O_(2)/N_(2)和O_(2)/CO_(2)气氛下煤半焦-生物质的混燃特性及影响因素

Combustion Characteristics and Influencing Factors of Coal Semi-coke and Biomass Blends under O_(2)/N_(2) and O_(2)/CO_(2) Atmospheres

为掌握煤半焦与生物质在O_(2)/N_(2)和O_(2)/CO_(2)条件下的混燃特性及其影响因素,采用全自动物理化学吸附仪获得了煤半焦-生物质混合燃料的孔隙结构,采用热重实验分析了两种燃料的混燃特性和反应动力学,通过多元线性回归法研究了燃料比、比表面积与混燃特性参数之间的关系。结果表明,O_(2)/N_(2)气氛下,掺混生物质可改善煤半焦的着火、燃尽及综合燃烧特性;O_(2)/CO_(2)气氛下,掺混生物质能改善煤半焦的着火特性,但会延迟其燃尽。混燃的活化能在低温区和高温区有显著差异,生物质掺混比增大,两个温区的活化能都降低;两种气氛下,低温区的活化能相近,但O_(2)/CO_(2)气氛下高温区的活化能显著高于O_(2)/N_(2)气氛下的。O_(2)/N_(2)气氛下孔隙结构对燃烧特性的影响更显著,而O_(2)/CO_(2)气氛下燃料比对燃烧特性的作用更显著。

To understand the combustion characteristics and influencing factors of coal semi-coke and biomass blends under O_(2)/N_(2) and O_(2)/CO_(2) atmospheres,an automated physical and chemical adsorption instrument was used to obtain the pore structure of semi-coke and biomass blends,and thermogravimetric experiments were carried out to analyze the co-combustion characteristics and reaction kinetics in this paper.In addition,multiple linear regression method was implied to investigate the relationship among the combustion characteristics parameters,fuel ratio and pore structure.The results indicated in O_(2)/N_(2) atmosphere,the ignition,burnout and comprehensive combustion characteristics of coal semi-coke were improved by blending of biomass.However,in O_(2)/CO_(2) atmosphere,blending of biomass can improve the ignition characteristics of semi-coke,yet delay the burnout of semi-coke.The activation energy of the blends exhibited significant differences in the low-temperature and high-temperature zones.As the blending ratio of biomass increased,the activation energies in both temperature zones gradually decreased.The activation energies in low-temperature zone were close in the two atmospheres,while the activation energies in high-temperature zone in O_(2)/CO_(2) atmosphere were observably higher than those in O_(2)/N_(2) atmosphere.In O_(2)/N_(2) atmosphere,the pore structure had a more significant impact on the combustion characteristics.While in O_(2)/CO_(2) atmosphere,the fuel ratio had more notable effect on the co-combustion characteristics.