A Study on the Universality of the Master Kinetics Curve Model: Using Three Types of Reaction Profiles and Different Curve Fitting Methods

• Main Authors: Wen-Hui Chen, 陳玟卉
• Other Authors: Mao-Hua Teng
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/9gm4f6

碩士 === 國立臺灣大學 === 地質科學研究所 === 107 === The Master Kinetics Curve (MKC) model is developed from a general reaction rate equation. The MKC model has three advantages easy to use, accurate predictions and wide applications. In previous studies, researchers had already applied the model to thermal decomposition, phase transformation, sintering reaction, and kerogen-to-oil conversion to show the possibility of the MKC model serving as a universal kinetic model. However, the reaction profile of the reaction mentioned above is S-shaped. Reactions with different reaction profiles (i.e. accelerating-type and decelerating-type) have not yet been tested. In this study, the thermogravimetric analysis data, dilatometric analysis data, theoretical synthetic data, and literature data on brucite thermal decomposition have been applied to the MKC model to explore whether the reactions in which the reaction profile is the decelerating-type, can be applied to the MKC model. The results show that the MKC model can be used to analyze and predict the decomposition reaction of brucite except for the dilatometric analysis data. The apparent activation energies of the thermogravimetric analysis data, dilatometric analysis data, theoretical synthetic data, and literature data were 135.0 kJ/mol, 153.2 kJ/mol, 147.0 kJ/mol, respectively. In the dilatometric experiment, the length change of green compact combines the shrinkage caused by the thermal decomposition and thermal expansion of the green compact. Since the shrinkage of the thermal decomposition reaction is only 1.6%, the effect of thermal expansion cannot be ignored. This situation caused the bad fitting of the MKC, because the MKC model cannot use single MKC to describe the reaction process with multiple reactions combined. To explore whether the reactions in which the reaction profile is accelerating-type can be applied to the MKC, theoretical synthetic data and literature data on coke oxidation reaction have been applied to the MKC model. The MKC results show that good fitting prediction curves and apparent activation energies can be obtained. The applicability of the MKC model is independent of the reaction profile. The application limits of the MKC model are only related to the general chemical reaction rate equation. If the reaction is a one-step or multi-step reaction with a rate-determining step, the kinetic study can be conducted using the MKC model. The MKC model does not limit the curve fitting method. Therefore, this study uses five different curve fitting equations to discuss the fittings of the S-type and accelerating-type MKCs. The fitting results show that the S-type fitting equation, which is currently used in this study, is the best fitting method. The S-type fitting equation has great fitting goodness and is suitable for various curves. This study proves that reactions with three types of reaction profiles can be applied to the MKC model, which indicates that reactions with all reaction models can be applied. Therefore, the MKCmodel is a universal kinetic model.