ABSTRACT

During the underground coal gasification process, due to the particularity of the gasification channel, a large amount of coal pyrolysis will occur in the coal seam. By studying the characteristics of pyrolysis and gasification of bituminous coal, using the gaseous material containing C element in pyrolysis atmosphere as the way to calculate the conversion rate of lignite. In this paper, thermogravimetric simulation test bench is used to study the pyrolysis characteristics and kinetics of bituminous coal. The weight loss rate under different pyrolysis conditions is analyzed and studied. The following main conclusions are obtained: in the process of bituminous coal pyrolysis, rapid heat transfer to the interior is an important means to improve the pyrolysis efficiency of bituminous coal. The residence time of pyrolysis process is increased, so that the temperature is fully transferred in the coal sample. Therefore, more pyrolysis gas and liquid products can be obtained. The faster the heating rate, the higher the critical temperature of the bituminous coal and the lower the conversion rate. This is because the temperature transfer is lagging and the heating rate is fast, which results in the bituminous coal below the set temperature. The temperature of bituminous coal is shifted back. The formation of CH₄ in bituminous coal mainly occurs in the depolymerizing stage. The formation of H₂ mainly occurs in the condensation polymerization stage, and its formation requires higher temperatures.

摘要

在煤炭地下气化过程中，由于气化通道的特殊性，煤层中会发生大量的煤热解。通过研究烟煤的热解气化特性，以热解气氛中含C元素的气态物质作为计算褐煤转化率的方法。本文利用热重模拟试验台研究烟煤的热解特性和动力学。分析研究了不同热解条件下的失重率。得出以下主要结论：在烟煤热解过程中，向内部快速传热是提高烟煤热解效率的重要手段。热解过程的停留时间增加，使温度在煤样中完全转移。因此，可以获得更多的裂解气液产品。升温速度越快，烟煤的临界温度越高，转化率越低。这是因为温度传递滞后，升温速度快，导致烟煤低于设定温度。烟煤的温度向后移动。CH的形成 这导致烟煤低于设定温度。烟煤的温度向后移动。CH的形成 这导致烟煤低于设定温度。烟煤的温度向后移动。CH的形成₄在烟煤中主要发生在解聚阶段。H ₂的形成主要发生在缩聚阶段，其形成需要较高的温度。