O_2含量对半焦燃烧动力学影响的热重研究

Study on Influences of O_2 Volume Fractions on Semicoke Combustion Kinetics by Non-isothermal Thermogravimetric Experiment

为了更进一步地清楚阐述半焦的燃烧过程,采用非等温热重法研究氧气体积分数对半焦燃烧动力学的影响。将半焦燃烧过程的第2次失重分为半焦热解脱挥发分（阶段1）、挥发分燃烧（阶段2）、挥发分燃烧且碳燃烧（阶段3）、碳单独燃烧（阶段4）4个阶段,采用Coats-Redfern法选取一级反应模型计算各个阶段的动力学参数。结果表明：24%φ（O_2）~30%φ（O_2）条件下,阶段3所需的表观活化能最小。24%φ（O_2）、26%φ（O2）、30%φ（O_2）条件下阶段4所需的表观活化能最大;28%φ（O_2）阶段2所需的表观活化能最大。

In order to describe semicoke combustion more clearly,influences of oxygen volume fractions on semicoke combustion kinetics was studied by the use of non- isothermal thermogravity. The second mass loss of semicoke combustion was divided into four stages,which were devolatilization（ stage 1） 、volatile combustion（stage2） 、volatile combustion and carbon combustion（ stage 3） 、carbon combustion alone（ stage 4）. Kinetic parameters in different conditions were calculated by Coats- Redfern method and first order reaction model. Results showed that the smallest apparent activation energy was in the third stage in 24% ψ（ O_2） ~ 30% ψ（ O_2）. The biggest apparent activation energy was in the second stage in 24% ψ（ O_2） 、26% ψ（ O_2） 、30% ψ（ O_2）. The biggest apparent activation energy was in the fourth stage in 28% ψ（ O_2）.