Reaction thermal runaway is one of the most important reasons leading to chemical accidents. With the rapid development of the chemical industry in the world, especially the fine chemical industry, various safety accidents also occur frequently. Therefore, it is necessary to study the exothermic behavior of the reaction process. In this study, reaction calorimeter was used to study the exothermic phenomena during the chlorination reaction and amination reaction. Differential scanning calorimetry was performed on the reactants, and thermogravimetric experiments were performed on the products. In addition, adiabatic experiment was performed to study the thermal runaway behavior of amination products under adiabatic conditions. The results showed that the target reactions generated a large amount of heat in the initial stage. The maximum temperature of amination reaction is higher than the initial decomposition temperature of the amination product under adiabatic condition. The pyrolysis of amination product was divided into three stages. The product had a high apparent activation energy at the beginning of decomposition, and the apparent activation energy decreased as the decomposition progressed. 相似文献
Risk evaluation of mixtures of asphalt and inorganic salts such as sodium nitrate, sodium nitrite, sodium carbonate and sodium dihydrogenphosphate was conducted. The ignition and the combustion characteristics of mixtures of asphalt and oxidizing salts were obtained. Quasi-heat-accumulation experiments of asphalt–salt mixtures were conducted using about 1 kg samples. Six types of asphalt–salt mixtures were made and their ignition characteristics were examined in the quasi-heat-accumulation experiments. Then to clarify burning behavior of the asphalt–salt mixtures, experiments for understanding their combustion characteristics were conducted using a cone calorimeter.
The main results are as follows.
(1) In the quasi-heat-accumulation experiment, a region with high concentration of the salt mixture particles was made at the bottom of the sample vessel through the process of their sedimentation. An exothermic reaction started in this region. Just before the asphalt–salt mixture was ignited, a huge amount of white smoke was released. A kind of jet flame of a few meters in height was created.
(2) Based on the data of ignition temperature from the cone calorimeter experiments, ignition of asphalt was caused by a chemical reaction of asphalt with an oxidizing salt. The combustion of the asphalt–salt mixture contained the self-heating reaction. 相似文献