Abstract:

Time to maximum rate under adiabatic condition (TMR_ad) is a widely-used parameter for evaluation of the probability of decomposition reactions of substances or reactive mixtures under adiabatic conditions. The traditional method for calculation of TMR_ad necessitates the kinetics and thermodynamics of the decomposition reactions, such as pre-exponential factor, activation energy, reaction order and decomposition enthalpy. To calculate the TMR_ad using accelerating rate calorimeter (ARC), a whole thermal curve including both onset decomposition temperature and final temperature is required. However, due to the complexity of reaction mechanism or safe operation of calorimetric experiment, the final temperature is often unavailable, meaning the traditional method is in failure. Therefore, to solve this problem, this paper proposes a new method for calculating TMR_ad, which is based on the assumption that the consumption of reactants is negligible within a narrow temperature range relative to the whole exothermic curve. Moreover, the experiment results also prove the flexibility of this new method to exothermic curve including final temperature.

Key words: secondary decomposition reactions, thermodynamics, safety, stability, time to maximum rate under adiabatic condition, accelerating rate calorimeter

摘要：

最大反应速率到达时间（TMR_ad）是物质热危险评价中一个非常重要的参数，常用于评估绝热条件下物质或混合物发生分解反应的可能性。传统的TMR_ad计算方法需要计算物质或混合物的分解动力学参数和热力学参数，如指前因子、活化能、反应级数和分解反应热。为了使用绝热加速量热仪（ARC）计算TMR_ad，需要用测得物质或混合物完整的放热曲线来计算动力学参数。然而，在实际的测量中，由于放热机理复杂或实验安全的考虑，常常难以得到完整的放热曲线，即没有放热终点。在这种情况下，传统的TMR_ad计算方法就失效了。因此，提出一种可以适用于这种情况计算TMR_ad的新方法。实验验证结果表明这种方法亦可以用于计算拥有完整放热曲线的TMR_ad。

关键词: 二次分解反应, 热力学, 安全, 稳定性, 最大反应速率到达时间, 绝热加速量热仪