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30 November 2014, Volume 48 Issue 6 Previous Issue    Next Issue

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Optimization of Liquefaction Technology of Bagasse in Water-tetralin Mixed Solvents CAO Jiang-fei, LI Cun-long, XIE Ning, ZHOU Xin-xin, HONG Ya-ming, LI Zhi-xia 2014, 48 (6):  1-5.  doi: 10.3969/j.issn.1673-5854.2014.06.001 Abstract ( 985 )   PDF (858KB) ( 1249 )   Save The effects of five factors on conversion rate during the liquefaction of bagasse in water-tetralin (W-T) mixed solvents were investigated by orthogonal test.The optimal conditions were reaction temperature 270 ℃, reaction time 30 min,mass ratio of bagasse to solvent 1:6,NaOH dosage in alkali-soaking pretreatment 4%, and tetralin dosage 50%(mass fraction in the total solvent). The sequence of influence factors was NaOH dosage>reaction temperature>tetralin dosage>mass ratio of bagasse to solvent>reaction time.The conversion rate of bagasse was 97.9% under the optimal conditions.The results also showed that partial substitute for water with tetralin in liquefaction solvents could increase liquefaction efficiency,reduce reaction temperature and pressure,and improve experimental operating condition. References | Related Articles | Metrics

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Antifeedant Activities of Dehydroabietyl Amides and Imines Derivatives Against Mythimna separata LIU Li, GAO Yan-qing, RAO Xiao-ping, SONG Zhan-qian, SHANG Shi-bin 2014, 48 (6):  6-10.  doi: 10.3969/j.issn.1673-5854.2014.06.002 Abstract ( 717 )   PDF (3983KB) ( 954 )   Save In this study,the antifeedant activities of rosin-based tricycle diterpenoids dehydroabietyl amides and imines derivatives against Mythimna separata were investigated by leaf-disc immersion method.The results showed that amide derivatives,A-1,A-3,A-4,A-8,A-10,and imine derivatives I-6 containing dehydroabietyl structure had good antifeedant activities to Mythimna separata and their antifeedant rates were all over 90% in 24 h.The antifeedant rates of A-1,A-4,A-8,A-10,and I-6 were over 80% in 48 h and 72 h.The majority of amide compounds showed antifeedant activities and some imine derivatives showed feeding attracion activities after long time.Some compounds could cause the death of armyworms during antifeedant activity test,so these compounds could be developed as insecticides. References | Related Articles | Metrics

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Liquefaction of Pretreated Furfural Residues WU Shu-ping, JI Yu-cheng, MA Bao-jun, XIE Hao, LIU Wan-yi 2014, 48 (6):  11-17.  doi: 10.3969/j.issn.1673-5854.2014.06.003 Abstract ( 1017 )   PDF (1802KB) ( 1132 )   Save The effects of pretreatment technology on the liquefaction of furfural residue in ethylene glycol were investigated.The experimental data showed that the liquefaction rate of furfural residues,which was pretreated via using the intermixture of 5% NaOH and 2.5% H2O2 at the ratio of 1:1(mL:mL), could reach 82.0%,under the conditions of 150 ℃ for 90 min with the solid-liquid ratio of 1:10(g:g) and catalyst dosage of 3%, respectively.Meanwhile, the furfural residues before and after the pretreatment as well as the liquefaction products were analyzed and characterized by scanning electron microscopy(SEM), infrared spectra (FT-IR), X-ray diffraction spectrum (XRD),13C NMR,and 1H NMR,respectively.The results showed that the composition and surface structure of furfural residues were changed in pretreatment process.It was beneficial to improve the liquefaction process of furfural residue.And the liquefaction products included alcohols,esters,ethers and so on. References | Related Articles | Metrics

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Optimization of Dilute-sulfuric Acid Pretreatment of Poplar Residues by Using Response Surface Design FANG Gui-gan, LIU Shan-shan, SHEN Kui-zhong 2014, 48 (6):  18-24.  doi: 10.3969/j.issn.1673-5854.2014.06.004 Abstract ( 795 )   PDF (1263KB) ( 940 )   Save The dilute acid hydrolysis was applied to the poplar residues conversion,and the polysaccharides conversion rate was figured out for the assessment of conversion efficiency.Several parameters concerned with the conversion efficiency,such as bio-mass substrate size,dosage of acid,hydrolysis pressure (or temperature) and reaction time were investigated.The response surface experimental design was used to optimize the dilute acid hydrolysis conditions.It was proposed that proper particle sizes were 0.075 to 0.096 mm and the optimal conditions for the dilute sulfuric acid hydrolysis were illustrated as the solid to liquid ratio of 1:10,temperature of 158 ℃,reaction time of 5 min,and the fraction of sulfuric acid of 2.5%.Under the optimal conditions, the polysaccharides conversion rate was up to 59.23%.The HPLC analysis of hydrolyzates showed that the main component was xylose (29.897 g/L) with a content of 64.8% in total sugar amount,and the second one was glucose (8.748 g/L) with a content of 18.9%.Less monosaccharides further degraded in the dilute acid hydrolysis.The SEM observation and XRD analysis of substrate samples before and after the dilute acid hydrolysis showed that the fiber structure of the hydrolysis residue was damaged obviously,and the crystallinity decreased from 57.45% of the raw material to 47.37% of the hydrolysis residue.It could be expected that the hydrolysis residue be utilized to make bioethanol by enzymatic hydrolysis and fermentation. References | Related Articles | Metrics

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Biodiesel Production from Palmitic Acid Esterificatin with Rare Earth Composite Solid Acid as Catalysts SI Zhan, JIANG Jian-chun, WANG Kui, XU Jun-ming 2014, 48 (6):  25-29.  doi: 10.3969/j.issn.1673-5854.2014.06.005 Abstract ( 693 )   PDF (856KB) ( 1063 )   Save Solid acid catalyst modified with rare earth,SO42-/TiO2/Ce4+, was prepared by sol-gel method and used for the esterification of palmitic acid and methanol.The effects of different preparation conditions on the catalyst activity were investigated,and its structure was characterized.The results indicated that the highest catalyst activity was exhibited when Ce4+ concentration 0.05 mol/L,H2SO4 concentration 1.38 mol/L,calcination temperature 450 ℃ and calcination time 3 h.It was found that the optimum condition were molar ratio of methanol to palmic acid 10:1,reaction temperature 110 ℃,reaction time 30 min and catalyst amount 3%,respectively.The conversion of palmitic acid was 96.33% under these conditions.The conversion rate was still above 50% when the catalysts were reused for four times. References | Related Articles | Metrics

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Pretreatment of Pennisetum Grass with Dilute Sulfuric Acid CHEN Shang-xing, FANG Kai, WANG Zong-de, FAN Guo-rong, WANG Peng 2014, 48 (6):  30-35.  doi: 10.3969/j.issn.1673-5854.2014.06.006 Abstract ( 1036 )   PDF (884KB) ( 1042 )   Save The effects of dilute acid pretreatment conditions of Pennisetum grass on the composition,celluloses enzymatic hydrolysis yield, and the yield of total sugars in liquids were investigated at medium-low temperature. And the fiber structures of pretreated residues were studied with scanning electron microscope (SEM).With the increase of sulfuric concentration,temperature,and retention time,the hemicelluloses content declined considerably,and the yield of enzymatic hydrolysis increased gradually.The recovery of cellulose was 87.48%,the hemicelluloses hydrolysis rate was 93.68%,the yield of enzymatic hydrolysis was 86.3%,and the total sugars yield was 54.53 g/100 g after the pretreatment when the pretreatment conditions were sulfuric acid concentration 4.0%,temperature 110 ℃,residence time 8 h,and cellulase dosage 40 FPIU/g cellulose.The results indicated that the fiber surface and cell wall of Pennisetum grass were broken after acid pretreatment,thus the specific surface area and pore volume increased,and it was beneficial to the enzymatic hydrolysis. References | Related Articles | Metrics

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Effect of Pyrolysis Temperature on Characteristics of Biomass Char and Coal Char MI Cui-li, FAN Xiao-hua, WEI Gang, MA Deng-qing, ZHANG Li-meng, WANG Xue-bin 2014, 48 (6):  36-43.  doi: 10.3969/j.issn.1673-5854.2014.06.007 Abstract ( 881 )   PDF (1500KB) ( 1160 )   Save The effects of fuel type and pyrolysis temperature on the physicochemical properties of coal char (C-char) and biomass char were investigated with straw,oak sawdust,and Huating bituminous coal as raw materials.BET,SEM-EDS,XRD,and TGA were used to analyze the coke specimens.Results show that the BET surface area and porous volume of C-char increase as the pyrolysis temperature increases,whereas those of wood char (W-char) insignificantly change,from 600 to 1 000 ℃.Straw char (S-char) has the largest surface area and pore volume at 800 ℃ as sintering occurs at higher temperatures.As the pyrolysis temperature increases,the C content of char increases and its H and O contents decrease.The ignition characteristic of S-char is superior to those of W-char and C-char.The ignition characteristics of Wood-char and C-char decrease with the increase of pyrolysis temperature.Straw-char exhibits the best ignition characteristic at 800 ℃. References | Related Articles | Metrics

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Delignification of Bagasse with CO2 Supercritical Fluid Extraction ZUO Lin, CHENG hao, LIU Jiang-yan 2014, 48 (6):  44-49.  doi: 10.3969/j.issn.1673-5854.2014.06.008 Abstract ( 918 )   PDF (851KB) ( 1215 )   Save This paper reported the delignification of bagasse with the supercritical fiuid of CO2 and the influence of extraction conditions.The pulp yield, holocellulose contents,and Klason lignin contents were obtained by orthogonal experiments to get the delignification rate and the optimal conditions.The experimental results showed that the temperature was the main factor that influenced the efficiency of delignification.Under the condition of 180 ℃,20 MPa,1,4-dioxane 2 mL within 60 min,the delignification rate could reach 79.61%.The GC-MS analysis of the supercritical extraction liquid under different temperature showed that the degradation of lignin not only occured by breaking the aryl-ether bonds of macromolecule,but also led to the fracture of methoxy on the benzene ring.And at high temperature,the other carbohydrates,cellulose,and hemicellulose in bagasse also degraded. References | Related Articles | Metrics

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Advance in Research of Polyaspartic Acid XIAO Feng-long, WEI Min, ZHAO Jian 2014, 48 (6):  50-55.  doi: 10.3969/j.issn.1673-5854.2014.06.009 Abstract ( 987 )   PDF (896KB) ( 1973 )   Save New advances of polyaspartic acid in synthesis method,biodegradation,and the applications to water treatment,metal corrosion inhibitors, pesticides,fertilizers,daily chemicals,medical, and other fields were reviewed.The developing direction of polyaspartic acid in the future was prospected. References | Related Articles | Metrics

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Research Progress of Lignocellulosic Biomass Pretreatment Methods for Thermo-chemical Conversion GUAN Qian, JIANG Jian-chun, XU Jun-ming, HE Xiao-liang, FENG Jun-feng 2014, 48 (6):  56-61.  doi: 10.3969/j.issn.1673-5854.2014.06.010 Abstract ( 858 )   PDF (797KB) ( 1441 )   Save This paper mainly introduced the composition of lignocellulosic biomass and summarized the research progress of three kinds of pretreatment methods including physical method,chemical-physical method,and chemical method for lignocellulosic biomass thermo-chemical conversion.The effects of various pretreatment methods on raw material and transformation products were expounded,and their defects and limitations in applications were pointed out.At last,the pretreatment technology of lignocellulosic biomass was prospected. References | Related Articles | Metrics