ABSTRACT

Blended coal combustion technology is being adopted by more and more power plants as a clean coal combustion technology, while the combustion of coal coke accounts for more than 85% of the total combustion process of pulverized coal. In order to investigate the effects of different factors on the pore structure and fractal properties of the blended coal coke, a low-temperature nitrogen adsorption method and scanning electron microscopy are used to study the coal coke consisting of three types of coal after pyrolysis. The adsorption isotherm analysis indicates that the pore structure in blended coal coke consisted mainly of semi-open pores with semi-cates. Petroleum coke can severely inhibit microporosity when the content of petroleum coke in the blended coal sample exceeds 10%. The microporosity distribution of blended coal coke with different blending ratios is more concentrated than that of mesopores. In addition, it is found that the trend of D1 is consistent with the trend of the ratio of the microporous specific surface area to the total specific surface area in the blended coal coke. Bituminous coal will make the blended coal coke have a complex structure and petroleum coke will make it have a smooth surface.

摘要

混煤燃烧技术作为一种洁净的煤燃烧技术正在被越来越多的电厂采用，而煤焦炭的燃烧占煤粉总燃烧过程的85%以上。为了研究不同因素对混合煤焦孔隙结构和分形特性的影响，采用低温氮气吸附法和扫描电镜对热解后由三种煤组成的煤焦进行了研究。吸附等温线分析表明，混合煤焦中的孔隙结构主要由半开孔和半链酸盐组成。当混配煤样中石油焦含量超过10%时，石油焦对微孔的抑制作用明显。不同配比混合煤焦的微孔分布比中孔更集中。另外发现，D1的变化趋势与调配煤焦中微孔比表面积占总比表面积的比值变化趋势一致。烟煤会使混合煤焦具有复杂的结构，而石油焦会使它具有光滑的表面。