Table of Content

30 April 2012, Volume 32 Issue 2 Previous Issue    Next Issue

专题报道——生物质能源

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Study of Liquefaction of Wood and Its Components in Polyhydric Alcohol ZHANG Hai-rong;PANG Hao;SHI Jin-zhi;LIAO Bing 2012, 32 (2):  14-20.  Abstract ( 755 )   PDF (1310KB) ( 1325 )   Save Liquefaction of wood powder, cellulose and lignin have been studied using ethylene glycol (EG) as liquefaction reagents in presence of sulfuric acid as catalyst, respectively. The results showed that the components of wood (lignin, hemicellulose and amorphous region of cellulose) were easily liquefied compared with crystalline region of cellulose. The liquefaction yield was up to 97%. The ReactIR reaction analysis system with the combination of gas chromatography and mass spectrometry (GC-MS) analysis showed that the liquefied wood products mainly contained EG and its derivatives (diethylene glycol trithylene glycol and dioxane), saccharides, alcohols, aldehydes, ketones, phenols, especially some acids such as formic acid, levulinic acid, oxalic acid and their esters. The structural characteristics of these products indicated that the cellulose can be degraded completely to butyl 4-oxopentanoate, ethyl 3-(2-methyl-1,3-dioxolan-2-yl)propanoate et al., and lignin phenyl propane units were decomposed to aromatic derivatives. Therefore, the liquefied product of wood was a mixture of polyether and/or polyester polyols. Related Articles | Metrics

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Study on the Refining Process of Light Oil from Biomass Alcoholysis ZOU Xian-wu;QIN Te-fu;HUANG Luo-hua 2012, 32 (2):  21-24.  Abstract ( 764 )   PDF (1084KB) ( 871 )   Save Based on the qualitative analysis of light oil from biomass alcoholysis, the thermogravimetry simulation and real distillation processes were performed to study the feasibility of separation of valuable chemicals from light oil. The results showed that the distillation processes could be divided into four stages: a) room temperature-141 ℃; b)141-207 ℃; c) 207-280 ℃ and d) 280-400 ℃. Near 70% fraction was distilled before 207℃. It was found that condensation reaction took place even at the first stage under the temperature of 141 ℃, which resulted in the formation of water. During this stage, 1-octanol could be entrained with the water in distillation process. At the second stage of temperature between 141-207 ℃, an azeotropic system was formed by 1-octanol, formic-acid-octyl-ester, acetic-acid-octyl-ester, and minor hexanoic-acid-4-octyl-ester as well as octyl-ether. Finally, the FTIR analysis on the distillation residue showed that aldol condensation and dehydration reaction took place during the distillation processes, which resulted in the formation of aromatic compounds and ethers. Related Articles | Metrics

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Esterification of Pyrolytic Oils by Mesoporous Materials XU Jun-ming;;XIAO Guo-min;ZHOU Yong-hong;JIANG Jian-chun 2012, 32 (2):  9-13.  Abstract ( 610 )   PDF (1182KB) ( 792 )   Save The mesoporous molecular sieve S2O82-/ZrO2-MCM-41 was synthesized for the esterification of pyrolytic oils. The optimum preparation conditions were obtained by model reactions. The structure of mesoporous molecular sieve was identified by XRD, N2-TPD and FT-IR. The activity of S2O82-/ZrO2-MCM-41 was studied. It was found that the catalyst could be reused for 3 times and gave more than 85 % conversion. Related Articles | Metrics

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Diesel-like Fuel Obtained from Tung Oil Using Pyrolysis and Esterification Coupling CHEN Jie;JIANG Jian-chun;NIE Xiao-an;XU Jun-ming 2012, 32 (2):  25-29.  Abstract ( 808 )   PDF (1259KB) ( 981 )   Save Processes of pyrolysis and esterification post-treatment of tung oil have been studied to make diesel-like fuel with low oxygen levels. The catalytic pyrolysis reactions of tung oil was carried out in self-assembled distillation system, which showed the effects of pyrolysis on molecular components of pyrolytic product (pyrolytic oil). By GC-MS and SEC analysis, it was found that the fraction distribution of product was modified by pyrolysis. The acid value of pyrolytic products was 2.9 mg/g , the density was 825 kg/m3, the viscosity was 4.07 mm2/s, the gross calorific value was 41 kJ/g, the freezing point was -43 ℃, and the cold filter plugging point was -22 ℃. From the results of FTIR and GC-MS measurements, the esterification products were determined to consist of alkanes, with carbon chain below C24, fatty acid methyl ester of short chains below C16 and lower average molecular weight. The acid value of esterification products was 2.9 mg/g, the carboxylic acid content was significantly lower, and the burning heat value increased. The properties and applicability of products were also further improved. Related Articles | Metrics

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Effects of Microwave Pretreatment on Liquefaction in the Preparation of Biomass Polyurethane CHEN Qiu-ling;SUN Ke-wei;ZHANG Chun-hong 2012, 32 (2):  43-46.  Abstract ( 749 )   PDF (1467KB) ( 818 )   Save In order to improve the efficiency of liquefaction, the straw fibers in water media was pretreated by microwave under different conditions to study the effect of microwave treatment on the efficiency of liquefaction. And the chemical structure, morphology and state of aggregation structure of wheat straw fibers before and after microwave pretreatment were investigated by FTIR, SEM, XRD and other instruments. The mechanism of microwave accelerating liquefaction was explored. The results showed that the pretreatment of wheat straw by microwave irradiation for 3 minutes can shorten the liquefaction time from 60 minutes to 40 minutes without changing the liquefaction mechanism at the same condition. The crystallinity of wheat straw fiber decreased from 46.35 % to 30.7 %. This resulted in an increase of accessibility to the fiber and broadened the chemical reactivity. Related Articles | Metrics

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Review on Chemical Constituents and Comprehensive Utilization of Xanthoceras sorbifolia, a Biodiesel Feedstock Tree QI Jian-hua;YAO Zeng-yu 2012, 32 (2):  47-54.  Abstract ( 667 )   PDF (1053KB) ( 1201 )   Save Xanthoceras sorbifolia is a biodiesel feedstock tree, whose leaves, stems, hulls, testa and kernals are diverse in chemical composition. In addition, the components identified in cell wall were those storage materials, such as lignin, cellulose, hemicellulose, pectin, carbohydrate and fat. Besides, secondary products including steroids, terpenoids, coumarins, flavonoids, organic acids, anthraquinones and others were also found. These species have potential utilization in the industries of dietary, medicine, feeding, chemical engineering and energy. Based on the review of the chemical composition and comprehensive analysis, the existing main problems were mentioned and prospect of this research field was pointed out. Related Articles | Metrics

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Thermogravimetric Analysis and Kinetics of Walnut Shell and Coal Co-pyrolysis HUANG Yuan-bo;ZHENG Zhi-feng;JIANG Jian-chun;DAI Wei-di;SUN Yun-juan 2012, 32 (2):  30-36.  Abstract ( 791 )   PDF (1300KB) ( 1008 )   Save The pyrolysis characteristics of walnut shell, coal and their blends sample at different heating rates (5-50 K/min) in a stream of N2 were studied using thermogravimetric analysis. The results showed that the pyrolysis speed increases with the heating rate for three samples increasing. It showed a good synergy during the co-pyrolysis of walnut shell and coal. The balance thermal decomposition temperature of walnut shell, coal and their blends was 568.9, 709.9 and 571.0 K, respectively. With the method of Coasts-Redfern, the pyrolysis process could be described by first-order global model for both of fast-pyrolysis and slow decomposition stage. The average activation energy was 50.6 and 17.3 kJ/mol for both pyrolysis stages of walnut shell, respectively. It was 21.1 kJ/mol for pyrolysis of lignite. But it decreased to 34.2 kJ/mol and 14.5 kJ/mol for both pyrolysis stages of blends of walnut shell/coal, respectively. Related Articles | Metrics

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Liquefaction of Camellia Oil Cake with Phenol and Structure Characterization of Reaction Product YE Jie-wang;YU Hong-wei;HUAI Min;YANG Zong-wu;FAN Xiang 2012, 32 (2):  37-42.  Abstract ( 792 )   PDF (1087KB) ( 976 )   Save For comprehensive utilization of camellia oil cake, the chemical compositions of camellia oil cake were analyzed. The total content of carbohydrate, crude fiber and protein is nearly 75 %. It indicated that camellia oil cake could be liquefied efficiently. Liquefaction technique of camellia oil cake was carried out using phenol as liquefacient, and sulfuric acid as catalyst. Effects of reaction temperature, mass ratio of phenol to camellia oil cake, reaction time, usage of catalyst on liquefaction were investigated. The optimal liquefaction conditions are as follows: liquefaction time of 1.5 h, liquefaction temperature of 140 ℃, li-quid ratio of 4 and catalyst dosage of 4%, with a liquefaction residue rate of 16.25 %. The structure of camellia oil cake, liquefied residue and liquefied products were characterized by Fourier Transform Infrared Spectroscopy (FT-IR). Result showed that camellia oil cake subjected to obvious phenolization and etherification reactions with phenol. This led to more active functional groups formed. Moreover, the structure of protein was destroyed during reaction. It means protein was undergoing liquefaction, as well. Related Articles | Metrics

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Progress in Bio-oil Refining Technology GU Shuai;YANG Hong-xue;MIAO Wei;XU Qing-li;YAN Yong-jie 2012, 32 (2):  55-60.  Abstract ( 728 )   PDF (1109KB) ( 1235 )   Save The study mainly introduces five kinds of bio-oil refining methods—hydrogenation, catalytic pyrolysis, emulsion, catalytic esterification and molecular distillation. Bio-oil refining technologies have their respective problems. For example, catalytic pyrolysis has advantages of simple equipment and low cost but catalyst is easily coked and deactivation; emulsion has simple operation but high cost and more energy consumption; catalytic esterification is a good modification methods but the quality of oil is not high after modification. All these bio-oil refining technologies are hard to realize industrialization. Finally, a new method of bio-oil refining in the CO/H2O systems was also introduced. Related Articles | Metrics

专题报道——多酚化学

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Study on Purification of Chestnut Shell Tannin DU Yun-ping;QIN Qing;XU Hao;ZHANG Zong-he;HUANG Jia-ling;CHEN Wen-wen;TAO Lin 2012, 32 (2):  61-65.  Abstract ( 662 )   PDF (1022KB) ( 1077 )   Save Purification of chestnut shell tannin from generally abandoned chestnut shell was studied. The effect of adsorbent, pre-column concentration, eluent, pH value of distilled water and flow rate on tannin yield was tested respectively. According to single factor and orthogonal experiment results, the optium experimental conditions were as follows: macroporous resin D301 as adsorbent, acetone as eluent, pre-column concentration 9%, pH value 7.0 of distilled water, flow rate 0.4 L/h. Finally, the best process condition was verified by stability test.Under these conditions, the yield of chestnut shell tannin was up to 82%, and tannin mass fraction was higher than 62%. Related Articles | Metrics

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Chestnut Shell Tannin Extract Used as Complexing Agent of Germanium Ion DU Yun-ping;QIN Qing;XU Hao;ZHANG Zong-he;HUANG Jia-ling;CHEN Wen-wen;TAO Lin 2012, 32 (2):  66-70.  Abstract ( 686 )   PDF (1034KB) ( 820 )   Save Germanium was widely used in the semiconductor materials, metal materials, infrared optics, optical communications,biomedicals, etc. In this study chestnut shell tannin extract that was prepared from usually abandoned chestnut shell as raw material, was used as a complexing precipitant of geranium ion. The effects of reaction time, reaction temperature, the amount of chestnut shell tannin extract, pH value,ZnSO4 concentration during complexing precipitation were tested respectively. According to single factor and orthogonal experiment results,the optium experimental conditions were as follows:pH value 2.5, the amount of tannin extract to ( 36 times of germanium), ZnSO4 content of 110 g/L. Under these conditions,the recovery of germanium was up to 99.0%. Related Articles | Metrics

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Synthesis of 2,3,4,4'-tetrahydroxybenzophenone via Hoesch Reaction QIN Qing;XU Hao;QIAN Xing;DU Yun-ping 2012, 32 (2):  71-74.  Abstract ( 915 )   PDF (1027KB) ( 734 )   Save A new synthetic approach to 2,3,4,4'-tetrahydroxybenzophenone was described. By means of pyrogallol and 4-cyanophenol as raw materials and diethyl ether as solvent, Hoesch reaction was carried out in the presence of HCl and ZnCl2 . Finally, 2,3,4,4'-tetrahydroxybenzophenone was synthesized. Influences of reaction were studied by orthogonal test method. The optimum process conditions were as follows: reaction material proportion of pyrogallol to 4-Cyanophenol 1:0.96(mol:mol),dosage of catalyzer 54.4 g(1 mol pyrogallol comparatively),reaction temperature 20 ℃ and reaction time 24 h.The yield of 2,3,4,4'-tetrahydroxybenzophenone was over 90 % and the product purity was over 98 % under this condition. Related Articles | Metrics

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Effects of Extraction and Refining Technology of Tara Tannin on Complexing Precipitation of Geranium QIN Qing;ZHONG Chong-mao;XU Hao;DU Yun-ping;CHANG Lian-ju 2012, 32 (2):  79-82.  Abstract ( 745 )   PDF (1018KB) ( 683 )   Save Using tara powder from Peru as raw material, rate of Ge precipitation from industrial mining liquor contaning zinc sulfate and germanium ion as index, the effects of extraction, refining and post-processing of tara extracts on the rate of Ge precipitation were studied. The results showed that using organic solvents (methanol, ethanol, ethyl acetate) extraction instead of water extraction, rate of Ge precipitation was more than 98%. Degumming of the extract with activated carbon and salting washing as well as through complexation by adding 1 % sodium chloride ammonium and 1% nitrilotriacetic acid effectively reduced non-tannin content in the product and enhanced the rate of Ge precipitation. When tara powder and gall flower of mixed in 8:2 as raw material,followed by complexation of the extract, the rate of Ge precipitation reached 99.05%. The cost of the product was reduced, as well. Related Articles | Metrics

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Extract of Tara Tannin by Methanol QIN Qing;XU Hao;WANG Jin-qiao;DU Yun-ping;CHEN Wen-wen;ZHANG Zong-he;HUANG Jia-ling 2012, 32 (2):  75-78.  Abstract ( 757 )   PDF (955KB) ( 710 )   Save Using Tara pod powder as raw material and methanol as extracting solvent, the effects of different solvents on extraction of tara tannin were studied. The results show that the optimum conditions were extraction temperature 60 ℃, extraction time 40 min, extraction three times and each for 1 h. Tara powder to solvent ratio were 4.5:1, 4:1,4:1(mL:g), respectively. The yield of product was 67.2 % to 68.4%, relative error was 1.77%. The tannin purity was 66.0% to 67.5%, relative error was 2.25%. The yield of tannin was 91.5%. Related Articles | Metrics

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Refining of Tara Tannin with Ethyl Acetate Mixed Solvent QIN Qing;XU Hao;WANG Jin-qiao;CHEN Wen-wen;DU Yun-ping;ZHANG Zong-he;HUANG Jia-ling 2012, 32 (2):  83-86.  Abstract ( 661 )   PDF (958KB) ( 711 )   Save Crude tara tannin was extracted by water and ethyl acetate at 60 ℃ for 30 min.The ratio of crude tannin-water-ethyl acetate was 1:1.5:4(g:mL:mL). The yield of product was 40.2 % and the purity of tannin was 80.4 %. Both yield and purity are low. The yield was still low when ethyl acetate was used to extract the recidual water phase. Refining tara tannin with mixed solvent of ethyl acetate and S-solvent (4:1) was studied. The optimum conditions are: solid to liquid ratio of m(crude tara tannin):V(water):V(mixed solvent)1:1.5:5(g:mL:mL), extraction temperature 60 ℃,extraction time 30 min. Under this condition, the yield of product was 67.1 %-69.0 %, the purity of tannin was 85.3 %-86.5 %, the extraction rate of tannin was 87.2 %-88.6 %. The yield and purity has been improved. Related Articles | Metrics

研究报告

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Synthesis of Mesoporous γ-Al2O3 Using Rosin-based Quaternary Ammonium Salt as Template Agent WANG Peng WANG Peng;ZHAO Zhen-dong;BI Liang-wu;CHEN Yu-xiang; 2012, 32 (2):  87-91.  Abstract ( 771 )   PDF (1283KB) ( 783 )   Save Aluminas with uniform mesoporous structure was synthesized using rosin-based quaternary ammo-nium salt as a template agent, and its structure was characterized with X-ray diffraction, transmission electron microscopy and N2 adsorption and desorption. The results indicated that the surface area and pore diameter of the mesoporous γ-Al2O3 calcinated at 650℃ were in the range of 194-213 m2/g and 4.18-5.18 nm respectively. The content of the rosin-based quaternary ammo-nium salt had significant influence on the textural properties of mesoporous γ-Al2O3. The addition of suitable amount of rosin-based quaternary ammonium salt endowed mesoporous γ-Al2O3 with large pore diameter and narrow pore distribution. Related Articles | Metrics

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Synthesis of Terpene-dimethyl Maleate Adduct under Atmospheric and Pressurized Conditions HUANG Kun;TANG Xiao-dong;LI Mei;LIAN Jian-wei;XIA Jian-ling; 2012, 32 (2):  92-96.  Abstract ( 714 )   PDF (1176KB) ( 916 )   Save Terpene-dimethyl maleate adduct was prepared under atmospheric and pressurized conditions from industrial dipentene and dimethyl maleate as a dienophile. Under atmospheric condition, the yield of terpene-dimethyl maleate adduct was 55% after reflux at 185 ℃ for 10 h. In the hermetic autoclave, the yield of terpene-dimethyl maleate adduct achieved at 78.6 % after 2 h at 240 ℃ and 1.5 MPa. The adduct was characterized by GC-MS, 1H NMR and FT-IR. GC-MS indicated that there were 20 geometric isomers. The mass charge ratio of those molecular ion peaks was 280.1 in the purified adduct and the purity was 95.2%. The content of the Diels-Alder adduct was about 35% of the purified adduct which was calculated from 1H NMR. Related Articles | Metrics

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The Fractionation and Composition Properties of Wheat Straw Lignin and LCC Extracted by Alkaline Solution at Ambient Temperature GAO Ya;ZHAI Hua-min;MA Pu 2012, 32 (2):  97-101.  Abstract ( 873 )   PDF (1046KB) ( 997 )   Save Acid precipitation method was used for fractionation and purification of alkali extraction lignin and lignin-carbohydrate complexes (LCC) from wheat straw at ambient temperature. Three fractions of pH 10.5, pH 9.0 and pH 2.0 were obtained respectively. The yeild of pH 10.5 fraction was 12.24 %. It consisted of and large amounts of carbohydrate which might be preci-pitated as water-insoluble LCC. The lignin content in the fractions reduced with the decreasing pH. pH 9.0 and pH 2.0 fractions mainly consisted of lignin. However, the monosaccharide composition of pH 2.0 fraction is different from that of the pH 10.5 and pH 9.0 fractions. There are more arabinose and galactose in pH 2.0 fraction. SiO2 in the extracted liquor were almost precipitated into the pH 10.5 and pH 9.0 fractions. The ash content in pH 9.0 fraction was up to 13.29 %. Acid precipitation method is a useful one for fractionation of the lignin and LCC from alkali extraction liquor. Related Articles | Metrics

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Extraction of Maire Yew Polysaccharide and Its Structure ZHENG De-yong;XU Li;ZHENG Yue-mei;LIN Qing-xia 2012, 32 (2):  102-106.  Abstract ( 700 )   PDF (1431KB) ( 904 )   Save A polysaccharide was prepared from the branches and leaves of the Taxus chinensis var.mairei by the processing of hot water extraction, concentration, alcohol-precipitation, dialysis and protein isolation successively. The polysaccharide molecular weight was determined by Sephadex G-100 gel permeation chromatography. The monosaccharide composition of the taxus polysaccharide was determined by gas chromatography. And IR spectra of taxus polysaccharide were determined, too. The results showed that the taxus polysaccharide’s molecular weight was 59.2 ku, which composed of 365 monosaccharide groups. The ratio of Rhamnose, Arabinose, Mannose, Glucose and Galactose was 4:6:1:1:4. The taxus polysaccharide was a glycoconjugate that composed of several kinds of monosaccharide, glucuronic acid and amino acid. The monosaccharide was in the form of pyran ring and linked by β-(1,3) glucosidic bond each other. The peptide in taxus polysaccharide couldn't be destructed by Sevag method. Related Articles | Metrics

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Synthesis of Carane by Catalytic Hydrogenation of 3-Carene HE Li-zhi;ZHAO Zhen-dong;WANG Jing;LI Dong-mei;CHEN Yu-xiang;BI Liang-wu; 2012, 32 (2):  107-109.  Abstract ( 899 )   PDF (1007KB) ( 728 )   Save Hydrogenation of 3-carene which is a component of some special turpentine to prepare carane was studied in an autoclave with a mechanical stirrer. The single factor experiment was carried out, while Raney Ni and Pd/C were used under the conditions of catalysts dosage of 4 %-10 %, time 3-12 h, temperature 60-180 ℃ and the hydrogen pressure 3-9 MPa. It resulted in the optimal reaction conditions as 6 % of Raney Ni based on the mass of 3-carene, pressure 9 MPa, temperature 100 ℃, and time 3 h. At these conditions, the yield of carane reached 96.7 % with a selectivity of 92.8 % and a conversion rate of 99.5% of carene. Related Articles | Metrics

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Preparation and Characterization of Activated Carbon by Mechanochemical Process with Zinc Chloride as Activator LI Su-qiong;HUANG Biao;LIN Guan-feng;CHEN Yan-dan;CHEN Wei-qun;CHEN Cui-xia 2012, 32 (2):  110-116.  Abstract ( 717 )   PDF (1686KB) ( 815 )   Save The regression model for factors affecting iodine adsorption of the prepared activated carbon was established and optimized by using Central Composite Design's central combination design and response surface method. The test of single factor showed the activated carbon with good adsorption properties prepared by mechanochemical process. The pore volume and pore size distribution of the prepared activated carbon under the optimum condition were derived from adsorption isotherms(N2 at 77 K). The results showed that the optimum technology condition include ZnCl2/wood flour ratio 3.00, milling time 10min, activation temperature 584 ℃, activation time 2.5 h. Related Articles | Metrics

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Analysis of Different Part of Z.jujuba. var. spinosa by Fourier Transform Infrared Spectroscopy CHE Yong;LI Song-tao;ZHANG Yong-qing;ZHOU Feng-qin 2012, 32 (2):  117-120.  Abstract ( 690 )   PDF (1714KB) ( 909 )   Save An analytic method with Fourier transform infrared spectroscopy (FT-IR) with two dimensional correlation spectroscopy (2D-IR) was established to analyze and evaluate chemical constituent in the different parts of Z.jujuba.var.spinosa. The shape and intensity of the peaks were distinct in single-dimensional FT-IR and the secondary derivative IR spectra of the different parts from Z.jujuba.var.spinosa. Some common peaks in the range of 1750-1300 cm-1 and major peaks were analyzed and assigned to chemical constituent or group. The fingerprint characters of the different parts in 2D-IR spectra were visualized. In the range of 1300-850 cm-1, 3 strong autopeaks arised in the root and leaf, 2 autopeaks in the hardcore,and 1 autopeak in the seed. FTIR combined with 2D-IR was a rapid and comprehensive approach to analyze and evaluate the imperceptible differences among diffe-rent parts of the medicinal herbs. Related Articles | Metrics

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Synthesis of the Bornadiene from 2,6-Dibromocamphane DOU Li-ying;YANG Xiao-qin;ZENG Tao;WU Zhen-hua 2012, 32 (2):  121-125.  Abstract ( 656 )   PDF (975KB) ( 751 )   Save This article states the preparation of bornadiene from 2,6-dibromocanmaphane. It was synthesized from Br2 and α-pinene by addition and isomerization reactions. In this study, α-pinene was used as raw material for synthesis of 2,6-dibromocamphane. The production processes have been improved. The optimal conditions were: mole ratio of Br2 to α-pinene 2.5:1, reaction temperature 0 ℃, and reaction time 24 h. The conversion rate of α-pinene reached 97.6 %, 2,6 - dibromocamphane selectivity of 48.8 %, yield 45.6 %. Self-made 2, 6-dibromocamphane was used to synthesize bornadiene. The optimal conditions were as follows: reaction temperature 100 ℃,reaction time 5 h, t-BuOK used as elimination reagent, the mole ratio of t-BuOK to 2,6-dibromocamphane was 4:1, conversion rate of α-pinene reached 99.12 %. FT-IR, GC-MS, 1H NMR and elemental analysis were used to identify the structure of 2,6-dibromocamphane and bornadiene. Related Articles | Metrics

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Viscosity Reduction Technology of Wheat Straw Alkaline-oxygen Pulping Black Liquor at Low Temperature CHEN Shuang-shuang;YANG Xu;CAO Yun-feng;YANG Yang;LIU Zhu-lan 2012, 32 (2):  131-134.  Abstract ( 686 )   PDF (974KB) ( 799 )   Save The wheat straw fibers after alkaline-AQ pulping was handled by oxygen directly without washing in present study. A L9(34) orthogonal design, including the factors of alkali charge, oxygen dosage, cooking temperature and holding time, was applied to evaluate their influences on black liquor viscosity and pulp Kappa number. The high quality pulp fibers with black viscosity 3.4 mPa·s and Kappa number 17.9 was obtained when the unwashed fibers were treated by 1% alkali charge (as NaOH) and 0.6 MPa oxygen pressure for 60 minutes at 85 ℃. In contrast to the pulp after first stage alkaline pulping, the black liquor viscosity and Kappa number decreased 33.3% and 11.8%, respectively. Related Articles | Metrics

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Preparation and Adsorption Properties of Activated Carbon with Developed Micropore from Coconut Shell by Pyrolysis Activation LIU Xue-mei;JIANG Jian-chun;SUN Kang;XU Fan;XU Yu; 2012, 32 (2):  126-130.  Abstract ( 798 )   PDF (1167KB) ( 1048 )   Save Activated carbons were prepared from coconut shell by pyrolysis activation. The effects of activation temperature and time on pore structure and adsorption properties of activated carbons were investigated. The results showed that the prepared carbon has mainly micropore under the condition of activation temperature at 900 ℃ for 4 hours. The surface area of the prepared carbon is 994.42 m2/g with the iodine adsorption of 1 295 mg/g and methylene blue adsorption of 135 mg/g. The results of N2 adsorption showed that the average pore size of the activated carbon is around 2 nm. The micropore volume is 0.430 3 cm3/g and total pore volume of 0.503 9 cm3/g. This indicated that ratio of micropore is 85.39%. The results of CO2 dynamic adsorption showed that the adsorption qulity is up to 56.61 mg/g. With the increase of activation temperature and activation time, the yield of activated carbons is reduced at different degree, in the preparation of activated carbons from cocomt shell by carbonzation. Related Articles | Metrics

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Synthesis and the Quantitative 13C NMR Analysis of PUF Resin for E0-Ⅱ-type Plywood JIANG Yu-feng;ZHANG Wei;ZHAO Lin-wu;ZHANG Ming-ming;WANG Chun-peng 2012, 32 (2):  135-139.  Abstract ( 627 )   PDF (974KB) ( 846 )   Save The phenol-urea-formaldehyde(PUF) resins with 95%-200% urea (base in phenol weight) were synthesized in alkaline condition by using CaO and NaOH as catalyst. It had long storage life(>30 d). These PUF resins were used to produce the plywood that meet the requirement of type Ⅱ by measuring the bond strength. The formaldehyde emission of the PUF resin bonded poplar plywood was less than 0.5 mg/L, which was regarded as E0 degree. PUF resin was synthesized in the conduction of urea/phenol (U/P) mass ratio 1.5:1 and formaldehyde and urea-phenol (F/(U+P)) molar ratio 0.97. The contents of methylene, hydroxymethyl and methylene-ether bonds which transformed from formaldehyde molecule, were quantitatively examined by the 13C NMR spectroscopy. The relationships between the formaldehyde emission and the bond strength of the PUF resin bonded poplar plywood were explained by the analysis of the contents of methylene (32.4%), hydroxymethyl (57%) and methylene-ether (10 %) bonds. Related Articles | Metrics

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Effects of Pore Structure of Granular Activated Carbon on n-Butane Adsorption LIU Xiao-min;DENG Xian-lun;ZHU Guang-zhen;WANG Guo-dong;XU Yu; 2012, 32 (2):  140-144.  Abstract ( 717 )   PDF (1159KB) ( 1302 )   Save Five kinds of wood-based granular activated carbons obtained from different raw materials and technologies have been experimentally studied for n-butane adsorption. The results indicate that butane adsorption capacity of activated carbon is strongly influenced by the specific surface area,pore volume and pore size distribution. It is the micropores between 1.16 nanometer and 2.0 nanometer that play the most important effect on adsorption. To obtain higher butane working capacity,it is important to form the micropores with diameter between 1.2 nanometer and 4 nanometer and high pore volume. The butane retentivity is significantly effected by the pores between 0.5 nanometer and 1.0 nanometer. Besides,as for macropore,it plays unappreciable role in the adsorption value,just acting transport for adsorbates. Related Articles | Metrics

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Effect of Triethanolamine on the Retardant Effectiveness and Hygroscopicity of Wood Fire-retardant SUN Ying-ying;CHENG Kang-hua 2012, 32 (2):  145-148.  Abstract ( 827 )   PDF (958KB) ( 871 )   Save Effect of triethanolamine(TEM) on the drug load, retardant effectiveness and hygroscopicity of wood treated by three fire-retardants(F1,F2,DPB) were investigated. The results showed that drug loading and oxygen index increased with the increase of triethanolamine and the retardant effectiveness was improved at the same time. When triethanolamine is increased to 3.5 %, the viscosity of the solution rises and the increase of the drug loading becomes insignificant. Adding 2.5 % to 3.5% of triethanolamine gave the minimum moisture absorption rate for the samples. Otherwise the experiments showed that F2 fire-retar-dant had the synergistic effect with triethanolamine only and F1 and DPB had little synergistic effect with triethanolamine. Related Articles | Metrics

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Extraction of Orange Peel Oil by SCF-CO2 and Analysis of Its Constituents LUO Jin-yue;WANG Ai;QIAN Yong 2012, 32 (2):  149-152.  Abstract ( 795 )   PDF (1018KB) ( 1151 )   Save Orange peel oil was extracted by supercritical fluid-CO2 (SCF-CO2) and its constituents were analyzed by GC-MS. The effects of extraction time, pressure, temperature, CO2 flow rateand separate temperature on the oil yield were studied. The optimal conditions were determined by orthogonal experiments. The optimal conditions were as follows: extraction time 60 min, extraction pressure 20 MPa, extraction temperature 40 ℃, separation temperature 50 ℃. At the conditions, the oil yield was 0.86%. GC-MS analysis revealed that the main constituent of the oil was 5,5'-dimethoxy-3,3'-dimethy-2,2'-bina-phthalene-1,1',4,4'-tetrone which amounted to 35.54%, and the other main constituent was β-hydroxy-methyl-norethisterone-methyl-oxime which amounted to 24.60 %. Related Articles | Metrics

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Antioxidation Stability of Silybum marianum Gaertn. Meal Protein Hydrolysates ZHU Shu-yun;DONG Ying;ZHOU Yue 2012, 32 (2):  153-157.  Abstract ( 684 )   PDF (1395KB) ( 782 )   Save The change of scavenging activity on DPPH· of the hydrolysates from Silybum marianum meal protein and on free radical scavenging activity of DPPH was selected as the index to investigate the effects of temperature,pH,food materials,preservative,metal ions and digestion mode on the antioxidation stability of the hydrolysates.The results showed that the activity retention rate of the hydrolysates was 92.19 % at 60 ℃ for 1 h. In the solution containing pH 3 or 11 for 2 h,its activity retention rate was 95.66 % and 86.69 %, respectively. In the solution containing NaCl,sucrose or glucose, its activity retention rate was all more than 96 %. In the 0.1 % solution of benzoic acid or sorbic acid , its activity retention rate decreased by 57.71 % and 45.48 %.These showed the hydrolysates has a strong heat-resistant ability. It can keep high activity in the acidity and alkali environment. NaCl,sucrose and glucose have little effects on its antioxidation stability while benzoic acid and sorbic acid can reduce its activity. All of K+, Ca2+, Mg2+, Fe3+, Zn2+, Cu2+ can affect the stability.In the 500 g/L solution of K+、Ca2+、Mg2+, its activity retention rare was all more than 90 %.In the 500 g/L solution of Fe3+, its activity retention rate was the lowest only at 48.64 %. And the hydrolysates can keep high activity in vitro digestive system. Related Articles | Metrics

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The Activation Process of Fluidization for Sawdust Charcoal BIAN Yi;LIU Shi-cai;JIAN Xiang-kun;DENG Xian-lun;XU Yu; 2012, 32 (2):  158-162.  Abstract ( 662 )   PDF (1226KB) ( 730 )   Save Activated carbon was prepared by fluidization progress from sawdust charcoal using water vapor as activator. The factors effects on properties of activated carbon such as activation temperature, carrier flow, water vapor flow, feed rate were studied. The optimum conditions obtained by the orthogonal experiments are as follows: activation temperature 870 ℃, carrier flow 250 m3/h, water vapor flow 150 m3/h, feed rate 54 kg/h. Under these conditions, the product yield is up to 31.62 % with the iodine adsorption up to 1 162 mg/g. The analysis of variance showed that the activation temperature is the only significant impact factor for product yield. The impact factors such as activation temperature, water vapor flow and carrier flow are significant for the iodine adsorption. Related Articles | Metrics

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Extraction of Total Flavonoids of Mulberry Leaves and Their Antibacterial Activities CHI Xiao-zhe;CAO Guang-qun 2012, 32 (2):  163-166.  Abstract ( 847 )   PDF (1018KB) ( 994 )   Save The extraction process of total flavonoids from mulberry leaves was optimized based on antibacterial activity. The curde extract obtained at the optimal condition was fractionated by different solvents and then qualitatively analyzed. The contents of total flavonoids of fractionated extracts were determined. The diameter of antibacterial circle and minimum inhibitory concentration of extracts on Escherichia coli (Ec.) and Staphyloccocus aureus Rosenbach (Sa.) were investigated. The stability of the better fractionated extract was tested. The results showed that the optimal extraction condition for curde extract is 70 ℃, 70 % ethanol concentration, 4 h and solid-liquid 1:30(g:mL). The fractionated extract being better antibacterial effect was ethyl acetate extract. Furthermore, ethyl acetate extract had better stabilities on temperature and UV irradiation. Related Articles | Metrics

专题报道——生物质能源

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Study on the Pyrolysis Products of Several Lignocellulosic Materials XIAO Zhi-liang;ZUO Song-lin 2012, 32 (2):  1-8.  Abstract ( 660 )   PDF (1469KB) ( 1135 )   Save Five types of lignocellulosic materials, i.e., ginkgo wood, fir wood,wheat straw, rice straw, corn cob, which are representative of woody materials and grass ones, were routinely pyrolyzed in nitrogen atmosphere. During pyrolysis reaction, the gaseous products were in-line detected by gas chromatography. The condensed products were analyzed by GC-MS.The water content in pyrolytic liquid products were measured by Karl-Fischer method. The results showed that the yield of solid char is about 30% for both of the woody and grassy materials. The yield of the liquid products from the woody materials was 33%-42% lower than that from the grassy ones(45%-51%), while the yield of the gaseous products from the woody materials was 30%-39% higher than that from the latter(18%-24%). The organic substances in the pyrolytic liquid products were mainly furan-type compounds and phenolic ones. The total content of the furan compounds from grassy materials were 25%-33%, which is higher than that from woody materials. The total content of phenolic compounds from gassy materials is 24%-30%. CO2 and CO are gaseous products mainly originated from the thermal decomposition of raw materials. CH4 and H2 were closely related to pyrolysis reaction of tar originated from raw materials and the structure formation of solid char. Related Articles | Metrics