Table of Content

30 May 2007, Volume 41 Issue 3 Previous Issue    Next Issue

研究报道

Select

Study on Pyrolysis Characteristics and Kinetics of Seaweed GUO Xiao-lan;WANG Jun;CHEN Ming-gong;LI De-mao;MIN Fan-fei;ZHANG Ming-xu;WANG Guang-ce;CHEN Ming-qiang 2007, 41 (3):  1-5.  Abstract ( 660 )   PDF (1127KB) ( 743 )   Save The pyrolytic characteristics of two seaweeds were investigated by thermogravimetric analysis technique. The pyrolysis experiments were performed up to 700℃ at heating rates of 10、20、30、50 and 80℃/min in a dynamic nitrogen flow of 100 mL/min.The results showed four stages (dehydration, two main devolatilizations and residual decomposition) appeared in the pyrolysis process. Activation energies and pre-exponential factors were calculated by Popescu method. Experment results indicated that Avrami-Erofeev equation was suitable for describing the main devolatilization process of seaweed. Thermolysis mechanism was random nucleation and nuclei growth.With the increasing of conversion,activation energies and pre-exponential factors were also increased. This showed that pyrolysis took place easily when conversion rate was low. Related Articles | Metrics

Select

Effect of Temperature Modulation on Hydrogen Fermentation from Steam Exploded Straw LI Dong-min;CHEN Hong-zhang 2007, 41 (3):  11-14.  Abstract ( 687 )   PDF (710KB) ( 747 )   Save Hydrogen was produced by simultaneous saccharification and fermentation from steam exploded straw using Clostridium butyricum AS1.209. However, the optimum temperature of enzymatic hydrolysis is far away from that of fermentation and the utilization of substrate is limited. To solve the problem of inconsistent temperature, the reaction temperature was modulated for two times when fermentation processed at the time of 10h and 30h, respectively. The temperature quickly increased to 45℃ and then decreased back to 35℃ after maintaining for 2 h. The temperature modulation was favorable for enzymatic hydrolysis and fermentation. The hydrogen yield of temperature changing process was 1.2 times higher than that at constant temperature. The conversion rates of cellulose and hemicellulose were 75% and 88%, respectively. Related Articles | Metrics

Select

Research and Practice to Synthesize Esters Perfumes with Clean Production Process ZHAO Zhen-dong;LI Dong-mei;BI Liang-wu;HU Gui-xian;SUN Zhen;LIU Xian-zhang 2007, 41 (3):  15-17.  Abstract ( 676 )   PDF (616KB) ( 602 )   Save A method was studied and developed to synthesize esters perfumes according to the principle and conception of green chemistry and clean process. Some esters perfumes such as low- and middle-carbon akyl acetate, fructone-A and fructone-B, etc. were prepared of the method, of which contents of main products were more than 95%, and purities of the products were more than 98% after distillation or fine distillation. A pilot test production for synthesizing fructone-A on the scale of 100L was done according to the experimental results. There are some merits of the method, such as process is simple; catalyst is easy to reuse; and there is very little waste gas, residue, and liquid to be drained. Related Articles | Metrics

综述

Select

Research Review on the Extracting Methods of Flavonoids from Plants CHEN Cong-jin;HUANG Ke-ying;LI De-liang;SUN Chong-lu 2007, 41 (3):  42-46.  Abstract ( 740 )   PDF (912KB) ( 869 )   Save The extracting methods of flavonoids from plants including traditional extracting methods and new methods such as microwave extraction,supercritical extraction,ultrasonic extraction,enzyme hydrolysis extraction, and semi-bionic extraction were reviewed in this paper in order to offer reference to the research,development and application of flavonoids. Related Articles | Metrics

Select

The Quality of Biodiesel and Its Standardization LIU Yan-li;MA Dan;LIU Shou-chang 2007, 41 (3):  53-55.  Abstract ( 633 )   PDF (617KB) ( 803 )   Save As an alternative fuel, biodiesel has become more attractive recently because of its environmental benefits. The influence of reaction conditions on various quality indexes and their analysis approach, controlling methods were described. The standardization of biodiesel and its application mode in China were discussed. Related Articles | Metrics

研究报道

Select

The Determination of Flavonoids in Different Parts of Eucommia Ulmoides Oliver DENG Su-lan;YU Ji-hong;GUAN Lin 2007, 41 (3):  37-38.  Abstract ( 748 )   PDF (388KB) ( 603 )   Save Flavonids in different parts of Eucommia ulmoides Oliver were determined by microwave extraction, Al(NO3)3-NaNO2 chromogenesis, and UV spectroscopy based on reference material of rutin. The content of flavonoids in old leaf, young leaf, twig, thick twig, annual branch, trunk, trunk bark, taproot, taproot bark, and fibrous root, was 6.05%,4.65%,0.52%,0.33%,0.285%,0.23%,0.15%,0.155%,0.165%,respectively. The experimental results showed that old leaves had the highest content of flavonoids. It was indicated that old leaves of Eucommia ulmoides Oliver were worth to be developed and utilized in the next step. Related Articles | Metrics

综述

Select

Current Status of Extraction and Application of Capsaicin ZHOU Wen-wen;LI Xiang-zhou;YAN Xian-zai 2007, 41 (3):  56-60.  Abstract ( 652 )   PDF (826KB) ( 761 )   Save In this paper the properties, extracting technics and the uses of capsaicin are reviewed. Some typical methods are enumerated such as solvent extraction, microwave and supercritical CO2 fluid extraction. Furthermore, the perspective of its utilization is briefly introduced. Related Articles | Metrics

研究报道

Select

A Study on the Performance of Drilling Mud Thinner Sulfomethylated Tannin of Tara(SMT-T) ZHANG Jian-yun;LI Zhi-guo;WU Hao;BAO Song-lian;YANG Shi-yu 2007, 41 (3):  21-26.  Abstract ( 938 )   PDF (774KB) ( 829 )   Save The performances of sulfomethylated tannin of tara (Caesalpinia spinosa Kuntze) (SMT-T) prepared by sulfomethylation and chelating of the extract from pod shell of tara, were studied. The results show that SMT-T could be used as drilling mud thinner and the drying method of SMT-T as well as its addition amount (0.5%-2.0%) have no significant influence on the viscosity reducing rate (VRR). When the temperature is 180℃ and the addition amount of SMT-T is 2%, the VRR is up to 80% and it is 82.5%-86.4%, when the temperature is 200-220℃. The quality indexes of SMT-T are exceeding those in the industry standard SY/T 5091-1993. SMT-T is suitable for the drilling deep well, gas well and high density well in the temperature range of 180-220℃. Related Articles | Metrics

Select

Study on the Properties of Extractives from the Bark of Pinus yunnanensis ZHANG Jia-yan;ZHANG Xiao-long;QIN Yong-jian 2007, 41 (3):  31-33.  Abstract ( 608 )   PDF (548KB) ( 611 )   Save The solubility, UV spectrum, heat stability, light stability and antioxidation activity of extractives extracted from the bark of pinus yunnanensis with ethyl acetate-water were studied. The results showed that the extractives had good water solubility, light and thermal stability(≤60℃) and maximum absorption wavelength (λmax) at 280 nm. The results also showed the OPCs had good antioxidation property. Related Articles | Metrics

Select

Analysis and Comparison on Composition of Essential Oils from Rosemary Leaf and Flower GUO Yi-na;WEI Teng-you;WEI Shi-yuan;LIN Cui-wu;WEI Wan-xing 2007, 41 (3):  34-36.  Abstract ( 771 )   PDF (557KB) ( 668 )   Save Essential oils were isolated from the leaves and flowers of Rosmarinus officinalis Linn. respectively in this experiment. The oils were analyzed by gas chromatography coupled to mass spectroscopy(GC/MS) in order to determine their chemical compositions and contents. We have found 30 compounds in the oils and identified 20 compounds of them. The results of analysis showed that the contents of low boiling point components such as α-pinene, camphene, β-pinene, α-phellandrene and β-myrcene in flower oil, which are 17.58%、13.19%、1.13%、2.03% and 1.02% respectively, are lower than those in leaf oil. And the contents of high boiling point components such as camphor, borneol and bornyl acetate in flower oil which are 11.97%、8.48% and 4.29% respectively, are higher than those in leaf oil. Related Articles | Metrics

专题讲座

Select

Conversion Technology and Utilization of Biomass Energy (Ⅰ) JIANG Jian-chun 2007, 41 (3):  61-65.  Abstract ( 694 )   PDF (1031KB) ( 1045 )   Save Biomass is the sole renewable carbon resource that can be transferred into liquid and gas fuels as well as other chemicals. As the fossil energy will be exhaustive, humans pay more attention to the problems of global environment. Many scholars and researchers in world have been focusing on the research and development of biomass energy to substitute for fossil energy. The annual available biomass resource is 3.14 hundred million tce, 54% of which is straw and 36% of which is firewood in China. Now there are more than 180 hundred million tons of total forestry biomass resource, of which 8-10 hundred million tons can be collected and 3 hundred million tons can be used for biomass energy. This article mainly discusses the main conversion methods for utilization of biomass,including pyrolysis gasification for power/heat/gas by thermochemical high efficient conversion technology: flash pyrolysis for liquid fuel(bio-oil) and biomass gasification for synthetic liquid fuel(such as diesel DME),as well as biochemical conversion technology. The paper also discusses the status on R & D of biomass energy utilization technology and industrialization in China. Related Articles | Metrics

研究报道

Select

Study on Cleaner Production of Rice Straw Pulp Using Alkaline Potassium Sulfite JIANG Qi-pei;ZHANG Xiao-yong;MO Hai-tao;LI Zuo-hu 2007, 41 (3):  6-10.  Abstract ( 584 )   PDF (965KB) ( 722 )   Save A pulping method using alkaline K2SO3-AQ system as cooking liquor to digest rice straw was studied in this paper. The optimal cooking conditions were 10% of total alkali, 0.8 of alkali ratio, 0.2% of AQ, 160℃ of maximum temperature and 120 min of cooking time.Pulp yield reached 53.8%, screened pulp yield reached 42.5%, and Kappa number was 14.5. It looks promising to use effluents of cooking into fertilizer because it contains rich nutrition such as potassium and lignin. A new ecological cycling maybe set up between paper industry and farming. Related Articles | Metrics

综述

Select

Study on Affecting Factors for Industrialized Continuous Production of p-Menthane WANG You-ping;LEI La;CHEN Yu-xiang; 2007, 41 (3):  39-41.  Abstract ( 644 )   PDF (616KB) ( 696 )   Save Affecting factors, such as content of heavier components in the raw material, reaction temperature and pressure on industrialized continuous production of p-menthane were studied. It concluds that the content of the heavier components in the raw material should not be over than 1.2%, the reaction temperature is 185~200℃, and the reaction pressure is 9~11 MPa. Related Articles | Metrics

Select

Research Progress of Co-pyrolysis of Biomass with Polymers and Coal MA Guang-lu;LIU Gang;CAO Qing 2007, 41 (3):  47-51.  Abstract ( 682 )   PDF (883KB) ( 761 )   Save The recent advances about co-pyrolysis of the biomass-coal and biomass-polymers are reviewed in this paper. Comparing the results from literatures for the alone pyrolysis and co-pyrolysis of biomass, coal and polymers, the co-pyrolysis of biomass and many polymers has some synergetic effects, which decreases the oxygen content in liquid product and increases the liquid yield etc. So the co-pyrolysis of biomass-polymers is more beneficial than the alone pyrolysis of biomass and polymers. But the coal is another matter, the co-pyrolysis of biomass-coal has not synergetic effects. In order to achieve the transfer of hydrogen from the biomass to the coal and improve the quality of the liquid derived from coal pyrolysis, based on the current research fruits, the new pyrolysis way that use two-step pyrolysis of biomass and coal is brought forward. Also, some suggestions about the research direction of the co-pyrolysis of biomass with coal and polymers in future are proposed. Related Articles | Metrics

研究报道

Select

Study on Synthesis of Borneol from Turpentine Catalyzed by MoO3/TiO2 Solid Superacid LIU Tian-cheng;NING Ping;WANG Ya-ming;GAO Hong 2007, 41 (3):  27-30.  Abstract ( 602 )   PDF (687KB) ( 664 )   Save Esterification of terpineol with oxalic acid, chloroacetic acid and trichloroacetic acid by solid superacid MoO3/TiO2 was studied. Results showed that chloroacetic acid was the best reagent for esterification and the catalyst had satisfactory catalytic activity and selectivity. The yield of borneol and isoborneol was 52.93%, and selectivity for borneol was 60.46% at the conditions of programmed temperatures, reaction time 315 min, saponification time 1h, mass part of catalyst 5%,and terpineol:chloroacetic acid 100:25(mass ratio). Related Articles | Metrics

Select

Study on Quantitative Determination of Ellagic Acid by UV-spectrophotometry CHEN Jia-hong;WU Dong-mei;WANG Yong-mei;WU Zai-song 2007, 41 (3):  18-20.  Abstract ( 1379 )   PDF (553KB) ( 1344 )   Save A new method for determination of ellagic acid content by UV spectrophotometry was studied. The technical key was that test solution of ellagic acid was prepared with diluent NaOH solution to resolve the insolubility of ellagic acid in water and many organic solvents. UV absorption peak of the test solution was determined at 357 nm. The linear relationship between concentration and UV absorbance under test conditions was proved. The measuring error was estimated.Stability test of determined value was also studied. The results indicated that this method could be used for quantitative determination of ellagic acid in industrial production for its simplicity, low consumption of solvents, cheapness, veracity and stability. Related Articles | Metrics