Table of Content

30 December 2011, Volume 31 Issue 6 Previous Issue    Next Issue

研究报告

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Preparation of Nano-TiO2/Cellulose Composite Fiber in Ionic Liquid and Its Photolytic Activities MA Ying-chong;LI Kun-lan;WEI Zhi-ping;WEI Li-gang;DU Jing;YANG Hai-jing 2011, 31 (6):  11-14.  Abstract ( 841 )   PDF (810KB) ( 807 )   Save Nano-TiO2/cellulose composite fiber can be widely employed in the processes of textile, material and catalysis, etc. In this work, nano-TiO2 powder was blended with a solution of cellulose/1-butyl, 3-methylimidazolium chloride (Cl) ionic liquid. The cellulose composite fibers with different nano-TiO2 content were prepared using wet molding technology. The me-chanical property, morphology and structure of the prepared fiber were further characterized through mechanical testing, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FT-IR), respectively. Photolytic performance of the composities was also investigated with methylene blue as model compound. The results indicate that the nano-TiO2 content significantly influences the property and morphology of the prepared composite fiber. With increasing nano-TiO2 content from 2.0 % to 16.7 %, the breaking strength decreases, the initial modulus decreases from 0.139 cN/dtex to 0.077 cN/dtex, but the photoly-tic activity descends first and then ascends. The composite fibers with nano-TiO2 16.7 % have a better photplytic activity. The optimized nano-TiO2 content is 2 %. Related Articles | Metrics

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Synthesis of Polyols from Oleic Acid LI Jing;JIANG Jian-chun;XU Jun-ming 2011, 31 (6):  1-6.  Abstract ( 939 )   PDF (832KB) ( 817 )   Save Oleic acid-based polyols were prepared through epoxidation, hydrolysis, and esterification of oleic acid and glycerin. The effects of different factors on epoxidation and esterification were discussed. The product and intermediate were analysed by IR and GC-MS. The optimum conditions were determined as follows:epoxidation temperature 60 ℃, epoxidation time 4 h, n(oleic acid)∶n(CH3COOH)∶n(H2O2)1∶0.5∶1.5, esterification temperature 180 ℃, esterification time 3 h, and 0.28 g ZnO as catalyst. The hydroxyl value of polyol from scale experiment reached 410 mg/g. The viscosity of the product was 4 350 mPa·s, density 1.036 g/cm3, moisture content 0.5 %, and acid value < 2 mg/g. Related Articles | Metrics

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A Two-step Statistical Optimization of Cultivation Conditions for Producing Lipid by Scenedesmus obliquus YANG Jing;JIANG Jian-chun;ZHANG Ning;WEI Min 2011, 31 (6):  7-10.  Abstract ( 691 )   PDF (279KB) ( 610 )   Save A fast and easy two-step statistical optimization of cultivation condition for producing lipid by Scenedesmus obliquus was described. At first, a fractional factorial design (FFD) was used to screen signi-ficant factors from six factors (illumination, temperature, pH value, inoculation, glucose concentration and nitrogen source concentration). Then an orthogonal experiment was executed to further determine optimal conditions. According to the results, nitrogen source concentration and temperature were selected as significant factors. The optimal conditions occurred at nitrogen source concentration 6.0 mmol/L, temperature 25 ℃ and illumination 80 μmol/(m2· s), with the highest lipid productivity of 75.46 mg/(L·d). Related Articles | Metrics

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Properties of Epoxy Resin Composites Reinforced with Poplar Wood Fiber Modified by Methyl Eleostearate Maleic Anhydride Adduct CHEN Jian;KONG Zhen-wu;JIAO Jian;FANG Gui-gan;WU Guo-min;HUO Shu-ping;NIE Ming-cai 2011, 31 (6):  25-28.  Abstract ( 987 )   PDF (875KB) ( 774 )   Save Fiber reinforced epoxy resin composites were prepared by compression molding based on poplar wood fiber modified by methyl eleostearate maleic anhydride adduct (MEMA-PWF) and bisphenol A epoxy resin/methyl tetrahydrophthalic anhydride (E51/MeTHPA). Surface properties and fracture morphology of the epoxy composites were characterized by a contact angle measurement and scanning electron microscopy (SEM). The impact strength and flexural strength were tested. It was shown from the results that the surface hydrophobicity of modified fiber, the compatibility between the modified fiber with epoxy matrix, and the mechanical properties of MEMA-PWF/epoxy composites were significantly improved. The impact strength and flexural strength of the composites were 7.95 kJ/m2 and 55.42 MPa, respectively. The composites had a better hydrophobic perfor- mance. Related Articles | Metrics

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Synthesis and Antibacterial Activity of Dihydrocumates GAO Yan-qing;WANG Dan;SHANG Shi-bin;;LI Jian 2011, 31 (6):  15-19.  Abstract ( 734 )   PDF (731KB) ( 637 )   Save Nopinic acid was synthesized using β-pinene as raw material and potassium permanganate as oxidant. After the dehydration of aqueous sulfuric acid, dihydrocumic acid was obtained. Fourteen esters were prepared by reactions of alcohols with dihydrocumic acid chloride. The preparation conditions were discussed and the structure of products were confirmed by IR, 1H NMR and MS. The antibacterial activity of products was tested through inhibition zone. Compared with the standard compound bromogeramine which diameter of inhibition zone is 9.67 mm, the compounds exhibit an excellent anti-bacterial activity against Escherichia coli(Gram-negative bacteria) except compounds 5f and 5g. Related Articles | Metrics

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Synthesis and Characterization of (β-methacryloyloxy) Ethyl Ester of Dehydroabietic Acid WANG Ji-fu;LIN Ming-tao;WANG Chun-peng;YU Juan;CHU Fu-xiang; 2011, 31 (6):  20-24.  Abstract ( 767 )   PDF (905KB) ( 724 )   Save (β-methacryloyloxy)Ethyl ester of dehydroabietic acid (DA-2-HEMA) with a purity of 99.8 % was synthesized by the reaction of dehydroabietic chloride with hydroxyethyl acrylate and characterized by using FT-IR, GC/MS, 13C NMR , DSC and GPC. The results showed that (β-methacryloyloxy)ethyl ester of dehydroabietic acid, a type of white crystals with melting point 54.23 ℃, can polymerize in the presence of initiator.The molecular weight of the homopolymer is about 20 000-30 000 g/mol and its glass transition temperature is 73.97 ℃. Related Articles | Metrics

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Effect of the Alkaline Sulfite Pretreatment on the Enzymatic Saccharification of Eucalyptus Wood WEI Wei-qi;WU Shu-bin;LIU Li-guo 2011, 31 (6):  29-34.  Abstract ( 700 )   PDF (945KB) ( 629 )   Save In order to improve the effect of enzymatic saccharification of eucalyptus wood, eucalyptus lignocellulose was pretreated by an alkaline sulfite pretreatment. The obtained samples were conducted for cellulose enzymolytic saccharification. According to the sugars yield in the enzymolysis liquid, the influence of pretreatment conditions on the reducing sugars yield was discussed. The results showed that with the increases of cooking temperature and NaOH dosage, both the glucose and xylose yields increased obviously in the enzymolysis liquid. Both glucose and xylose yields increased at first, then decreased. When the heating time and Na2SO3 dosage increased. The optimal pretreatment conditions are as follows: cooking temperature 170 ℃, sodium sulfite charge 10 %, sodium hydroxide charge 3 %, reaction time of temperature keeping 3 h. In addition, the yields of glucose and the xylose reached 60.79 % and 15.37 %, which are 3.93 and 7.88 times higher than that of the untreated, respectively. Related Articles | Metrics

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Biorefinery of Corn Stover for Fuel Ethanol ZHU Jun-jun;CHEN Shang-xing;YONG Qiang;XU Yong;CHEN Mu;YU Shi-yuan 2011, 31 (6):  35-40.  Abstract ( 976 )   PDF (1085KB) ( 914 )   Save Corn stover was pretreated by moderate acid and then washed by water. The solid residue after filtration was hydrolyzated to monosaccharide with cellulase for further fermentation to ethanol, while the liquid fraction after filtration was detoxified with trialkylamine extraction to ferment to ethanol. The material balance was carried out in the whole process. The results showed that the optimal pretreatment conditions were temperature 100 ℃, sulfuric acid mass fraction 3 % and time 12 h. After 24 h fermentation of the condensed enzymatic hydrolyzate containing 138.72 g/L of glucose, the sugar utilization rate was 99.02 % and the ethanol mass concentration reached its peak value of 62.98 g/L, which corresponded to 89.90 % of the theoretical value. Prehydrolyzate was detoxified by trialkylamine extraction, 72.73 % of acetic acid, 42.86 % of 5-hydroxymethylfurfural and 100 % furfural could be removed. The fermentability of the detoxified prehydrolyzate was significantly improved. After 48 h fermentation of the detoxificated prehydrolyzate containing 7.80 g/L of glucose and 52.80 g/L of xylose, the sugar utilization rate was 93.17 %, and the ethanol concentration reached its peak value of 21.76 g/L, which corresponded to 82.34 % of the theoretical value. After materials balance, it required 6.8 t absolutely dry corn stover to produce one ton ethanol. The process of this study provided the reference to realize the industrialization of hexose and pentose fermentation separately. Related Articles | Metrics

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Comparison of the Antioxidant Activity of the Bark Extracts of Myrica esculenta,Phyllanthus emblica and Larix gmelinii XU Man;WANG Yong-mei;ZHANG Liang-liang;WU Dong-mei;CHEN Jia-hong 2011, 31 (6):  41-45.  Abstract ( 822 )   PDF (859KB) ( 605 )   Save Proanthocyanidins, which are the predominant compounds of the bark extracts of Myrica esculenta,Phyllantus emblica and Larix gmelini, were separated and purified in the present study. Three different systems, i.e., the DPPH radical scavenging assay,FRAP and lipid peroxidation inhibitory activity were used to investigate the antioxidant activity of the extracts. The results showed that all three extracts had high antioxidant activity. The bark extracts of M. esculenta had a stronger antioxidant ability than those of P. emblica and L. gmelini. The structure-activity relationship of proanthocyanidins was confirmed on the basis of the results obtained. The more hydroxyl groups (—OH) of these compounds might contribute to the higher antioxidant activity. Related Articles | Metrics

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Fatty Acid Analysis of the Seed Oil in a Germplasm Collection of 94 Species in 58 Genera of Brassicaceae SUN Xiao-qin;PANG Hui;GUO Jian-lin;PENG Bin;BAI Ming-ming;HANG Yue-yu 2011, 31 (6):  46-54.  Abstract ( 683 )   PDF (1007KB) ( 776 )   Save Fatty acid composition and their correlation with other quality traits in a germplasm collection of 94 species in 58 genuses of Brassicaceae were analyzed by the gas chromatography. The results showed that there were 13 kinds of main fatty acid components in seed oil. Their average contents were ranked from high to low as linolenic, erucic, linoleic, and oleic acids. There existed 10 pairs with extremely significant positive correlation between palmitics acid, and stearic acid, 11 pairs with extremely significant negative correlation between linolenic acid and erucic acid, 6 pairs with significant positive correlation between palmitic acid and linoleic acid, 4 pairs with, significant negative correlation between oleic acid and linolenic acid. As correlation coefficients reflecting the degree of relationship between some fatty acid pairs were relatively low, in these fatty acid pairs, only part or very few species were consistent with the corresponding relationship, or even none showed consistency with the relationship among 19 species with the highest or lowest fatty acid content. Some excellent germplasms were found with good development potentiality and application prospect, comprehensively as high oleic acid (L. fendleri (A. Gray) S. Watson, etc.), high linoleic acid (O. violaceus L.O.E.Schulz, etc.), zero erucic acid (M. africana (Linnaeus) R. Brown, etc.), low linolenic acid (L. annua L., etc.), high oleic acid and low linolenic acid (C. hispanica L., etc.). High oleic acid and low erucic acid (O. violaceus L.O.E.Schulz, etc.) germplasms meeting the standard of edible oil and high erucic acid (B. rapa L., etc.), and high linolenic acid (S. eurycarpa (Maxim.) Botsch. var. brevistipes Y.C. Lan et T. Y. Cheo, etc.) germplasms had important industrial uses. This study also laid a theoretical foundation for further exploration. Related Articles | Metrics

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Inhibition Performance of Furfural on Carbon Steel in Hydrochloric Acid YANG Chang-yan;YANG Guang-hong;LIU Dong;DING Yi-gang;WU Yuan-xin;JI Jun;LI Shu 2011, 31 (6):  83-86.  Abstract ( 965 )   PDF (1192KB) ( 791 )   Save As a corrosion inhibitor, the corrosion inhibition of furfural obtained from straws by microwave pyrolysis was investigated in hydrochloric acid solution. The weight loss and electrochemistry polarization evaluation, and the absorbance of furfural on carbon steel was preliminary discussed. The results showed that furfural, as a complex inhibitor, gives nice inhibition efficiency on carbon steel in hydrochloric acid medium. The inhibition efficiency of furfural was up to 91.3 % when the mass fraction of furfural reaches 0.7 % at room temperature. It can also reduce the activation energy of corrosion reaction. This results in a decrease of corrosion rate. The inhibition performance of furfural is affected by temperature, and its absorbance behaviors can be expressed by the equation of Langmuir model. Related Articles | Metrics

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Synthesis and Structure Characterization of Rosin Starch Ester TANG Shi-hua;LI Jing-quan;QIN Hao-peng;YANG You-bao;LIN Yu 2011, 31 (6):  55-60.  Abstract ( 951 )   PDF (1317KB) ( 789 )   Save In the presence of DMF/LiCl solvent, rosin starch ester with the degree of substitution (Ds) of 0.125 2 was synthesized by O-acylation of starch with rosin acid chloride. The target product was analyzed and characterized by means of FT-IR, solid state 13C NMR, XRD and SEM. The reaction conditions were studied with single factor experiments and response surface methodology. A reaction model and the optimum conditions were obained. The optimum synthesis conditions were as follows: reaction time 6.5 h, reaction temperature 95 ℃, pyridine amount 3.5 mL, activation time of starch 52.5 min, DMF 29 mL and molar ratio 1∶1 (rosin acid chloride/the hydroxyl group per D-glucose unit). Under optimal conditions, the yield of RSE and Ds were 65.89 % and 0.125 2, respectively. Furthermore, its solubility and diaphaneity were determined. The results showed that compared with the unmodified starch, the crystal linity and diaphaneity of the target product decreased, and its hydrophobicity increased. Related Articles | Metrics

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Optimization of Acid Hydrolysis Processing of Nanocellulose Crystal Using Response Surface Methodology TANG Li-rong;OU Wen;LIN Wen-yi;CHEN Yan-dan;CHEN Xue-rong;HUANG Biao 2011, 31 (6):  61-65.  Abstract ( 1635 )   PDF (1278KB) ( 1093 )   Save Nanocellulose crystal was prepared by sulfuric acid hydrolysis. The effects of sulfuric acid mass fraction, temperature and time on the yield of nanocellulose crystal were optimized with response surface methodology. The mathematical model was established using the Design-Expert software. The effect of various factors and their interactions were analyzed as well. The results showed that quadratic model was the best model to describe the relationship between the yield of nanocellulose crystal and the factors. The determination coefficient and adjusted determination coefficient were 99.31 % and 98.43 %, respectively. The interactions between sulfuric acid concentration and temperature, sulfuric acid concentration and time, temperature and time were significant. When sulfuric acid concentration, temperature and time corresponded to 54 %, 52 ℃ and 125 min, the yield of nanocellulose crystal would reach 69.31 %. It is the highest value in this investigation. Related Articles | Metrics

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Enzyme-catalyzed Crosslinking of Lignin and Polysaccharides in Fiberboard WANG Lei;XIE Yi-min;XIAO Yi;YANG Hai-tao;WANG Peng 2011, 31 (6):  66-72.  Abstract ( 861 )   PDF (2304KB) ( 721 )   Save In the present research, coniferin-[α-13C]is co-polymerized with fibers of Bio-CMP of wheat straw and pectin catalyzed by laccase. A wet method was used for the formation of high-strength fiberboards. The results indicated that the thickness expansion rate of water absorbing (TS), the internal bond (IB), the modulus of rupture (MOR), and the modulus of elasticity (MOE) reached 16.7 %, 0.6 MPa, 25.1 MPa and 2 500 MPa,respectively. As a result, all mechanical properties of the medium-density fiberboard (MDF) can meet or exceed the standards of GB/T 11718-2009. According to CP/MAS 13C NMR, lignin-carbohydrate complexes(LCC) were formed between lignin and polysaccharide. Pectin and xylan in fibers were crosslinked with high through benzyl ether linkages and ester bonds, and β-aryl ether linkages were formed between lignin. Furthermore, pectin and coniferin were easy to form pectin-DHP in the presence of laccase. These complexes and linkages result in a further improvement of mechanical properties of MDF and reduction of TS. Related Articles | Metrics

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Pichia stipitis Adaptation and Xylose Fermentation in Hydrolysate Solution ZHAO Chen;FANG Hao;KONG Duan-nan;YU Shi-yuan 2011, 31 (6):  78-82.  Abstract ( 790 )   PDF (841KB) ( 740 )   Save Through adapting in steam-exploded corn stalk hydrolysate, Pichia stipitis was capable of fermenting xylose to ethanol in presence of inhibitory components. The xylose consumption rate and the ethanol yield were 94.1% and 82.1%, respectively. Fermentation started at initial xylose concentrations of 30, 45 and 60 g/L. It was found that 45 g/L had a higher average ethanol productivity and a lower average biomass productivity. According to carbon balance and carbon metabolic effluence analysis, the carbon recovery was 89.7%, and 48.5% of carbon was converted to ethanol in the hydrolysate of 51.6 g/L xylose for 36 h. Related Articles | Metrics

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Preliminary Study on Subcritical Water Extraction and Antioxidant Activity of Polyphenols from Pine Bark BO Cai-ying;ZHENG Guang-yao;CHEN Yan;ZHOU Wei-chun;LI Ruo-da;XIE Xue-rong 2011, 31 (6):  73-77.  Abstract ( 954 )   PDF (887KB) ( 1053 )   Save Subcritical water was used to extract polyphenol from pine bark. Its effects on the polyphenol yield were investigated.The DPPH radical scavenging activity of polyphenol by subcritical water extraction was determined. The results showed that the optimum process conditions were extraction temperature 150 ℃, extraction time 5 min, liquid-feed ratio 20∶1, and extraction pressure 4 MPa. Under this condition the yield of polyphenol was 4.86 %. Compared with the ultrasound-assisted extraction and heat reflux extraction, the subcritical water extraction improved the yields of polyphenol by 33.52 % and 37.68 %, respectively. The polyphenol extracted by subcritical water had a better DPPH radicals scavenging activity than that of the antioxidant BHA(7.82 mg/L). The half inhibitory concentration (IC50) of the polyphenol was 7.10 mg/L. Related Articles | Metrics

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Preparation Optimization and Morphology Analysis of Nanocrystalline Cellulose from Reed Pulp LIU Zhi-ming;XIE Cheng;FANG Gui-zhen;BU Liang-xiao;LIU Li-yang 2011, 31 (6):  87-90.  Abstract ( 741 )   PDF (897KB) ( 822 )   Save Nanocrystalline cellulose (NCC) was prepared from reed pulp with sulfuric acid hydrolysis, and the technological parameters were optimized by conducting orthogonal test. The effects of sulfuric acid mass fraction, reaction temperature and hydrolysis time on the yield of NCC were studied. The morphology of NCC was characterized by transmission electron microscopy (TEM). The results show that the sulfuric acid mass fraction has the strongest effect on the yield of NCC, reaction temperature is the second, and the hydrolysis time has a weak influence on the yield among the three paprameters. The optimizing condition is sulfuric acid mass fraction 52 %, reaction temperature 47 ℃ and hydrolysis time 4 h for NCC preparation from reed pulp with sulfuric acid hydrolysis. The yield of NCC is the highest (82.81 %) under the optimized condition. The morphology of NCC from reed pulp appeares rod-like, and the lengths of NCC reach up to nanometer grade under TEM. Related Articles | Metrics

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Optimized Biotransformation Technology of Polydatin from Polygonum cuspidatum by Solid State Fermentation to Produce Resveratrol WANG Wei;LI Xiao-pei;ZENG Bo-quan;LI Ji-lie;YAO Yue-fei 2011, 31 (6):  91-94.  Abstract ( 744 )   PDF (844KB) ( 625 )   Save Based on the solid state hydrolysis of polydatin by β-glucosidase in Aspergillus niger, the yield of resveratrol from Polygonum cuspidatum Sieb.et Zncc. increase. Using the content of resveratrol from P. cuspidatum as an evaluation standard, four factors were chosen in the solid state fermentation. They are cell age, temperature, inoculum size and ratio of water to material as the observation factors. The influencing factors of the fermentation technology of polydatin biotransformation from P. cuspidatum were studied by using univariate and L9(34) orthogonal test. The optimum fermentation technology of polydatin transformation from P. cuspidatum was as follows: temperature at 40 ℃, ratio of water to material 2∶1, a inoculum size in 1 % and a cell age at 40 h. The experimental results showed that after solid state fermentation in 48 h, the yield of resveratrol from P. cuspidatum increased to 1.48 % and was 4.35 times of the resveratrol content in the raw P. cuspidatum. Related Articles | Metrics

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Furfural Production from Bamboo (Sinocalamus affinis) Chippings by a 2-Step Dilute Sulfuric Acid Hydrolysis YIN Yan-fei;FANG Gui-gan;DENG Yong-jun;HAN Shan-ming;JIAO Jian;LIU Shan-shan;LIU Chun 2011, 31 (6):  95-99.  Abstract ( 830 )   PDF (920KB) ( 695 )   Save Different hydrolysis conditions were tested for the first hydrolysis step. The variable parameters were studied, such as the reaction temperature, the concentration of dilute sulfuric acid, the liquid-solid ratio and the reaction time. Besides, according to orthogonal experiment to study the optionization conditions of pentose production, visual and variance analysis was made. Hydrolysate for experiments on the second hydrolysis step was produced under these conditions. As a result, at liquid-solid ratio 10∶1(mL∶g), reaction temperature 115 ℃, reaction time 2.5 h, and concentration of sulfuric acid 3.5 %, the optimium pentosan conversion is 72.06 %. At the second step, with a reaction temperature 154 ℃, a reaction time 6 h, a concentration of sulfuric acid 19.34 %, and an initial pentose content 4.53%,the maximum furfural yield can reach 63.36 % of the theoretical yield. Related Articles | Metrics

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Research on Sucrose Esters─Natural Glycosyl Surfactants:A Review WANG Kui;JIANG Jian-chun;GAO Yi-wei;LI Xiang-yu 2011, 31 (6):  100-106.  Abstract ( 700 )   PDF (361KB) ( 684 )   Save This paper aims at presenting a review of the available literatures on the preparation technology of natural nonionic glycosyl surfactant sucrose esters(SE), such as acyl chloride esterification method, transesterification method and enzyme-catalysis method. It is pointed out that transesterification method is a mature technology which includes solvent method, water solvent method and solvent-free method. According to different methods, this review also describes the purification and detection presents the problem in the most convenient way and discusses the potential future research areas. Related Articles | Metrics

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Progress in Production of Alkyl Levulinates from Biomass ZHAO Geng;LIN Lu;SUN Yong 2011, 31 (6):  107-111.  Abstract ( 766 )   PDF (813KB) ( 1042 )   Save With the decrease of unrenewable resources,it has become the global attention focussing on producing fuel and chemicals from renewable biomass resource. Alkyl levulinates, which have extensive uses in the chemical industry, are a kind of important chemical product. In this paper, the production of alkyl levulinates from biomass is reviewed, and the future research trends of the production are also prospected. Related Articles | Metrics

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The State of the Art of Synthesis Gas Production Technology from Biomass TU Jun-ling;YING Hao;LI Lin-na 2011, 31 (6):  112-118.  Abstract ( 790 )   PDF (1036KB) ( 885 )   Save The research status of synthesis gas production technology from biomass is reviewed. The effects of gisifier, gasification medium, temperature and pressure on components of synthesis gas are discussed. Bio-oil gasification and gasification in supercritical water for synthesis gas production are introduced and other related technologies like gas cleaning, reforming and gas shifting are summarized. Finally, the features of these technologies are analyzed and the development trend is pointed out. Related Articles | Metrics