配煤比例及温度对气化反应特性影响

Effect of coal blending ratio and temperature on gasification characteristics

为降低制气成本,实现用煤当地化,文中以工程示范项目所用广汇煤为原煤,掺混当地气化活性低、气化过程中易结渣的红沙岗煤,利用热重分析仪考察配煤比例和气化温度对混煤气化特性的影响,采用等转化率法计算气化反应表观活化能。研究结果表明:碳转化率、气化速率以及反应性指数R随混煤中红沙岗煤质量分数增加而降低,随气化温度升高而增加;配煤质量比为10%和20%时反应性指数增加率在1 050℃最小,配煤比为40%和60%时反应性指数在1 000℃时增加率最大,而配煤比为30%和50%时反应性指数在950℃时增加率最大;混煤气化反应表观活化能与配煤比不成线性关系,广汇煤和红沙岗煤在气化过程中存在相互作用,混煤的相互作用与配煤比及碳转化率有关。

In order to reduce the fuel gas production cost of a coal gasification demonstration project,blending low-price local coal is a feasible method.However Hongshagang coal is a low-active and low-rank coal,which is not a suitable coal for gasification.Therefore,it is necessary to select high active coal as coal blending and investigate the effect of blending ratio on gasification characteristics,so as to provide the theoretical basis for selecting appropriate ratio for the project.In this paper,the gasification characteristics were investigated by thermogravimetric analysis and the isoconversional method were employed to calculate the apparent activation energy.Results show that the carbon conversion rate,gasification rate and the reactivity index R decrease with increasing the blending ratio,while increase with increasing gasification temperature.When the coal blending ratio is 10%or 20%,the reactivity index increases minimum at 1 000℃,when the ratio is 40%or 60%,the reactivity index increases maximum at 1 000℃,and when the ratio is 30%or 50%,the reactivity index increases maximum at 950℃.The apparent activation energy is not linear with the blending ratio.The interaction between Guanghui coal and Hongshagang coal is related to the coal blending ratio and the carbon conversion rate.