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采用热重分析法(TGA)对丹参中药渣的热解特性及其动力学规律进行了研究。分析了不同升温速率(10、30和50℃/min)和不同粒径(0.85~0.6、0.3~0.18和0.125~0.1 mm)药渣的热解特性。结果表明,药渣热解可分为3个阶段:预热干燥阶段、主热解阶段和碳化阶段,随升温速率的升高,热重(TG)和微分热重(DTG)曲线向高温侧移动,药渣的最大失重速率也显著增加;与大颗粒相比较小颗粒的挥发分产量较大。采用Coats-Redfern法和Flynn-Wall-Ozawa(FWO)法对药渣热解的动力学进行分析,选出了较为合理的机理函数,并计算得出药渣热解活化能为62~72 kJ/mol。
The thermogravimetric analysis (TGA) was used to study the pyrolysis characteristics and kinetics of Danshen Chinese medicinal residue. The pyrolysis characteristics of dregs with different heating rates (10, 30 and 50 ℃ / min) and different particle sizes (0.85 ~ 0.6, 0.3 ~ 0.18 and 0.125 ~ 0.1 mm) were analyzed. The results showed that the pyrolysis of dregs can be divided into three stages: preheat drying stage, main pyrolysis stage and carbonization stage. With the increase of the heating rate, the thermogravimetric (TG) and differential thermogravimetry (DTG) As a result, the maximum rate of weight loss of dregs also increased significantly, while the smaller particles produced larger volatiles than large particles. The kinetics of pyrolysis of dregs were analyzed by Coats-Redfern method and Flynn-Wall-Ozawa (FWO) method, and a reasonable mechanism function was selected. The calculated activation energy of dregs was 62-72 kJ / mol.