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    30 July 2013, Volume 47 Issue 4 Previous Issue    Next Issue
    Effects of Catalyst CaO on Fast Pyrolysis of Pine for the Production of Bio-oils
    YUAN Liang;LIU Yun-quan;WANG Duo;ZANG Yun-hao
    2013, 47 (4):  1-6. 
    Abstract ( 522 )   PDF (927KB) ( 839 )   Save
    The effects of CaO on fast pyrolysis of pine were investigated in a small bubbling fluidized bed reactor. The generated pyrolysis vapor was condensed by three-stage cooling: quench with coolant at the first stage, water cooling with shell-and-tube heat exchanger at the second stage, and ice bath cooling at the last stage. The liquids obtained from each stage were named bio-oil 1, bio-oil 2 and bio-oil 3, correspondingly. It was found that with the addition of CaO to pine, the water content in bio-oils increased, the heating value decreased, the pH increased, the content of ketones and hydrocarbons increased while phenols decreased. The bio-oils stability tests showed that phenols content increased (increased to 50% when 30% of CaO is added), esters decreased and the water content increased after the bio-oils stored for 30 days at room temperature.
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    Promotion and Inhibition Effects of Phenolic Acids on Clostridium Acetobutylicum Fermentation
    ZHANG Lian-hua;WANG Lan;CHEN Hong-zhang
    2013, 47 (4):  7-11. 
    Abstract ( 443 )   PDF (905KB) ( 874 )   Save
    Phenol acids generated during lignocellulose pretreatment process can affect the growth and metabolism of Clostridium acetobutylicum. Promotion and inhibition effects of ferulic acid, vanillic acid, syringic acid and p-hydroxybenzoic acid on butanol fermentation were investigated. The results showed that low concentration of phenolic acids (lower than 100 mg/L) played a promotion role in butanol fermentation. Butanol yield was increased by 21.72% when 60 mg/L hydroxybenzoic acid was added into fermentation culture, whereas biomass reached 4.50 times that of the control group when 100 mg/L vanillic acid was added. However as the inhibitor concentrations increased (higher than 100 mg/L), the effect of inhibition became more obvious. Butanol production was inhibited 96.67% when 1 000 mg/L of vanilla acid was added, and the biomass of all experimental groups failed to detect. A way of direct butanol fermentation without detoxification steps by increasing the inoculation rate to enhance bacterial inhibition point was established. Butanol yield of 9.16 g/L, which was the normal fermentation level, was obtained by 30% inoculation. These four phenolic acids had similar effects on butanol fermentation, but differed in their toxicity to bacteria. The toxicity of phenolic acids was significantly correlated with their ionization constants and molecular weight, and the correlation coefficients were 0.816 and 0.876, respectively, by quantitative structure activity relationships (QSAR) method, i.e. the smaller ionization constants and molecular weight, the greater the toxicity. But the toxicity presented no significant negative correlation with the hydrophobic.
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    Studies on Steam Explosion of Broussonetia papyrifera Bark
    ZHAO Jian;WEI Min;LIU Jun-li;JIANG Jian-chun
    2013, 47 (4):  12-16. 
    Abstract ( 463 )   PDF (1816KB) ( 701 )   Save
    The effects of steam explosion pressure and pressure holding time on the yield of reducing sugar degraded by acid hydrolysis after steam explosion pretreatment of Broussonetia papyrifera bark were investigated. The greatest reducing sugar yield 76.48%. It was obtained under a steam explosion pressure of 2.2 MPa, and a pressure holding time of 9 min. In the process of acid hydrolysis of the raw material without steam explosion pretreatment, reducing sugar yield was only 47.25% of the theoretical amount. Comparing with the non-pretreatment material, the reducing sugar yield of pretreatment material was increased by 61.86%. The structural variations of the fibres of B.papyrifera bark before and after steam explosion pretreatment were observed by scanning electron microscope.
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    Synthesis of Tributyl Citrate Catalyzed by Ionic Acid Catalyst
    YIN Yan-bai;HAN Jia;ZHANG Ya-li;LIU Tao
    2013, 47 (4):  26-28. 
    Abstract ( 515 )   PDF (796KB) ( 1381 )   Save
    Synthesis of Tributyl Citrate under the catalysis of [Hmim]+[HSO4]- was investigated. The optimum reaction conditions were as follows:15% catalyst based on the reactants, n(butyl alcohol):n(citric acid)=6:1, cyclohexane as water-carrying agent, reaction temperature 110, and reaction time 7 h. Under these conditions, the yield of product was above 97%. The catalyst can be reused 10 times. The structure of product was characterized by FT-IR 1H NMR. The quality of Tributyl Citrate synthesized in this paper is superior to general commercial products with low chrominance value, similar acid value and moisture.
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    The Effect of Solvent Extraction on Pyrolytic Decomposition and Combustion of Cut Tobacco
    ZHAO Wei;HAN Jing-mei;ZHENG Qi;LIU Chun-bo;LIU Zhi-hua;MIAO Ming-ming;WANG Ya-ming
    2013, 47 (4):  17-20. 
    Abstract ( 467 )   PDF (860KB) ( 1237 )   Save
    The thermogravimetry analysis was used to study the effects of solvent extract on pyrolytic decomposition and combustion of cut tobacco. The results indicated that the thermal chemical properties of hexane and ethyl acetate extraction were much more like the ones of normal tobacco and other than the ones of methanol extraction. By calculation, the order of combustion index was Sn(normal tobacco)>Sn(hexane extracting)>Sn(ethyl acetate extracting)>Sn(methanol extracting).
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    Research of Producing Acids Condition in Countercurrent Anaerobic Fermentation of Cassava Dregs
    ZHU Yu-lian;NIE Wei;LI Rui;KONG Qiao-ping;GU Bi;ZHOU Jing-hong
    2013, 47 (4):  21-25. 
    Abstract ( 478 )   PDF (861KB) ( 769 )   Save
    During the countercurrent anaerobic fermentation of cassava dregs, the effects of different substrate concentrations and substrate residence time on of acid production and degradation rate of the substrate were investigated. The best substrate concentration is 80 g/L, and the best sludge retention time is 12 d. Under this condition, the concentration of VOA reach 6.75 g/L,and the ratio of acetic acid to VOA reach 75.9%,and substrate degradation rate reach 27.1%.
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    The Domestic and Abroad Research Status of Biomass Pyrolysis Kinetics Model
    LI San-ping;WANG Shu-yang;SUN Xue;CAO You-wei
    2013, 47 (4):  29-36. 
    Abstract ( 673 )   PDF (1033KB) ( 3120 )   Save
    This paper provides an updated review on the domestic and abroad research status of biomass pyrolysis kinetics model. The kinetics model is divided into single component global model and multi-component global model. The multi-component global model mainly includes cellulose, hemicellulose, lignose pyrolysis kinetics model, Miller model and Janse model etc..
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    A Review of Technology in Small-scale Biomass Combustion System for Heating
    LUO Bing;HE Fang;ZHANG Yong-jian;LI Yong-jun
    2013, 47 (4):  37-40. 
    Abstract ( 475 )   PDF (1617KB) ( 1570 )   Save
    Small-scale heat production via direct biomass combustion is flexible and convenient. It is suitable for the utilization of biomass which has low energy density and is decentralized distribution. In this paper, technology in small-scale biomass combustion system for heating has been summarized and the market problems of this technology in our country have been analysed. The work provides reference for the development of technology in small-scale biomass combustion system for heating in our country.
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    Removal Technologies of Mercury from Coal-burning Flue Gas
    XIE Xin-ping;JIANG Jian-chun;Sun Kang;LU Xin-cheng;WANG Jin-biao
    2013, 47 (4):  41-46. 
    Abstract ( 444 )   PDF (897KB) ( 1230 )   Save
    With the more and more strict control of mercury emission limit, studies on mercury control are focused on removal of mercury from coal-burning flue gas. Emission sources and harm of mercury are briefly described. The control technologies of flue gas are systematically summarized.
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    An Approach to Levulinic Acid Production from Cassava Starch and Market Prospect
    CHEN Ke-qiang
    2013, 47 (4):  47-52. 
    Abstract ( 565 )   PDF (1250KB) ( 1401 )   Save
    Using starch as material, levulinic acid (LA) is obtained by heating and hydrolysis under H2SO4 condition. In this process, starch splits into hexose monomers and then further degrade to 5-hydroxymethylfural by dehydration, which finally degrade to levulinic acid. The paper summarized the processes of Nebraska Lincolnt University's and Biofine's. Levulinic acid is separated and purified by adsorbent resin. Both processes are suitable for commercial production of levulinic aidc. The process has low cost and is suitable for industrial production. It is possible on technology and feasible on economy to use cassava starch as raw material to produce levulinic acid on a pilot scale of 50-500 t/a.
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