A Kinetic Assessment of Entrained Flow Gasification Modeling

Abstract

A kinetics assessment of the quasi-global homogeneous and heterogeneous reaction mechanisms is carried out for entrained flow coal gasification modeling. Accurate closure of the chemical source term in gasification modeling necessitates a detailed study of turbulence-chemistry interaction. Toward this end, a time-scale analysis of the homogeneous reactions is discussed using eigenvalue analysis of the reaction rate Jacobian matrix. A singular value decomposition (SVD) of the stoichiometric reaction matrix is performed to assess the behavior of the homogeneous reactions in a reduced species vector space. The significant factors affecting the heterogeneous char reactions are assessed, and the relative importance of bulk diffusion and inherent char kinetics is analyzed in a gasifier. The overall study is carried out using numerical and experimental results of an actual pilot scale gasifier.