热解条件对煤焦比表面积及孔隙分布的影响

在固定床反应器与高温沉降炉中由神木煤和华亭煤制得6组煤焦，考察了升温速率、热解温度对煤焦比表面积和孔隙分布的影响.煤粒在固定床中的升温速率为10 K/min，热解终温900 ℃；在高温沉降炉中升温速率大于1 000 K/s，热解终温为1 100 ℃和1 500 ℃，煤焦的孔隙结构采用低温氮吸附法进行分析.可以发现，快速热解煤焦的比表面积远大于慢速热解煤焦，并随着热解温度的升高而减小.说明挥发分在析出慢时易堵塞孔隙，而热解温度升高使快速热解煤焦的部分微孔转变为中孔和大孔，从而减小比表面积.

Effect of pyrolysis conditions on the char surface area and pore distribution

Shenmu and Huating bituminous coals were devolatilized in a fixed bed reactor and a drop tube furnace, to investigate the effect of heating rate and pyrolysis temperature on the surface area and pore distribution of chars. The heating rate in the fixed bed reactor was 10 K/min and the maximum temperature was 900 ℃, while the heating rate in the drop tube furnace was higher than 1 000 K/s and the furnace temperatures were 1 100 ℃ and 1 500 ℃. The specific surface area and pore volume of chars were determined by N2 adsorption. The surface areas of rapid pyrolysis chars are much larger than those of slow pyrolysis chars, and decrease with increasing pyrolysis temperature. The experimental results show that the micro pores are blocked with slow heating rate, and the proportion of meso pore and macro pore increase with increasing pyrolysis temperature.