复合阻化剂抑制煤自燃的热重动力学实验研究
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摘要
为研究聚丙烯酸钠-花青素复合阻化剂对煤自燃的阻化效果,选用褐煤和长焰煤制备阻化煤样,并与原煤和常规阻化剂CaCl_2溶液处理的煤样进行对比。首先通过煤自燃倾向性氧化动力学测试实验对比原煤煤样与阻化后煤样的70℃出口氧浓度与交叉点温度(CPT)。其次开展热重动力学实验,选取特征温度点进行分析,并基于4种升温速率下煤氧化自燃过程3个阶段的热重数据,利用Starink模型等转化率法求解动力学参数。结果表明:聚丙烯酸钠-花青素复合阻化剂对褐煤及长焰煤自燃过程起到持续抑制作用,阻化后煤样自燃氧化动力学判定指数I大幅下降,高温下阻化效果显著优于CaCl_2溶液,具有较好的温度适应性。阻化煤样自燃过程的低温氧化阶段、吸氧增重阶段及着火阶段的表观活化能值均相应提高,煤氧复合放热反应活性大幅降低。
In order to study the inhibition mechanism of sodium polyacrylate-anthocyanin compound inhibitor on coal spontaneous combustion,lignite and long flame coal were used to make coal samples which were compared with raw coal and coal samples treated by conventional inhibitor CaCl_2 solution.The 70℃outlet oxygen concentration and cross-point temperature(CPT)of the coal sample and inhibited coal sample were compared by the coal spontaneous combustion propensity oxidation kinetics test.Then the thermogravimetric kinetics experiment was carried out,and the characteristic temperature points were selected for analysis.Based on the thermogravimetric data of three stages of coal oxidation and spontaneous combustion at four heating rates,the kinetic parameters were solved by the conversion method such as Starink model.The results showed that the composite inhibitor of Sodium Polyacrylate-Anthocyanin had a resisting effect on spontaneous combustion process of lignite and long flame coal,which can greatly reduce the coal spontaneous combustion determination index I of lignite and long flame coal after inhibition,and its inhibition effect at high temperature was better than that of CaCl_2 solution,with a good temperature adaptability.The apparent activation energy values of the low-temperature oxidation stage,the oxygen absorption weightincreasing stage and the ignition stage of inhibited coal sample in spontaneous combustion process correspondingly increased,and the coal-oxygen composite exothermic reaction activity greatly reduced.
In order to study the inhibition mechanism of sodium polyacrylate-anthocyanin compound inhibitor on coal spontaneous combustion,lignite and long flame coal were used to make coal samples which were compared with raw coal and coal samples treated by conventional inhibitor CaCl_2 solution.The 70℃outlet oxygen concentration and cross-point temperature(CPT)of the coal sample and inhibited coal sample were compared by the coal spontaneous combustion propensity oxidation kinetics test.Then the thermogravimetric kinetics experiment was carried out,and the characteristic temperature points were selected for analysis.Based on the thermogravimetric data of three stages of coal oxidation and spontaneous combustion at four heating rates,the kinetic parameters were solved by the conversion method such as Starink model.The results showed that the composite inhibitor of Sodium Polyacrylate-Anthocyanin had a resisting effect on spontaneous combustion process of lignite and long flame coal,which can greatly reduce the coal spontaneous combustion determination index I of lignite and long flame coal after inhibition,and its inhibition effect at high temperature was better than that of CaCl_2 solution,with a good temperature adaptability.The apparent activation energy values of the low-temperature oxidation stage,the oxygen absorption weightincreasing stage and the ignition stage of inhibited coal sample in spontaneous combustion process correspondingly increased,and the coal-oxygen composite exothermic reaction activity greatly reduced.
引文
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[3]底翠翠,辛海会,李金帅.基于煤自燃倾向性的绝热氧化时间预测方法研究[J].科学技术与工程,2017,17(21):13-17.
[4]张磊,秦岭,包军,等.基于温升速率的煤自燃倾向性测定方法[J].科学技术与工程,2017,17(30):186-189.
[5]Qin B,Jia Y,Lu Y,et al.Micro fly-ash particles stabilized Pickering foams and its combustion-retardant characteristics[J].Fuel,2015,154:174-180.
[6]李金亮,陆伟,徐俊.化学阻化剂防治煤自燃及其阻化机理分析[J].煤炭科学技术,2012,40(1):50-53.
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