Determination of excess-sorptive kinetics and equilibrium loadings of oxy-fuel gas components on solid fuels

An important initial step of a heterogeneous burning reaction is the adsorption of a gaseous component onto the solid material. Since the gas phase composition for Oxy-Fuel-combustion and well-investigated burning processes in air atmospheres is significantly different, there is a variety of thermochemical challenges to be solved. Project A6 explores ad- and desorption phenomena of the used feed- and pyrolysis-gases with the aim to provide data for sorption kinetics and equilibrium loadings.

In well-known carbon burnout models, sorption kinetics are taken into account by using effective diffusion coefficients. Conventionally these coefficients are determined using the parallel pore model. This model requires values for the tortuosity of the solid fuel, which cannot be determined by experimental work and have to be assumed. In contrast to this model, project A6 determines the effective diffusion coefficients by measuring and analysing the sorption process. Providing a comprehensive dataset of effective diffusion coefficients as well as the integration of those parameters into carbon burnout models are the main objectives for the second funding period.