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    30 July 2021, Volume 55 Issue 4 Previous Issue    Next Issue
    Research Report
    Pyrolysis Characteristics and Pyrolysis Products of Sunflower Stem
    Donghua JI, Hongyan LI, Zhendong LEI, Gaojian MIAO, Ming ZHAO, Zhihe WANG
    2021, 55 (4):  1-6.  doi: 10.3969/j.issn.1673-5854.2021.04.001
    Abstract ( 85 )   HTML ( 49 )   PDF (485KB) ( 68 )   Save

    In order to make full use of biomass sunflower stalks, the simultaneous thermal analyzer was used to study the pyrolysis characteristics of sunflower stalks with heating rate as an influencing factor. The Coats-Redfern integral method was used to calculate the main phase pyrolysis kinetic parameters. And the quantitative analysis of pyrolysis products were studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results showed that the pyrolysis process of sunflower stalk could be divided into three stages: preheating and drying, main pyrolysis and charring; as the heating rate increased, the TG curve of sunflower stalk pyrolysis moved to the high temperature zone. In the main pyrolysis stage (125-400℃), the weight loss rate of sunflower stalk was about 85% of the total weight loss, the activation energies (E) were 37.02-40.48 kJ/mol, and the pre-exponential factors (A) were 6.10×102-27.67×102 min-1, the linear fitting correlation coefficients were all greater than 0.97. During the rapid thermal cracking process, 106 characteristic peaks and 86 characteristic substances were detected, which could be divided into 11 categories according to different chemical types. The main characteristic products of thermal cracking were stearic acid(29.991%), palmitic acid(27.642%), n-octadecane(7.185%), methyl stearate(2.239%), isoprene(1.678%).

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    Low-energy Consumption Technology for Industrial Production of Corn Fuel Ethanol
    Xinchun JIANG, Jingshen OU, Fan LI, Hongcai ZHOU, Yi TONG, Xinshu ZHUANG
    2021, 55 (4):  7-13.  doi: 10.3969/j.issn.1673-5854.2021.04.002
    Abstract ( 73 )   HTML ( 21 )   PDF (3403KB) ( 80 )   Save

    The new low-energy consumption process of corn fuel ethanol developed by our team adopted low temperature liquefaction, synchronous saccharification and batch fermentation of concentrated mash, three-tower differential pressure distillation and molecular sieve dehydration process and waste heat recovery technology from various sections of the plant. At present, it has successfully applied to a number of fuel ethanol distillery. Taking the Heilongjiang Hongzhan Science and Technology Co., Ltd. 300 000-ton fuel ethanol project as an example, the technical characteristics, energy consumption and product quality were compared and analyzed between the new and the traditional process. The results showed that the steam consumption, process water and amount of circulating water of the new process were reduced by 10.26%, 28.09% and 11.11% compared with those of traditional process, respectively. The production of 1 ton fuel ethanol could save 49 kg standard coal; thus 14 700 tons of standard coal could be saved annually and the energy consumption cost of fuel ethanol could be saved by about 8 million Yuan. At the same time, the product qualities of fuel ethanol and corn distiller's grains (DDGS) were in line with the national standards, some indicators were higher than the national standards, such as the purity of ethanol could reach 99.9%, methanol content was as low as 0.01%, crude protein content was 26.1%, crude fat content was 10.5% and the crude fiber content was 8.7%.

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    Preparation and Hydrogenation Performance of Cobalt-orange Peel Carbon Hydrogen Transfer Catalyst
    Hongye ZHAO, Yi WU, Zhengjiang DU, Quansheng LIU, Huacong ZHOU
    2021, 55 (4):  14-20.  doi: 10.3969/j.issn.1673-5854.2021.04.003
    Abstract ( 60 )   HTML ( 27 )   PDF (4822KB) ( 52 )   Save

    The biomass waste orange peel was used as raw material to prepare orange peel carbon material by pyrolysis. Then, the cobalt-orange peel carbon catalyst was constructed by one-step liquid phase reduction method with orange peel carbon as the support. The catalyst was used to catalyze the conversion of ethyl levulinate (EL) to γ-valerolactone(GVL).The catalysts were characterized by SEM, XRD, FT-IR and TG. The results showed that the cobalt particles were uniformly distributed on the surface of the carbon support, with the particle size of 0.1-2 μm. The orange peel carbon support was rich in oxygen-containing structure. The Co-orange peel carbon catalyst prepared at 300℃ with the loading amount of Co 20% was used as hydrogen transfer catalyst and had good catalytic effect and stability for the conversion of EL to GVL. After 5 h reaction at 160℃ with isopropanol as liquid hydrogen source, the conversion of EL was up to 99.3%, and the yield of GVL was 85.2%. The catalytic performance decreased after reused for 4 times.

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    Physicochemical and Infrared Spectroscopic Properties of Gramineae Plants Biochar at Different Pyrolysis Temperatures
    Qilin ZHU, Ming CAO, Xuebin ZHANG, Kai TAO, Yongchun KE, Lei MENG
    2021, 55 (4):  21-28.  doi: 10.3969/j.issn.1673-5854.2021.04.004
    Abstract ( 69 )   HTML ( 41 )   PDF (7739KB) ( 46 )   Save

    The biochars I, R, S and M were prepared at 300, 500 and 700℃ with the grasses of king grass, rice straw, bagasse and corn straw as raw materials, respectively. The effects of different pyrolysis temperatures on the structure and composition of biochar were studied. Results showed that with pyrolysis temperature increasing, the yield of the four kinds of biochars decreased, carbon content and ash content increased. The yields of I, R, S and M at 300℃ were 45.81%, 48.67%, 46.81% and 46.00%, and the yields at 700℃ were 33.95%, 35.47%, 25.42% and 31.23%. The ash contents and I, R, S and M at 700℃ increased by 54.39%, 65.44%, 95.54% and 71.85% compared those at 300℃. The C/N ratio of R, S, and M were increased with pyrolysis temperature increasing, but that of R was opposite. The pH values of the four biochars increased with pyrolysis temperature increasing. The pH values of I, R, S and M at 700℃ were 7.68, 9.87, 7.59 and 9.33. I and S was porosity and the number of pore increased with the increase of pyrolysis temperature. Both R and M formed a certain amount of flocs at 700℃. EDX analysis revealed that the elemental composition of Si was contained higher in R. Infrared spectroscopy showed that with the increase of pyrolysis temperature, the alkane groups, methyl groups (—CH3) and methylene groups (—CH3) of the four kinds of biochars gradually disappear. The biochar structure was dominated by aromatic compounds and oxygen functional groups, and the structure was more stable.

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    Fast Pyrolysis Experiments of Corn Stalk by Py-GC/MS
    Zhichao LIU, Yanyan WANG, Fangdong ZHENG, Di WAN
    2021, 55 (4):  29-33.  doi: 10.3969/j.issn.1673-5854.2021.04.005
    Abstract ( 64 )   HTML ( 20 )   PDF (461KB) ( 59 )   Save

    Fast pyrolysis experiments were studied by using pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS) under different pyrolysis conditions with corn stalk as material, and the pyrolysis gases were online analyzed. The effects of pyrolysis time, pyrolytic temperature and ZSM-5 catalyst on the pyrolysis characteristics and distribution of pyrolysis products of corn stalk were focused. The experimental results showed that the higher pyrolysis temperature was, the more fully pyrolysis reaction would be, and the pyrolysis products of 550℃ had the highest quality, the content of aromatic compound was the maximum(28.3%). Pyrolysis reaction constantly intensified with the increase of pyrolysis time, and the pyrolysis products of 10 s had the highest quality, the content of ketones was the minimum(11.8%) and the content of aromatic compound was the maximum(28.3%); ZSM-5 catalyst could significantly promote the polycondensation reaction to generate benzene ring in the secondary reactions, and could also promote a series of aromatization reactions, remove oxygen out of oxygen species of aromatic compounds, generate a large number of aromatic hydrocarbons. So ZSM-5 catalyst had good performance of catalytic deoxidization, and it could effectively improve the quality of the pyrolysis products.

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    Review Comment
    Current Situation in Extraction and Large-scale Production of Eucommia ulmoides Gum and Its Development Issues
    Ling XIE, Xuejun ZHANG, Chun JI, Yangjie HE, Han TAO
    2021, 55 (4):  34-42.  doi: 10.3969/j.issn.1673-5854.2021.04.006
    Abstract ( 52 )   HTML ( 21 )   PDF (756KB) ( 87 )   Save

    Eucommia ulmoides gum is a valuable strategic resource in China, and it is the core driving force for the development of E. ulmoides. The development of E. ulmoides gum industry can not only improve the status quo of insufficient natural rubber in China, but also provide China with new sources of sufficient reserve rubber, to form a new international natural rubber market pattern with China's E. ulmoides gum emerging industry as the leader. In recent years, although remarkable progress has been made in the industrialization and application development of E. ulmoides gum, it is still far from meeting the needs of the development of the situation. The reason is that the development of the industrial chain of E. ulmoides has some outstanding problems, such as imperfect technology and insufficient funds. In this article, the changes of gum content in leaves, bark and fruit of E. ulmoides during the growth period were described, its extraction technology(alkaline cooking, solvent extraction, microbial fermentation, bioenzymolysis and comprehensive method) and large-scale production status were mainly summarized. At the same time, many problems in the development of the industry such as lack of research fund and team, disconnect between basic research and engineering applications of gum, lack of product standards, and so on, were deeply analyzed and discussed, and advanced suggestions and measures to solve these key problems in the development. In order to help the development and utilization of E. ulmoides gum in system material engineering, and provide reference for the sustainable development of E. ulmoides rubber industry.

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    Recent Advances in Synthesis of Alkoxymethylfuran Ether from Biomass Resources
    Hongbo SHEN, Xinglong LI, Yao FU
    2021, 55 (4):  43-58.  doi: 10.3969/j.issn.1673-5854.2021.04.007
    Abstract ( 73 )   HTML ( 13 )   PDF (909KB) ( 84 )   Save

    Biomass resources are the only organic carbon resources in nature, which can synthesize a variety of high value-added fuels and chemicals. Biomass ethers compounds are one of the most important biomass derivatives. Among them, alkoxymethylfuran ether has been applied to diesel and diesel additives. Especially, 5-(ethoxymethyl)furfural (EMF) has attracted much attention due to its high energy density, low toxicity, good stability and good fluidity. Recent advances in the synthesis of alkoxymethylfuran ether from different biomass materials with 5-(hydroxymethyl)furfural (HMF) as the basic structure were reviewed. The effects of Lewis acid and Brønsted acid on the selectivity of etherification products were discussed. On the basis of summarizing the synthesis methods of alkoxymethylfuran ether, the future development direction of the catalytic system was discussed.

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    Research Progress in Absorption Regeneration of Waste Lubricant
    Ruting XU, Ao WANG, Kang SUN
    2021, 55 (4):  59-65.  doi: 10.3969/j.issn.1673-5854.2021.04.008
    Abstract ( 64 )   HTML ( 41 )   PDF (474KB) ( 66 )   Save

    With the rapid development of automobiles and manufacturing, the demand for lubricant has also greatly increased, and a large amount of waste lubricant has also been produced. Based on the current pollution status of waste lubricant, this article introduced its deterioration process, pollutant composition, and commonly regeneration processes (flocculation, distillation, extraction, hydrotreating, adsorption, etc.). The article introduced the adsorbents, such as clay, activated carbon, fly ash, natural polymer adsorbents and so on and new technologies (electrostatic adsorption) in detail. The overseas and domestic research status of adsorption regeneration were summarized and the merits and demerits of the adsorbents and adsorption technologies were summarized. Therefore, the problems and development trends of waste lubricant absorption regeneration in the future were proposed.

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    Research Progress on Zirconium/Hafnium Based Hydrogen Transfer Catalyst
    Xiaolu WANG, Xuefeng YAO, Yuxin CHEN, Huacong ZHOU, Quansheng LIU
    2021, 55 (4):  66-76.  doi: 10.3969/j.issn.1673-5854.2021.04.009
    Abstract ( 58 )   HTML ( 15 )   PDF (707KB) ( 61 )   Save

    Catalytic conversion is an important route for the utilization of the renewable biomass resources, and the construction of highly efficient catalysts is a crucial step for the catalytic conversion of biomass and its derivatives. The hydrogenation conversion of biomass derived carbonyl derivatives into alcohols or ester compounds is an important step during the catalytic conversion processes of biomass. Due to the mild reaction conditions of the transfer hydrogenation process, the heterogeneous transfer hydrogenation catalysts have broad applications in the conversion of biomass derived carbonyl compound platforms. The transition metal zirconium and hafnium are commonly used as active metals for the transfer hydrogenation reaction. This review summarized the preparation of the zirconium and hafnium based transfer hydrogenation catalysts and their applications in the hydrogenation conversion of biomass derived platforms. Firstly, the preparation of the zirconium and hafnium based transfer hydrogenation catalysts were briefly introduced. Then, zirconium oxide or hydroxide, zirconium/hafnium based catalyst with different ligand (hydroxyl, carboxylic acid, phosphonic acid, sulfonic acid, tungsten acid, amine, organic metal skeleton, zeolite molecular sieve) ligand, the double metal catalyst and the comparative analysis of their catalytic performance, cycle stability and structural mechanism were reviewed in detail, and the performances of these catalysts were compared. Finally, the future perspectives of the catalytic transfer hydrogenation of biomass and the construction of the catalysts were prospected.

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    Research Review on Cracking and Removal of Tar Catalyzed by Biomass Coke
    Dongyang HE, Guowei LIANG, Xinyang LI, Shuangyi WU, Miaomiao NIU
    2021, 55 (4):  77-84.  doi: 10.3969/j.issn.1673-5854.2021.04.010
    Abstract ( 84 )   HTML ( 12 )   PDF (867KB) ( 65 )   Save

    Based on the composition characteristics, hazards and treatment methods of biomass tar, the mechanism of catalytic cracking of biomass tar and the research progress in recent years are briefly introduced, and the catalytic conversion mechanism of biomass charcoal (mainly involving cracking, The three reactions of reforming and condensation), the adsorption and reforming of biomass charcoal, and the catalytic conversion process, the catalytic performance of biomass charcoal is affected by factors such as raw materials, cracking temperature, heating rate and residence time. By analyzing the performance changes of biomass charcoal after modification, it is found that the addition of metal promoters or structural modification of biomass charcoal has the potential for high-efficiency catalytic cracking of tar, which provides a direction for further research and development of low-cost composite catalysts.

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