| Hydrogen peroxide is a common chemical raw material which widely used in the production and living areas, such as the productions of perpropionic acid, medical disinfectant and bleach. Hydrogen peroxide is a thermal unstable material that occurs decomposing at certain low environment temperature.The decomposition can release vast heat and generate large quantities of oxygen.The higher the concentration and temperature are, the more intense the decomposition reaction is. This exothermic reaction creates oxygen at high temperature and pressure, which is permitted to expand. This process may likely lead to vessels broken down or explosion accidents. The decomposed oxygen mixed with combustible gases or steams. When the combustible mixture comes in contact with an open flame or high heat, it may cause catastrophe. Therefore, it is of great significance to evaluate the thermo-safety of Hydrogen peroxide decomposition reaction. The work and conclusions are summarized as follows:(1) Calorimetry of exothermic reaction based on C600 calorimeterThe heat flow curves of four concentrations of hydrogen peroxide were tested experimentally by C600 calorimeter from room temperature to 300℃ under different scanning rates.The test results were usually served as preliminary risk analysis of the Hydrogen peroxide. Some essential thermal data is acquired,such as T0,Tp,ΔH. Besides that, using an application called AKTS which analyzes certain assessment parameters (TMRad, ΔTad, SADT) of thermal hazard is applicable. The dynamics analysis results indicated its decomposition reaction process conforms to first-order reaction model.Using the C600 calorimeter studied the effect of pH and Fe3+ on hydrogen peroxide decomposition reaction. The results showed that the stability of hydrogen peroxide improved at first and then descended in the pH range of 1.0～7.0. When the pH value was about 4, the hydrogen peroxide was the most stable. The stablility descended sharply at first and then improved slightly under alkaline conditions. When the pH value was about 9, the stablility was worst. At a certain temperature, the TMRad of hydrogen peroxide without Fe3+ was approximately equal to the data, which came from the experiment of hydrogen peroxide with 10ppm Fe3+ at 5℃ lower than before. It also equaled to the TMRad of hydrogen peroxide with 30ppm Fe3+ at 15℃ lower. Based upon the experimental data analysis, when the Fe3+contents in hydrogen peroxide is less than 30ppm, the similar conclusion can be analogized.(2) Amplification of calorimetryUsing the VSP2 adiabatic calorimeter (general measuring dozens of grams), hydrogen peroxide of middling concentration (40%,50%) was detected for the essential thermal data.Meanwhile,hydrogen peroxide of low concentration(10%,15%) was studied by Vent sizing simulation device (general test for kilogram magnitude). The experiment results showed that all the thermodynamic and kinetic parameters were quite close. Preliminary risk parameters from VSP2 (50g of 50%H2O2) were very close to those from venting sizing simulation device (2.8kg of 15%H2O2) and C600 calorimeter (0.3g of 70%H2O2).Hydrogen peroxide, tested by vent sizing simulation device for analyzing its thermal decomposition, was 2.8kg with the concentration of 10% and 15%. The concentration of 10% and the concentration of 15% have the maximum temperature rise rate of 11.7℃/min and 81.6℃/min and the maximum pressure rise rate was 6.0MPa/min and 12.97MPa/min, respectively. The TMRad, under the same condition, dropped considerably compared to the data from VSP2 or C600, was only 0.37h at 40℃. The amplifying test data demonstrated that the hydrogen peroxide of low concentration with a relatively great quantity was very intense. Therefore, the danger of the low can not be ignored with a large amount of production, storage, transportation according to amplifying studies. |
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