Computational Simulation of Thermal and Chemical Phenomena for Honeycomb-Structured Catalytic Reforming Reactor

Abstract

A fully coupled numerical model for solid and fluid phases is developed to investigate the performance of catalytic reforming reactors. The transport of mass, momentum, energy and species in a reforming reactor are simultaneously solved using a three dimensional fully implicit unstructured finite volume approach. The nonlinear system of equations is solved by Newton’s method. Eight gas-phase species (CH4, CO2, H2O, N2, O2, CO, OH and H2) are considered for the simulation. The surface chemistry is modeled by detailed reaction mechanisms including 38 heterogeneous reactions with 20 surface-adsorbed species for rhodium catalyst and solved using the mean-field approximation model to obtain the surface convergence and reaction rates. The numerical results are compared with the experimental data and good agreement is observed. The simulation is performed for two different honeycomb-structured reactors. The governing equations for fluid and solid regions of the monolith are simultaneously solved with considering the catalytic combustion at their interface. The performance of the reforming reactor is numerically studied.

Computational optimization and sensitivity analysis of fuel reformer

“…Applying the chain rule yields: (13) At convergence the residual and therefore the total differential are zero, that is 0, and therefore the above may be solved for the sensitivity of the conserved variables as: 12 (14) In this linear system the Jacobian and sensitivity matrices, ∂R/∂Q and ∂R/∂β, are evaluated using the CTSE method. Applying the chain rule to the cost function, assuming in general that this function has both explicit and implicit dependencies on the design variables, yields: (15) The linearization of the cost function can be evaluated analytically or using the CTSE method. Direct differentiation requires the solution to a linear system of equations for each design variable and, thus, provides an efficient method when the number of design variables is relatively small.…”

“…The catalytic partial oxidation (CPOX) of methane over a honeycomb reactor was numerically studied by Hettel et al (2015) [13], where OpenFOAM and DETCHEM [14] where coupled to model a large-scale COPX reactor. Raoufi et al (2016) [15] developed a fully coupled numerical model to investigate the catalytic partial oxidation of methane over a honeycomb-structured Rh/Al2O3 coated catalyst. In that work, the governing equations for fluid and solid regions of the monolithic reactor are solved simultaneously.…”