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One-pot three-component Mannich reaction catalyzed by sucrose char sulfonic acid

Qiong XU, Zhigao YANG, Dulin YIN, Jihui WANG

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 201-205 doi: 10.1007/s11705-009-0052-5

摘要： Sucrose char sulfonic acid efficiently catalyzed the one-pot three-component Mannich reaction of ketones, aromatic aldehydes and amines in ethanol to afford the corresponding -amino carbonyl compounds in good to excellent yields. A series of heteroaromatic -amino carbonyl compounds can be obtained when using 2-acetylpyrazine as substrate. This reaction can be performed under mild reaction conditions with clean reaction profiles and a simple workup procedure.

关键词： One–pot synthesis     b-amino ketone     char sulfonic acid     2-acetylpyrazine     catalysis    

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Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1198-1210 doi: 10.1007/s11705-021-2133-z

摘要： Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated. The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscope-energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area, thermogravimetric analysis and n-butylamine acidity. The shape of catalysts particles plays an important role in its activity. The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production. The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid, oleic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, catalyst amount, reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion. It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts. Additionally, the catalyst was regenerated and reused up to three cycles without any significant loss in activity. The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

关键词： solid acid catalyst     mesoporous silica     sulfonic acid     biodiesel     esterification     oleic acid    

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Mesoporous silicon sulfonic acid as a highly efficient and stable catalyst for the selective hydroamination

Jingbin Wen, Kuiyi You, Minjuan Chen, Jian Jian, Fangfang Zhao, Pingle Liu, Qiuhong Ai, He’an Luo

《化学科学与工程前沿（英文）》 2021年 第15卷 第3期   页码 654-665 doi: 10.1007/s11705-020-1973-2

摘要： In this work, a new mesoporous silicon sulfonic acid catalyst derived from silicic acid has been successfully prepared by the chemical bonding method. The physicochemical properties of mesoporous silicon sulfonic acid catalysts have been systematically characterized using various techniques. The results demonstrate that sulfonic acid groups have been grafted on silicic acid by forming a new chemical bond (Si–O–S). The mesoporous silicon sulfonic acid exhibits excellent catalytic performance and stability in the vapor phase hydroamination reaction of cyclohexene with cyclohexylamine. Cyclohexene conversion of 61% and 97% selectivity to dicyclohexylamine was maintained after running the reaction for over 350 h at 280 °C. The developed mesoporous silicon sulfonic acid catalyst shows advantages of low cost, superior acid site accessibility, and long term reactivity stability. Moreover, a possible catalytic hydroamination reaction mechanism over silicon sulfonic acid was suggested. It has been demonstrated that the sulfonic acid groups of the catalyst play an important role in the hydroamination. The present work provides a simple, efficient, and environmentally friendly method for the hydroamination of cyclohexene to valuable dicyclohexylamine, which also shows important industrial application prospects.

关键词： mesoporous silicon sulfonic acid     catalytic hydroamination     cyclohexene     dicyclohexylamine     vapor phase    

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Intrinsic kinetics and external diffusion of catalytic steam gasification of fine coal char particles

Xuantao Wu, Jie Wang

《化学科学与工程前沿（英文）》 2019年 第13卷 第2期   页码 415-426 doi: 10.1007/s11705-018-1725-8

摘要： Catalytic steam gasification of fine coal char particles was carried out using a self-made laboratory reactor to determine the intrinsic kinetics and external diffusion under varying pressures (0.1–0.5 MPa) and superficial gas flow velocities (GFVs) of 13.8–68.8 cm?s . In order to estimate the gas release rate at a low GFV, the transported effect of effluent gas on the temporal gasification rate pattern was simulated by the Fluent computation and verified experimentally. The external mass transfer coefficients ( ) and the effectiveness factors were determined at lower GFVs, based on the intrinsic gasification rate obtained at a high GFV of 55.0 cm?s . The was found to be almost invariable in a wider carbon conversion of 0.2–0.7. The variations of at a median carbon conversion with GFV, temperature and pressure were found to follow a modified Chilton-Colburn correlation: (0.04< <0.19), where is total pressure and is atmospheric pressure. An intrinsic kinetics/external diffusion integrating model could well describe the gasification rate as a function of GFV, temperature and pressure over a whole gasification process.

关键词： coal char     catalytic steam gasification     pressure     kinetics     diffusion    

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Reaction kinetics and internal diffusion of Zhundong char gasification with CO

Yun Liu, Jiangyuan Qu, Xuehui Wu, Kai Zhang, Yuan Zhang

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 373-383 doi: 10.1007/s11705-020-1949-2

摘要： Mass transfer usually affects the rate of chemical reactions in coal. The effect of internal diffusion on char gasification with CO in the temperature range from 1123 K to 1273 K was investigated via thermo-gravimetric analysis and assessment of char morphology features. The results revealed that the effect of internal diffusion on the initial reaction rate was more significant with an increase of particle size, due to the concentration gradient of the gasification agent within the solid particles. In the early stage of gasification, the generation of new micropores and the opening of closed pores led to an increase in specific surface area. As the reaction proceeded, the openings were gradually expanded and the specific surface area continued to increase. However, with further reaction, disappearance of edge pores, melting and collapse of the pore structure led to a decrease in specific surface area. The intrinsic activation energy and reaction order based on the th-order model were 157.67 kJ∙mol and 0.36, respectively. Thus, temperature zones corresponding to chemical reaction and diffusion control were identified. Moreover, the calculated effectiveness factor provided a quantitative estimation of internal diffusion in the initial stage.

关键词： coal char     CO2 gasification     internal diffusion     pore evolution    

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Effect of Fe on NO release during char combustion in air and O

Ying GU, Xiaowei LIU, Bo ZHAO, Minghou XU

《能源前沿（英文）》 2012年 第6卷 第2期   页码 200-206 doi: 10.1007/s11708-012-0181-2

摘要： The chemistry of char was probed by studying nitrogen release under the reactions with air and oxy-fuel combustion. The experiments were conducted in a drop tube furnace and a fixed bed flow reactor. NO was observed during those experiments. The results show that the particle size of char generated at 1073 K in CO is larger than that in N . However, at 1573 K, it is smaller in CO atmosphere due to particle breaking by gasification of char and CO . The Fe addition increases the NO conversion ratio, and the effect of Fe rises steeply with the process going until it becomes stable in the end. The results also indicate that the release of NO increases more significantly with the Fe addition in oxy-fuel environment.

关键词： NO     Fe     char     combustion     CO2    

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Effects of pyrolyzed semi-char blend ratio on coal combustion and pollution emission in a 0.35 MW pulverized

Yonghong YAN, Liutao SUN, Zhengkang PENG, Hongliang QI, Li LIU, Rui SUN

《能源前沿（英文）》 2021年 第15卷 第1期   页码 78-90 doi: 10.1007/s11708-020-0678-z

摘要： The effects of blend ratio on combustion and pollution emission characteristics for co-combustion of Shenmu pyrolyzed semi-char (SC), i.e., residuals of the coal pyrolysis chemical processing, and Shenhua bituminous coal (SB) were investigated in a 0.35 MW pilot-scale pulverized coal-fired furnace. The gas temperature and concentrations of gaseous species (O , CO, CO , NO and HCN) were measured in the primary combustion zone at different blend ratios. It is found that the standoff distance of ignition changes monotonically from 132 to 384 mm with the increase in pyrolyzed semi-char blend ratio. The effects on the combustion characteristics may be neglected when the blend ratio is less than 30%. Above the 30% blend ratio, the increase in blend ratio postpones ignition in the primary stage and lowers the burnout rate. With the blend ratio increasing, NO emission at the furnace exit is smallest for the 30% blend ratio and highest for the 100% SC. The NO concentration was 425 mg/m at 6% O and char burnout was 76.23% for the 45% blend ratio. The above results indicate that the change of standoff distance and NO emission were not obvious when the blend ratio of semi-char is less than 45%, and carbon burnout changed a little at all blend ratios. The goal of this study is to achieve blending combustion with a large proportion of semi-char without great changes in combustion characteristics. So, an SC blend ratio of no more than 45% can be suitable for the burning of semi-char.

关键词： pulverized-coal combustion     pyrolyzed semi-char     ignition characteristics     pollution emission     char burnout     blend ratio    

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Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

Yandi ZHANG, Yinhe LIU, Xiaoli DUAN, Yao ZHOU, Xiaoqian LIU, Shijin XU

《能源前沿（英文）》 2021年 第15卷 第1期   页码 14-25 doi: 10.1007/s11708-020-0805-x

摘要： In the process of pyrolysis and combustion of coal particles, coal structure evolution will be affected by the ash behavior, which will further affect the char reactivity, especially in the ash melting temperature zone. Lu’an bituminous char and ash samples were prepared at the N and air atmospheres respectively across ash melting temperature. A scanning electron microscope (SEM) was used to observe the morphology of char and ash. The specific surface area (SSA) analyzer and thermogravimetric analyzer were respectively adopted to obtain the pore structure characteristics of the coal chars and combustion parameters. Besides, an X-ray diffractometer (XRD) was applied to investigate the graphitization degree of coal chars prepared at different pyrolysis temperatures. The SEM results indicated that the number density and physical dimension of ash spheres exuded from the char particles both gradually increased with the increasing temperature, thus the coalescence of ash spheres could be observed obviously above 1100°C. Some flocculent materials appeared on the surface of the char particles at 1300°C, and it could be speculated that -Si N was generated in the pyrolysis process under N . The SSA of the chars decreased with the increasing pyrolysis temperature. Inside the char particles, the micropore area and its proportion in the SSA also declined as the pyrolysis temperature increased. Furthermore, the constantly increasing pyrolysis temperature also caused the reactivity of char decrease, which is consistent with the results obtained by XRD. The higher combustion temperature resulted in the lower porosity and more fragments of the ash.

关键词： bituminous char     pyrolysis     ash     structure evolution     reactivity    

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Effect of particle size on coal char----NO reaction

Xiumin JIANG, Xiangyong HUANG, Jiaxun LIU, Chaoqun ZHANG

《能源前沿（英文）》 2011年 第5卷 第2期   页码 221-228 doi: 10.1007/s11708-011-0146-x

摘要： Surface nitrogen complex formation upon reaction of coal char with NO at 600°C was studied by X-ray photoelectron spectroscopy. Particle size had a noticeable effect on the magnitude of changes, which was observed on the surface of the coal char in the nitrogen functional group. The surface increased its -NO, pyridine-N-oxide, and -NO functional group contents with a decrease in particle size. The chemisorption processes of NO molecules on the char were simulated using the ab initio Hartree–Fock method and density functional theory. Molecular modeling was applied to determine the thermodynamics of the reactions. Mechanisms were proposed to explain the formation of the -NO, pyridine-N-oxide, and -NO functional groups at 600°C.

关键词： NO reduction     chemisorption     particle size     X-ray photoelectron spectroscopy     density functional theory (DFT)    

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Higher heating value prediction of torrefaction char produced from non-woody biomass

Nitipong SOPONPONGPIPAT,Dussadeeporn SITTIKUL,Unchana SAE-UENG

《能源前沿（英文）》 2015年 第9卷 第4期   页码 461-471 doi: 10.1007/s11708-015-0377-3

摘要： The higher heating value of five types of non-woody biomass and their torrefaction char was predicted and compared with the experimental data obtained in this paper. The correlation proposed in this paper and the ones suggested by previous researches were used for prediction. For prediction using proximate analysis data, the mass fraction of fixed carbon and volatile matter had a strong effect on the higher heating value prediction of torrefaction char of non-woody biomass. The high ash fraction found in torrefied char resulted in a decrease in prediction accuracy. However, the prediction could be improved by taking into account the effect of ash fraction. The correlation developed in this paper gave a better prediction than the ones suggested by previous researches, and had an absolute average error (AAE) of 2.74% and an absolute bias error (ABE) of 0.52%. For prediction using elemental analysis data, the mass fraction of carbon, hydrogen, and oxygen had a strong effect on the higher heating value, while no relationship between the higher heating value and mass fractions of nitrogen and sulfur was discovered. The best correlation gave an AAE of 2.28% and an ABE of 1.36%.

关键词： higher heating value     correlation     biomass     proximate analysis     ultimate analysis    

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Amino acid promoted hydrogen battery system using Mn-pincer complex for reversible CO hydrogenation toformic acid

《能源前沿（英文）》 2022年 第16卷 第5期   页码 697-699 doi: 10.1007/s11708-022-0843-7

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Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 784-794 doi: 10.1007/s11705-022-2278-4

摘要： In situ encapsulation is an effective way to synthesize enzyme@metal–organic framework biocatalysts; however, it is limited by the conditions of metal–organic framework synthesis and its acid-base stability. Herein, a biocatalytic platform with improved acid-base stability was constructed via a one-pot method using bismuth-ellagic acid as the carrier. Bismuth-ellagic acid is a green phenol-based metal–organic framework whose organic precursor is extracted from natural plants. After encapsulation, the stability, especially the acid-base stability, of amyloglucosidases@bismuth-ellagic acid was enhanced, which remained stable over a wide pH range (2–12) and achieved multiple recycling. By selecting a suitable buffer, bismuth-ellagic acid can encapsulate different types of enzymes and enable interactions between the encapsulated enzymes and cofactors, as well as between multiple enzymes. The green precursor, simple and convenient preparation process provided a versatile strategy for enzymes encapsulation.

关键词： bismuth-ellagic acid     in situ encapsulation     enzyme@MOF biocomposites    

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Discovery of novel ursolic acid derivatives as effective antimicrobial agents through a ROS-mediated

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 2101-2113 doi: 10.1007/s11705-023-2361-5

摘要： In response to the reduction of food production and economic losses caused by plant bacterial diseases, it is necessary to develop new, efficient, and green pesticides. Natural products are rich and sustainable source for the development of new pesticides due to their low toxicity, easy degradation, and eco-friendliness. In this study, we prepared three series of ursolic acid derivatives and assessed their antibacterial ability. Most target compounds exhibited outstanding antibacterial activities. Among them, the relative optimal EC50 values of Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri were 2.23 (A17) and 1.39 (A16) μg·mL–1, respectively. The antimicrobial mechanism showed that compound A17 induced an excessive accumulation and production of reactive oxygen species in bacteria and damaged the cell membrane integrity to kill bacteria. More interestingly, the addition of low concentrations of exogenous hydrogen peroxide enhanced the antibacterial efficacy of compound A17 against Xanthomonas oryzae pv. oryzae. These entertaining results suggested that compound A17 induced an apparent apoptotic behavior in the tested bacteria. Overall, we developed the promising antimicrobial agents that destroyed the redox system of phytopathogenic bacteria, further demonstrating the unprecedented potential of ursolic acid for agricultural applications.

关键词： ursolic acid     antibacterial activities     reactive oxygen species     apoptosis    

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Synergistic scale inhibition of polyaspartic acid composite with magnetic field

LIU Zhenfa, WANG Yanji, GAO Yuhua, ZHANG Lihui

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 261-265 doi: 10.1007/s11705-007-0047-z

摘要： Polyaspartic acid (PASP) composite, a scale inhibitor, was prepared from PASP, itaconic acid–acrylic acid–acrylic ester (IA-AA-AE) terpolymer and 2-phosphonobutane- 1,2,4-tricarboxylic acid (PBTCA). The scale inhibition of PASP composite and the effect of its synergism with a magnetic field on scale inhibition were investigated. Calcium carbonate crystals in scale samples were characterized by means of SEM and XRD. The static and dynamic experiments show that the chelating function of PASP composite for Ca can be enhanced by synergism with a magnetic field. Under Ca 650 mg/L, HCO 1,300 mg/L and PASP composite 4 mg/L, the scale inhibition rate of PASP composite in magnetic water can increase by 10% in static state and by 20% in dynamic experiments. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that calcite and aragonite can be completely transformed into vaterite by using PASP composite.

关键词： synergism     magnetic     PBTCA     dynamic     acid–acrylic acid–acrylic    

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Abiotic association of phthalic acid esters with humic acid of a sludge landfill

Xiaoli CHAI, Yongxia HAO, Xin ZHAO, Guixiang LIU, Ying ZHU, Rong JI, Jun WU, Huanhuan TONG, Youcai ZHAO

《环境科学与工程前沿（英文）》 2012年 第6卷 第6期   页码 778-783 doi: 10.1007/s11783-012-0434-7

摘要： The abiotic association between phthalic acid esters (PAEs) and humic substances (HS) in sludge landfill plays an important role in the fate and stability of PAEs. An equilibrium dialysis combined with C-labeling was used to study the abiotic association of two abundant PAEs (diethyl phthalate and di- -butyl phthalate) with humic acid (HA) isolated from a sludge landfill with different stabilization times and different molecular weights. Elemental analysis and Fourier Transform Infrared Spectrophotometer (FTIR) suggested that high value of HA was related to the high aromatic content and large molecular weight of HA. The results indicated that the association strength of PAEs with HA depended on both the properties of the PAEs and the characteristics of HA. The values of the association were strongly dependent on solution pH, and decreased dramatically as the pH was increased from 3.0 to 9.0. The results suggested that non-specific hydrophobic interaction between PAEs and HA was the main contributor to the association of the PAEs with HA. The interactive hydrogen-bonds between the HA and the PAEs molecules may also be involved in the association.

关键词： abiotic association     phthalic acid esters (PAEs)     humic acid     sludge     landfill    

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标题 作者 时间 类型 操作

One-pot three-component Mannich reaction catalyzed by sucrose char sulfonic acid

Qiong XU, Zhigao YANG, Dulin YIN, Jihui WANG

期刊论文

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

期刊论文

Mesoporous silicon sulfonic acid as a highly efficient and stable catalyst for the selective hydroamination

Jingbin Wen, Kuiyi You, Minjuan Chen, Jian Jian, Fangfang Zhao, Pingle Liu, Qiuhong Ai, He’an Luo

期刊论文

Intrinsic kinetics and external diffusion of catalytic steam gasification of fine coal char particles

Xuantao Wu, Jie Wang

期刊论文

Reaction kinetics and internal diffusion of Zhundong char gasification with CO

Yun Liu, Jiangyuan Qu, Xuehui Wu, Kai Zhang, Yuan Zhang

期刊论文

Effect of Fe on NO release during char combustion in air and O

Ying GU, Xiaowei LIU, Bo ZHAO, Minghou XU

期刊论文

Effects of pyrolyzed semi-char blend ratio on coal combustion and pollution emission in a 0.35 MW pulverized

Yonghong YAN, Liutao SUN, Zhengkang PENG, Hongliang QI, Li LIU, Rui SUN

期刊论文

Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

Yandi ZHANG, Yinhe LIU, Xiaoli DUAN, Yao ZHOU, Xiaoqian LIU, Shijin XU

期刊论文

Effect of particle size on coal char----NO reaction

Xiumin JIANG, Xiangyong HUANG, Jiaxun LIU, Chaoqun ZHANG

期刊论文

Higher heating value prediction of torrefaction char produced from non-woody biomass

Nitipong SOPONPONGPIPAT,Dussadeeporn SITTIKUL,Unchana SAE-UENG

期刊论文

Amino acid promoted hydrogen battery system using Mn-pincer complex for reversible CO hydrogenation toformic acid

期刊论文

Enzyme@bismuth-ellagic acid: a versatile platform for enzyme immobilization with enhanced acid-base stability

期刊论文

Discovery of novel ursolic acid derivatives as effective antimicrobial agents through a ROS-mediated

期刊论文

Synergistic scale inhibition of polyaspartic acid composite with magnetic field

LIU Zhenfa, WANG Yanji, GAO Yuhua, ZHANG Lihui

期刊论文

Abiotic association of phthalic acid esters with humic acid of a sludge landfill

Xiaoli CHAI, Yongxia HAO, Xin ZHAO, Guixiang LIU, Ying ZHU, Rong JI, Jun WU, Huanhuan TONG, Youcai ZHAO

期刊论文