Journal of Henan Agricultural Sciences ›› 2023, Vol. 52 ›› Issue (5): 170-180.DOI: 10.15933/j.cnki.1004-3268.2023.05.020

• Agricultural Information and Engineering Agricultural Product... • Previous Articles    

Physicochemical Properties and Microstructure Changes of Tomato Straw Hydrothermal Biochar under Different Reaction Conditions

HUANG Jiaqing1,LIU Cenwei1,YE Jing1,WANG Yixiang1,2,REN Lihua3   

  1. (1.Agricultural Ecology Institute,Fujian Academy of Agricultural Sciences/Fujian Key Laboratory of Agricultural Ecological Process of Red Soil Mountain,Fuzhou 350013,China;2.Institute of Soil and Fertilizer,Fujian Academy of Agricultural Sciences,Fuzhou 350013,China;3.Institute of Agricultural Quality Standards and Testing Technology Research,Fujian Academy of Agricultural Sciences,Fuzhou 350003,China)
  • Received:2022-12-16 Published:2023-05-15 Online:2023-06-09

不同反应条件下番茄秸秆水热生物炭的理化性质和微观结构变化

黄家庆1,刘岑薇1,叶菁1,王义祥1,2,任丽花3   

  1. (1.福建省农业科学院农业生态研究所/福建省红壤山地农业生态过程重点实验室,福建 福州 350013;2.福建省农业科学院土壤肥料研究所,福建 福州 350013;3.福建省农业科学院农业质量标准与检测技术研究所,福建 福州 350003)
  • 通讯作者: 王义祥(1978-),男,山东泰安人,研究员,博士,主要从事农业废弃物资源化利用研究。E-mail:sd_wolong@163.com
  • 作者简介:黄家庆(1979-),男,广西北流人,助理研究员,博士,主要从事农业环境与生态修复研究。E-mail:hjq19791001@126.com
  • 基金资助:
    中央引导地方科技发展专项(2021L3021);福建省红壤山地农业生态过程重点实验室开放课题(ephrs-202101);福建省农业高质量发展“5511”协同创新工程项目(XTCXGC2021010);福建省公益类科研院所基本科研专项(2021R1021004)

Abstract: To investigate the effects of carbonization temperature and pyrolysis time on the microstructure,physicochemical properties,principal components,and carbonization efficiency of tomato straw hydrothermal biochar(TSHB)and obtain efficient carbonization conditions,tomato straw was decomposed into TSHB by hydrothermal carbonization method with low energy consumption.This experiment set up three carbonization temperature(180,220,and 260℃)and four pyrolysis time(2,4,6,and 8 h),with a total of twelve experimental treatments,to study the effects of different combinations of carbonization
temperature and pyrolysis time on the morphology,structure,functional groups,pH value,conductivity(EC)and biochar composition of TSHB,and to analyze the principal components changes of TSHB.The results showed that the porous and hollow vascular bundle structure of tomato straw was conducive to the rapid transfer of water and heat within the tomato straw.Increasing the hydrothermal carbonization temperature could accelerate the destruction of the vascular bundle structure of tomato straw and carbonize the strip‐shaped tomato straw into granular hydrothermal carbon. The functional groups of TSHB were mainly fat ether C-O,alkane C-H,saturated fatty acid ester C-O,amine C-N,and the groups of C-O,C=O,C-N,and C-O-C in the cell wall. Increasing the carbonization temperature could increase the functional groups of TSHB,but those functional groups could be destroyed and reduced significantly if the carbonization temperature exceeded 260℃.TSHB prepared by hydrothermal pyrolysis was acidic biochar(pH value 5.13—5.33).Under the same pyrolysis time,compared to the carbonization temperature of 180℃ or 260℃,the TSHB prepared at 220℃ had the highest EC value(6 213—7 899 μs/cm),but the EC values of TSHB significantly decreased by 18.19%—26.92% as the pyrolysis time was extended from 2 h to 8 h.Increasing the carbonization temperature and prolonging the pyrolysis time could significantly increase the fixed carbon content of TSHB(2.23—27.99 percentage points),but significantly reduce the volatile content of TSHB(2.46—30.97 percentage points).Increasing the carbonization temperature could increase the carbonization yield,total nitrogen content,and ash content of TSHB by 10.63—29.91,0.58—0.87,and 1.82—3.09 percentage points,respectively.In summary,compared with prolonging the pyrolysis time,increasing the hydrothermal carbonization temperature could more effectively improve the carbonization efficiency of tomato straw and increase the content of nitrogen‐oxygen functional groups,fixed carbon,and total nitrogen of TSHB.The hydrothermal carbonization temperature was the critical factor determining the microstructure,functional groups,pH value,and principal components of TSHB.The carbonization temperature of 220℃ and the pyrolysis time of 4—6 h were suitable carbonization conditions for preparing tomato straw biochar by hydrothermal carbonization method.

Key words: Tomato straw, Hydrothermal biochar, Carbonization temperature, Functional group

摘要: 为探究炭化温度和裂解时间对番茄秸秆水热生物炭(TSHB)微观结构、理化性质、主要成分及炭化效率的影响,并获得高效的炭化条件,采用低耗能的水热炭化法将番茄秸秆裂解为番茄秸秆水热生物炭。设置3个炭化温度(180、220、260 ℃)和4个裂解时间(2、4、6、8 h),共12个处理,研究不同组合的炭化温度和裂解时间对番茄秸秆水热生物炭形貌结构、功能基团、pH值、电导率(EC值)、生物炭成分的影响,并分析番茄秸秆水热生物炭主要成分的变化。结果表明,番茄秸秆多孔且中空的维管束结构有利于水分和热量在番茄秸秆内部的快速传递,增加水热炭化温度能加速破坏番茄秸秆维管束结构和将条状番茄秸秆炭化为颗粒状水热生物炭。番茄秸秆水热生物炭的功能基团主要是脂肪醚C-O、烷烃C-H、饱和脂肪酸酯C-O、胺C-N以及细胞壁基团C-O、C=O、C-N、C-O-C。提高炭化温度可增加番茄秸秆水热生物炭功能基团数量,但炭化温度达到260 ℃时,明显破坏且大幅度减少番茄秸秆水热生物炭功能基团数量。水热炭化法制备的番茄秸秆水热生物炭为酸性生物炭(pH值5.13~5.33)。在相同的裂解时间下,相较于180℃和260℃炭化温度,220 ℃炭化温度制备的番茄秸秆水热生物炭均获得最高的EC值(6 213~7 899 μs/cm),但裂解时间从2 h延长到8 h,番茄秸秆水热生物炭EC值大幅下降18.19%~26.92%。提高炭化温度和延长裂解时间均显著增加番茄秸秆水热生物炭固定碳含量(2.23~27.99个百分点),但降低番茄秸秆水热生物炭挥发分含量(2.46~30.97个百分点)。提高炭化温度能增加番茄秸秆水热生物炭的总有机碳含量及全氮、灰分含量,增加幅度分别为10.63~29.91、0.58~0.87、1.82~3.09个百分点。综上,相对于延长裂解时间,提高水热炭化温度能更有效地提高番茄秸秆的炭化效率,增加番茄秸秆水热生物炭的氮氧功能基团数量及固定碳、全氮含量。水热炭化温度是决定番茄秸秆水热生物炭微观结构、功能基团、pH值、主要成分的关键因素,220 ℃炭化温度和4~6 h 裂解时间是水热炭化法制备番茄秸秆水热生物炭较为合适的炭化条件。

关键词: 番茄秸秆, 水热生物炭, 炭化温度, 功能基团

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