A thermo fluid dynamic model of wood particle gasification- and combustion processes

Abstract

In order to qualitatively understand and evaluate the thermo- fluid dynamic situation within a wood gasification reactor, a 1D particle model has been created. The presented tool accounts for the highly in- stationary, kineticand thermo chemical effects, leading to partial gasification and combustion of a wood particle embedded within a packed bed collective. It considers the fluid- dynamic situation within the changing porous bulk structure of the packed bed, its impact on species- and heat transition mechanisms, the energy- and mass balances of wood, coal, pyrolysisgas, wood- gas and off- gas phases, the thermodynamics of locally developing gasification- and combustion reaction equilibria, as well as the presence of the chemical species hydrogen, water, carbon (di-) oxide, methane, oxygen, solid carbon and gaseous, longer chain hydrocarbons from pyrolysis. Model results can be shown to yield very good, qualitative agreement with measurements, found in literature.