Hybrid optimization model for the kinetic mechanism of a methan reactor

Moreira, R. P. M, Almeida, L. C., Ropelato, K. (ESSS), Bacchi, R. D. A., Passarelli, F. M., Bidart, A. M. F., Quintella Coelho, E. F. A (CENPES-PETROBAS)


The CFD simulation in this paper is coupled with a genetic multi-objective algorithm, the whole application is done in order to obtain a reaction mechanism for steam methane reforming, methane combustion inside a catalytic reactor and for water gas shifts.


The optimization methodology makes it possible for the engineering professional to prevent the tedious task of manually executing analyses in a try-and-error approach and to minimize the total number of experiments, introducing a procedure where numerical simulations are executed without much user intervention. Two objectives, based on least-square difference between numerical and experimental results were applied and 6 kinetic parameters of reaction rate equations of single step methane reforming water gas shift and methane combustion were evaluated as optimizing variables. Due to heat transfer effects between the plates, between the catalyst and the gas mixture, due to the uncertainties regarding the catalyst load, the direct application of the reaction rate obtained from the references could not be applied.


The multipurpose optimization software modeFRONTIER allowed an automatically change of inputs parameters (kinetic constants) in the CFD simulation in order to calculate temperature and methane conversion profiles.