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    30 March 2016, Volume 50 Issue 2 Previous Issue    Next Issue
    Preparation of Epoxided Rubber Seed Oil Catalyzed by Ti-SBA-15 Mesoporous Molecular Sieve
    GONG Hui-ying, ZHENG Zhi-feng, HUANG Yuan-bo, YANG Xiao-qin, ZHENG Yun-wu, MA Huan
    2016, 50 (2):  1-5. 
    Abstract ( 707 )   PDF (896KB) ( 781 )   Save
    Epoxided rubber seed oil (ERSO) was prepared from rubber seed oil (RSO) by using heterogeneous mesoporous molecular sieve Ti-SBA-15 as catalyst. The influences of catalyst dosage, the oxidant tert-butyl hydroperoxide (TBHP), reaction time and reaction temperature on the epoxidation of RSO were discussed. Results showed that the ERSO with epoxy value of 68.9 mmol/g was obtained with the dosage of RSO 0.062% (mole fraction, based on the mole value of RSO), the molar ratio for TBHP to RSO 1.3:1, reaction time 6 h and reaction temperature 70℃. Under these optimal conditions, the RSO conversion was 82.22%, and the conversion of double bond was 69.93%. Furthermore, the formation of epoxy group was confirmed by FT-IR.
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    Pyrolysis Characteristics and Kinetics of Guanzhong Wheat Straw Using TG-FT-IR
    HU Bing-tao, LI Zhi-jian
    2016, 50 (2):  6-12. 
    Abstract ( 541 )   PDF (1082KB) ( 1077 )   Save
    The pyrolysis behavior, characteristics and kinetics of Guanzhong wheat straw were investigated with a TG-FT-IR system at heating rates of 5, 10 and 20℃/min from ambient temperature to 1000℃. The results showed that the pyrolysis process of Guanzhong wheat straw could be divided into 4 stages:dehydration(room temperature-150℃), the pyrolysis processes of hemicellulose(150-300℃), cellulose(300-380℃) and lignin(380-1000℃). The main pyrolysis products at maximum pyrolysis rate under heating rate of 20℃/min identified by FT-IR included H2O, CH4, CO2 and CO as well as aromatics, acids, alcohols, alkanes, phenols, ethers, ketones and aldehydes. The apparent activation energies determined by using model-free methods of FWO and KAS were determined with the appaoximate average value of 202 kJ/mol at conversion rates of 0.1-0.8. The activation energy estimated by the Kissinger method was 171.12 kJ/mol and lower than those obtained by FWO and KAS method.
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    Preparation and Electrochemical Performance of Coconut Shell-based Activated Carbon for Supercapacitor
    HOU Min, SUN Kang, DENG Xian-lun, XIAO Feng-long, YANG Hua, LIN Guan-feng
    2016, 50 (2):  13-18. 
    Abstract ( 872 )   PDF (994KB) ( 1638 )   Save
    Activated carbon for supercapacitor was prepared from coconut shell carbide by KOH activation. The effects of the ratio of KOH/carbon, activation temperature and activation time on the pore structures and specific capacitance of activated carbon were investigated. The results showed that the high quality activated carbon as electrode material could be prepared under the conditions of the mass ratio of KOH/carbon 4:1, activation temperature 800℃ and activation time 60 min. Under these conditions, its specific surface area of the sample was 2 891 m2/g, total pore volume was 1.488 cm3/g, the mesopore ratio was 73.6 % and specific capacitance was 235 F/g.
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    Preparation and Characterization of Nanofibrillated Cellulose/TiO2 Aerogel from Phyllostachys heterocycla cv. Pubescens
    LI Jing, LIU Zhi-ming, JIN Chun-de
    2016, 50 (2):  19-23. 
    Abstract ( 585 )   PDF (2742KB) ( 1157 )   Save
    Nanofibrillated cellulose(NFC)/TiO2 aerogel was prepared with tetrabutyl titanate as raw material and NFC as template. NFC/TiO2 aerogel was characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared(FT-IR) and specific surface area and pore size analyzer, respectively. The results showed that the original space network structure of NFC was kept in NFC/TiO2 aerogel.TiO2 mainly existed in the form of particles attached on the surface of cellulose nanofibrils.For NFC/TiO2 aerogel, the specific surface area was 12.55 m2/g and the average pore size was 17.07 nm analyzed by BET method.
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    Multi-index Analytical Test Method of the Identification in Adulteration in Chinese Sweetgum Oleoresin
    SHEN Xu-biao, CHEN Zhu-hui, ZENG Tao
    2016, 50 (2):  24-28. 
    Abstract ( 493 )   PDF (878KB) ( 807 )   Save
    To identify more accurately about the adulteration of Chinese sweetgum oleoresin, starch and pine resin were added to the pure Chinese sweetgum oleoresin from different regions. Physical and chemical properties of Chinese sweetgum oleoresin and main components and contents of essential oil were analyzed before and after adulteration. Multi-index analytical test method of the identification of adulteration in Chinese sweetgum oleoresin was put forward depending on the above studies. The results indicated that the pure Chinese sweetgum oleoresin did not cause iodine chromogenic reaction, but after mixed with starch, iodine chromogenic reaction was obvious. The acid value, the saponification value, the ultraviolet absorption peak and the high performance liquid chromatography had presented different changes. They were easy to be identified after mixed with pine resin in different proportions, and the contents of α-pinene, β-pinene and β-caryophyllene of essential oil of Chinese sweetgum oleoresin changed obviously. The combination of one or a few indicators of the analytical test methods could be sensitive to verify the identification of adulteration in Chinese sweetgum oleoresin.
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    Steam Gasification of Sawdust for Production of Hydrogen-rich Gas
    SUN Ning, YING Hao, XU Wei, SUN Yun-juan, XU Yu, JIA Shuang
    2016, 50 (2):  29-33. 
    Abstract ( 522 )   PDF (860KB) ( 821 )   Save
    Steam gasification experiments of sawdust for the production of hydrogen-rich gas were carried out on the high-temperature fixed bed reactor.The effects of temperature (750 -1000℃) and steam flow rate (0.290-1.409 g/min) on the gas volume fraction, low heating value (QLHV) of the gas and gas yield were investigated .The results showed that different temperatures and steam flow rates had great influences on the gas volume fraction. Increasing reactor temperature and introducing appropriate steam were beneficial to the production of hydrogen. However, the heating value of product was decreased with the increasing amount of steam at high temperature.Taking influence of various aspects into consideration, the optimal gasification conditions were the flow rate of steam 1.033 g/min and 900℃.At these conditions, the hydrogen content was 45.74%, the QLHV of the gas was 11.69 MJ/m3 and the dry gas yield was 1.96 L/g.
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    Structure and Properties of Caragana korshinskii Kom. Activated Carbon
    XING Ze-bing, SUN Feng-kun, GUO Yu-ming, FAN Hua, LIU Chun-ling
    2016, 50 (2):  34-38. 
    Abstract ( 674 )   PDF (1054KB) ( 951 )   Save
    Activated carbon was made by pyrolysis of Caragana korshinskii Kom.(caragana) at 350 and 600℃ and activated by water vapor at 800℃ for 1 h. The mechanism of pyrolysis, functional group and structure of C.korshinskii carbon were analyzed by TGA and FT-IR. The pore structure of C.korshinskii activated carbon was analyzed by SEM and specific surface area analyzer. The adsorptive property was measured by iodine sorption. As a result, in the course of charring, hemicellulose, cellulose and lignin were cracked in the wide temperature range of 150-680℃ to obtain the biomass carbon. The principle of charring was to form aromatic compound by breaking the long chain alcoholic hydroxyl group and hydroxy group.C.korshinskii activated carbon obtained by carbonization at 600℃ and activation with water vapor at 800℃ kept the structure of fibrous tissue and had anundant pore structure with pore size less than 5 nm mostly. Its specific surface area was 187 m2/g, and iodine sorption value could be up to 221 mg/g. It was seen that C.korshinskii could be acted as a kind of excellent material for making activated carbon.
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    Preparation and Characterization of Hydrophobic Cellulose/SiO2 Composite Aerogel
    LIU Xin-xin, LIU Zhi-ming
    2016, 50 (2):  39-44. 
    Abstract ( 603 )   PDF (1636KB) ( 1171 )   Save
    Four kinds of regenerated cellulose/SiO2 composite aerogels were prepared by sol-gel method with microcrystalline cellulose and tetraethoxysilane (TEOS) as raw materials and hydrophobically modified with octadecyl trichlorosilane (OTS).All samples were characterized by X-ray diffraction (XRD), energy spectrum (EDS), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), respectively.The results showed that all the regenerated cellulose/SiO2 composite aerogels were white solid and the densities were in the range of 43.6-50.7 mg/cm3. XRD, EDS and FT-IR analysis results showed that silicon element appeared in the regenerated cellulose/SiO2 composite aerogels, and both silicon and chlorine element appeared in the hydrophobic cellulose/SiO2 composite aerogels. SEM analysis results showed that the structure of the regenerated cellulose/SiO2 composite aerogels and the modified products were all three-dimensional network, and the pore became smaller after modification. The contact angel test showed that the contact angels of four kinds of hydrophobic cellulose/SiO2 composite aerogels were more than 90°, and hydrophobic state was reached.Contact angle was gradually increased with the increase of SiO2 content, and the biggest contact angle was 144.5°.Hydrophobic property of hydrophobic cellulose/SiO2 composite aerogels were improved .
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    Research Progress of Numerical Simulation of Downdraft Biomass Gasifier
    XUE Ai-jun, PAN Ji-hong, TIAN Mao-cheng, ZHANG Guan-min
    2016, 50 (2):  45-52. 
    Abstract ( 597 )   PDF (834KB) ( 1210 )   Save
    Numerical simulation which developed the mathematical model of downdraft biomass gasifier could help to understand the chemical and physical phenomena in downdraft gasifier. Also, it could help to find optimum operating conditions, design the gasifier and assist the development of new technology. The paper discussed different models available for downdraft gasifier such as thermodynamic equilibrium, chemical kinetic, computational fluid dynamics(CFD), ASPEN Plus, multiple zones models. And the single particle model was combined to the multiple zones models. The comparative analysis among the models was carried out. The results showed that the multiple zones model combined with single particle models has more broad developing prospects.
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    Advances in Pretreatment Technology of Sugarcane Bagasse for Bioethanol Production
    BI Shuai-zhu, PENG Lin-cai, CHEN Ke-li
    2016, 50 (2):  53-60. 
    Abstract ( 813 )   PDF (858KB) ( 1344 )   Save
    Considering the physicochemical characteristics and pretreatment necessity of sugarcane bagasse, the recent domestic and abroad research progresses on different pretreatment technologies including physical method, chemical method, biological method and combination method are reviewed systematically. The results and features of various pretreatment technologies are summarized and compared. Finally, the development direction of pretreatment methods in the future is prospected.Sugarcane bagasse is a major solid waste of cane sugar manufacturing process. It has the advantages of high quantity, concentration and abundant fiber content. It could be one of main and potential raw material for the second-generation bioethanol production. The effective pretreatment for lignocellulosic biomass is critical for bioethanol production. It also directly affects enzymatic saccharification and ethanol fermentation of post-processing.
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