Development of Advanced Coal Devolatilization and Secondary Pyrolysis Kinetics Models for CFD (and process simulation) Codes Kiran Pandurang Chaudhari Detailed kinetic expressions for the gasification of a wide variety of coals in existing Computational Fluid Dynamics (CFD) codes such as Multiphase Flow with Interphase Exchanges (MFIX) developed by NETL. These expressions describe the fundamental steps taking place in the gasification of coal, namely, coal devolatilization, tar-gas chemistry, soot formation and the heterogeneous and homogeneous gasification reaction along with combustion reactions. For this purpose, the data generated by PC Coal Lab (PCCL) is 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 fluidsolids systems comprising the contents of a gasifier. The implementation of gasification kinetics in MFIX is currently done through a set of subroutines making up the Carbonaceous Chemistry for Continuum Modeling (C 3 M) code. C 3 M 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. This project focuses on the development of a seamless connection between PC Coal Lab and the C 3 M .The interface is designed to allow MFIX to transfer information through C 3 M to PC Coal Lab, run PC Coal Lab with the input data from MFIX, send kinetic information back to C 3 M in a form that allows C 3 M to update and continue the MFIX simulation using updated parameters from PC Coal Lab. Current work is focused on developing similar expressions for biomass devolatilization. In this research PCCL predictions for biomass devolatilization were compared with experimental results and they show a good agreement with experimental results. The algorithm developed is being used to develop a Graphical User Interphase (GUI) at NETL site Morgantown by Phil Nicolletti.

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The U.S. Department of Energy’s National Energy Technology Laboratory has developed a software platform titled Carbonaceous Chemistry for Computational Modeling (C3M) that can be used to seamlessly connect the reaction kinetics typically found in the gasification process to various computational fluid dynamic (CFD) packages, including MFIX, ANSYS-FLUENT, and BARRACUDA, for advanced gasifier simulation. In this study, a pilot-scale transport gasifier was simulated by employing the C3M platform to incorporate various kinetics into the CFD simulation. It was found that appropriate chemical kinetics for gasification reactions are key to the numerical prediction of syngas composition and the kinetics from Niksa Energy Associate’s PC Coal Lab yielded reasonable agreement to the experimental data. Using the C3M platform, different chemistry kinetics for coal devolatilizationgenerated by METC Gasifier Advanced Simulation (MGAS), Niksa Energy Associate’s PC Coal Lab (PCCL), Chemical Percolation Model for Coal Devolatilization (CPD), and Advanced Fuel Research’s Functional-Group, Depolymerization, Vaporization, Cross-linking (FG-DVC)were evaluated for the transport gasifier simulation. Results showed that the effect of devolatilization kinetics on the transport gasifier simulation is considered to be secondary comparing to the char gasification reactions because of the relatively long residence time of coal particles in the system.