水煤浆热解产物的分布、组成和产率对水煤浆的高效燃烧具有重要影响，同时水煤浆热解产生的H₂、CH₄、CO等气体有助于改善脱硝温度窗口，提高脱硝效率。采用高频加热炉对神木煤制成的水煤浆进行热解，测定并分析了热解气的产率和组成成分，探究了热解温度和加热速率对水煤浆热解特性的影响。结果表明，随着温度的升高，水煤浆的除水失重率持续增加，从700～1 200 ℃增加了约10%，挥发分和热解气体的产率继续增加，从0.50 L/g增加到0.73 L/g，说明水煤浆的热解程度逐渐增加。热解气体的组成主要是H₂、CO、CH₄和CO₂。随着温度的升高，总热解气体中H₂、CH₄、CO₂和CO总体积分数在700～900 ℃降低，在900～1 100 ℃保持稳定，1 100 ℃以上继续下降，从最初700 ℃ 时的90%下降到1 200 ℃时的78%，其中H₂、CO₂和CH₄体积分数呈阶梯式下降，而CO体积分数几乎不变，H₂体积分数下降最明显，约6.1%，而CH₄则下降了约4%，CO₂下降了2.6%左右。随着温度的升高，H₂、CO₂和CH₄产率先增加后减小，峰值出现在1 100 ℃左右，而CO产率则持续增加。升温速率也影响挥发物的产率，升温速率667 ℃/min的除水失重率比400 ℃/min高6%，但总体影响不大。研究结果为掌握水煤浆初级热解产物的形成特征提供了参考。

The distribution,composition and yield of pyrolysis products of coal water slurry have an important influence on the effective combustion of coal-water slurry,while H₂,CH₄,CO and other gases produced by pyrolysis of coal-water slurry are conducive to improve the denitration temperature window and the denitration efficiency. In this paper,the coal-water slurry made from Shenmu coal(bituminous coal）was pyrolyzed by a high-frequency heating furnace,and the yield and composition of pyrolysis gas were measured and analyzed. The effects of pyrolysis temperature and heating rate on the pyrolysis characteristics of coal-water slurry were explored. The results show that as the temperature increases,the weight loss rate without water of coal-water slurry continues to increase,increasing by about 10% from 700 ℃ to 1 200 ℃. The yield of volatile matter and pyrolysis gas continue to increase,from 0.50 L/g to 0.73 L/g,which shows that the degree of pyrolysis of coal-water slurry gradually increases. The pyrolysis gas is mainly composed of H₂,CO,CH₄ and CO₂. As the temperature rises,the total volume concentration of H₂,CH₄,CO₂ and CO in the total pyrolysis gas decreases in the range of 700-900 ℃,and remains stable in the range of 900-1 100 ℃,and then continues to decline above 1 100 ℃,from initially 90% at 700 ℃ to 78% at 1 200 ℃,in which the volume concentration of H₂,CO₂ and CH4 decrease in a stepwise manner,while the volume concentration of CO remains almost unchanged. The volume concentration of H₂ decreases most significantly,about 6.1%,while CH4 decreases by about 4% and CO₂ decreases by about 2.6%. As the temperature increases,the yields of H₂,CO₂ and CH₄ increase first and then decrease,and the peak appears at about 1 100 ℃,while the CO yield continues to increase. The yield of volatiles is affected by the rate of temperature increase. The weight loss rate without water at 667 ℃/min is 6% higher than that at 400 ℃/min. On the whole,the heating rate has not significantly influence on the pyrolysis. The research results provide a reference for understanding the formation characteristics of primary pyrolysis products of coal water slurry.

0 引言

1 试验

   1.1 高频炉参数

   1.2 热解加热系统

   1.3 试验方案

2 试验结果及分析

   2.1 质量损失率和热解气产率

   2.2 热解气组分产率

   2.3 体积分数

   2.4 加热速率

3 结论