Table of Content

30 April 2013, Volume 33 Issue 2 Previous Issue    Next Issue

研究报告

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Adsorption of Pb2+ from Aqueous Solution by β-Cyclodextrin/Wood Flour Grafted Copolymer: Kinetic and Thermodynamic Studies SI Hong-yan;LI Bin;WANG Ting;XU Zu-wei 2013, 33 (2):  1-9.  doi: 10.3969/j.issn.0253-2417.2013.02.001 Abstract ( 817 )   PDF (934KB) ( 901 )   Save β-cyclodextrin/wood flour (β-CD/WF) grafted copolymer was prepared by esterification- crosslinking technology, i.e., grafting β-CD onto poplar wood flour in the presence of citric acid. The properties of this grafted copolymer were characterized by FT-IR, TGA and the technique of phenolphthalein probe respectively. The adsorption property of this copolymer for Pb2+ in a batch adsorption system as a function of contact time, pH and initial Pb2+ concentration was investigated in this study. The results showed that β-CD was not only grafted onto the surface of wood flour but also demonstrated an encapsulation activity. The kinetic data were analyzed by the pseudo-first,second-order kinetics and intraparticle diffusion, and the equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption equilibrium was reached within 30 min at 298 K under the proper pH between 4.0 and 8.0 , and the adsorption capacity increased with the rise of initial Pb2+ concentration. It was found that the adsorption kinetics followed the second-order model. This suggested that the adsorption of Pb2+ by copolymer was a chemisorption process, and the intraparticle diffusion was not the primary rate-determining step. Besides, Langmuir model fitted the equilibrium data better than the Freundlich isotherm. It reflected the adsorption of Pb2+ on copolymer was monolayer adsorption. The thermodynamic properties, ΔGΘ, ΔHΘ and ΔSΘ showed that adsorption of Pb2+ onto β-CD/WF flour grafted copolymer was endothermic and spontaneous in the temperature range of 293-313 K. Related Articles | Metrics

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Four Kinds of Pretreatment Methods for Lignocellulosics MA Bin;CHU Qiu-lu;ZHU Jun-jun;OUYANG Jia;YU Shi-yuan;YONG Qiang 2013, 33 (2):  25-30.  doi: 10.3969/j.issn.0253-2417.2013.02.004 Abstract ( 1505 )   PDF (858KB) ( 1192 )   Save Corn stalk was pretreated by four kinds of pretreatment methods, namely, dilute acid, dilute acid refining, neutral steam explosion and dilute acid steam explosion. The effects of pretreatment on enzymatic hydrolysis and yield of fermentable su-gars were investigated. The components of pretreated corn stalk, sugars in pre-hydrolyzate, carbohydrate and lignin degradation products in pre-hydrolyate were also analyzed. After 100 g corn stalk was pretreated by dilute acid, dilute acid refining, neutral steam explosion and dilute acid steam explosion followed by washing, the cellulose content -dropped from 37.17g to 33.96, 33.54, 32.63 and 32.88 g, respectively; the xylan content declined from 22.84 g to 2.77, 2.47, 3.56 and 2.05 g respectively and lignin content reduced to 17.63, 17.42, 16.90 and 17.25 g from 18.76 g, respectively. When dilute acid steam explosion pretreated corn stalk was treated by 20 FPIU/g cellulose cellulase and 3 IU/g cellulose β-glucosidase for 48 h as the substrate concentration was 100g/L, the hydrolysis yield of cellulose was 75.91 % (based on corn stover). The yield of fermentable sugars was 44.93 % (based on corn stover) as the corn stover was pretreated by dilute acid steam explosion and enzymatic hydrolysis. Related Articles | Metrics

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Optimization of Fermentation Conditions for 1,3-Propanediol Production by Klebsiella pneumoniae Mutant Using Response Surface Methodology DONG Xiao-yu;ZHU Xiao-li;YUAN Yu-lian;XIU Zhi-long 2013, 33 (2):  10-18.  doi: 10.3969/j.issn.0253-2417.2013.02.002 Abstract ( 867 )   PDF (928KB) ( 743 )   Save Response surface methodology (RSM) was employed to optimize fermentation parameters for high-level production of 1,3-propanediol(1,3-PD) by the Klebsiella pneumoniae mutant Kp-M2. Based on the Plackett-Burman design, original concentration of glycerol, original pH and seed age were selected as the most critical parameters. The center points of these three parameters were determined using the steepest accent (descent), and all three parameters were then optimized by the Box-Behnken design. A maximum 1,3-PD concentration of 21.6 g/L was predicted by the optimized glycerol concentration (57 g/L), pH (7.3) and seed age (10 h). Using these three optimized parameters, 20.7 g/L 1,3-PD was obtained from flask fermentation, which represented a 30% increase over that obtained under non-optimized conditions. Under batch and fed-batch fermentations using the same optimized parameters, the concentration of 1,3-PD increased to 29.5 and 92.0 g/L, respectively, compared to 19.9 and 76.7 g/L previously obtained for non-optimized fermentation conditions. This showed that RSM could be effectively used to enhance the production of 1,3-PD via fermentation. Related Articles | Metrics

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Optimized Dialysis Preparation of Low Molecular Mass Glycopeptide from Panax ginseng Using the Response Surface Methodology WANG Ying;LUO Hao-ming;CHEN Ying-hong;JIANG Rui-zhi 2013, 33 (2):  37-40.  doi: 10.3969/j.issn.0253-2417.2013.02.006 Abstract ( 786 )   PDF (951KB) ( 605 )   Save Response surface methodology (RSM) was used to study the technology of preparation of low molecular mass glycopeptide from panax ginseng by dialysis. The effects of three factors, i.e., the ultrafiltrate concentration before dialysis (A), dialysis time (B) and water consumption (C) on the content of glycopeptide were investigated. The optimal conditions for dialysis were ultrafiltrate concentration 0.6 g/mL, dialysis time 5 h 1 min 48 s and water consumption 3.92 L. The experimental values (79.26 %) agree with the predicted values(78.99 %). The panax ginseng peptide with relatively high purity can be prepared by dialysis. A model equation obtained can be used to predict the experiment through the RSM. Related Articles | Metrics

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Synthesis and Characterization of Terpene-based Cyclic Carbonate CHEN Cai-feng;LIU Gui-feng;KONG Zhen-wu;WU Guo-min; 2013, 33 (2):  19-24.  doi: 10.3969/j.issn.0253-2417.2013.02.003 Abstract ( 855 )   PDF (881KB) ( 868 )   Save A novel biomass terpene-based cyclic carbonate (TCC) was prepared by treatment of terpene-based epoxy resin (TME) with carbon dioxide in the conjunctional catalysis of triethylbenzylammonium and ethylene glycol without any organic solvent. The effects of catalyst dosage, carbon dioxide pressure, reaction temperature and time on the reaction were investigated. The cyclocarbonate value of the product was obtained by the method of potentiometric titration. The results showed that the cyclocar bonate value of the product was 0.267, the conversion of terpene-based epoxy resin and the selectivity for cyclic carbonate were as high as 99.7 % and 94.0 % under optimum conditions (catalyst concentration 1.0 %, CO2 pressure 1.0 MPa, reaction temperature 130 ℃ and reaction time 7 h), respectively. The chemical structure of the novel terpene-based cyclic carbonate was characterized by GPC, FT-IR, MS, 1H NMR and 13C NMR . Related Articles | Metrics

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Component Varieties of Ginkgo biloba Leaves before and after Extraction with Water by Py-GC-MS TAO Ran;WANG Cheng-zhang;KONG Zhen-wu; 2013, 33 (2):  55-60.  doi: 10.3969/j.issn.0253-2417.2013.02.009 Abstract ( 849 )   PDF (882KB) ( 693 )   Save Ginkgo biloba leaves before and after extraction with water were treated by online pyrolytic methylation using tetramethylammonium hydroxide(TMAH) in the injector at 423 ℃. Forty-three compounds were identified and inferred by Py-GC-MS with the aid of Nist02 standard MS database. The GC content of original chemical compounds was determined by normalization method. The main compounds were classified. Comparing between Ginkgo biloba leaves before and after extraction with water, the results showed that the GC content of small molecule compounds with less than 12 carbon atoms reduced from 38% to 30%, and the GC content of aliphatic acid with less than 20 carbon atoms increased from 17% to 20%. The GC content of gingkolic acid, steroids and aliphatic acid compounds with more than 20 carbon atoms increased from 45% to 50%. Related Articles | Metrics

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Conversion of Glucose into Butyl Levulinate over Solid Acid SO42-/SnO2 Catalyst LIU Di;LIN Lu;ZENG Shan-shan;PENG Lin-cai 2013, 33 (2):  66-70.  doi: 10.3969/j.issn.0253-2417.2013.02.011 Abstract ( 858 )   PDF (866KB) ( 743 )   Save Solid acid catalysts SO42-/SnO2 were prepared by precipitation and impregnation method for conversion of glucose to butyl levulinate in butanol. The effects of different reaction conditions and catalyst reuse on yields of butyl levulinate were also investigated. The surface structure and acidity of the fresh and reused catalysts were characterized by XRD and NH3-TPD. The results indicated that butyl levulinate yield of 33.1% could be obtained under the conditions of the catalyst calcined at 500 ℃ for 3 h, catalyst dosage 2.5 %, reaction temperature 200 ℃ and reaction time 2 h. And the catalytic performance for the reused catalysts after calcinations decreased from 33.1% to 12.8% after the fifth reuse. XRD and NH3-TPD results showed that crystallization structure of catalyst was preserved well after reuse, but the acid strength and total amounts of acid were decreased slightly with the increase of the number of reuse. Related Articles | Metrics

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Wetting Property of Modified Nanocrystalline Cellulose on Waterborne Polyurethane SHE Ying;ZHANG Hao;SONG Shu-ping;CHEN He-yu;PU Jun-wen 2013, 33 (2):  77-80.  doi: 10.3969/j.issn.0253-2417.2013.02.013 Abstract ( 955 )   PDF (856KB) ( 687 )   Save The wetting property of surface modified nanocrystalline cellulose (NCC) by silane coupling agent (SCA-1, SCA-2, and SCA-3) on waterborne polyurethane was improved in this study. The contact angle was selected to estimate the wetting effects of modified NCC on waterborne polyurethane. The results indicated that all the different lipophilic groups of SCA-1, SCA-2, and SCA-3 could lead to the improvements of wetting property between NCC and waterborne polyurethane. The wetting property of NCC modified by SCA-3 increased significantly by 37.7% due to the steric hinerance of epoxide groups. This was higher than that of SCA-1 and SCA-2. Related Articles | Metrics

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Synthesis and Surface Active Properties of Cardanol-based Cyclic Carbonate and Its Quaternary Ammonium Salt Derivatives LIU Gui-feng;CHEN Cai-feng;HUO Shu-ping;KONG Zhen-wu; 2013, 33 (2):  85-90.  doi: 10.3969/j.issn.0253-2417.2013.02.015 Abstract ( 973 )   PDF (11462KB) ( 487 )   Save Three carbamate group-containing quaternary ammonium salt derivatives were synthesized from the novel biomass cardanol-based cyclic carbonate (C-CC) which was prepared by reaction of carbon dioxide with cardanol-based epoxides (C-E). The chemical structures of the novel cardanol-based cyclic carbonate, cardanol-based carbamate (C-Ca) and its quaternary ammonium salt derivatives (C-QAS) were characterized by FT-IR, 1H NMR and 13C NMR. Surface tension, emulsifying ability and the foaming power of the quaternary ammonium salt derivatives were investigated. The critical micelle concentration (CMC), the surface excess concentration (Γmax) and the minimum surface area at the interface occupied by each molecule (Amin) were determined. The results showed that the critical micelle concentrations (CMC) of the three quaternary ammonium salt derivatives' aqueous solutions were 8.55, 6.97 and 11.93 mg/L, respectively; the surface tensions of the three aqueous solutions at CMC were 26.67, 25.32 and 38.92 mN/m, respectively; the Γmax of the three C-QAS were 0.384, 0.345 and 0.217 mol/m2, respectively; the Amin of the three C-QAS were 4.3×10-6, 4.81×10-6 and 7.65×10-6 nm2, respectively; and the products with strong emulsifying ability, foaming ability and superior foaming stability. Related Articles | Metrics

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Properties and Microstructure of Phenolic Foam Modified by Nitrile Butadiene Rubber Powder LI Ling;XU Yu-zhi;WANG Chun-peng;CHU Fu-xiang; 2013, 33 (2):  31-36.  doi: 10.3969/j.issn.0253-2417.2013.02.005 Abstract ( 1037 )   PDF (891KB) ( 1131 )   Save The performance of phenolic-formaldehyde(PF) foam was improved by co-foaming of PF resin with nitrile butadiene rubber power(NBRP) and other additives in the closing mould at 70 ℃. The influence of NBRP modification method including pre-NBRP and post-NBRP on the properties of phenolic foams was studied. The effects of amount of pre-NBRP modification on mechanical properties, fragile properties, flame-retardant properties and microscopic structure of NBRP-PF foam were further investigated. The results indicated that the pre-NBRP-modified PF foam had better properties compared with that of Post-NBRP, when 2 % NBRP was used. The overall performance of PF foam was the best. This could be a consequence of cooperation of NBRP and PF resin. Related Articles | Metrics

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Pressurized Gasification of Pine Sawdust with Steam JIANG Jun-fei;YING Hao;SUN Yun-juan;GAO Yi-wei;TU Jun-ling;WANG Yan-jie 2013, 33 (2):  41-48.  doi: 10.3969/j.issn.0253-2417.2013.02.007 Abstract ( 790 )   PDF (892KB) ( 981 )   Save Evolutionary behavior of gas chemical composition and yield had been examined for pine sawdust at four different temperatures of 800, 850, 900 and 950 ℃ under pressures range of 0.1-0.6 MPa, using steam as the gasification agent at a constant flow rate. The results showed that high temperature could accelerate reactions rate and tend to generate hydrogen-rich gas product. Hydrogen is mast aboundant gas composition during sawdust gasification, which content reached more than 50%. Meanwhile, elevated temperature led to an increasing amount of H2 and CO while a decreasing amount of CO2 and CH4. The results also showed that the overall output of product increased with elevated pressure gas while the tar decreased. The concentration of H2 and CO2 increased while CO and CH4 decreased with gasification pressure gradually rising. Related Articles | Metrics

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Separation and Characterization of Polyunsaturated Fatty Acids from Rubber Seed Oil YANG Jing;XIE Chao;XU Juan;HUANG Yuan-bo;LIU Shou-qing;ZHENG Yun-wu;ZHENG Zhi-feng; 2013, 33 (2):  49-54.  doi: 10.3969/j.issn.0253-2417.2013.02.008 Abstract ( 914 )   PDF (889KB) ( 1855 )   Save The separation of polyunsaturated fatty acids (PUFA) from rubber seed oil by urea complex fractionation was studied. Reaction conditions of urea inclusion were optimized using orthogonal test method. The fatty acid composition was determined after ethyl esterification by gas chromatography (GC). The maximum purity of PUFA was over 96 % with the ratio of recovery up to 35 % under optimal conditions at urea-to-fatty acids ratio of 55:30(g:g), methanol-to-urea ratio of 130:55(mL:g), reaction temperature of 65 ℃, reaction time of 150 min, crystallization temperature of -5 ℃, and crystallization time of 18 h, respectively. The components of separated PUFA from rubber seed oil contain 56.95 % of linoleic acid (C18:2), 40.28 % of linolenic acid (C18:3), respectively. Only 2.77 % of oleic acid (C18:1) was charaeterized in the product. Related Articles | Metrics

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Effects of Eco-friendly Halogen-free Flame Retardants on the Properties of Phenolic Foams (PFs) MA Yu-feng;WANG Chun-peng;ZHANG Wei;XU Yu-zhi;CHU Fu-xiang 2013, 33 (2):  61-65.  doi: 10.3969/j.issn.0253-2417.2013.02.010 Abstract ( 924 )   PDF (855KB) ( 735 )   Save The resol phenolic resin with high solid content was prepared with formaldehyde (1.24 mol), paraformaldehyde (7.28 mol) and phenol (4.26 mol), using NaOH as catalyst, via step polymerization. Three eco-friendly halogen-free flame retardants (ammonium polyphosphate (APP), melamine phosphate (MP) and LM-NPP 8081) were chosen. The effects of their presences on the mechanical properties, flame retardancy, fragility, thermal conductivity and heat resistance of PFs were investigated. The results showed that the flame retardancy of the PFs was significantly improved, while both thermal resistant and thermal conductivity of PFs were not enhanced. When the amount of flame retardant was 8%, machanical properties of PFs were the best, and the comprehensive performances of MP composite PFs was better than the other two. Limited oxygen index, compression strength, bending strength, fragitily properties, thermal conductivity and carbon residue of MP composite PFs were 55.22 %, 0.30 MPa, 0.28 MPa, 34.40%, 0.045 W/(m·K), 87.50 %(300 ℃) and 61.12 % (600 ℃) respectively. The results showed that MP was better flame retardant for PFs than the other two. Related Articles | Metrics

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Molecular Structure of Lignin Pharmaceutical Samples by Reductive Cleavage ZHANG Jing;XU Ge;YU Da-gang;WU Guo-ping;CHEN He-xin 2013, 33 (2):  71-76.  doi: 10.3969/j.issn.0253-2417.2013.02.012 Abstract ( 920 )   PDF (868KB) ( 852 )   Save Degradation of lignin pharmaceutical by derivatization followed by reductive cleavage (DFRC) was studied. The compositions and structures of degraded products were analyzed by GC-MS. The results showed that the degraded products from lignin pharmaceutical consisted of four types of compound, i.e., butylated hydroxyltoluene (BHT), monose, organic acid and related lignin units. In 1# and 2# pharmaceutical, the content of previous four kinds compounds was 12.696 %, 17.456 %, 17.989 % and 51.859 %; 8.736 %, 2.991 %, 44.812 % and 43.461 %, respectively. According to the biological activity of degraded products obtained by lignin pharmaceutical, the drug actions presumed could be due to the decomposition of lignin pharmaceutical in the human to BHT, ferulic acid and glycerine units. In 1# and 2# pharmaceutical, the content of total compounds converted into ferulic acid in the body was 12.572 % and 5.613 %. Furthermore, the content of total containing glycerine units compounds was 6.322 % and 25.430 %, respectively. Related Articles | Metrics

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Preparation and Properties of Formed Biomass Charcoal LU Xin-cheng;JIANG Jian-chun;MENG Zhong-lei;SUN Kang;XIE Xin-ping 2013, 33 (2):  81-84.  doi: 10.3969/j.issn.0253-2417.2013.02.014 Abstract ( 769 )   PDF (909KB) ( 1041 )   Save Formed biomass charcoal was prepared by powder charcoal from biomass. The influences of category, dosage of adhesive and temperature of the heat treatment on the properties of the formed biomass charcoal were studied. It was found that formed biomass charcoal prepared using carboxymethylcellulose as an adhesive has a better performance than that from amylum. The optimum technological process is that the dosage of adhesive is 6 % and heat treatment at 200 ℃ for one hour. Physical and chemical properties of the formed charcoal were also studied. The results showed that the formed biomass charcoal has the fixed carbon content of 88.95 %, heat value of 30.6 kJ/g and abrasion resistance of 99.83 %. Related Articles | Metrics

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The Status of Biomass Briquetting Fuel in China Based on Market Analysis WANG Zhi-wei;LEI Ting-zhou;SHI Xin-guang;LI Zai-feng;HE Xiao-feng;ZHU Jin-ling;XU Hai-yan;REN Su-xia; 2013, 33 (2):  95-102.  doi: 10.3969/j.issn.0253-2417.2013.02.017 Abstract ( 921 )   PDF (877KB) ( 1021 )   Save Briquetting is one of the important utilization routes for agricultural and forestry residues. The objective of this paper is to explore the development status of biomass briquetting fuel (BBF) in China in 2010, especially those made from agricultural and forestry residues. Biomass briquetting technology in China was firstly discussed. The agricultural and forestry residue resources in China and their energy potential were analyzed. And the development situation of BBF in each part of China was evaluated based on market analysis and strengths, weaknesses, opportunities, threats (SWOT) analysis. The market analysis shows that main agricultural residues and a lot of forestry residues in China are good feedstock for BBF and they represent an enormous energy potential. The status of BBF market is better in Central, East, South, North and Northeast than other areas in China. The SWOT analysis indicates that the status of BBF will become better in China if the briquetting technology and BBF combustion technology are further developed and improved; more effective supporting policies are given to the BBF industry; more demonstration plants for BBF production are set up; the environmental awareness is streng-thened and coal combustion is restricted. Related Articles | Metrics

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Production of 2,3-Butanediol from Corncob by Simultaneous Saccharification and Fermentation Process JIANG Xing;XIA Li-ming 2013, 33 (2):  91-94.  doi: 10.3969/j.issn.0253-2417.2013.02.016 Abstract ( 821 )   PDF (865KB) ( 843 )   Save Production of 2,3-Butanediol from corncob was carried out by simultaneous saccharification and fermentation(SSF) process.The optimal SSF conditions were obtained as 100-120 g/L substrates were treated by 25 FPIU/g substrate cellulose, 15 IU/g substrate cellobiase and 300 IU/g substrate xylanase under pH 6.0 and 36 ℃ environment.The concentration,productivity and conversion rate of 2,3-butanediol were 46.02 g/L, 1.28 g/(L·h) and 0.424 g/g( based on cellulose and hemicellulose) respectively by SSF treatment for 36 h when the substrate concentration is 120 g/L. Related Articles | Metrics

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Kinetic Study for Catalytic Hydrogenation of Rosin over Pd/C CHEN Shao-fang;RAN Qi-bin;CHEN Xiao-peng;WANG Lin-lin;YANG Cheng-li;LIANG Jie-zhen 2013, 33 (2):  103-107.  doi: 10.3969/j.issn.0253-2417.2013.02.018 Abstract ( 893 )   PDF (866KB) ( 829 )   Save Catalytic hydrogenation of rosin was studied with rosin as raw material, modified Pd/C as catalyst and oil No.200 as solvent. The effects of internal and external diffusion were eliminated by improving the type of stirrer, adding solvent oil No.200, raising rotational speed to more than 600 r/min and reducing granularity of catalyst at 10-20 μm. The changes of components with reaction time were traced on-line at temperature 403 K to 433 K and pressure 5 MPa by capillary gas chromatography. The pseudo-homogeneous reaction kinetics of catalytic hydrogenation of rosin was studied. The result shows that the reaction velocity of catalytic hydrogenation of rosin is the first order with respect to abietic acid concentration. The intrinsic kinetic equation is r=1.13×105exp(-5.904×103/T)C1 and the activation energy is 4.909×104 J/mol. Related Articles | Metrics

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Preparation and Characterization of High Specific Surface Area Activated Carbon from Coconut Shell Carbide by KOH WANG Guo-dong;DENG Xian-lun;ZHU Guang-zhen;GUO Hao 2013, 33 (2):  108-112.  doi: 10.3969/j.issn.0253-2417.2013.02.019 Abstract ( 858 )   PDF (842KB) ( 1027 )   Save Coconut shell carbide was used as raw material to prepare high specific surface area activated carbon activated by KOH. The relationships between the adsorption ability and the factor of soaking time, activating temperature and impregnation ratio (KOH/Raw material) were also investigated. From single factor experiments, the suitable preparation coditions are as follows, i.e., impregnation ratio of 5 and reaction at 800 ℃ for 60 min.The basic properties of prepared product are as follows, the surface area is 3 360 m2/g, the total pole volume of pores is 1.798 cm3/g, the average pore width is 2.140 nm.The iodine number and methylene blue value of the activated carbon are 2 809 mg/g and 675 mg/g, respectively. Related Articles | Metrics

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Sugar Preparation from Pulping Black Liquor by Hydrolysis YANG Jing;JIANG Jian-chun;ZHANG Ning;WEI Min;ZHAO Jian 2013, 33 (2):  119-122.  doi: 10.3969/j.issn.0253-2417.2013.02.021 Abstract ( 786 )   PDF (840KB) ( 700 )   Save The reducing sugar preparation by various hydrolysis methods from sulfate pulping black liquor of Pinus massoniana was investigated in present study. The results indicated enzymatic hydrolysis had high efficiency on sugar reducing in contrast to acid hydrolysis. A reducing sugar content of 9.18 g/L was obtained by enzymatic hydrolysis after delignification. And the optimum conditions for delignification was conducted as black liquore was hydrolyzed by 6%, sulfuric acid solution at 75℃ under pH 3.0 environment. The highest hemicellulose content of 47.61 g/L was obtained in the supernatant residual.The dominant products in hydrolysate were 3.63 g/L glucose, followed by 2.94 g/L xylitol and 1.81 g/L cellobiose. But small amounts of xylose and arabinose were obtained, and their contents, represented 0.80 and 0.02 g/L respectively. Related Articles | Metrics

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Extraction of Unsaturated Fatty Acids from Eucalyptus Leaves and its Components YANG Qiao-li;XIE Yao-jian;TAN Xiao-feng;ZHANG Jing;HUANG Chi-fu;WU Zhi-hua 2013, 33 (2):  113-118.  doi: 10.3969/j.issn.0253-2417.2013.02.020 Abstract ( 873 )   PDF (975KB) ( 750 )   Save The optimal extraction process of unsaturated fatty acids from Eucalyptus leaves was obtained by orthogonal test based on factors such as different solvents,material particle size,solid-liquid ratio,immersion time and extraction time. The components of extracts were analysed by GC-MS after methylation. The results from 16 tests of 5 factors and 4 levels showed that the extraction yield was 14.9 % on the optimal extraction conditions, i.e., acetone as solvent, material particle size 0.075-0.150 mm, solid-liquid ratio 1:15(g:mL), immersion time 8 h and extraction time 1.5 h. Six compounds including five fatty acids, for example unsaturated fatty acids, linoleic acid and linolenic acid, were indentified. There was 36.01 mg unsaturated fatty acids in 10 g dried Eucalyptus leaves. Eucalyptus leaves have potential values to develop because of unsaturated fatty acids. Related Articles | Metrics

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Covalent Grafting of Aminopyridine Molecules on the Surface of Activated Carbon LI Tao;TANG Li-rong;CHEN Cui-xia;LU Qi-lin;WU Geng-feng;LV Jian-hua;CHEN Xu-rong;HUANG Biao 2013, 33 (2):  123-128.  doi: 10.3969/j.issn.0253-2417.2013.02.022 Abstract ( 821 )   PDF (939KB) ( 660 )   Save Three kinds of pyridine molecules were grafted by covalent bonds onto activated carbons using the processes of oxidative and acylation. Regularity for the changes of the surface physicochemical properties and pore structure before and after modification were studied by the measurement technologies such as FT-IR,XPS,elemental analysis and N2 adsorption. The structural differences of grafting molecules and the reaction performance of activated carbon were investigated. The results showed 3-aminopyridine has the highest grafting efficiency. It was determined that the surface N/C value of activated carbon was 0.10 and the nitrogen content was up to 7.74%. The results showed that the difference of the electron effect of the grafted molecules affected the grafting efficiency. This provided a scientific basis for highly efficiently grafting by acylation on activated carbon. Related Articles | Metrics

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Determination of γ-Aminobutyric Acid in Leaves of Santalum album L. by HPLC YANG Yan;HE Li-ping;GAO Xiang-yang 2013, 33 (2):  134-138.  doi: 10.3969/j.issn.0253-2417.2013.02.024 Abstract ( 913 )   PDF (869KB) ( 977 )   Save A method was established by reversed-phase high performance liquid chromatography for determining the content of γ-aminobutyric acid (GABA) in leaves of Santalum album L. The sample was pretreated by soxhlet extraction to eliminate the pigments with ether, and then by water extraction and alcohol precipitation to eliminate sugar and protein. GABA was derivatized with dansyl chloride (Dns-Cl) and isolated by reversed-phase HPLC. GABA was detected quantitatively by HPLC with fluorescence detection. Nice linear relationship between peak area and concentration was obtained with the linear regression equation as y=475 211x+69 037,R2=0.999 8. The recovery of standard addition was in the range of 112% to 120%. The detection limit of GABA was 7 μg/g. The established HPLC method is simple, economic, stable and accurate with good reproducibility. It can be applied on determination of GABA in leaves of Santalum album L. Related Articles | Metrics

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Corrosion Inhibition of Extracts from Phyllostachy sulphurea Leaves for Aluminum in HCl Solution LIU Jian-xiang;WANG Rui-ling;FU Hui;LI Xiang-hong 2013, 33 (2):  129-133.  doi: 10.3969/j.issn.0253-2417.2013.02.023 Abstract ( 930 )   PDF (867KB) ( 719 )   Save Fourier transform infrared(FT-IR) spectroscopy was employed to characterize the main functional groups of extracts from Phyllostachy sulphurea leaves(PSLE). The inhibition effect of PSLE on the corrosion of aluminum in 1.0 mol/L HCl was studied by mass loss and electrochemical impedance spectroscopy(EIS).The results showed that the PSLE was a good inhibitor in hydrochloric acid for aluminum, and the maximum inhibition efficiency was 77.7 %. The corrosion inhibition of bamboo leaves was good at 20 ℃ and 30 ℃.The adsorption of PSLE on the aluminum surface obeys the Langmuir adsorption isotherm equation. Adsorption heat ΔHads was calculated by Van't Hoff, and the inhibition mechanism was discussed in detail according to the parameters. All EIS exhibited that corrosion inhibitor at the aluminum surface had good are resistance. PSLE was a mix-type inhibition. Related Articles | Metrics

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Synthesis of Methyleugenol with Dimethyl Carbonate as Methylating Agent SUN Li-yuan;ZHU Kai 2013, 33 (2):  139-143.  doi: 10.3969/j.issn.0253-2417.2013.02.025 Abstract ( 2422 )   PDF (855KB) ( 1278 )   Save Methyleugenol was prepared from eugenol in the presence of potassium carbonate (K2CO3), using dimethyl carbonate(DMC) as methylating agent instead of the conventional toxic agents. Using the yield of methyleugenol as the evalution index, central composite design process was used to optimize the methylation reaction of eugenol and DMC. An optimum reaction condition for the preparation of the targeted product was as follows, reaction temperature 155 ℃, the amount of K2CO3 6.12 %(mea-sured by the molar ratio of eugenol), the molar ratio of DMC and eugenol 4.3:1 and reaction time 6 h. Under this condition the conversion rate reached 96.16 %. Meanwhile, repeated experiments showed that the reaction process was easy to be controlled and excellent repetitiveness can be acquired. GC-MS and IR spectral analysis were employed to confirm the structure of the product. Related Articles | Metrics

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Review on Isomerization of the Major Monoterpenes in Turpentine WANG Jing;ZHAO Zhen-dong;BI Liang-wu;LI Dong-mei; 2013, 33 (2):  144-150.  doi: 10.3969/j.issn.0253-2417.2013.02.026 Abstract ( 936 )   PDF (888KB) ( 1379 )   Save It was reviewed according to the home and aboard literatures on the isomerization of main terpenes in turpentine, which are α-pinene, β-pinene and 3-carene. All these terpenes could be transformed by thermal energy or catalysis, especially the combined effect by both factors. They could give a complicated product which consisted of limonene, camphene, myrcene and p-cymene and so on. They would be used as materials or intermediates for further applications. Related Articles | Metrics