不同还原性煤的低温氧化气体解析动力学

Kinetics of Low-Temperature Oxidation Gas Release of Coal with Different Deoxidization Degree

基于煤升温氧化过程中，氧气消耗速率和气体产物的解析速率增大的原理，选用煤升温氧化实验系统，采集一对变质程度相同而煤岩成分与还原程度不同的太原组和山西组对比煤样，研究升温过程空气中氧气反应的动力学特征．结果表明：太原组和山西组煤的耗氧速率、氧化产物和C1～C4烃的解析速率的对数与热力学温度的倒数呈一次线性关系．强还原程度的太原组煤解析CH4的活化能Ea最低，其次是CO2；解析C3H6的Ea最高，其次是C2H4．弱还原程度的山西组煤解析CO2的Ea最低，其次是C2H6；解析i-C4H8的Ea最高，其次是C3H6．两种组煤与氧化合的强度及其气体产物解析的强度存在很大差异，为不同还原程度煤的自燃倾向性预测提供了理论依据．

The exothermic characteristics of low-temperature oxidation of coal were investigated based on the basic principle that oxygen consumption rate and gas release rate increase during the temperature-rising process of coal. Using a coal temperature programmed experimental facility, the kinetic characteristics of Taiyuan formation and Shanxi formation coal of different deoxidization degree were studied when reacting with oxygen in air during the temperature-programmed oxidation process. The results show that the logarithms of oxygen consumption rate and gas release rate of oxidation products and C1-C4 hydrocarbons are linearly proportional to the reciprocal of thermodynamic temperature for Taiyuan formation and Shanxi formation coal. For Taiyuan formation coal with strong deoxidization degree, CH4 presents the lowest activation energy Ea, followed by CO2, while C3H6 presents the highest activation energy Ea, followed by C2H4. For Shanxi formation coal with feeble deoxidation degree, activation energy Ea of CO2 is the lowest, followed by that of C2 H6 ; activation energy Ea of i-C4 Hs is the the highest, followed by that of C3 H6. There are significant differences in the intensity of oxidation and the amount of gas release of the two coals. The present work provides a theoretical basis on which the propensity of spontaneous combustion can be predicted for coals with different oxidation characteristics and gas release processes.