Abstract

A self-developed superheated water vapor pyrolysis system was used to conduct superheated water vapor pyrolysis experiments on Tashan and Madaotou long-flame coals at 350–534 °C. The gas phase products were analyzed by gas chromatography. The yield and composition of gas phase pyrolysis products from two different long-flame coals were determined, and the role of superheated water vapor in the pyrolysis process was elucidated. The optimal temperature of the long-flame coal injection superheated water vapor mining technology was obtained through heat value analysis. The results showed that when the temperature of the superheated water vapor exceeded 400 °C, the yield and combustible components of the gas phase products rapidly increased. As such, the release rate reached 10–15 times that observed below 400 °C, and the components of the combustible gases, such as hydrocarbon gas and hydrogen, exceeded 80%. Superheated water vapor not only is an excellent heat and mass transfer medium, but also provides a reactant for the re-formation reaction of hydrocarbon gas. The pyrolysis of long-flame coal under superheated water vapor at 500 °C yielded the best economic benefits. The low calorific value of gas phase products produced via pyrolysis per ton of coal per unit time could reach 715 MJ/(t·h).

摘要

采用自主研发的过热水蒸气热解系统，对塔山和马道头长焰煤在350~534 ℃下进行过热水蒸气热解实验。通过气相色谱分析气相产物。测定了两种不同长焰煤气相裂解产物的产率和组成，阐明了过热水蒸汽在裂解过程中的作用。通过热值分析得到长焰喷煤过热水蒸汽开采工艺的最佳温度。结果表明，当过热水蒸气温度超过400 ℃时，气相产物的收率和可燃成分迅速增加。因此，释放速率达到 400 °C 以下观察到的 10-15 倍，烃类气体、氢气等可燃气体成分超过80%。过热水蒸气不仅是一种优良的传热传质介质，而且为烃类气体的再形成反应提供了反应物。长焰煤在500℃过热水蒸汽条件下的热解产生了最好的经济效益。单位时间每吨煤热解产生的气相产物的低热值可达715 MJ/(t·h)。