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Table of Content

    30 December 2013, Volume 33 Issue 6 Previous Issue    Next Issue
    1研究报告
    Ultrasonic Wave-assisted Preparation of Bamboo Powder-based Adsorbents for Pb2+ Removal
    GUO Dou-dou;PANG Hao;LIU Hai-lu;XU Li-li;ZHENG Jing-xin;LIAO Bing
    2013, 33 (6):  1-6.  doi: 10.3969/j.issn.0253-2417.2013.06.001
    Abstract ( 743 )   PDF (2165KB) ( 587 )   Save
    In this study a ultrasonic wave-assisted chemical modification of bamboo powder was carried out to prepare an effective amidoximated bamboo powder-based absorbents for Pb2+ removal from water. The bamboo powders were first pretreated by ultrasonic wave, then subsequently modified by acrylonitrile in alkaline medium and aqueous hydroxylamine. The resulting absorbents were characterized using Fourier transform infrared (FT-IR) and the characteristic absorption peaks corresponding to —C≡N,—CN and N—OH groups were observed. XRD showed that the degree of crystalline of resulting product decreased from 64% to 42%. The nitrogen content determined by elemental analysis is 9.8%. This indicated that the amidoxime group was successfully attached onto the bamboo powders. Adsorption of Pb (Ⅱ) ions by the modified bamboo powder adsorbents were also performed by batch experiments in order to investigate the effects of the adsorbent dosage, initial pH of the solution, and initial Pb2+ concentration on the adsorption of Pb2+, respectively. Langmuir-Freundlich plots and their isotherm coefficients for the adsorption of Pb(Ⅱ) using the adsorbent were probed. It was found that modified bamboo powders with the aid of ultrasound have a maximum absorption of Pb2+ 243.09 mg/g under the condition of pH at 6.0, amount of 2.5g/L for absorption and initial ionic concentration of 1 300 mg/L. It agreed with Langmuir-Freundlich isotherm model.
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    Thermal Stability, Decomposition Kinetics and Storage Time of Gutta-percha
    XIAO Zhuo-bing;GUO Man-man;GUO Rui-ke;XIONG Li-zhi;
    2013, 33 (6):  7-13.  doi: 10.3969/j.issn.0253-2417.2013.06.002
    Abstract ( 897 )   PDF (1560KB) ( 689 )   Save
    The natural polymeric material, gutta-percha, was non-isothermally analyzed by thermogravimetric and differential thermogravimetric techniques at different heating rates of 5, 7.5, 10, 15℃/min under the nitrogen atmosphere. Thermal analysis kinetics methods of multi-heating rate methods (Starink, Kissinger and Flynn-Wall-Ozawa methods) and single heating rate methods (Coats-Redfern and Achar methods) were applied to infer the most probable reaction mechanism and calculate the corresponding kinetic parameters of apparent activation energy Ea and pre-exponential factor A. The results showed that thermal decomposition of gutta-percha began at 268℃ and ended at 459℃ with a complete mass loss. The increasing of heating rates had a significant effect on the decomposition. The TG-DTG curves moved to higher temperatures while a hysteresis effect of thermal decomposition occurred. The most probable thermal decomposition mechanism was Chemical Reaction, corresponding with Reaction Order Equation. The values of apparent activation energy Ea and pre-exponential factor lnA were 191.54 kJ/mol and 33.34, respectively. Compared with other modified natural or synthetic rubbers, characteristic parameters of gutta-percha revealed its strong thermostability while at high temperatures it decomposed fast. Through integral calculation for the differential kinetic equation, the storage time of heat resistance at 200℃ were 170 days.
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    Preparation of Solid Carbon Product from Lignocellulosic Materials Via High Temperature Steam Pyrolysis
    LIU Jun-li;JIANG Jian-chun;YANG Wei-hong
    2013, 33 (6):  19-24.  doi: 10.3969/j.issn.0253-2417.2013.06.004
    Abstract ( 685 )   PDF (5786KB) ( 550 )   Save
    The super-high temperature medium with low cost was obtained by the technology of the honeycomb ceramic heat exchanger. The pyrolysis behavior of super-high temperature medium(steam and nitrogen) and their influences on the components of pyrolysis products were investigated in the fixed bed pyrolysis reactor. The research results showed that the technology of super-high temperature steam pyrolysis trends to prepare high value solid carbon materials with low volatile content and large specific surface area by high-temperature steam pyrolysis. The surface area of solid char from willow pyrolysis at 958 K under steam medium is 280 m2/g. The loss of mass ratio under different mediums is about 80% and the yield of solid carbon is 20%-30% using willow and caragana as raw materials. With the increase of pyrolysis medium temperature, the ratio of mass loss is improved and the time of pyrolysis becomes short. At the same of pyrolysis temperature, the rate of mass loss in the steam medium is greater than that in the N2 medium.
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    Antioxidant Effect of Light Distillates Separated by Molecular Distillation from Lipids of Ginkgo Biloba L. Leaves Using Sigmoidal Curve Fitting Method
    TAO Ran;WANG Cheng-zhang;KONG Zhen-wu;
    2013, 33 (6):  14-18.  doi: 10.3969/j.issn.0253-2417.2013.06.003
    Abstract ( 740 )   PDF (2214KB) ( 587 )   Save
    The fractions separated from light distillates of ginkgo lipids were prepared by extraction with petroleum ether, saponification, molecular distillation and silica gelcolumn chromatographic isolation. Four methods (DPPH, ABTS, superoxide anion and hydroxy radical) with Sigmoidal curve fitting method arriving at respective IC50 values were used to determine the antioxidant effect of the seven fractions. The results showed that light distillates of ginkgo lipids had antioxidant effect and the fraction 2 (95% petroleum ether/5% acetic ether) had the highest antioxidant effect in all tested fractions. IC50 values were (51.0±0.061), (51.3±0.042), (56.9±0.045) and (124.4±0.037)mg/L. The relative deviation between experimental scavenging rate and scavenging rate (50%) of the fraction having maximum deviation in all fractions was 1.4%. Consequently, it is reasonable that the IC50 values of different polar fractions of light distillates separated from ginkgo lipids are generated with Sigmoidal curve fitting method.
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    Structural Characterization of Reaction Product of Dehydroabietic Acid and DMSO and Its Reaction Mechanism
    NIE Yuan-mei;WANG Ying;SHEN Li-qun;YAO Xing-dong;
    2013, 33 (6):  25-28.  doi: 10.3969/j.issn.0253-2417.2013.06.005
    Abstract ( 763 )   PDF (1476KB) ( 611 )   Save
    The reaction of dehydroabietic acid and DMSO produced a new compound when they were heated to 215 ℃ for 3 h in the presence of KOH catalyst. The structure of the reaction product has been characterized by UV, IR, NMR and MS analysis to be methylthiomethyl dehydroabietate. The possible reaction mechanism has been proposed based on the reaction between DMSO and acetic acid or acetic anhydride. The acid was firstly dehydrated to form acid anhydride. Then it reacted with DMSO to produce the ester via. Pummerer rearrangement.
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    Influence of Brönsted and Lewis Acid Sites on Pyrolytic Behaviors of Cellulose over Zeolite-based Catalysts
    XIA Hai-an;WANG Xiu-cong;XU Ran-ran;WU Pin;WU Yi-zhu;YANG Li;ZUO Song-lin
    2013, 33 (6):  29-36.  doi: 10.3969/j.issn.0253-2417.2013.06.006
    Abstract ( 790 )   PDF (1717KB) ( 610 )   Save
    The catalytic pyrolysis of cellulose was investigated using H-ZSM-5 with different Si/Al ratios and Zn/ZSM-5 catalysts with different Zn content. The nature of these catalysts was characterized by ammonia temperature programmed desorption (NH3-TPD), IR spectra of pyridine adsorption, and X-ray diffraction (XRD) techniques. The no-catalytic and catalyic pyrolytic behaviors of cellulose were studied by thermo-gravimetric (TG) technique, and pyrolytic liquid product, i.e. bio-oil, was analyzed by gas chromatography-mass spectrometry (GC-MS). The major components of bio-oil are described as follows: anhydrosugars including levoglucosan (LGA, 1,6-anhydro-β-glucopyranose), levoglucosenone (LGO, 1,6-anhydro-3,4-dideoxy-β-D-pyranosen-2-one), 1,4:3,6-dianhydro-α-D-glucopyranose (DGP), furan compounds such as furfural and 2,5-dimethyl furan, aldehydes, etc. H-ZSM-5 and Zn/ZSM-5 samples with Brönsted acid and Lewis acid sites exhibited a remarkable effect on the pyrolytic behaviors of cellulose, where H-ZSM-5 could increase the yield of bio-gas but decrease the yield of bio-char and bio-oil. Moreover, it was found that Brönsted acid and Lewis acid sites could enhance the formation of a specific compound of bio-oils, e.g. Zn ions could produce some esters.
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    Preparation of Porous Silica Using a Modified Rosin as Template
    MA Yu-ling;SHANG Xu-ting;CUI Shu-fen;HAN Shi-yan
    2013, 33 (6):  37-40.  doi: 10.3969/j.issn.0253-2417.2013.06.007
    Abstract ( 599 )   PDF (11322KB) ( 380 )   Save
    Porous silica was prepared with tetraethyl orthosilicate as starting materials and rosin derivatives-based gemini surfactant as a template using sol-gel method. Its structure was characterized and the morphology was analysized by SEM,TEM and XRD. The pore volume and diameter was analysized by nitrogen adsorption-desorption experiments, too. The results showed that the particle size of silica was about 30 nm and worm-like voids were observed among the particles. The particle size mainly focuses on 29.8 nm in mesoporous range. The specific surface area and the cumulative pore volume are 116.83 m2/g and 0.45 cm3/g, respectively.
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    Preparation of High Adsorption Performance Activated Carbon by Phosphoric Acid Activation
    GUO Hao;DENG Xian-lun;ZHU Guang-zhen;WANG Guo-dong
    2013, 33 (6):  55-58.  doi: 10.3969/j.issn.0253-2417.2013.06.010
    Abstract ( 741 )   PDF (1596KB) ( 796 )   Save
    Activated carbons were prepared using fir sawdust as raw material after pretreatment and the combination of phosphoric acid and sulfuric acid as activator. The methylene blue adsorption value is higher than 338 mg/g, the iodine value is higher than 1 287 mg/g with the yield is higher than 45%. The effect of concentrated sulfuric acid amount, pretreatment time, pretreatment temperature, impregnation ratio and activation temperature on the methylene blue and iodine adsorption properties of the activated carbons were studied.The results showed that adding a small amount of concentrated sulfuric acid solution could promote the penetration of phosphoric acid into lignocellulose, enhance the activation of phosphoric acid,and increase the adsorption capability of activated carbon. The pretreatment time and temperature were controlled for 1 h at 240 ℃. This condition can significantly improve the activated carbon adsorption capacity. The expansion effect of impregnation ratio on the microporous activated carbon was not significant. The activation temperature significantly affects the adsorption capacity of activated carbon, and the activation temperature should be controlled at 450 ℃.
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    Comparison of Fast Pyrolysis of Poplar and Pine Woods on the Basis of Py-GC-MS Analysis
    DONG Chang-qing;ZHANG Zhi-bo;LIAO Hang-tao;LU Qiang
    2013, 33 (6):  41-47.  doi: 10.3969/j.issn.0253-2417.2013.06.008
    Abstract ( 944 )   PDF (2665KB) ( 820 )   Save
    Poplar wood (a typical hardwood) and pine wood (a typical softwood) were pyrolyzed using the pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) technique. The difference of components during fast pyrolysis reaction was investigated. The results indicated that due to the lignin composition difference of these two woods, the pyrolytic products from the pine wood did not contain syringol-type phenolics. Since the hemicellulose in poplar has more acetylated formation than the hemicellulose in pine. The GC contents of the acid products from the poplar wood reached 11.22%, compared with only 4.28% of the acid products from the pine wood. Moreover, the ash in these two woods had no great effects on the furans and phenolic products, but it would inhibit the formation of the anhydrosugars remarkably. After the demineralization pretreatment, the GC contents of the anhydrosugars from the poplar and pine woods increased by 86.4% and 52.4%, respectively.
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    Homogenate Extraction of Polysaccharides from Gardenia jasminoides Ellis by Response Surface Methodology
    HAN Dong;WANG Jue;ZHU Xing-yi;XIE Jie
    2013, 33 (6):  59-62.  doi: 10.3969/j.issn.0253-2417.2013.06.011
    Abstract ( 844 )   PDF (1791KB) ( 770 )   Save
    Homogenate extraction conditions of polysaccharides from Gardenia jasminoides Ellis were studied. Single factors including extraction time, alcohol concentration, and liquid to solid ratio were investigated separately. The response surface analysis method followed by verification test was conducted for obtaining the appropriate operation conditions. Results showed that the optimal conditions of polysaccharides extraction were as follows: extraction time 42 s, alcohol concentration 5% and liquid to solid ratio 27:1(mL:g). Under the above conditions, the yield of polysaccharides was 6.38%. It matched with the predicted yield. Yield of polysaccharides using homogenate extraction was 32.5% higher than that in traditional heat refluxing extraction. Hence, homogenate extraction is a good alternative to extract polysaccharides from G.jasminoides.
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    Liquefaction of Bamboo Powder in Polyols and Its Application in Preparation of Semi-rigid Polyurethane
    XU Li-li;LIAO Bing;NIAN Fu-wei;HUANG Jian-heng;GUO Dou-dou;DENG Mu-jian;PANG Hao
    2013, 33 (6):  48-54.  doi: 10.3969/j.issn.0253-2417.2013.06.009
    Abstract ( 743 )   PDF (5224KB) ( 644 )   Save
    Liquefaction of bamboo powder was conducted in polyols such as poly ethyleneglycol (PEG400), ethylene glycol or glycerol using sulfuric acid catalyst. Effects of liquefying agents, types of catalyst and reaction conditions on the liquefaction procedure, were investigated in detail. The results showed that the yield of liquefied bamboo power was obtained when PEG400 was used as liquefaction solvent and 98% sulfuric acid as catalyst. The residue rate for this case is low to 0.8% in 180 min when the liquefaction was performed at 150 ℃ with 3% catalyst and the ratio of PEG 400 to bamboo powder by weight of 5:1. The resulting liquefaction bamboo products(LB) shows a hydroxy value of 178 mg/g, an acid value of 41 mg/g and excellent flowing property. Additionally, the abundant —OH groups that further conformed by infrared absorption spectrum, allowed this resulting LB to be used to prepare semi-rigid polyurethane (PU) foam. A semi-rigid polyurethane foam from LB and TDI (Toluylene Diisocyanate)(LB-PU) was then prepared using water as vesicant. These LB-PU forms had an apparent density of 69 kg/m3. In conclusion, our work on a new application of bamboo powder material has provided a novel way to develop the "green" polyurethane products.
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    Preparation of Phenolic Resin Spheres
    ZHANG Li;LIU Bin;MA Ye;ZHOU Jian-bin
    2013, 33 (6):  63-68.  doi: 10.3969/j.issn.0253-2417.2013.06.012
    Abstract ( 779 )   PDF (3635KB) ( 700 )   Save
    Using phenol and formaldehyde as raw materials, the millimeter-sized phenolic resin spheres were prepared by suspension polymerization. The effects of four influencing factors on the sphere diameter and sphericity were investigated. They were formaldehyde to phenol ratio (nF:nP), the amount of dispersant(PVA), curing agent(HMTA) and stirring speed. The results showed that the optimum process conditions were as follows: formaldehyde to phenol ratio was 0.9:1, the mass fraction of added PVA was 8%, HMTA was 10% and stirring speed was 300-360 r/min. Under this condition, the average sphere diameter of phenolic resin spheres was 1.04 mm and the average sphericity was 0.97. Industrial analysis and elementary analysis showed that phenolic resin spheres were free of ash and contained 74.27% carbon. In addition, the result of thermogravimetric analysis indicated that carbon yield was up to 62%.
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    Optimization of Ultrasonic Extraction of Acorn Tannin
    YANG Jing;JIANG Jian-chun;ZHANG Ning;WEI Min;ZHAO Jian
    2013, 33 (6):  81-84.  doi: 10.3969/j.issn.0253-2417.2013.06.015
    Abstract ( 731 )   PDF (1424KB) ( 672 )   Save
    Orthogonal test design was employed to optimize the ultrasonic extraction of acorn tannin. The optimal extraction conditions were as follows: crude starch of acorn 2.0 g, ultrasonic power 300 W, 30% ethanol as extractant, temperature 30 ℃, extraction time 50 min,liquid-to-solid ratio 20:1. The maximum extraction efficiency obtained was 10.02% after 3 times extraction.
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    Ethanol Production from Detoxified Acid Steam Exploded Corn Stover by Washing
    CHU Qiu-lu;YANG De-liang;HUANG Yang;YU Shi-yuan;YONG Qiang
    2013, 33 (6):  69-75.  doi: 10.3969/j.issn.0253-2417.2013.06.013
    Abstract ( 713 )   PDF (1503KB) ( 568 )   Save
    The effects of water-washing on inhibitors removal, enzymatic hydrolysis and fermentation of acid steam-exploded corn stover were investigated. The results revealed that the washing process (solid-to-liquid ratio of 1:7.5, room temperature) removed more than 50% of the carbohydrate degradation products and more than 70% of lignin degradation products. The washing process obviously enhanced the fermentability of the concentrated enzymatic hydrolysate and decreased yeast inoculum in fermentation. The concentrated hydrolysate containing 170.69 g/L glucose, which was hydrolyzed, solid-liquid separation and concentrated from washing pretreated corn stover at solid-to-liquid ratio of 1:7.5(g:mL), was fermented by Saccharomyces cerevisiae with a low initial yeast inoculation of OD600 3.84 for 48 h. 80.67 g/L ethanol and 93.66% of ethanol yield were obtained, respectively. The corresponding ethanol production was 173.00 g based on 1 000 g dry pretreated corn stover. The whole enzymatic hydrolysate of the washed substrate at a substrate loading of 350 g/L with a yeast inoculum of 1.0×107 cfu/mL hydrolysate was fermented for 48 h. 54.50 g/L ethanol was formed from 106.64 g/L glucose, and the corresponding ethanol production was 162.17 g based on 1 000 g pretreated dry corn stover.
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    The Variation of Moisture and Temperature in the Internal of Wood during Desorption Process
    ZHAO Tian-xin;XU Bo;ZHANG Wen-jie;MA Er-ni
    2013, 33 (6):  76-80.  doi: 10.3969/j.issn.0253-2417.2013.06.014
    Abstract ( 532 )   PDF (2064KB) ( 585 )   Save
    Desorption processing of poplar(Populus euramericana Cv.)with size of 20 mm× 20 mm×10 mm were investigated from 100% to 3 different relative humidity conditions of 22%, 47%, and 75% at 25℃. A self-designed temperature chamber was used in order to take thermal images at a certain time intervals during the processes. The results showed that with the moisture content of the specimens decreased, the average temperature were also reduced of 1-5 ℃ at the beginning of desorption process. During the desorption process, the moisture content and average temperature of the specimens was gradually approaching the equilibrium state. The temperature for center layer along the longitudinal direction of the specimens was higher than that for surface layer. The temperature difference between the center and surface reached the maximum value of 0.7 ℃ at the first 5 min and eventually reduced to 0.2 ℃ at equilibrium state.
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    Preparation and Antioxidation Biological Activity of Total Triterpenoids Extracts from Scrophularia ningponesis
    CHEN Li-hua;WU Ling;LI Lin-zhi;HE Ling-zhi
    2013, 33 (6):  85-90.  doi: 10.3969/j.issn.0253-2417.2013.06.016
    Abstract ( 519 )   PDF (2413KB) ( 690 )   Save
    Total triterpenoids was extracted from Scrophularia ningponesis Hemsl. with ethanol and ultrasonic-assisted. The influence factors such as material-to-liquid ratio(g:mL), ethanol volume fraction, ultrasonic extracting time and temperature were investigated based on single factor and orthogonal test. The total triterpenoids extract was purified by macro-porous resin and analyzed with oleanic acid. Research on hydroxyl radicals scavenging of purified total triterpenoids extracts was carried out. The antioxidation to oils and fats of purified total triterpenoids extracts were evaluated and compared with gallic acid and Vc. The results showed that the optimal extracting conditions were obtained as follows: 70% ethanol, 1:30(g:mL) material-to-liquid ratio, 40 min ultrasonic extracting time at 250 W and 70 ℃,twice extraction. Under above conditions, the extracts yield was 2.56% and the content of oleanic acid in purified total triterpenoids extracts was 88.50%. The purified total triterpenoids extracts exhibited excellent ability to remove ·OH and the oleanic acid concentration of IC50 to ·OH was 12 mg/L. When antioxidation test was carried out at the condition of being kept in oven at 40 ℃ for 360 min, the protection rate was 20.5% to oil and 29.0% to fat,respectively. The antioxidating effect of purified total triterpenoids extracts was better than that of gallic acid and Vc to oils and almost the same as gallic acid and Vc to fats, respectively.
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    Synthesis of Cinnamaldehyde Catalyzed by Solid Superbase Na2CO3/γ-Al2O3
    CHEN Lu;WANG Yi-wang;LUO Jin-yue;
    2013, 33 (6):  91-94.  doi: 10.3969/j.issn.0253-2417.2013.06.017
    Abstract ( 1581 )   PDF (1482KB) ( 913 )   Save
    Benzaldehyde is used as a raw material, to synthesize cinnamaldehyde from acetaldehyde in catalysis by aldol condensation reaction. The conditions of the catalytic reaction were discussed. The product was characterized by GC-MS,IR and 1H NMR. The results show that: When the catalyst is Na2CO3/γ-Al2O3, the molar proportion of benzaldehyde and acetaldehyde is 1.3:1, the reaction temperature is 30 ℃, reaction time is 1 h, the amount of catalyst is 1 g (according to 11.6 g 40% acetaldehyde), the yield of cinnamaldehyde reaches 40.9%.
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    Optimization of Ultrasound Extraction of Total Triterpenoids from Synsepalum dulcificum Leaf by Response Surface Methodology
    LU Sheng-lou;LIU Hong;ZANG Wen-xia;LI Yun;ZHANG Qiang;WANG Zi-huan
    2013, 33 (6):  95-100.  doi: 10.3969/j.issn.0253-2417.2013.06.018
    Abstract ( 526 )   PDF (3115KB) ( 753 )   Save
    The ultrasound extraction process parameters of total triterpenoids from Synsepalum dulcificum leaf from Hainan province was optimized by response surface methodology. The experiments were arranged according to Box-Behnken central composite experiment design. Four independent influencing factors of extraction, such as concentration of ethanol, extraction temperature, the ratio of liquid to solid and ultrasonic time, were considered on the basis of single factor experiments. The results showed that the optimum ultrasound extraction conditions for total triterpenoids were as follows: concentration of ethanol 70%, extraction temperature 50 ℃, the ratio of liquid to solid 30:1(mL:g) and ultrasonic time 33 min. The experimental yield (0.92%) was in good agreement with its predicted value (0.94%) by model.
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    Optimization of the Extraction Technology of Flavonoids from Fallen Pine Needles by Orthogonal Experiment
    FENG Shi-jing;LI Hong-ping;GAO Jing;XU Li;LIU Guo-ji
    2013, 33 (6):  101-105.  doi: 10.3969/j.issn.0253-2417.2013.06.019
    Abstract ( 600 )   PDF (1979KB) ( 653 )   Save
    The extraction conditions for subcritical fluid extraction of flavonoids from the cedar fallen pine needles were studied by orthogonal experimental design. In this paper, the total flavonoids content in pine needles was determined by UV Spectrophotometry. The contrast sample was rutin and the analyzed wavelength was 360 nm. The results showed that, the sequence of the impact of various factors on the extraction was as follows: extraction temperature >extraction time >liquid-material ratio >extraction pressure.The excellent levels of extraction of total flavonoids were as follows: extraction temperature 60 ℃, extraction pressure 4 MPa, extraction time 60 min, liquid-material ratio for the 3:1. Under these extraction conditions, the extraction amount of flavonoids rose up to 6.677 mg/g.
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    Application of Supercritical Carbon Dioxide Fluid Extraction Technology in Furfural Production Process
    LI Zhi-song;ZHU Bin;TANG Xin-jun;ZHOU Guo-e
    2013, 33 (6):  106-110.  doi: 10.3969/j.issn.0253-2417.2013.06.020
    Abstract ( 631 )   PDF (1833KB) ( 699 )   Save
    The supercritical carbon dioxide fluid extraction technology was used in the furfural production process by dehydration and cyclization of xylose. Under the conditions of feeding mass fraction 5.0% xylose 680 g and mass fraction 5.0% dilute sulfuric acid 6.8 g,with the flow rate of SC-CO2 extractant 0.10 g/s and reaction for 180 min. under 170 ℃, the conversion of xylose increased 2.4 percent point. The selectivity of furfural increased 29.8 percent point and the furfural yield increased 23.4 percent point, compared with that without using SC-CO2. Under experiment conditions with SC-CO2 as extractant, SC-CO2 temperature (35±1) ℃, pressure (16±0.5) MPa, the optimum xylose dehydration and cyclization reaction temperature 180 ℃, the flow rate of SC-CO2 extractant 0.10 g/s,and reaction time 180 min, the furfural yield was up to 63.0%
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    Cd2+Adsorption Property of Modified Activated Carbon Prepared from Beet Pulp
    WU Ying-jie;ZHOU Jian-bin
    2013, 33 (6):  111-115.  doi: 10.3969/j.issn.0253-2417.2013.06.021
    Abstract ( 541 )   PDF (1894KB) ( 524 )   Save
    Beet pulp was used as the raw material for the first time to prepare activated carbon using steam as activating agent and 70% nitric acid solution. The functional group and structure of the carbon were analyzed by Boehm Titration and BET method.The amount of oxygenerated functional group after modifition was increased. The specific surface area of activated carbon is 1 322 m2/g, with methylene blue adsorption value 195 mg/g and iodine adsorption value 1 065 mg/g. The performance of Cd2+ adsorption using the modified activated carbon was also discussed. The influence of the factors on the adsorption performance, such as temperature, pH, activated carbon particle size, adsorption time and solution initial concentration are investigated. The results showed that the modified beet pulp activated carbon has a good adsorption of Cd2+ when the temperature is 25 ℃, the pH 8.5, particle size 75-100 μm and amount of 15 g/L.
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    Optimization on Calcium Ion Precipitation Separation Technology of Quercetin for Hypericum japonicum by Response Surface Methodology
    OUYANG Yu-zhu;WEI Yan;LI Xue-feng;XU Yong-wei
    2013, 33 (6):  116-120.  doi: 10.3969/j.issn.0253-2417.2013.06.022
    Abstract ( 494 )   PDF (2121KB) ( 615 )   Save
    Calcium ion precipitation separation conditions of quercetin from Hypericum japonicum Thumb. were optimized by response surface methodology (RSM). Influence of calcium hydroxide water solution dosage, precipitation temperature and times on extraction ratio of quercetin were studied. The results show that extraction rate of quercetin from Hypericum japonicum is 3.256% with 64 mL calcium hydroxide water solution as precipitator, 61 ℃ precipitation for 31 min. The separation product agrees with standard substance by high performance liquid chromatography (HPLC) analysis.
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    综述评论
    A Review of Biomass Carbon Dioxide Gasification
    WANG Yan-jie;YING Hao;JIANG Jun-fei
    2013, 33 (6):  121-127.  doi: 10.3969/j.issn.0253-2417.2013.06.023
    Abstract ( 806 )   PDF (2518KB) ( 715 )   Save
    The effect of temperature, pressure, catalyst and the concentration of monoxide on biomass carbon dioxide gasification was reviewed. With the increment of temperature, the reactivity of biomass was accelerated dramatically. The effect of the pressure was complex for the reaction of gasification. It was influenced both by partial pressure of components and the whole pressure. Alkali metal and alkali earth metal can be used as catalysts for accelerating the reaction of biomass carbon dioxide gasification. According to the mechanism of carbon dioxide gasification, increasing the amount of monoxide inhibits the reaction to the favorable side. However, reducing the partial pressure and the amount of monoxide in the syngas can promote the reaction rate. The prospect of biomass carbon dioxide gasification application was also presented.
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    Development and Prospect of Furfural Production Technology
    BO De-chen;LI Ping-li
    2013, 33 (6):  128-134.  doi: 10.3969/j.issn.0253-2417.2013.06.024
    Abstract ( 602 )   PDF (2625KB) ( 762 )   Save
    The furfural production technologies are reviewed. The technology of furfural production from pentaose is briefly illustrated. The furfural production by reaction-extraction coupled process is the most promising new furfural production technology. If the two-step furfural production technology and cellulose ethanol technology can be combined, it will be contributed to realizing the comprehensive utilization of biomass raw materials. It will also be contributed to speeding up the industrial application of two-step furfural production technology and cellulose ethanol technology.
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    Research Progress in Plant Resources and Chemistry of Paulownia
    XING Ya-li;BI Liang-wu;ZHAO Zhen-dong;HAN Lu-lu;XIA Tian-juan
    2013, 33 (6):  135-140.  doi: 10.3969/j.issn.0253-2417.2013.06.025
    Abstract ( 731 )   PDF (2445KB) ( 688 )   Save
    Research situations of Paulownia species distribution, biological characteristics and chemical components in different tissue of Paulownia were reviewed in this paper. Paulownia is an important fast-growing species and widely distributed in China. The quality of Paulownia's timber is good. The leaves, flowers, bark, fruits, roots, wood of Paulownia also have different medicinal value. Understanding the research progress of plant resources and chemistry of Paulownia could help to develop and utilize the Paulownia resources multi-levelly and comprehensively.
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