热分析法研究硝酸羟铵水溶液的分解

Investigation on the decomposition process of hydroxyl ammonium nitrate solution by thermal analysis

为了获得硝酸羟铵水体系的分解性能,利用TG-DSC技术测试和研究了硝酸羟铵(HAN)水溶液的热分解和催化分解特性,通过测试不同升温速率下的分解曲线,对HAN水溶液的热分解动力学进行了研究,在此基础上,通过傅里叶红外(FTIR)和在线质谱(MS)对硝酸羟铵水溶液的催化分解气体产物进行分析。研究结果表明:HAN水溶液的催化分解放热峰是109.8℃,比热分解放热峰155.6℃提前了45.8℃;利用Kissinger和Fly-Wall-Ozawa方程得出HAN水溶液热分解活化能和催化分解活化能分别是110.6 kJ/mol和87.8 kJ/mol;催化剂的加入能降低HAN的活化能,使其分解温度提前;硝酸羟铵水溶液催化分解的气体产物主要是NO,N2和N2O,并提出了其可能的催化分解机理。

In order to study the decomposition performance of hydroxyl ammonium nitrate,the thermal decomposition and catalytic decomposition of the hydroxyl ammonium nitrate(HAN) solution were investigated by using the TG-DSC technology.The decomposition kinetic of HAN solution was researched by testing at different heating rate and the major gas phase products were measured by MS and FTIR.The results showed that the peak temperature of catalytic decomposition and thermal decomposition were 109.8 ℃ and 155.6 ℃ respectively.The peak temperature of catalytic decomposition was decreased by 45.8 ℃ compared to the peak temperature of thermal decomposition.The activation energy of the thermal decomposition and catalytic decomposition were 110.6 kJ/mol and 87.8 kJ/mol respectively by Kissinger and Fly-Wall-Ozawa equation.The addition of catalyst could reduce decomposition activation energy of HAN-water solution and make the decomposition temperature reduced.The major gas phase products were NO, N2 and N2O.A possible mechanism of catalytic decomposition was proposed.