Numerical simulation of coal pyrolysis with Tar and Gas products prediction

Abstract

Coal pyrolysis products can vary both in species and composition that are influenced by internal coal properties and process parameters, including temperature and heating rate during the pyrolysis process. In order to accurately predict the composition of the pyrolysis products, a mathematical model with correct formulation of heat transfer inside the coal particle is necessary to be developed. In this report, the inclusion of heat transfer term to the recent development of fragmentation and diffusion (FD) model is discussed and used to determine the coal pyrolysis products in various operating conditions. Derived from the model result, it concludes that the increment of reaction temperature led to higher rate of secondary reactions and suppress the production of tar. Taking the lignite-type coal pyrolysis of Zap North Dakota (average particle radius of 30 µm) as the sample, at temperature of 600°C, 96.4% of primary tar was produced by the primary reaction and diffused outward, while at temperature of 950°C, 49.9% of primary tar undergo secondary reactions.

Assessment of the mathematical modelling of thermophysical properties during the pyrolysis of coking coals

“…From the work of Buczynski [38], the true density data was extrapolated and compared with the other coals, which show almost identical results in their behavior. The density correlation developed by Merrick [25] was widely used by most researchers [39][40][41] for coal pyrolysis.…”