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    30 January 2024, Volume 58 Issue 1 Previous Issue    Next Issue
    Research Report
    Grubbs Catalyst Catalyzes the Complex Decomposition of Methyl Oleate and Ethylene
    Jian CHENG, Shiwen LI, Zhanfang MA, Huayi LI
    2024, 58 (1):  1-8.  doi: 10.3969/j.issn.1673-5854.2024.01.001
    Abstract ( 59 )   HTML ( 5 )   PDF (1355KB) ( 115 )   Save

    Using biomass methyl biooleate(MO) as raw material, 1-decene and methyl 9-decenoate could be simultaneously prepared by cross-metathesis reaction with ethylene. Firstly, the effects of three commonly used olefin metathesis catalysts on the system were evaluated, and Grubbs Ⅰ was selected as the best catalyst. The conversion rate of methyl oleate and the yield of 1-decene and methyl 9-decenoate were taken as evaluation indexes to explore the process conditions of Grubbs Ⅰ catalyst. The results showed that when the temperature was 40℃, the ethylene pressure was 0.2 MPa, the reaction time was 2 h, the catalyst dosage was 1% of methyl oleate, the solvent was toluene, and the concentration was 0.1 mol/L, the conversion rate of methyl oleate was 97.4%, the yield and selectivity of 1-decene were 97.4% and 100%, respectively, and the yield and selectivity of methyl 9-decenoate were 76.4% and 78.4%, respectively. Then, the process conditions of Grubbs Ⅱ catalyst were explored. When ethylene pressure was 0.5 MPa, temperature was 40℃, reaction time was 1 h, and catalyst dosage was 0.5% of methyl oleate, the yield of 1-decene reached 76.4%, the yield of methyl 9-decenoate was 80.1%, and the conversion rate was 92.7%.

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    Study on Preparation and Electrochemical Properties of Wood Fibers Anchored CeO2 Electrode Material
    Ge YAN, Yan QING, Yangyang CHEN, Yu LIAO, Zhen ZHANG, Lei LI
    2024, 58 (1):  9-17.  doi: 10.3969/j.issn.1673-5854.2024.01.002
    Abstract ( 62 )   HTML ( 2 )   PDF (7868KB) ( 109 )   Save

    Using the adsorption of oxygen-containing groups in wood fibers to anchor the growth of cerium dioxide, one-dimensional hollow tubular structure composite electrode material (WF@ CeO2) was successfully prepared. The electrochemical properties of the electrode materials were improved by adjusting the addition amount of cerium nitrate, and the synergistic effect of wood fibers on cerium dioxide was discussed. The results showed that the specific surface area of WF@ CeO2-2 sample could reach 303.73 m2/g when the amount of cerium nitrate was 2 mmol. The prepared electrode exhibited a high specific capacitance of 371 F/g at the current density of 0.5 A/g. The existence of wood fiber greatly improved the electrochemical performance of cerium dioxide electrode material. The specific capacitance of the asymmetric supercapacitor assembled with WF@ CeO2-2 electrode could reach 34.5 F/g, the peak energy density was 44.16 Wh/kg, and the peak power density was 4 002.7 W/kg. After 5 000 cycles of charge and discharge, the capacitor retention rate was 91.1%, showing good cycle stability.

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    Comparation of Three Methods of Analytical Methodology of Indigo and Indirubin in Different Indigo Extracts
    Chengzhang WANG, Yangyang YAN, Hao ZHOU, Danyang LIU, Shibin SHANG, Huaxing ZHANG
    2024, 58 (1):  18-26.  doi: 10.3969/j.issn.1673-5854.2024.01.003
    Abstract ( 66 )   HTML ( 5 )   PDF (1256KB) ( 90 )   Save

    Using indigo paste as raw material, indigo acidification substances, glucose reducing substances, and ethyl acetate extractives were prepared using three processes of hydrochloric acid acidification, glucose reduction, and ethyl acetate extraction, respectively. High performance liquid chromatography(HPLC), ultraviolet visible spectrophotometry(UV), and dual wavelength ultraviolet spectrophotometry(dW-UV) were established to analyze the contents of indigo and indirubin in samples from three processes. The optimal analysis methods for each of three samples were determined through Kolmogorov Smirnov test, comparison of Bland Altman deviation plots, and Spearman test. The results showed that the established HPLC, UV, and dW-UV methods were simple, accurate, highly sensitive, stable, and reproducible. Three methods for detecting the content of indigo extract components all followed the normal distribution, and there were significant differences between each the two measured values. The UV method was more suitable for analyzing the content of indigo in indigo acidified substances and indigo reducing substances. HPLC method was more suitable for measuring the content of indigo and indirubin in ethyl acetate extract.

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    Efficient Extraction of Highly Reactive Lignin and Its Preparation of Bio-polyurethane Foam
    Yangliu CHEN, Dengfeng WANG, Xiujin GONG, Mengyuan DIAO, Lin LIU
    2024, 58 (1):  27-34.  doi: 10.3969/j.issn.1673-5854.2024.01.004
    Abstract ( 51 )   HTML ( 2 )   PDF (4328KB) ( 94 )   Save

    In order to solve the problems of lignin involved in bio-polyurethane foam reaction due to its complex structure, low purity, large molecular weight, and low reactivity, phenolic lignin with high activity was extracted from natural bamboo powder by deep eutectic solvent(DES) prepared by choline chloride(ChCl) and oxalate hexahydrate(Oad) combined with ultrasonic assisted technology. It was used as a reaction monomer to partly replace petroleum-based polyols to prepare lignin-based polyurethane foam(LPUF) via all water foaming method, and the chemical structure, micromorphology and mechanical properties were analyzed. The results showed that the optimal process conditions were the ultrasonic temperature of 80℃, ultrasonic action time of 0.5 h, and ultrasonic power of 70 W. Under these conditions, the content of phenolic hydroxyl groups of the extracted lignin was 8.8%, and the lignin extraction rate reached to 87.8%. The basic structure of lignin was not destroyed by DES ultrasonic assisted treatment, and LPUF was successfully prepared. When the mass ratio of lignin: polyethylene glycol 200(PEG-200): polyethylene glycol 400(PEG-400): hexamethylene diisocyanate(HDI) was 1:84:23:155, the average cell size of the prepared lignin polyurethane foam(LPUF-2) was 261.66 μm, and the elasticity modulus reached to 3 MPa. After 1 000 compression cycles, the maximal stress of LPUF-2 still maintained initial 84%, reached 22.26 kPa, showing excellent mechanical properties and mechanical stability.

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    Simulation Investigation of Turbulent Flow Characteristics in Constant Volume Combustion Bomb
    Xuan ZHANG, Genzhu JIANG
    2024, 58 (1):  35-40.  doi: 10.3969/j.issn.1673-5854.2024.01.005
    Abstract ( 42 )   HTML ( 4 )   PDF (2759KB) ( 91 )   Save

    In order to explore the evaporation process and mechanism of diesel-Jatropha biodiesel hybrid fuel and achieve the purpose of mixing biodiesel and diesel for stable combustion in diesel engine cylinders, Jatropha biodiesel and diesel were mixed at ambient temperatures of 723 and 873 K, and the proportion of Jatropha biodiesel was 10%, 20% and 50%, respectively. The micro-explosion characteristics of diesel-Jatropha biodiesel hybrid fuel(JME10, JME20, JME50) were analyzed using thermocouple hanging drop technology, high-speed camera and Halcon software code processes droplet images. It was concluded that the diesel-Jatropha biodiesel with different mixing ratios and the droplet microburst intensity had a function relationship similar to parabola, and JME20 was the best mixing ratio. In this case, the increase or decrease of the mixing ratio would affect the droplet microburst effect, and the droplet microburst under this ratio had a minimum microburst delay time, which was conducive to the full mixing of fuel and air. The increase of ambient temperature can promote the improvement of fuel droplet microburst quality of JME10, JME20 and JME50, and can shorten the evaporation time.

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    Effect of CH3COOK on the Phenols Production Characteristics of Tobacco Pyrolysis
    Shuyuan BEI, Rongcheng WU, Hongliang LU, Dawei ZHAO, Pengfei LU
    2024, 58 (1):  41-48.  doi: 10.3969/j.issn.1673-5854.2024.01.006
    Abstract ( 42 )   HTML ( 3 )   PDF (918KB) ( 87 )   Save

    In order to investigate the effect of CH3COOK on the phenols production characteristics of waste tobacco pyrolysis and its influencing factors, the effect of different potassium salts on the generation of typical phenolic compounds from the pyrolysis of waste tobacco was investigated. The effect of CH3COOK on the phenols production characteristics of biomasses pyrolysis with different protein, cellulose, and lignin contents was also analyzed. The results showed that at a loading amount of 5.00%, compared to the unloaded spent secondary tobacco, CH3COOK could significantly reduce the phenol and catechol percentage and enhance the hydroquinone percentage in the tobacco pyrolysis products. Among them, phenol decreased by 45.63%, catechol decreased by 67.88%, and hydroquinone increased by 32.80%. CH3COOK could decrease the proportion of phenol and catechol in the pyrolysis products of tobacco, mulberry leaf and ginkgo biloba with high protein content, and increase the percentage of phenol, catechol, and guaiacol produced by the pyrolysis of pine chips with low protein and high cellulosic lignin. The significant percentage of phenol, p-cresol, and catechol in the pyrolysis products of tobacco proteins was 19.99%, 3.08%, and 2.69%, respectively. After loading CH3COOK, the proportions of phenol and p-cresol in pyrolysis products were reduced by 77.09% and 79.37%, respectively, and no catechol was detected. CH3COOK mainly reduced the percentage of corresponding phenols in tobacco pyrolysis products by inhibiting the pyrolysis of proteins to produce phenol and catechol in tobacco.

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    Fluent Numerical Simulation and Experimental Study of the Heat Transfer Behaviour of Biomass Solid Heat Carrier Pyrolysis
    Xin ZHANG, Shumiao QUAN
    2024, 58 (1):  49-55.  doi: 10.3969/j.issn.1673-5854.2024.01.007
    Abstract ( 50 )   HTML ( 3 )   PDF (1500KB) ( 90 )   Save

    Due to the differences in heat transfer modes and temperature fields experienced by the pyrolysis volatiles, the heat transfer behaviors and pyrolysis behaviour exhibited by solid heat carrier pyrolysis(SHC) and external thermal ordinary pyrolysis(CP) were different significantly. The heat transfer behaviors and pyrolysis laws of walnut shell(WS) were studied in a small closed fixed bed reactor, with quartz sand(QS) as solid heat carrier under the conditions of QS preheating temperature(PT) of 800℃ and QS to WS mass ratio of 9:1. The heat transfer behaviors of SHC process were investigated by experiment and Fluent simulation, and the temperature field was decoupled into average pyrolysis temperature(TWS) and volatiles temperature(TQS-h). The results showed that the experimental data of the maximum temperature of TWS and TQS-h(460 and 508℃) were smaller than the data from simulation(490 and 612℃), indicating that there was a heat dissipation phenomenon in the experimental process. The experimental and simulated values of the temperature difference between the average of TWS(${\bar T}$WS) and TQS-h(${\bar T}$QS-h) were 39 and 72℃, respectively, indicating that the low temperature volatiles through the high temperature QS layer underwent a violent secondary reaction during the escape process. Compared with CP, the char and gas yields of SHC pyrolysis were higher(67.42% and 12.51%, respectiely), while the oil and water yields were lower(8.69% and 11.38%, respectiely). At the same time, the content of very light oil(VLO), light oil(LO) and heavy oil(HO) in the oil under SHC pyrolysis method increased significantly, while the content of residual fraction(CR) decreased and the oil quality increased.

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    Review Comment
    Progress of Wood Adhesives from Lignin and Lignin-derived Compounds
    Meiyu HUO, Guifeng LIU, Shuping HUO, Zhenwu KONG
    2024, 58 (1):  56-66.  doi: 10.3969/j.issn.1673-5854.2024.01.008
    Abstract ( 101 )   HTML ( 6 )   PDF (1618KB) ( 166 )   Save

    The development of eco-friendly and excellent wood adhesive from sustainable and renewable resources instead of traditional fossil resources had attracted considerable attention in the wood-based panel industry. Lignin had a wide range of sources and low prices, and its molecular structure contained active groups, such as hydroxyl, methoxyl and carboxyl groups, which were easy to be functionalized and modified, and it was an ideal raw material for making wood adhesive. In this paper, the applications and research status of lignin and its derivatives in wood adhesives of phenolic resins, urea-formaldehyde resins, epoxy resins and polyurethanes and other synthetic resins were reviewed. Furthermore, the effects of pretreatment methods such as chemical modification, depolymerization and solvent fraction on the chemical reactivity of lignin and the mechanical properties of synthetic resin adhesives were discussed. The problems and challenges of lignin-based wood adhesives existed in the current development of were investigated, and the future application and research directions were prospected, in order to provide theoretical and technical references for the efficient and high-value added utilization of lignin resources and the development of high-performance bio-based wood adhesives.

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    Research Progress in Biomass Hydrothermal Liquefaction
    Hongwei ZHANG, Shunyuan ZHANG, Kejiang ZHANG
    2024, 58 (1):  67-76.  doi: 10.3969/j.issn.1673-5854.2024.01.009
    Abstract ( 64 )   HTML ( 4 )   PDF (1209KB) ( 120 )   Save

    Hydrothermal liquefaction technology could handle high moisture content biomass without the need for high energy consumption links such as dehydration, and had good economic and industrial prospects. It had become a highly potential way of utilizing biomass energy. This article reviewed the mechanism of hydrothermal liquefaction of biomass components and summarized their application and production. This article retrospected the research process of biomass hydrothermal liquefaction, and mainly described the main component structures and hydrothermal liquefaction reaction mechanisms of biomass such as cellulose, hemicellulose, lignin, lipids, and proteins, as well as the process flow of biomass hydrothermal liquefaction reactors. The existing problems of biomass hydrothermal liquefaction were clarified, and its development direction was prospected.

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