温度梯度对秸秆炭化物质产率及特性的影响

在300～700℃温度区间,玉米秸秆、水稻秸秆以每100℃为间隔,大豆秸秆以200℃为间隔,研究炭化热解,量化对比产物。结果表明,秸秆热解炭比表面积、总孔容积、pH和碱式官能团随温度升高而增加,孔径和酸式官能团随温度升高而降低;热解液随热解温度升高,酸度降低;热解气中氢气和甲烷含量随温度升高而增加。热解温度平均每升高100℃,热解炭产率平均减少9.31%,热解液产率平均增加4.55%,热解气产率平均增加4.35%。玉米秸秆热解炭、热解液和热解气产率拐点分别为600、611和666℃,水稻秸秆热解炭、热解液和热解气产率拐点分别为666、600和666℃。量化参数可为优化秸秆炭化工艺提供技术支持。

Effect of temperature gradient on yields and characteristics of straw carbonized material

In order to explore the solid-liquid-gas yield and main characteristics of pyrolysis products of straw materials at different temperatures, corn straw and rice straw were selected from 300 to 700 ℃. The products were quantitatively analyzed by carbonization pyrolysis at intervals of 100 and200 ℃. The results showed that the specific surface area, the total pore volume, p H and basic functional groups of all the straw pyrolytic carbon increased with the increase of temperature, while the pore size and acid functional groups decreased with the increase of temperature; the acidity of pyrolytic solution decreased with the increase of pyrolysis temperature, and the content of hydrogen and methane in pyrolysis gas increased with the increase of temperature. When the pyrolysis temperature increased by 100 ℃, the yield of pyrolytic carbon decreased by 9.31%, the yield of pyrolytic liquid increased by 4.55%, and the yield of pyrolytic gas increased by 4.35%. The yield inflection points of corn straw pyrolytic carbon, pyrolytic liquid and pyrolytic gas were 600, 611 and 666 ℃, respectively,and the yield inflection points of rice straw pyrolytic carbon, pyrolytic liquid and pyrolytic gas were 666,600 and 666 ℃, respectively. The quantitative parameters obtained could provide technical supports for straw carbonization process.