纯氧气氛下褐煤高压自燃规律的研究

摘要

为开发深部褐煤地下气化非接触式加压氧化点火工艺,通过加压热重实验,研究了纯氧气氛.不同压力下褐煤的自燃着火特征温度的变化规律及动力学参数,研究结果表明:当压力由常压上升到2.0MPa时,失重点T1由230.3℃上升到241.4℃,着火点T2由360.5℃下降到315.4℃,最大失重速率点T3由413.0℃下降到373.1℃,而且特征温度点随着压力的变化呈现线性变化规律;当压力由常压上升到2.0MPa时,表观活化能E由36.652kJ/mol下降到13.766kJ/mol,指前因子A由0.03479s-1下降到0.00079s-1,随着压力的增大E和A基本呈现线性下降趋势.因此,加压能促进褐煤的自燃,有利于煤层着火.%In order to develop the deep lignite underground gasification non-contact ignition pressurization oxidation process,pressurized TGA experiments were carried,to study the temperature of coal spontaneous ignition characteristics and the change rule of kinetic parameters in pure oxygen atmosphere under different pressure.The results showed that when the pressure rises form atmospheric pressure to 2.0MPa,weight-loss-start temperature T1 rises from 230.3℃ to 241.4℃,ignition temperature T2 drops from 360.5℃ to 315.4℃,maximum weight-loss temperature T3 drops from 413.0℃ to 373.1℃,and the characteristic temperature points change in linear relationship just like the pressure changes;the activation energy E drops from 36.652 kJ/mol to 13.766 kJ/mol and pre-exponential factor A drops from 0.03479 s-1 to 0.00079 s-1.Besides,activation energy E and pre-exponential factor A decreases with the increase of pressure.Therefore,high pressure of oxygen makes spontaneous combustion of lignite easier,which is conducive to coal seam ignition.