CIESC Journal

GREEN CHEMISTRY AND CHEMICAL ENGINEERING—2003

MIN Enze

2004, 55(12): 1933-1937.

Abstract ( 842 )

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Green chemistry and chemical engineering are recognized as multidisciplinary science and engineering to address global environmental issues.The commercialization of 3 new units of manufacturing caprolactam by SINOPEC has proved China’s capability of developing advanced green processes.The manufacturing of transportation fuels and commodity chemicals from renewable resources is also reviewed.The scientific frontier fields, which may bring technological breakthrough for developing green processes such as ionic liquid, supercritical reaction engineering and process intensification are discussed.

NEW CHEMICAL INDUSTRY BASED ON BIOMASS

YAN Lifeng;ZHU Qingshi

2004, 55(12): 1938-1943.

Abstract ( 684 )

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Biomass is a kind of alternative feedstock to fossil fuel resources,such as oil and coal.A new kind of biomass-chemical industry will come into being,similar to modern chemical industries based on oil and coal.This paper gives a review on the development of biomass-based chemical industry, and also discusses the problems and how to solve them in the future.

SOME THOUGHTS ABOUT DEVELOPMENT OF CHINESE GREEN CHEMISTRY AND CHEMICAL ENGINEERING IN CHINA IN 21ST CENTURY

WANG Jingkang;GONG Junbo;BAO Ying

2004, 55(12): 1944-1949.

Abstract ( 742 )

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Chemistry and chemical engineering are the core science and key technology, which make great contribution to the development of science and advancement of human society.In the new century,chemistry and chemical engineering should develop along the green and sustainable route and make man and nature coexist harmoniously. In this paper, the development of green chemistry and chemical engineering in China is discussed in 8 areas.

PROGRESS AND TREND OF INDUSTRIAL BIOTECHNOLOGY

ZHU Yuezhao, LU Dingqiang, WAN Honggui, WEI Ping, ZHOU Hua, OUYANG Pingkai

2004, 55(12): 1950-1956.

Abstract ( 640 )

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Industrial biotechnology is to produce chemicals, medicines, materials and energy at a large scale by using biological or enzymatic processes.It is considered to be one of efficient methods to solve problems of resource, energy and environment.OECD recently pointed out that industrial biotechnology is one of the most promising technologies for sustainable development.Studies of industrial biotechnology have emerged and have been the development strategy of science and industry in the developed country.The progress and trend of industrial biotechnology, especially technology of bioenergy, biomaterial and utilization of biomass resource, are reviewed.The common key questions of industrial biotechnology are summarized as follows:(1)the pool of microbial resource and functional genomics of microbe；(2)effective methods for improving biocatalyst performance under industrial conditions;(3)metabolic engineering of important industrial microbes.The prospect of industrial biotechnology development in China is given.

RESEARCH AND APPLICATION OF IONIC LIQUIDS IN CATALYSIS AND SEPARATION

GU Yanlong;SHI Feng;DENG Youquan

2004, 55(12): 1957-1963.

Abstract ( 627 )

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The study of room temperature ionic liquids has been rapidly expanded into functional materials, energy, environmental protection and life sciences from green chemistry and chemical engineering, which typically demonstrates the interaction and integration of multiple disciplines in the development of science and technology.In this paper, the recent research and application of the room temperature ionic liquid in catalysis and separation are summarized and discussed to provide reference for future work.

PALLADIUM-CATALYZED ORGANIC REACTIONS IN SUPERCRITICAL CARBON DIOXIDE

YANG Shaorong;JIANG Huanfeng

2004, 55(12): 1964-1970.

Abstract ( 659 )

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This review presents recent advances of the palladium-catalyzed organic reactions in supercritical carbon dioxide in the authors’group.The reactions include carbonylation of alkenes and alkynes, oxidation of alkenes, cyclotrimerization of alkynes, etc.

GREEN ELECTROCHEMICAL SYNTHESIS OF p-AMINOPHENOL AND INDUSTRIALIZATION

MA Chun’an, CHU Youqun, TONG Shaoping, MAO Xinbiao, LI Meichao, ZHU Yinghong

2004, 55(12): 1971-1975.

Abstract ( 1363 )

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The studies on the industrialization of electrochemical synthesis of p-aminophenol (PAP) from nitrobenzene in a divided electrolytic cell with a rotating Cu-Hg cathode were presented.The experimental results showed that the electrolytic properties are greatly depended on the operation parameters, such as cathode rotating speed, current, temperature, as well as anode materials.The reduction of nitrobenzene to PAP was favored by increasing temperature and cathode rotating speed.Compared with Ti/Ir anode, the Pb-Sb-Sn-Ag-Cu alloy was more suitable as anode material when the cost and operating life were concerned.Industrialization tests of electrochemical synthesis of PAP were conducted at the following conditions: Pb alloy anode material, temperature 90℃, cathode rotating speed 900 r•min^-1, current 3000 A.The average current efficiency and conversion ratio of nitrobenzene were 57% and 99% respectively.The average yield of PAP was up to 69.9% and DC power consumption was 7.24 kW•h•(kg PAP)^-1.The purity of the product was higher than 98%, and its average melting point was 186.1—187.3℃.

PREPARATION OF NANOFIBROUS γ-Al₂O₃ PARTICLES WITH LARGE PORE VOLUME FROM H₂O₂ AND SODIUM ALUMINATE SOLUTIONS

CAI Weiquan;LI Huiquan;ZHANG Yi

2004, 55(12): 1976-1981.

Abstract ( 1064 )

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Nanofibrous γ-Al₂O₃ with very large pore volume was successfully prepared by precipitation from H₂O₂and sodium aluminate solutions combined with dispersing and washing the precipitate with ethanol.The effects of ethanol washing and water washing on structure, morphology and texture properties of pseudoboehmite-calcined γ-Al₂O₃ were comparatively studied with XRD, FT-IR,TG-DSC,TEM,BET and mercury porosimeter.The ethanol-processed γ-Al₂O₃ presented fibrous-like texture about 10 nm thick and over 100 nm long whose pore volume and BET surface area could reach about 2.23 ml•g^-1 and 222.0 m²•g^-1, respectively.However,the secondary particles of the water-processed γ-Al₂O₃ had no regular shape and its as-mentioned texture properties of pore volume and BET surface were only 0.37 ml•g^-1 and 162.3 m²•g^-1,respectively. CH3CH2O— groups on the surface of ethanol-processed pseudoboehmite particles could not only induce fiber formation through hydrogen bonding between the oxide groups and the surface OH—groups, but also inhibit chemical Al—O—Al bonds formation among the adjacent particles and thus hard agglomerate could be prevented.

PROCESS ANALYSIS AND PILOT EXPERIMENT FOR MONOAMMONIUM PHOSPHATE PRODUCTION COMBINING WITH DIAMMONIUM PHOSPHATE EXHAUST GAS RECYCLING

ZHU Jiahua;XIA Sulan;DU Huaiming;MA Kongjun;YU Hui;WANG Jiangping;GUO Shiwei;LU Qingguo;ZHANG Hongying

2004, 55(12): 1982-1988.

Abstract ( 887 )

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Process thermodynamics analysis was made of the mechanism of P-NH₃ polluted droplets formation in the exhaust gas discharged from a 600 kt•a^-1 diammonium phosphate (DAP) production line.The key factor was the overly high humidity of tail gas, which caused condensation taking place locally in the stack.A recirculation technique was proposed to combine the tail gas dehumidification into the process of monoammonium phosphate (MAP) production in which the heat energy, released from reducing water content in the tail gas below 0.065 kg H₂O•(kg air)^-1, could be used to substitute as much as 45% of the heat energy consumption for a 240 kt•a^-1 MAP production line.To obtain the high efficiency of secondary energy utilization for this process,an unique technique was developed to integrate the processes of partial condensation of tail gas with falling film evaporation of raw phosphoric acid.The feasibility was demonstrated by the pilot experiments in which the total heat transfer coefficient reached 500—600 W•m^-2•K^-1.Some other advantages were also found significant for phosphoric acid concentration compared with the traditional technique, such as lower evaporation temperature，lower recycling rate and especially expansion of evaporation surface areas. The experimental results displayed a very promising future application for the cleaner process of MAP production combined with recirculation of DAP exhaust gases.

PLASMA METHANOL DECOMPOSITION USING CORONA DISCHARGES

LI Huiqing;ZOU Jijun;ZHANG Yueping;LIU Changjun

2004, 55(12): 1989-1993.

Abstract ( 759 )

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Methanol decomposition to hydrogen and carbon monoxide at ambient condition was conducted via corona discharge.DC corona and AC corona with frequency of 2000 Hz were tested.The experiment confirmed that a short residence time（< 10^-1s）through the corona region could give a significantly high H₂ yield from methanol decomposition.Hydrogen production rate and energy efficiency increased with increasing CH₃OH feed concentration.Relative to DC corona discharge,AC corona with waveform of sinusoid, or sinusoidal triangle was much more effective to generate H₂.However AC corona with waveform of sawtooth was relatively weak for the decomposition of CH₃OH.

THREE PHASE SLURRY BED METHANOL SYNTHESIS WITHn-HEXANE IN SUPERCRITICAL STATE

ZHANG Shuhua;LI Tao;ZHU Bingchen;ZHU Zibin

2004, 55(12): 1994-2000.

Abstract ( 977 )

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Supercritical three-phase methanol synthesis on C302-2 catalyst was studied in a mechanically agitated slurry reactor with paraffin oil as the inert liquid medium and n-hexane as the supercritical medium under the operation conditions of the temperature ranging from 235 ℃ to 260 ℃, the pressure ranging from 6.0 MPa to 7.0 MPa and the mass space velocity ranging from 450 L(STP) •(kg cat)^-1•h^-1 to 1600 L(STP) •(kg cat)^-1•h^-1.The effects of operation conditions on the conversion of carbon monoxide and outlet methanol mole fraction were discussed in detail.The result showed that both the conversion of CO and methanol mole fraction decreased with the increasing mass space velocity and temperature under the condition of supercritical n-hexane.In addition, three-phase slurry bed methanol synthesis with and without supercritical n-hexane was compared.CO conversion and methanol mole fraction under supercritical condition were higher than those at three-phase slurry bed without supercritical n-hexane.

TOLUENE OXIDATION TO BENZALDEHYDE IN SUPERCRITICAL (SUBCRITICAL) FLUIDS

ZHU Xian, WANG Qian, JIANG Chao

2004, 55(12): 2001-2007.

Abstract ( 999 )

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The optimum technology and reaction kinetics of toluene oxidation to benzaldehyde in supercritical carbon dioxide and subcritical water without catalyst were studied.The experimental results showed that the oxidation in supercritical carbon dioxide was a zero order reaction with activation energy 50.9 kJ•mol^-1 and the oxidation in subcritical water was a consecutive reaction consisting of two first order reactions with activation energy 89 kJ•mol^-1 and 76 kJ•mol^-1 respectively.The optimum conditions for supercritical carbon dioxide were:P=25 MPa，T=180 ℃，t=4 h，η=2.5 and those for subcritical water were:P>P₀，T=350 ℃，t=1 h，η=3.5.

ANALYSIS OF DEACTIVATION OF PdCl₂-CuCl₂-KOAc/AC CATALYST FOR SYNTHESIS OF DIMETHYL CARBONATE

WANG Shufang;CUI Yongmei;ZHAO Xinqiang;WANG Yanji

2004, 55(12): 2008-2014.

Abstract ( 916 )

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The deactivation of PdCl₂-CuCl₂-KOAc/AC catalyst for gas-phase direct synthesis of dimethyl carbonate and the effects of reaction conditions on the catalyst stability were studied.The possible active centers were Pd²⁺ and Cu⁺.Treating the catalyst with chloro-organic compounds could increase the content of Cu²⁺ and Pd²⁺ on the surface of the catalyst.Cu2+ is the oxidant of Pd⁰.The synergistic effect between Pd and Cu could complete the oxidation-reduction cycle between Pd²⁺/Pd⁰ and Cu²⁺/Cu⁺.With the loss of Cl^- anion ,the ratios of both Cu²⁺/Cu+ and Pd²⁺/Pd⁰ were changed.This change was one of the main reasons for the reversible deactivation of the catalyst.The loss of Pd component, carbon deposition and aggregation of metal particles were the main reasons for the irreversible deactivation.The stability of the catalyst could be improved by increasing the reaction temperature or by lowering the reaction pressure and the concentration of oxygen in the feed.The chloro-organic compounds added in the feed could increase the service time of the catalyst effectively.The activity could be kept stable for more than 150 h at the STY of 700～750 g•L^-1•h^-1 when the reaction pressure was 0.3 MPa and the concentration of the chloro-organic compound was 5%(vol).

PREPARATION OF MCM-22 ZEOLITE PELLETS BY VPT METHOD AND ALKYLATION CATALYTIC PERFORMANCE

LI Yingxia;CHEN Biaohua;MU Zhijun;LI Chengyue;WANG Wenxing

2004, 55(12): 2015-2019.

Abstract ( 711 )

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The vapor-phase -transport (VPT) method was adopted to prepare the grainy MCM-22 zeolite catalyst. Its physical and textural properties were characterized with XRD,SEM and BET.The catalytic performance of the catalyst was evaluated in a liquid-solid fixed bed reactor for the alkylation of benzene with propylene as a model reaction system.It was found that the MCM-22 zeolite catalyst prepared by the VPT method not only showed good crystallinity and high BET surface area， but also better crystal growth orientation and denser structure.The catalyst showed high activity, selectivity and good stability for alkylation of benzene with propylene, especially better selectivity to the end product cumene.The shaped MCM-22 zeolite catalyst prepared by the VPT method has good prospect of industrial application in synthesis of cumene.

OLEFIN HYDROFORMYLATION CATALYZED BY WATER-SOLUBLE RHODIUM COMPLEXES——ACCELERATION BY CATIONIC SURFACTANT

FU Haiyan;LI Min;CHEN Hua;LI Yaozhong;LI Xianjun

2004, 55(12): 2020-2026.

Abstract ( 978 )

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The studies of olefin hydroformylation in aqueous/organic bi-phase catalyzed by water soluble RhCl(CO)(TPPTS)₂-cationic surfactant complex system was introduced.The acceleration of the reaction by cationic surfactant was connected with the mechanism of meta-stable micellar-ionic pair synergistic action.The enrichment of rhodium catalyst on the micellar interface and solubilization of olefin in hydrophobic core of micelle created a very favorable microcircumstance for olefin coordination with rhodium complex.Therefore the high region-selective and high active rhodium catalyst systems could be designed and prepared by molecular assembly on biphasic interface.The modification of catalytic performance of rhodium complex was realized by the application of CTAB-SDS mixed surfactants and TPPTS-TPPDS mixed ligands.TOF(turnover frequency,h^-1)and normal/isomer aldehyde ratio (n/i)in 1-dodecene hydroformylation catalyzed by the modified rhodium catalyst reached 200—350 h^-1 and 18—40,respectively.The matching effect between chain length of olefin and surfactant was discovered.If both the chains length were similar the catalyst had high region-selectivity.When cationic surfactant with double long chain combined with water soluble rhodium phosphine complex, the catalyst system exhibited high activity and TOF of 1-dodecene hydroformylation could reach over 1000 h-1 even without stirring.

LIQUID-PHASE SELECTIVE OXIDATION OF CYCLOHEXANE WITH MODIFIED-VPO CATALYSTS UNDER MILD CONDITION

JI Hongbing;QIAN Yu;LUO Sirui;HE Dugui

2004, 55(12): 2027-2031.

Abstract ( 839 )

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Elements including La, Ce and Bi were used to modify V-P oxide(VPO)catalyst which were used to catalyze cyclohexane oxidation in the liquid phase.Bi-VPO catalyst showed the best performance in liquid-phase oxidation.2 mmol of cyclohexane in 10 ml of acetonitrile could be well converted at 60℃ for 12 h by adding 3 ml (26 mmol) of H₂O₂, and 72% of cyclohexane conversion rate, 38% of cyclohexanone yield, and 34% of cyclohexanol yield were achieved with 0.01 g (V: 0.068 mmol) of Bi-VPO catalyst.Modified VPO catalysts could greatly enhance the catalytic performance in liquid-phase oxidation of cyclohexane.

NOVEL TECHNOLOGY FOR GREEN SYNTHESIS OF p-NITROBENZALDEHYDE WITH METALLOPORPHYRINS AS BIOMIMETIC CATALYSTS

SHE Yuanbin;FAN Lili;ZHANG Yanhui;SONG Xufeng

2004, 55(12): 2032-2037.

Abstract ( 914 )

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p-Nitrobenzaldehyde,an important intermediate for the manufacture of fine chemicals，was widely used for the preparation of pharmaceutical drugs，dyes, pesticides and non-linear optic materials.p-Nitrobenzaldehyde was prepared indirectly in industrial scale via p-nitrotoluene with chemical oxidants such as potassium permanganate or nitric acid.However such problems as severe environmental pollution, equipment corrosion,and large energy consumption remain to be solved.A novel technology for green synthesis of p-nitrobenzaldehyde by dioxygen oxidation of p-nitrotoluene under mild conditions of 30—50 ℃,0.5—2.0 MPa for 6—12 h was investigated in order to solve above problems.The novel technology was characterized by metalloporphyrin biomimetic catalysts to replace conventional catalysts,with clean oxygen/air replacing chemical oxidants polluting environment,and methanol-NaOH alkali medium replacing corrosive acidic medium.The effects of the center metal ions, substituents and their position, and ligands in axis of catalysts and reaction time on the conversion of p-nitrotoluene, selectivity and yield of p-nitrobenzaldehyde were investigated systematically.The results showed that the conversion of p-nitrotoluene was up to 83.0%,and the maximum selectivity and yield of p-nitrobenzaldehyde were 87.9% and 73.0% respectively under the optimum conditions: methanol as solvent,1.8 mol•L^-1 of NaOH concentration, 6.0×10^-5 mol•L^-1 of T(o-Cl)PPMn catalyst, reaction at 45 ℃, 1.6 MPa for 10h.

RECYCLING SET-UP FOR ALKYLATION OF BENZENE WITH 1-DODECENE CATALYSED BY IONIC LIQUID

QIAO Congzhen;LI Chengyue;CHEN Biaohua;TIAN Xiaoning

2004, 55(12): 2038-2042.

Abstract ( 733 )

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Based on the bi-phase and high reaction rate properties of benzene alkylation with 1-dodecene catalyzed by ［BMIM］［AlCl₄］ ionic liquid, a continuous mixing-reacting-separating-recycling experimental setup was developed.A static mixing reactor was used to realize the needed fast mixing and chemical reaction.The continuous fast separation of ionic liquid from reaction mixture was carried out in a combined settling separator.Running tests showed that the continuous efficient mixing and separation between ionic liquid catalyst and reaction mixture could be accomplished within some flow rate ranges of the recycling reaction mixture and the ionic liquid catalyst injected.The moisture-sensitive ionic liquid catalyst could be effectively ratained in the system and recycled.Alkylation tests demonstrated that the setup could be successfully used to synthesize LAB with relatively higher 2-phenyl LAB selectivity.

MANNICH REACTION OF ALDEHYDES, KETONES AND AMINES CATALYZED BY BRONSTED ACID IONIC LIQUIDS

LIU Baoyou;XU Danqian;LUO Shuping;ZHANG Fan;XU Zhenyuan

2004, 55(12): 2043-2046.

Abstract ( 838 )

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Mannich reaction of a series of aldehydes, ketones and amines catalyzed by Bronsted acid ionic liquids (ILs) was investigated.1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF₄) /1-butyl-3- methylimidazolium dihydrogen phosphate (BMImH₂PO₄) and 1-ethylimidazolium trifluoroacetic acid (HEImTA) were chosen as reaction media.Shorter reaction time and the excellent yield were obtained as compared with the traditional processes.Product isolation was easy (by hydrolysis of reaction mixture and subsequent filtration), and the acid ionic liquids (also acting as a catalyst) could be easily to be recycled efficiently.The application scope of the established process was also discussed.

ACETALIZATION OF ALDEHYDES WITH DIOLS CATALYZED BY IONIC LIQUIDS

ZHANG Fan; XU Danqian;LUO Shuping;LIU Baoyou ;XU Zhenyuan

2004, 55(12): 2047-2050.

Abstract ( 887 )

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The acetalization of aldehydes with diols was accomplished by using ionic liquids as catalyst and reaction media.The effects of ionic liquids,reaction time, reaction temperature and reactants ratio on the conversion and selectivity of acetalization were investigated.In the reaction process removal of water produced and use of other acidic catalysts were not necessary.Medium to high conversion and good selectivity were obtained.The ionic liquid could be recycled and reused after removal of water under reduced pressure.

ADSORPTION BEHAVIOR OF SOLID WASTE OF LEATHER MANUFACTURE

LIAO Xuepin;ZHANG Mina;WANG Ru;SHI Bi

2004, 55(12): 2051-2059.

Abstract ( 759 )

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The adsorption behavior of chrome-containing and tannins-containing solid waste originated from leather manufacture was investigated. The experimental results indicated that the chrome-containing leather waste could substantially adsorb acid dyes and direct dyes.However it was ineffective for the adsorption of alkali dyes.The adsorption equilibrium of chrome-containing leather waste to acid dyes and direct dyes could be described by the Langmuir equation and the pseudo-second-order rate model gave perfect fitting to the adsorption kinetics.The tannins-containing leather waste exhibited high adsorption capacities to Au3+、U6+、Th4+ and Hg2+.However the adsorption equilibrium of metal ions on the tannins-containing leather waste could not be described by single equation.The adsorption equilibrium of Cu2+、U6+、Pb2+ and Hg2+ could be described by the Freundlich equation, while that of Au3+ and Th4+ could be described by the Langmuir equation.These facts implied that the different adsorption mechanisms might be involved in the adsorption processes of metal ions on the tannins-containing leather waste. The pseudo-second-order rate model also gave perfect fitting to the adsorption rate data of metal ions on the tannins-containing leather waste. The adsorption column of chrome-containing leather waste could be easily regenerated after adsorption of dyes. Similarly, the adsorption column of tannins-containing leather waste could be also easily regenerated after adsorption of metal ions except Au3+. The change of adsorption behavior of the regenerated columns was not considerable, which indicated the potential value of a using solid waste of leather processing in environmental protection.

INFLUENCE OF MAIN PARAMETERS ON WOOD SAWDUST GASIFICATION IN SUPERCRITICAL WATER

LV Youjun, GUO Liejin, HAO Xiaohong, JI Chengmeng

2004, 55(12): 2060-2066.

Abstract ( 796 )

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Hydrogen is gaining increasing attention as an encouraging future energy.Thermochemcial gasification of biomass in supercritical water has been identified as a promising approach to producing renewable hydrogen.The raw biomass feedstock of wood sawdust mixed in sodium carboxymethylcellulose (CMC) was gasified at a pressure range from 17.5 MPa to 30 MPa and 650 ℃ in a tubular flow reactor with a reactor residence time of 14.4—50 s.The influence of the main parameters (pressure, temperature,residence time and concentration of solution) on wood sawdust gasification was investigated.Wood sawdust was gasified almost completely.The product gas was composed of hydrogen, carbon dioxide, methane, carbon monoxide and a small amount of ethane and ethylene.The molar fraction of hydrogen in excess of 40% was reached.Results from the experiments showed that recycling liquid effluent was possible.

AMMONIA SYNTHESIS AT SUPERCRITICAL CONDITIONS

LIU Huazhang;TANG Haodong;LI Xiaonian

2004, 55(12): 2067-2071.

Abstract ( 828 )

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Ammonia synthesis at supercritical conditions was first studied over iron and active carbon-supported ruthenium catalysts in a fixed-bed reactor.The influences of 15 kinds of different supercritical media,such as alkanes of C7—C13, 1,2,3,4-tetrahydronaphthalene,cis-decalin,o-xylene,ethylbenzene,quinolin,n-hexane and aniline etc.and reaction conditions (catalyst, temperature, space velocity, particial pressure of media) on ammonia at supercritical condition were investigated.Supercritical medium was decomposed under reaction conditions over Fe and Ru/AC catalysts.The decomposition products deactivated the catalysts.Alkane decomposed the least,and the rate of deactivation was the slowest.Therefore alklane was a relatively good medium.The decomposion of supercritical medium was the key for the deactivation of catalysts.Another important reason for the decrease of ammonia concentration was that the effective pressure of syngas decreased because of the presence of supercritical media.The active temperature of catalyst was the decisive factor in supercritical ammonia synthesis.Supercritical catalytic reaction was viable only at a lower temperature.Ammonia synthesis at supercritical conditions is possible if a catalyst with active temperature lower than 573 K could be developed and the decomposition of supercritical media could be prevented.

CLEAN PROCESS OF FLUTHIACET-METHYL AS SUPER EFFECTIVE HERBICIDE

DU Xiaohua;XU Xiangsheng;LIU Haihui;XU Zhenyuan

2004, 55(12): 2072-2075.

Abstract ( 918 )

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A clean process with 3 steps for the synthesis of Fluthiacet-methyl as a super effective herbicide is developed.The product was prepared in several patented methods.However, those methods had the disadvantages of using hazardous materials such as thiophosgene, chloroformate, hexahydropyridazine and phosgene.In the present work, the hazardous materials were replaced by safe reagents,for example, thiophosgene by carbon disulfide, chloroformate and phosgene by bis(trichloromethyl) carbonate(BTC) and hexahydropyridazine by hexahydropridazine hydrochloride.Therefore, the process is operationally convenient and safe with little environmental hazard.Furthermore, the total yield (63%) is quite higher than that (39%) reported in literature.The clean process is valuable for manufacturing Fluthiacet methyl in industrial scale.

PREPARATION OF NOVEL ULTRAFINE EMBEDDED CATALYST FOR OXIDATIVE CARBONYLATION OF PHENOL TO DIPHENYL CARBONATE

XUE Wei, ZHANG Jingchang, WANG Yanji, ZHAO Xinqiang, ZHAO Qian

2004, 55(12): 2076-2081.

Abstract ( 736 )

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A novel catalytic material, ultrafine silica embedded catalyst, was prepared through the hydrolysis of tetraethoxysilane (TEOS) in W/O microemulsion, which was composed of cyclohexane, polyoxyethylene (10) nonylphenyl (NP-10), hexanol and aqua ammonia of PdCl₂ and Cu(OAc)₂.It was found that the active species was wholly or partly embedded in the spherical silica particles with diameters in the range of 40—120 nm.The catalytic behavior of the catalyst in oxidative carbonylation of phenol to diphenyl carbonate (DPC) was studied. Under the optimized conditions(80℃，3.9 MPa and 8 h), the yield of DPC was 35.4%. In comparison with the catalysts prepared by the impregnation and sol-gel method, the ultrafine embedded catalyst showed high activity and long service time.When the catalyst was used at 80 ℃，3.9 MPa and 4 h for 4 times, the yield of DPC was 25.2%, 16.5%, 14.5% and 13.4%, respectively.

CATALYSTS FOR MANUFACTURING METHYL METHACRYLATE FROM ISOBUTYLENE

WANG Lei;ZHANG Suojiang;LI Zengxi;LI Guihua;LI Mingxiu

2004, 55(12): 2082-2085.

Abstract ( 1126 )

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The catalysts used for manufacturing methyl methacrylate (MMA) by two-step conversion of isobutylene via methacrolein (MAL) were studied. The selective oxidation of isobutylene to MAL was carried out in a fixed-bed flow microreactor using a series of Mo-Bi-containing catalysts and the oxidative esterification of MAL to MMA was carried out in a slurry-bed reactor using a series of palladium-containing catalysts.By means of BET and XPS, the properties of the catalysts were characterized.It was found that the performance of Mo-Bi-Co-Fe-Ce-O catalyst was improved distinctly when Cs was added for the selective oxidation of isobutylene to MAL, and the Pd₅Bi₂PbFe/CaCO₃ catalyst with the loading sequence of Pd, Pb and Bi, Fe showed the best performance for the oxidative esterification of MAL to MMA.

PREPARATION OF METALLOPORPHYRINS AND THEIR ELECTROCHEMICAL CHARACTERISTICS

XIE Xianyu;REN Qizhi;MA Zifeng

2004, 55(12): 2086-2090.

Abstract ( 910 )

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Metalloporphyrins containing different substitute groups (methyl, methoxy) on the base of phenyl and different metals (Zn，Fe，Co) were synthesized and characterized by EA, UV/vis and ¹H NMR.Effects of different substitute groups and metal ions showed above on the electrochemical behavior of redox were studied by means of the cyclic voltammograms method(CV)in the DMSO solution with TBAP as supporting electrolyte. Furthermore, catalyzed oxygen reduction behavior of cobalt tetramethoxyphenylporphyrin (CoTMPP) based catalysts by CV in 0.5 mol•L^-1 H₂SO₄ was investigated.

SEPARATION OF AROMATIC HYDROCARBONS OR OLEFINS FROM PARAFFINS USING NEW IONIC LIQUIDS

ZHU Jiqin;CHEN Jian;FEI Weiyang

2004, 55(12): 2091-2094.

Abstract ( 804 )

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The separation of aromatic hydrocarbons or olefins from paraffins is very important in chemical industry.The volatile organic solvents used are usually harmful to environment and human health.As green solvents，room temperature ionic liquids are potential substitutes for the separation of hydrocarbon products.Activity coefficients at infinite dilution of hydrocarbon solutes，such as alkanes，hexenes，alkylbenzenes and styrene，in 1-butyl-3-methyl imidazolium hexafluorophosphate (［BMIM］［PF₆］)，1-allyl-3-methylimidazolium tetrafluoroborate (［AMIM］［BF₄］)，1-isobutenyl-3-methylimidazolium tetrafluoroborate (［MPMIM］［BF₄］) and ［MPMIM］［BF₄］＋AgBF₄ were determined by gas-liquid chromatography.The measurements were carried out at different temperatures between 298.15 K and 318.15 K.The separation effects of these ionic liquids for olefin/paraffin, alkanes/benzene and hexene isomers were discussed.

CATALYTIC DEGRADATION OF MACROMOLECULAR CONSTITUENTS OF ASPHALTIC SANDS IN IONIC LIQUIDS

ZOU Changjun, LIU Chao, HUANG Zhiyu, LUO Pingya

2004, 55(12): 2095-2098.

Abstract ( 843 )

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This paper illustrates the reaction pattern of catalytic degradation of macromolecules in asphaltic sands.Such parameters as ionic liquid catalyst system and H⁺ proton donor,that affect the change of the organic phase and the mass of organic matter in residual phase of asphaltic sands,were investigated.It was found that chloroaluminate (Ⅲ) ionic liquid/H₃PO₄ systems as reaction medium was an effective catalyst system for asphaltic sands degradation.The catalytic degradation of asphaltic sands was related to the kinds of chloroaluminate (Ⅲ) ionic liquids and H⁺ proton donor. In ［BMIM］［AlCl₄］/H₃PO₄ reaction catalytic medium, the degradation of asphaltenes in the organic phase reached 16.44%, the degradation of asphaltenes in the residual phase reached 30.74%.TLC-FID analysis of asphaltic sands showed that the main degradation products were saturates and aromatics,and resin fractions as well.At a temperature close to oil-bearing formation and with absense of oxygen,the yield of H₂S reached 74%, which indicated that catalytic degradation of sulphur-containing compounds was easier.

CHEMICAL ANALYSIS OF PUBESCENS AND ITS PYROLYSIS

DU Ying;QI Weiyan;MIAO Xia;LI Guiying;HU Changwei

2004, 55(12): 2099-2102.

Abstract ( 1035 )

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In recent years, great attention has been paid to the exploitation and use of biomass energy.Using bamboo as the raw material to produce energy and other chemicals is significantly important.A primary study was made on the pubescens,one kind of bamboo distributed broadly in China with fast growth rate.The contents of cellulose, hemi-cellulose, and lignin in different parts of pubescens with different growth ages, as major components of the cell wall,were determined.The analysis procedures were as follows:firstly the substances other than the above mentioned three were removed chemically, then the hydrolyzed cellulose liquid was oxidized with excess oxidants,and at last titrated.Pubescens powder was packed into the quartz tube reactor, then was heated from room temperature to 300,350, 400, 450, 500, 550 ℃ and 600 ℃ respectively in flowing N₂.Pyrolysis was held at the final temperature for 10 h.The liquid products were analyzed with GC/MS.The main products in the liquid obtained were: acetic acid, 2,6-dimethoxy phenol, 2,3-dihydrobenzofuran，etc.The pyrolysis temperature exerted great effect on the composition of the liquid products.The distribution of the products could be regulated by controlling pyrolysis temperature.

Hβ AND MODIFIED Hβ ZEOLITES AS CATALYSTS FOR BECKMANN REARRANGEMENT OF CYCLOHEXANONE OXIME

ZHANG Yongjie;WANG Yaquan;BU Yifeng;WANG Li;MI Zhentao;HE Fei;WU Wei;MIN Enze;FU Songbao;Zhu Zehua

2004, 55(12): 2103-2105.

Abstract ( 869 )

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