Mathematical modeling of lignite combustion in a bed: A one-dimensional approach

Thermal plant design and choice of suitable technology requires the understanding of the fuel thermo-chemical properties. The reactions that consist of different phases may be approached in two ways. One is to determine the kinetics of each individual reaction and its interaction with the environment. The other method is to use an integrated approach, when, based on the results, the summary formula for the behaviour of combustible matter is obtained. This is an empirical approach. Despite possible objections, particularly regarding its accuracy, the narrow range of applicability, etc., the attractiveness of this procedure is evident due to direct results, simplicity and far lower costs to the experiment. That is the reason why this paper focuses on determining the kinetic parameters of the integrated model of group reactions that are part of the combustion of lignite at low temperatures. The paper develops a simple mathematical model of the combustion process for lignite in bed which is then confirmed by modelling the experimental results.