Table of Content

30 November 2010, Volume 44 Issue 6 Previous Issue    Next Issue

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Exergy Analysis of Photosynthetic Biological Hydrogen Production System in Midsize ZENG Fan;ZHANG Quan-guo;ZHAO Yuan-liang;HAN Bin-xu 2010, 44 (6):  1-5.  Abstract ( 657 )   PDF (1138KB) ( 917 )   Save Using the second law of thermodynamics the exergy photosynthetic biological hydrogen production system was analyzed by a white-box model.The results show that the yield of hydrogen was less and the exergy efficiencies of the system is 24.4%, and light losing is the biggest one in the total exergy losing which account for 64.4%. Factors that affect the light conversion efficiency was analyzed in the weak links of the system and the corresponding solutions were proposed. The aspects in system and the utilization of the effective energy were improved and a science reference for the process of the industrialization in the photosynthetic biological hydrogen production system were provided. Related Articles | Metrics

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Quantitative Determination of Methyl Gallate by HPLC Method WU Dong-mei;CHEN Jia-hong;WANG Yong-mei;ZHANG Liang-liang;XU Man 2010, 44 (6):  6-9.  Abstract ( 734 )   PDF (880KB) ( 1213 )   Save The content of methyl gallate (MG) was determined by HPLC. The characteristic absorption of MG was determined by ultraviolet scanning and the wavelength of characteristic absorption was 279 nm. The results showed that relationship between peak area of MG and the content of sample solutions in definite range obey Lombard Beer's law. The measured values were analyzed by statistical method, and it obey the normal distribution. The standard deviation of measured values was 0.02% which was within the limit of requirements. Statistic analysis showed that the measured values from two laboratories using F test and t test had no significant difference, which demonstrated that the method for determination of MG had high precision and accuracy. The method appeared to be simple and quick, cheap and stable. Related Articles | Metrics

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Study on Process of Steam Distillation of Chinese Sweetgum Resin SONG Xiao;ZENG Tao 2010, 44 (6):  10-13.  Abstract ( 695 )   PDF (1012KB) ( 1214 )   Save Steam distilliation process conditions of Chinese sweetgum resin from Jiangxi, Guizhou and Guangxi provinces of China were studied. The physicochemical properties of the Chinese sweetgum resin and the essential oil obtained from steam distillation with different temperature, including appearance, oil content, acid value, saponification value, softening point, viscocity and color etc. By comparative analysis of the physical and chemical data, the optimal distillation technology was selected as follows:the time of distillation 30 min, the distillation temperature of Jiangxi resin 175-180℃, Guangxi resin 190-195℃ and Guizhou resin 200-205℃. Related Articles | Metrics

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Determination of Xylo-oligosaccharides by Sulfuric Acid Hydrolysis-High Performance Liquid Chromatography Detection CHEN Mu;LIAN Zhi-na;XU Yong;YONG Qiang;YU Shi-yuan; 2010, 44 (6):  14-17.  Abstract ( 822 )   PDF (992KB) ( 1822 )   Save A simple and convenient method on xylo-oligosaccharide product (XOS) quantitative determination was established based on dilute sulfuric acid hydrolysis combined with high performance liquid chromatography (SAH-HPLC) detection. The protocol is as following:on HPLC system, the xylose content of XOS, the standard xylose and its hydrolysates was determined, and then total XOS content was calculated according to its xylose content changes, the xylose decomposition ratio and the conversion ratio of XOS to xylose during SAH. The optimum conditions for SAH step is at 6.0% sulfuric acid content and 100℃ for 60 min. The optimum conditions for HPLC detection step is at the lution rate of 0.6 mL/min with 0.005 mol/L sulfuric acid by the column Bio-Rad Aminex HPX-87H under 55℃, and the xylose content was quantitatively detected and calculated according to the external standard method and peak area integration. The repeatability and accuracy of the SAH-HPLC method was tested for some XOS product determination. The result showed the XOS content was 39.94% in the product at a good repeatability and accuracy and the standard deviation of 0.36%. Related Articles | Metrics

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Study on Kinetics Model of Synthesis of Lyral from Myrac Aldehyde CHEN Yan-ping;WANG Bi-yu;HUANG Zhi-xian;WU Yan-xiang 2010, 44 (6):  18-22.  Abstract ( 819 )   PDF (965KB) ( 929 )   Save The hydration kinetics of lyral synthesis using myrac aldehyde as raw materials was studied. Reaction conditions on reaction rate constant were investigated. The optimum conditions were identified:reaction temperature 338 K, initial concentration of myrac aldehyde 0.5346mol/L and the flow rate 3.58×10-3 m/s. Kinetic data of myrac aldehyde synthesis lyral were fitted based on homogeneous reaction model. A kinetics model was gained, -rA=1.26×107CACH2Oexp(-66670/RT)-3.68×106CBexp(-57939/RT). Activation energy of the positive reaction is Ea+ 66.670 kJ/mol, and the reverse reaction is Ea- 57.939 kJ/mol. Relative deviations between the calculated values and the experimental values were all below 5%, which showed that the kinetic model could preferably describe the hydration of lyral. Related Articles | Metrics

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Chemical Compositions of Essential Oil of Four Eucalyptus Leaves from Africa CHEN Hong-xia;WANG Cheng-zhang 2010, 44 (6):  23-27.  Abstract ( 844 )   PDF (972KB) ( 1971 )   Save The four types of essential oil of Eucalyptus leaves from Africa were obtained by steam distillation and analyzed by gas chromatography/mass spectrometry(GC-MS).The compounds of 1# and 2# oil were eucalyptol, terpinyl acetate, α-gurjunene, aromadendrene, alloaromadendrene, ledene, globulol and ledol. The compounds of 3# and 4# oil were p-cymene, eucalyptol, cryptone, cumaldehyde, phellandral, spathulenol, eudesmol, and 9,12-octadecadienoic acid. Related Articles | Metrics

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Study on Adsorption Behavior of the Bamboo-charcoal for Hg2+and Pb2+in the Mixed Solution ZHANG Xiao-yan;WANG Gui-xian;ZHANG Qi-wei 2010, 44 (6):  28-31.  Abstract ( 704 )   PDF (862KB) ( 1207 )   Save The adsorption behavior of the bamboo-charcoal for Hg2+ and Pb2+ in mixed solution were studied. Experimental results shows that mercury and lead could were adsorbed synchronously by bamboo-charcoal. The bamboo-charcoal showed high adsorption ability for mercury and lead at a wide pH range(pH 3.2～6.2), The optimal adsorption acidity is pH 5.90 in HAc-NaAc medium. The equilibrium time of adsorption is 270 min. In certain conditions, adsorption capacity increased, but adsorption ratio decreased with increases in concentration of adsorbed ion in mixed solution, and adsorption capacity decreased, but adsorption ratio increased with increases in mass of absorbent. If the absorbent amount is appropriate, Hg2+ and Pb2+ in mixed solution could were removed complete. The adsorption behavior of the bamboo-carbon for Hg2+ and Pb2+ in mixed solution obeys the Freundlich isotherm model respectively. Related Articles | Metrics

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Analysis of Chemical Compositions of Volatile oil in Kalopanax septemlobus (Thunb.) Koidz. Trunk and Bark by Headspace Solid-phase Micro-extraction YE Chong;MAO Han-bing;HE Jun;YUAN Hong-liu;LIU Ke-qian 2010, 44 (6):  32-35.  Abstract ( 698 )   PDF (881KB) ( 1305 )   Save The volatile compounds were extracted in the trunk and bark of Kalopanax septemlobus(Thunb.) Koidz. by headspace solid-phase micro-extraction(HS-SPME). Their constituents were analyzed and identified by gas chromatography-mass spectrometry combined with Kovats retention index,and the relative contents were quantified by calculating basing on the peak areas norma-lization method. The results showed that 53 volatile constituents in the trunk and 67 volatile constituents in the bark of K.septemlobus were identified, accounting for 95.91% and 96.60% of the total peak areas, respectively.The main components obtained from trunk and bark were found to be quite similar. γ-elemene(18.59%,14.60%), germacrene d (19.09%,15.79%), trans-β-farnesene (13.94%,16.88%). Related Articles | Metrics

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Research on Chemical Composition Analysis and Utilization Evaluation on Hickory of Three Epicarps ZHANG Jiang-li;ZHUANG Xiao-wei;CHEN Shun-wei;PAN Xin;JIANG Ying-ti 2010, 44 (6):  36-39.  Abstract ( 592 )   PDF (840KB) ( 1491 )   Save This paper comparatively analyzed ash contents, extractives, cellulose, lignin and etc., in total nine chemical components from epicarps of hickory, chestnut, and sasanqua to pine sawdusts and fir sawdusts, which are normal materials for machine-made charcoal briquettes. The conclusions are:the hickory epicarp is constrained in massive production of machine-made charcoal as a substitute of sawdust due to too much ash content(12.23%);the amont of extractives from the hickory epicarp and the chestnut epicarp, extrated by means of cold water extracting, hot water extracting, and 1% NaOH extracting separately, are all higher than that from pine sawdusts and fir sawdusts, which illustrates the epicarp contents more low-molecular pentosan and low-molecular lignin than that of pine and fir dust that the former is limited to replace the latter in producing machine-made charcoal in great number. Related Articles | Metrics

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Preparation of Carboxymethyl Cellulose by Using Bio-butanol By-product as Raw Material HAN Chun-guo;WANG Chun-peng;JIN Tie-ling;CHU Fu-xiang; 2010, 44 (6):  40-45.  Abstract ( 839 )   PDF (1040KB) ( 1456 )   Save Carboxymethyl cellulose (CMC) was prepared using bio-butanol by-product as raw material. The effects of different processing methods of raw materials, alkali dosage, ether dosage and self-made additives on properties of CMC were discussed. The products were charaterized by Haake Rheometer Rheostress and FT-IR. The results showed that CMC excellent properties could be obtained with bio-butanol by-product from corn stalks or corncob hemi-cellulose, especially those bleaching with hydrogen peroxide but without a procedure of steam explosion treatment. The CMC had high viscosity when the alkali/etherifying agent in the amount of material than about 2.0. The CMC had high substitution degree when the alkali/etherifying agent in the amount of material than about 2.3. The CMC solution viscosity increased with the decrease of shear rate, it showed a strong shear dilution. The CMC had strong absorption peaks in 1500-1700 cm-1. It was also demonstrated that the additives could increase significantly the viscosity of CMC. The physical and chemical data of CMC were as follows:pH value 7.8-8.3;water content≤6.6%;viscosity (2%, 25℃)35-6300 mPa·s;substitution degree 0.65-1.16. Related Articles | Metrics

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Progress on the Separation and Purification of Bio-oil LI Yun-chao;WANG Xian-hua;YANG Hai-ping;ZHANG Shi-hong;CHEN Han-ping 2010, 44 (6):  46-51.  Abstract ( 624 )   PDF (984KB) ( 1422 )   Save Based on the analysis of bio-oil properties, the current status of bio-oil separation and purification technology is summarized, including distillation, fractional condensation, solvent separation, centrifugal separation, chromatography, membrane separation and supercritical extraction. The main problems existing in bio-oil separation are summarized. Investigation trend of the technology is presented. It is suggested that energy utilization and chemical product separation can be integrated through fractional condensation and economical benefits can be maximized. It is also suggested that membrane separation and supercritical extraction have potential research value in the separation of bio-oil. Related Articles | Metrics

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Research Progress in the Activated Carbon Adsorption on Volatile Organic Compounds LIU Xiao-min;DENG Xian-lun;ZHU Guang-zhen 2010, 44 (6):  52-58.  Abstract ( 777 )   PDF (1028KB) ( 1887 )   Save The sources, harmfulness of VOCs and methods of treating VOCs were introduced based on the concept of volatile organic compunds (VOCs). Activated carbon adsorption technology was mainly introduced. Factors that influenced the perfor-mance of activated carbon adsorption were summarized, including pore structure of activated carbon, surface chemical structure, activated methods, the import concentration of VOCs, the physical-chemical properties of the VOCs, mixed VOCs adsorption and packing density of adsorption column. Related Articles | Metrics

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Near Infrared Spectroscopy Technology and Analysis in Quality Traits of Vegetable Oil YUAN Jiao-jiao;WANG Cheng-zhang;CHEN Hong-xia 2010, 44 (6):  59-65.  Abstract ( 640 )   PDF (960KB) ( 1266 )   Save Technical principle,modeling establishment and evaluation,chemometrics methods of the near-infrared spectroscopy technology (NIRS) were described. Its application in analysis of quality traits of vegetable oil is emphasized. NIRS can identify the type of vegetable oil quickly,and analyse the oil content and fatty acid chemical composition accurately. At present,oil quality has been affected seriously by the adulteration. Therefore,NIRS,which is a quick, convenient, environmental amd non-destructive technology , will have a extremely broad application prospects. Related Articles | Metrics