Classification and Operation of Critical Runaway Conditions and its Criteria of Thermal Stability in Exothermic Chemical Reaction System

• Main Authors: Sheann-Huei Lin, 林憲輝
• Other Authors: Kuo-Ming Luo
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/46735151531105908075

博士 === 國防大學中正理工學院 === 國防科學研究所 === 90 === The runaway reaction or thermal explosion always occurs in the exothermic chemical reaction system. In fact this kind of chemical reaction is very sensitive. In an exothermic reaction, when the total generation heat rate of a reactive system exceeds the removed heat rate of the ambient cooling medium, the whole system very easily accumulates its energy and increases its temperature. Then, this heat makes the system unbalanced and a self-ignition reaction is triggered off. As soon as the temperature reaches a critical point, this reactive system goes to the runaway situation and may even result in explosion. In many chemical industrial catastrophes abroad or domestic, the frequency of thermal runaway reaction involving peroxide compounds and the polymerization and nitration reaction is relatively higher than other kinds of reaction. Thus, the reactive hazard of peroxide compounds and the polymerization and nitration reaction has to be clearly identified and the critical runaway temperature and stable reaction criterion have to be determined. In this study, the Semenov parameter in thermal explosion theory is adopted and modified to analyze and calculate the critical runaway temperature and stability criteria in these highly dangerous chemical reaction systems. The apparatus DSC and VSP, etc. are used to measure their reaction thermal kinetic data and estimate their kinetic parameters. Then, these kinetic parameters are incorporated with the critical temperature equations of thermal explosive to evaluate the runaway and stable criteria in these reaction systems. The critical temperature equations are derived from both the mass and energy equations. Consequently, these critical runaway temperature and stability criteria are determined from the evaluated equations briefly. The required heat transfer coefficients in these critical conditions can also be estimated. The values of Frank-Kamenetskii parameters are used to evaluate the critical temperature of thermal explosion for TNT explosive inside a bomb. The critical temperature is affected by the ambient conditions. These results can be applied efficiently to control the reaction process in a chemical plant and to reduce accidents as much as possible. This investigation plays an important role in the production, transportation, storage process, and reactor design for all exothermic chemical reaction systems.