Modelling of an Oil Shale Combustion Reactor: Particle Model Effects in an Idealized Fluidized Bed

Abstract

A mathematical model has been developed to investigate the behavior of fluidized-bed reactors used for the combustion of retorted shale particles. The model formulation consists of conversion distribution functions and mass and energy balances describing the physicochemical processes taking place inside the reactor. The intraparticle interactions between the reaction-diffusion processes and the evolution of the shale matrix are incorporated into the overall model by considering single-particle models of varying degrees of complexity. The results elucidate the influence of several operating conditions and key parameters on the general behavior of the system. The simulations have shown that the predictions of the heterogeneous and pseudohomogeneous models may differ considerably in the multiplicity region. It is shown that the role played by the calcite and gasification reactions is significant at high residence limes. The homogeneous reaction was found to have a dramatic effect on the reactor carbon conversion at high reactor pressures.

Key words:

• combustion
• shale
• reaction diffusion
• heterogeneous model

Additional information

Notes on contributors

NEAL R. AMUNDSON

Author to whom correspondence should be addressed.