煤焦燃烧特性及反应活性探究

中国褐煤资源丰富,然而由于褐煤自身特点使其应用受到了极大的限制。针对中国褐煤应用最广的途径———燃烧,借助热重分析仪对不同热解终温的褐煤半焦及热解终温为1273 K的褐煤半焦与原煤的混合燃料的燃烧特性进行了分析。并利用Coats-Redfern法进行了燃烧动力学的分析,通过求得的表观活化能表征煤焦的燃烧反应活性。研究发现：热解终温越高,煤焦的燃烧特性越差;掺混褐煤有助于提高其半焦的燃烧特性,而掺混燃料的燃烧稳定性几乎和原煤无差别,且随着掺混比例的增加,混合燃料的活化能逐渐增大,越不易点燃,掺混半焦对燃料的燃烧特性和反应活性都有影响。相同制备条件下的烟煤半焦和褐煤半焦的燃烧动力学参数尤其是活化能相差很大,可见煤焦的燃烧反应活性与煤种有关。

Combustion performance and reaction activity of coal char

China is abundant in lignite,while its application is greatly limited by its characteristics.With the help of thermal gravimetric analyzer,study the reaction activity of chars.Analyse the combustion characteristics of blended fuel combining char whose pyrolysis final temperature is 1273 K and raw coal with different proportion.Analyse the combustion kinetics with Coats-Redfern method.The combustion reactivity of char can be charactered by the apparent activation energy.The results show that,the char reaction activity decreass with the increase of final temperature of pyrolysis,the added lignite help increase the combustion characteristics of char,while compared with the raw coal,the combustion stability of blended fuel change little.Continue to increase the ratio of lignite,the activation energy of blended fuel gradually increase,it become harder to light.The added lignite influence the combustion characteristics and reactivity of blended fuel.Under the same preparation condition,the combustion kinetic index of bituminous coal char and lignite char vary widely.That indicate that,the combustion reaction activity is related to the coal type.