煤低温氧化过程中自由基浓度与气体产物之间的关系

Relation between free radicals concentration and gas products in process of coal low temperature oxidation

利用煤低温氧化装置和顺磁共振实验,研究了褐煤、气煤、气肥煤和无烟煤在不同氧化温度下气体及自由基的变化规律,宏观和微观相结合来揭示煤自热低温氧化规律。研究结果表明:煤低温氧化过程中,煤被氧化分子侧链断裂,产生气体与自由基,生成的CO,C2H4标志性气体生成量随温度增加而增加,相应地自由基浓度也随氧化温度的增加而增加。煤被氧化生成CO,C2H4标志气体量与自由基浓度呈阶段性规律:低温氧化蓄热阶段,CO气体生成量小或未出现CO气体,此时自由基浓度变化小;从开始出现CO至出现C2H4气体的氧化自热阶段,CO生成量随氧化温度缓慢增加,而自由基浓度也逐步增加;从出现C2H4至出现H2气体的深度氧化阶段,CO和C2H4生成量随氧化温度增加而快速增加,自由基浓度随氧化温度增加而增幅变小。

Using low temperature oxidation equipment of the coal and electron paramagnetic resonance（EPR）,researched the variation of gas products and redical concentration of lignite,gas coal,gas-fat coal and anthracite at different low temperature oxidation temperature and opened out the laws of low-temperature oxidation of coal self-heating in such a way of the combination of macro and micro.The results show that the oxidized molecular side of the coal is broken that come into being CO gas,C2H4 gas and free radicals,and CO and C2H4 sign gas and free radicals concentration is being to increase with the increasing of the temperature;coal being oxidized to product the amount of CO gas and C2H4 gas and the concentration of free redicals that have a periodic law：the regenerative stage of low-temperature oxidation,CO gas is a small amount or does not appear,and free radical concentration has a small change;the stage of the thermal oxidation is to appear from the CO gas to C2H4 gas,CO formation with the oxidation temperature increases slowly,the concentration of free radicals increases gradually;the stage of the depth of oxidation is to appear C2H4 gas to H2 gas,the formation of CO and C2H4 have a rapid increase with the increase of oxidation temperature,free radical concentration increasing with the increase of oxidation temperature becomes smaller.