Table of Content

30 May 2009, Volume 43 Issue 3 Previous Issue    Next Issue

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The Kinetic Study of Dissociation and Activation of Walnut Shell with Phenol LIU Chun-hui;LING Min;ZHANG Hong-jian;WANG Rong 2009, 43 (3):  1-4.  Abstract ( 418 )   PDF (675KB) ( 636 )   Save The reaction mechanism of dissociation and activation of walnut shell in liquefaction with phenol by acid catalyst was studied by determination of the free phenol content and residue content in the conditions of different reaction time and temperature by application of Arrhenius equation, transition theory and kinetic analysis. The results showed that the free phenol content and residue content in dissociated product decreased with the extending of reaction time. The dissociation and activation of walnut shell with phenol by acid catalyst accorded with a bimolecular second-order endothermic reaction. The activation energy, pre-exponential factor, activation enthalpy and activation entropy were 65.24 kJ/mol,2.39×106 min-1, 65.24 kJ/mol, and -122.09 J/mol, respectively. Related Articles | Metrics

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Study on Fractal Characteristics of Biomass Chars LIN Xiao-fen;ZHANG Jun;YIN Yan-shan;SHENG Chang-dong 2009, 43 (3):  9-12.  Abstract ( 490 )   PDF (791KB) ( 780 )   Save The fractal dimensions of four biomass chars from rice shell, leaves of Platanus orientalis L., corn stalk and cotton stalk were calculated using Menger sponge model and thermodynamic model based on measured results of their pore structure by mercury porosimetry. The results showed that thermodynamic model was close to pore structures of biomass chars. The fractal dimensions of biomass chars were bigger,i.e. irregularity and changed with varieties of biomass. The fractal dimension of biomass char from leaves of P.orientalis L. was the biggest in four biomass chars, meanwhile that from corn stalk was the smallest. The fractal dimensions of biomass chars were influenced by factors such as pyrolysis temperature, pyrolysis rate, and pyrolysis time for preparation of chars. The influence of pyrolysis temperature was the biggest in above factors. The influences of pyrolysis conditions depend on the plasticity of biomass. Related Articles | Metrics

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Research on Thermodynamics and Kinetics of Pyrolysis and Activation Processes of Corn Stalk Pellet JIA Shao-gang;WANG Cui-ping;LV Zi-an;LI Ding-kai 2009, 43 (3):  13-17.  Abstract ( 609 )   PDF (861KB) ( 718 )   Save The processes of pyrolysis and activation of corn stalk pellets for the activated carbon production were studied by thermogravimetry. The pyrolysis conditions were: nitrogen as shield gas, temperature rate 5K/min, final temperature 723 K and thermostatic time 30 min. The process of pyrolysis occured primarily between 450-620 K, the microcellular structure and mechanical strength of pyrolysis char were good. The activation conditions were: carbon dioxide as shield gas, temperature rate 10K/min, final temperature 1073 K and thermostatic time 20 min. The process of activation occured primarily between 950-1070 K, the obtained activated carbon has high specific surface(404.6 m2/g) and excellent adsorption abilities. The activation energy and frequency factor parameters were determined by analysis of the thermogravimetric and differential thermal charac-teristics of the pyrolysis and activation processes.The thermodynamic and kinetic characteristics of pyrolysis and activation processes were concluded. It will provide theoretical guide to the production of better biomass activated carbon pellets. Related Articles | Metrics

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Enhancement of Sulfuric Acid Catalytic Hydrolysis of Rice Straw by Microwave Irradiation GONG Yan;YIN Du-lin;LI Hui;GUO Jian-ping 2009, 43 (3):  5-8.  Abstract ( 578 )   PDF (680KB) ( 799 )   Save Under microwaves irradiation, the enhancement of sulfuric acid hydrolysis process of rice straw was studied. The effects of microwave power, irradiation time, mass fraction of sulfuric acid and rice straw amount in 1L sulfuric acid solution on yield of reducing sugar were investigated. Compared with conventional acid hydrolysis, microwave radiation can significantly raise the rate of hydrolysis and shorten the time of saccharification. By means of orthogonal experiment, the conditions for sulfuric acid hydrolysis of rice straw under microwaves irradiation were optimized as follows: microwave power 280 W, irradiation time 30 min, sulfuric acid mass fraction 25%, rice straw amount in 1 L sulfuric acid solution 30 g, and the reducing sugar yield reached 26.45%. Related Articles | Metrics

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Preparation and Adsorption Property of Silver Loaded Bamboo-charcoal WEI Hua-juan;NI Yu-yu;YAO Li-li;ZHANG Qi-wei 2009, 43 (3):  18-20.  Abstract ( 704 )   PDF (527KB) ( 619 )   Save Silver loaded bamboo-charcoal was prepared by adsorption method. The influence of adsorption conditions on mass fraction of silver was studied. The results showed that the higher the concentration of silver nitrate, the bigger the mass fraction of silver loaded and the bigger the amount of bamboo-charcoal, the smaller the mass fraction of silver loaded in a definite silver nitrate solution. The influence of mass fraction of silver on adsorption capacity was also studied. The results showed that the loaded bamboo-charcoal still had a good adsorption capacity in spite of a little decline. The research results of adsorption and distribution characteristics of Ag+ in bamboo-charcoal showed that the adsorption of Ag+ on bamboo-charcoal was a mixed adsorption process, but mainly was a reduction adsorption. Ag+ mainly distributed on outer surface and in macropores of bamboo-charcoal. Related Articles | Metrics

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Antioxidative Activities of Extracts from Pinus massoniana Needles by Different Extraction Processes PAN Xin;CHEN Shun-wei;ZHUANG Xiao-wei 2009, 43 (3):  21-24.  Abstract ( 506 )   PDF (699KB) ( 629 )   Save Four extracts from Pinus massoniana needles such as SCDEP,IUEP,OUEP and EEP were prepared by supercritical carbon dioxide extraction,internal ultrasonic extraction,outer ultrasonic extraction and ethanol extraction. The contents of total phenols and total flavonoids in four extracts were determined. The antioxidative activities of four extracts were also investigated. The results showed that the content of total phenols and total flavonoids in SCDEP was 22.18% and 4.96%, respectively, which was highest in four extracts. The content of total phenols and total flavonoids in EEP was 13.47% and 2.98%, respectively, which was lowest in four extracts. All of the four extracts had good antioxidative activities. The capacities of DPPH free radical scavenging and reduction of ferric ion of SCDEP, IUEP and OUEP were stronger than those of BHT. The capacity of reduction of ferric ion of EEP was weaker than that of BHT. The contents of total phenols and total flavonoids in extracts had obvious interrelationship with their antioxidative activities. Related Articles | Metrics

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GC-MS Analysis of Chemical Components of Essential Oil from Leaves of Cinnamomum chekiangense YANG Qing;CHEN Shi-pin;ZOU Li-qing;LIAN Pei-hua 2009, 43 (3):  25-28.  Abstract ( 473 )   PDF (758KB) ( 611 )   Save Essential oil from leaves of Cinnamomum chekiangense was obtained at the ratio of 100 g leaves to 100 mL water by 2.5 h of steam distillation and then 3 h of ethanol extraction. The oil yield was 1.84%. 60 compounds in oil which were about 98.57% of mass fraction of the oil were identified by GC-MS method. The content of p-cymene which was the highest in oil was 22.14%, and that of cinnamaldehyde was only 0.162%, safrole which was forbidden to be used in food was not detected. The oil from leaves of C.chekiangense had different usage because its main components were different markedly with that of other plants in the same genus. Related Articles | Metrics

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Study on the Effect of Maleic Anhydride-α-olefin Copolymers and Their Esters on Biodiesel Pour Point Depression CHEN Xu-tang;YU Shai-cheng;ZHU Zhi-hua 2009, 43 (3):  28-33.  Abstract ( 782 )   PDF (949KB) ( 621 )   Save The maleic anhydride-α-olefin copolymers and their esters were prepared from maleic anhydride, α-C12-18 olefins and C12-18 alcohols by binary polymerization and alcoholysis.The copolymers and their esters were employed as pour point depressant to improve the low-temperature fluidity of biodiesel. The effects of prepared pour point depressants on the pour point of palm oil biodiesel, before and after diluted by anhydrous ethanol and O# diesel, were evaluated. In addition, the pour point depression effects of prepared pour point depressants were verified when applied to reduce the pour point of soybean oil biodiesel. The results indicated that: when the mass fraction of anhydrous ethanol and O# diesel in palm oil biodiesel was 40% and 80%, adding 3% prepared pour point depressants, the pour point reduced by 8℃and 25℃, respectively;by adding of 0.5% prepared pour point depressants into soybean oil biodiesel, the pour point reduced by 15℃. Related Articles | Metrics

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Technical Optimization of Preparing Vanillin by Oxidation of Isoeugenol XU Ming 2009, 43 (3):  34-36.  Abstract ( 790 )   PDF (511KB) ( 889 )   Save The technique of preparing vanillin by oxidation of isoeugenol was optimized through orthogonal test. The yield of crude product was over 55% at the condition of isoeugenol 60 g,reaction time 5 h,oxidant 108 g,32% NaOH solution145 g. The content of vanillin after recrystallization in ethanol was over 99%.The technique could increase the yield of product and purify aroma of product compared with orginal technique. Related Articles | Metrics

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Research Progresses on Liquefaction Technology of Lignin FENG Guo-dong;ZHOU Yong-hong;HU Li-hong; 2009, 43 (3):  37-41.  Abstract ( 724 )   PDF (835KB) ( 913 )   Save Liquefaction technology of lignin at home and abroad was reviewed. The liquefaction technologies including pyrolysis, catalytic hydrogenation, coliquefaction and supercritical was introduced. The mechanism of liquefaction, analytical method and application of liquefied products were also summarized. Related Articles | Metrics

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Application of Lignin in Wood Adhesives MU You-bing;SHI Juan-juan;WANG Chun-peng;ZHAO Lin-wu;CHU Fu-xiang;MO Ya-li 2009, 43 (3):  42-46.  Abstract ( 627 )   PDF (929KB) ( 895 )   Save The development and application of lignin adhesive,lignin-phenol-formaldehyde adhesive and lignin-urea-formaldehyde adhesive were reviewed at home and abroad. The developing prospects were also advanced. Related Articles | Metrics

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Research Progress on Production of Ethanol as Fuel from Fast Pyrolysis Products of Lignocellulose REN Pu-xian;JIANG Jian-chun;YANG Xiu-shan;LIU Jun-li 2009, 43 (3):  47-51.  Abstract ( 674 )   PDF (981KB) ( 822 )   Save The research progress of pretreatment of lignocellulosic material, fast pyrolysis, treatment of fast pyrolysate, and fermentation of pyrolysate at home and abroad was introduced. The problems of ethanol production from lignocellulose and production method of ethanol as fuel from pyrolysate were discussed. Related Articles | Metrics