Development of Coal Devolatilization and Secondary Pyrolysis Kinetics Models for CFD Codes

The objective of this research is to implement detailed kinetic expressions for the gasification of a wide variety of coals in existing CFD codes such as Multiphase Flow with Interphase Exchange (MFIX). These expressions describe the fundamental steps taking place in the gasification of coal, namely, coal devolatilization, tar-gas chemistry, and soot formation. For this purpose, the data generated by PC Coal Lab (licensed by Niksa Energy Associates, LLC) will be used to simulate the gasification of various coals in CFD codes. The CFD code of most interest is MFIX, which is used to describe the hydrodynamics, heat transfer and chemical reactions in the reacting fluid-solids systems comprising the contents of a gasifier. The implementation of coal gasification kinetics in MFIX is currently done through a set of subroutines making up the module Carbonaceous Chemistry for Continuum Modeling (C₃M) code. C ₃M has default gasification kinetics for only a few coals. While on the other hand, PC Coal lab can predict the gasification kinetics for over 2000 coal species. Currently, there is no soot formation mechanism available in MFIX, hence the following mechanism for soot formation was introduced: Tar ↔PAH, Tar→ Soot, PAH →Soot. This project focuses on the development of a seamless connection between PC Coal Lab and the C₃M .The interface will be designed to allow MFIX to transfer information through C₃M to PC Coal Lab, run PC Coal Lab with the input data from MFIX, send kinetic information back to C₃M in a form that allows C₃M to update and continue the MFIX simulation using updated parameters from PC Coal Lab. Current work is focused on developing similar expressions for biomass and these results will also be discussed.