chloroaluminate ionic liquid as a novel catalyst for alkylation with high reactivity and easy separation from reactants. These included the acidity, characterization, determination and catalysis technologies in batch and continuous operation mode for different scales. According to published data and several results of pilot alkylation,including the authors’ experience,the prospect of chloroaluminate ionic liquids for commercials was also discussed. It has been pointed out that there still are many difficulties and challenges to be overcome for commercial application of the ionic liquid catalyst.

关键词: different     petrochemical     characterization     introduction     chloroaluminate    

Continuous reaction performances of benzene alkylation with long chain olefins catalyzed by ionic liquid

QIAO Congzhen, LI Chengyue

《化学科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 69-73 doi: 10.1007/s11705-008-0014-3

摘要: Based on a compulsive mixing-reacting-separating-recycling small experimental setup,the continuous reaction performances of benzene alkylation with long chain olefins catalyzed by [BMIM]Cl-AlCl ionic liquid were investigated. Three different situations including normal continuous operation mode (reagent materials), sidetrack feeding from different axial positions along the static mixing reactor (reagent materials) and normal continuous alkylation using industrial paraffin and olefins materials were examined. Even under the relatively hypecritical reaction conditions, the single pass conversion of pure 1-dodecene could reach to nearly 100.0%, and the selectivity of 2-phenyl isomer was higher than 37.7%. Although the positions along the reactor for sidetrack feeding were different, the 100.0% single pass conversion of 1-dodecene was also attained before the outlet of the reactor. The refined industrial olefins as raw material could meet with the requirements of continuous alkylation. The influences of impurities such as di-olefins and non-benzene aromatics on the catalytic activity and stability should be studied further.

关键词: stability     different     hypecritical     compulsive mixing-reacting-separating-recycling     non-benzene    

Silver-catalyzed bioleaching for raw low-grade copper sulphide ores

Tianlong DENG, Yafei GUO, Mengxia LIAO, Dongchan LI

《化学科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 250-254 doi: 10.1007/s11705-009-0049-0

摘要: This research was conducted to investigate the biooxidation and copper dissolution from raw low-grade refractory copper sulphide ores located in the Xinjiang Autonomous Region of China using adapted bacteria. In order to accelerate the bioleaching rate, the adapted mixed bacteria and silver ion catalyst were tested in the leach columns at laboratory scale. The overall acid consumption was 4.3 kg sulphuric acid per kg of dissolved copper and was linearly related to the percent copper dissolution. The calculated copper dissolution rates obey the Shrinking Core Model. The relative activation energy of the whole biooxidative leaching stages was calculated to be 48.58 kJ/mol.

关键词: green process     biohydrometallurgy     bioleaching     reaction kinetics     sulphide ores    

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 251-255 doi: 10.1007/s11705-007-0045-1

摘要: A heterogeneous chiral catalyst Fe(III)-CS (chitosan) complex/mesoporous molecular sieve SBA-15 (Santa Barbara Amorphous) was prepared. The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor. Effects of Fe content in catalyst, reaction temperature, reaction time and promoter KOH concentration on the conversion of substrates and enantioselectivity were investigated. Fe-CS/SBA-15 with 2.2% mass fraction Fe exhibits considerable enantioselectivity and catalytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone. Under optimal reaction conditions: KOH concentration 0.03 mol/L, reaction temperature 70ºC and reaction time 4 h, enantiomer excess (ee) of ()-1-phenylethanol and conversion of acetophenone can reach 87.4% and 27.7%, respectively. Under the above KOH concentration and reaction temperature and reaction time of 8 h, the ee of ()-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2% and 25.5%, respectively.

关键词: asymmetric transfer     enantioselectivity     Fe-CS/SBA-15     aliphatic     aromatic    

Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid

BAI Shu, REN Mengyuan, WANG Lele, SUN Yan

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 301-307 doi: 10.1007/s11705-008-0060-x

摘要: The regioselective acylation of pyridoxine catalyzed by immobilized lipase () in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF) has been investigated, and compared with that in acetonitrile (ACN). The acetylation of pyridoxine using acetic anhydride in [BMIM]PF gave comparable conversion of pyridoxine to 5-monoacetyl pyridoxine with considerably higher regioselectivity (93%–95%) than that in ACN (70%–73%). Among the tested parameters, water activity () and temperature have profound effects on the reaction performances in either [BMIM]PF or ACN. For the reaction in [BMIM]PF, higher temperature (50°C–55°C) and lower (<0.01) are preferable conditions to obtain better conversion and regioselectivity. Mass transfer limitation and intrinsic kinetic from the ionic nature of ionic liquids (ILs) may account for a different rate-temperature profile and a lower velocity at lower temperature in [BMIM]PF-mediated reaction. Moreover, consecutive batch reactions for enzyme reuse also show that lipase exhibited a much higher thermal stability and better reusability in [BMIM]PF than in ACN, which represents another advantage of ILs as an alternative to traditional solvents beyond green technology.

关键词: ACN     stability     1-butyl-3-methylimidazolium hexafluorophosphate     different rate-temperature     alternative    

Copolymerization of polyketones catalyzed by polyacrylonitrile resin-supported palladium acetate

GUO Jintang, ZHANG Hongxin, WANG Bo, YE Yaqin

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 165-170 doi: 10.1007/s11705-008-0010-7

摘要: The crosslinked polyacrylonitrile (PAN) was synthesized by suspension polymerization using acrylonitrile (ANT) and divinylbenzene (DVB). Effects of a variety of conditions on the polymerization of PAN particle size and stiffness were investigated. Polyketone was prepared by the copolymerization of carbon monoxide (CO) and styrene (ST) catalyzed by PAN resin-supported palladium acetate. The resin-supported catalyst and the copolymerization product were characterized by infrared spectroscopy (IR) and Scanning Electron Microscopy (SEM). Effects of the components of a catalytic system and reaction time on the catalytic activity were studied. The reusability of the resin-supported catalyst was also investigated. Results indicated that the resin-supported catalyst has excellent catalytic property. The yield of polyketone was 6.2348 g when using 1 g of resin and 22.4 mg of palladium acetate.

关键词: copolymerization     Electron Microscopy     monoxide     excellent catalytic     Polyketone    

Facile synthesis of isoindoline-1,3-diones by palladium-catalyzed carbonylative cyclization of

Mayur V. KHEDKAR, Bhalchandra M. BHANAGE

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 226-232 doi: 10.1007/s11705-013-1321-x

摘要: A facile method for the carbonylative cyclization of -bromobenzoic acid with primary amine using Pd(OAC) as a metal precursor and 1,1'-bis(diphenylphosphino)ferrocene (dppf) as a ligand has been developed. The effect of various reaction parameters such as ligand, solvent, base, time and temperature on this cyclization was studied. The optimized protocol was used for a wide variety of substituted aryl amines with different steric and electronic properties, affording the corresponding isoindoline-1,3-diones in good to excellent yields under atmospheric pressure of carbon monoxide at 100°C within 10 h using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a base. The reaction system finds attractive alternative to the conventional multistep synthetic process and thus represents an effective utilization of carbonylative protocol for synthesis of valuable chemicals.

关键词: carbonylative cyclization reactions     isoindole-1     3-dinones     homogeneous catalysis     dppf    

Thermal decomposition mechanism of ammonium sulfate catalyzed by ferric oxide

Xingfu SONG, Jingcai ZHAO, Yunzhao LI, Ze SUN, Jianguo YU

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 210-217 doi: 10.1007/s11705-013-1320-y

摘要: The decomposition mechanism of ammonium sulfate catalyzed by ferric oxide was investigated in this paper. The decomposition kinetics parameters were determined via a global optimization of the Kissinger iterative method using the non-isothermal thermogravimetric analysis data. The products and intermediates were synchronously characterized by X-ray diffraction and mass spectrometry. The obtained results indicate that the decomposition process of ammonium sulfate catalyzed by ferric oxide can be divided into four stages of which the activation energies are 123.64, 126.58, 178.77 and 216.99 kJ·mol respectively. The decomposition mechanisms at the first and the fourth stage both belong to Mample power theorem, the second stage belongs to Avrami-Erofeev equation and the third belongs to contracting sphere (volume) equation. The corresponding pre-exponential factors ( ) are calculated simultaneously.

关键词: ammonium sulfate     decomposition kinetics     ferric oxide     thermogravimetric analysis    

Experimental study on oxidative decomposition of nitrobenzene in aqueous solution by honeycomb ceramic-catalyzed

ZHAO Lei, MA Jun, LIU Zhengqian, YANG Yixin, SUN Zhizhong

《环境科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 44-50 doi: 10.1007/s11783-008-0012-1

摘要: The ozonation of nitrobenzene in aqueous solution was carried out in a semi-batch reactor to investigate the degradation efficiency, the effect factors, and the reaction mechanism, where honeycomb ceramic was used as a catalyst. The presence of honeycomb ceramic could improve the degradation rate of nitrobenzene by 15.46% compared to the results of ozonation alone. Under the conditions of this experiment, the degradation rate of honeycomb ceramic-catalyzed ozonation increased by 12.94% with the increase of the amount of catalyst from 1 to 5 blocks. The degradation rates all increased greatly with the increase of temperature and pH of the solution in the processes of honeycomb ceramic-catalyzed ozonation and ozonation alone. But, when the pH of the solution increased to 9.50, the advantage of the honeycomb ceramic-catalyzed ozonation process would be lost. The experimental findings indicated that in the processes of ozonation alone and honeycomb ceramic-catalyzed ozonation, nitrobenzene was primarily oxidized by OH free radical in aqueous solution. The adsorption of nitrobenzene was too limited to have an important influence on the degradation rate of nitrobenzene. With the same total dosage of applied ozone, the multiple step addition of ozone showed much higher removal efficiency than that obtained by one step in the two processes.

标题 作者 时间 类型 操作

Stability analysis of alkaline nitrobenzene-containing wastewater by a catalyzed Fe-Cu treatment process

FAN Jinhong, XU Wenying, GAO Tingyao, MA Luming

期刊论文

Octane compositions in sulfuric acid catalyzed isobutane/butene alkylation products: experimental and

Lina Liang, Youzhi Liu, Weizhou Jiao, Qiaoling Zhang, Chao Zhang

期刊论文

Alkylation of benzene with propylene catalyzed by FeCl3-chloropyridine ionic liquid

SUN Xuewen, ZHAO Suoqi, LI Hui

期刊论文

Study of ultrasound-promoted, lipase-catalyzed synthesis of fructose ester

Kai ZHU, Hui LIU, Pingfang HAN, Ping WEI,

期刊论文

Mild and highly regioselective synthesis of biaryl acids via Rh(I)-catalyzed cross-dehydrogenative coupling

Yun Liu, Youquan Zhu, Chaojun Li

期刊论文

Chemical reactions of oily sludge catalyzed by iron oxide under supercritical water gasification condition

期刊论文

Benzene alkylation with long chain olefins catalyzed by ionic liquids: a review

QIAO Congzhen, CAI Yonghong, GUO Quanhui

期刊论文

Continuous reaction performances of benzene alkylation with long chain olefins catalyzed by ionic liquid

QIAO Congzhen, LI Chengyue

期刊论文

Silver-catalyzed bioleaching for raw low-grade copper sulphide ores

Tianlong DENG, Yafei GUO, Mengxia LIAO, Dongchan LI

期刊论文

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

期刊论文

Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid

BAI Shu, REN Mengyuan, WANG Lele, SUN Yan

期刊论文

Copolymerization of polyketones catalyzed by polyacrylonitrile resin-supported palladium acetate

GUO Jintang, ZHANG Hongxin, WANG Bo, YE Yaqin

期刊论文

Facile synthesis of isoindoline-1,3-diones by palladium-catalyzed carbonylative cyclization of

Mayur V. KHEDKAR, Bhalchandra M. BHANAGE

期刊论文

Thermal decomposition mechanism of ammonium sulfate catalyzed by ferric oxide

Xingfu SONG, Jingcai ZHAO, Yunzhao LI, Ze SUN, Jianguo YU

期刊论文

Experimental study on oxidative decomposition of nitrobenzene in aqueous solution by honeycomb ceramic-catalyzed

ZHAO Lei, MA Jun, LIU Zhengqian, YANG Yixin, SUN Zhizhong

期刊论文