过氧乙酸溶液的热爆炸分析

Thermal explosion analysis of peroxyacetic acid

为有效预防生产、储运和使用中过氧乙酸引发的火灾爆炸事故,采用绝热加速量热仪模拟了15%和10%浓度的过氧乙酸溶液的热爆炸过程,得到了两种浓度的PAA溶液的热分解温度、压力、温升速率随时间变化的关系曲线,并用速率常数法分别计算了反应级数n、表观活化能Ea和指前因子A。经过绝热修正,得到最危险状态下的温度和压力等相关热危险参数,并基于Semenov热爆炸理论推算了三种包装条件下两种样品的不可逆温度和自加速分解温度。结果表明,15%PAA和10%PAA溶液热分解反应级数均为一级,表观活化能分别为104.4 kJ.mol-1和103.2 kJ.mol-1;绝热条件下初始放热温度分别为42.9℃和29.3℃;自加速分解温度受反应系统到达最大反应速率的时间、物料存储规模及散热条件的影响,建议PAA应储存在通风背阴处且单个包装容积应控制在25L以下。

Peroxyacetic acid （PAA） has a wide usage as disinfectant. For reducing the potential hazard of thermal explosion caused by PAA in production, transportation, storage and usage, the variations of temperature, pressure, self-heating rate which were revolved in thermal decomposition reactions of 15% PAA and 10% PAA were measured by adiabatic accelerating rate calorimeter （ARC）. The reaction order n, activation energy Ea and pre-exponential factor A of these two samples were calculated by the rate constant method. Modified by the thermal inertia factor, the temperature and pressure related parameters at the worst condition were obtained. Based on Semenov thermal explosion theory, the self-accelerating decomposition temperatures （SADT） as well as no-return temperature were also calculated for the two samples at three specific package conditions. It showed that the decomposition reaction of 15% PAA and 10% PAA are both first order. For 15% PAA and 10% PAA, it is shown that the initial exothermic temperatures are 42.9℃ and 29.3℃ respectively under thermal insulation condition. The calculated SADT results reveal that time to maximum self-heating rate, package bulk and cooling condition are the main factors for the SADT. It was suggested that based on the test data the package bulk for PAA should be under 25 L.