不同制备方法对荞麦秸秆生物炭理化性质的影响  

Effects of different preparation methods on physicochemical properties of buckwheat straw biochar

作　　者：韩春风 桑梓繁 尚楷林 张伎 邢泽炳[1,2] HAN Chun-feng;SANG Zi-fan;SHANG Kai-lin;ZHANG Qi;XING Ze-bing(College of Agricultural Engineering,Shanxi Agricultural University,Jinzhong Shanxi 030801;Experimental Teaching Center,Shanxi Agricultural University,Jinzhong Shanxi 030801)

机构地区：[1]山西农业大学农业工程学院,山西晋中030801 [2]山西农业大学实验教学中心,山西晋中030801

出　　处：《中国土壤与肥料》2024年第6期231-240,共10页Soil and Fertilizer Sciences in China

基　　金：山西省高等教育“1331工程”提质增效建设计划项目(201903D211002)。

摘　　要：为了了解荞麦秸秆生物炭的理化性质,探究了不同温度与升温速率对荞麦秸秆热解特性的影响,通过差示扫描量热法、比表面积、孔径以及傅里叶红外光谱等检测揭示了荞麦秸秆生物炭的理化性质。结果表明:荞麦秸秆的差热曲线具有相似的变化,随着升温速率的增加热解反应向右偏移;炭得率与热解温度呈负相关;pH值、电导率逐渐增大(9.16~12.27、2.56~4.96 mS/cm);随着热解温度的升高,荞麦秸秆生物炭的表面官能团种类逐渐减少,并随着升温速率的增加伸缩振动增强;生物炭的比表面积与孔径体积随着热解温度的升高呈先增加后降低的趋势,但与升温速率不具有相关性,在较低温度时随着升温速率的增加孔隙结构逐渐由介孔为主过渡为大孔为主;不同热解温度下制备的荞麦秸秆生物炭的分形维数范围为[2.3709,2.9368]。综上所述,在热解温度700℃与升温速率12.5℃/min的条件下制备的荞麦秸秆生物炭,其结构稳定、比表面积最大且具有良好的炭得率,综合性质最佳。In order to understand the physicochemical properties of buckwheat straw biochar,the effect of different temperatures and heating rates on the pyrolysis characteristics of buckwheat straw was investigated,and the physicochemical characteristics of buckwheat straw biochar were revealed by differential scanning calorimetry,specific surface area and pore size and Fourier infrared spectroscopy.The results showed that the differential heat curves of buckwheat straw at different heating rates had a similar change curve,the pyrolysis reaction shifted to the right with the increase in the heating rate;The yield of biochar was negatively correlated with pyrolysis temperature;pH and conductivity gradually increased(9.16-12.27 and 2.56-4.96 mS/cm);With the increase of pyrolysis temperature,the types of surface functional groups of buckwheat straw biochar gradually was decreased,and the stretching vibration was increased with the increase of heating rate.The specific surface area and pore volume of biochar increased with the increase in pyrolysis temperature and then decreased,but there was no correlation with the rate of heating,at lower temperatures,with the increase in the rate of heating,pore structure gradually transitioned from mesoporous to macroporous;The fractal dimension range of buckwheat straw biochar prepared at different pyrolysis temperatures was[2.3709,2.9368].In summary,the buckwheat straw biochar prepared under the conditions of pyrolysis temperature of 700℃and heating rate of 12.5℃/min had the best comprehensive properties in terms of its stable structure,maximum specific surface area and high biochar yield.

关 键 词：荞麦秸秆 升温速率 微波热解 孔隙结构 分形维数 Frenkel-Halsey-Hill方程 

分 类 号：TQ127.11[化学工程—无机化工] S216[农业科学—农业机械化工程]