微藻热解特性及其动力学分析

Characteristics and Dynamics of Pyrolysis Process Microalgae

通过热重分析手段研究了杜氏盐藻在室温至900℃下的热解行为和特性,采用高纯氮气作保护气,升温速率分别为5℃/min、10℃/min、20℃/min和40℃/min.TG、DTG曲线的分析表明,热解过程随温度升高经历3个不同阶段.此外,随着升温速率增大,热解的初始温度和峰值温度均增大,且总失重增加.采用等转化速率法和主曲线法对盐藻热解过程进行动力学分析.结果表明,表观热解反应遵循单一动力学机理模型,反应动力学过程为简单级数反应机理模型Fn.求得热解反应表观平均活化能Ea为146.3 kJ/mol,指前因子A为4.28×1013s-1,指数n为2.4.

The pyrolysis characteristics of Dunaliella tertiolecta was investigated by thermogravimetric analysis. The experiments were conducted with a thermogravimetric analyzer from ambient temperature to 900 ℃ at different heating rates of 5, 10, 20, 30 and 40 ℃/min trader high purified N2. TG and DTG analyses were adopted to study the pyrolysis behavior of Dunaliella tertiolecta systematically. Results showed that three stages appeared in the pyrolysis process with increasing temperature. Moreover, the ini- tial temperature of pyrolysis and the temperature at which the pyrolysis rate reached the peak value rose with increasing the heating rate. The kinetic analysis was made by using a composite procedure involving the iso-conversional method and the master plots method. The iso-conversional method indicated that the pyrolysis reaction can be dealt with as a single reaction model, and the master plots method revealed that this process conforms to the simple order reaction mode, Fa. The kinetic parameters were determined, of which the apparent activation energy Ea is 146.3 kJ/mol, the pre-exponential factor is 4.28 × 10^13 s^-1and the kinetic exponent n is 2.4.