Abstract View
Carbon Black and Hydrogen Production: An Optimized Reaction Mechanism for Methane Pyrolysis
AMBUJ PUNIA, James Tatum, Larry Kostiuk, Jason S. Olfert, Marc Secanell, University of Alberta
Abstract Number: 227
Working Group: Combustion
Abstract
Methane pyrolysis (anaerobically decomposing methane at high temperatures) can be used to transform methane into carbon black and hydrogen without any greenhouse gas emissions. The carbon black can be used in many commercial products and the hydrogen can be used in many energy applications. This process depends on the temperature and pressure and during the process, other intermediate species, such as acetylene (C2H2), ethylene (C2H4) and ethane (C2H6), are also observed. Accurate prediction of these species requires an understanding of the formation and consumption kinetics and the development of a reaction mechanism consisting of the different elementary reactions occurring inside the reactor. However, a mechanism that accurately predicts this process in the temperature range of 1000-1400 K and 0.1-4 atm does not exist.
In this contribution, a previously proposed reaction mechanism by Dean was modified, and the best fit values of the pre-exponential factors were obtained using sensitivity analysis and optimization. A significant improvement in the model predictions was observed once the optimal pre-exponential factor values were implemented in the reaction mechanism. The numerical results obtained in the temperature and pressure range of 1000-1400 K and 0.1-4 atm, respectively, were validated against the gas-phase species profiles obtained from the literature. Additionally, an in-house batch reactor experimental facility was created, and the decomposition products were analyzed at 4 atm and in the temperature range of 873-1273 K, and the model was compared to the new experimental data. The model can be used to design new reactors which optimize carbon black and hydrogen production.