Recent development in Carbonaceous Chemistry for Computational Modeling (C3M)

The features and capabilities of Carbonaceous Chemistry for Computational Modeling (C3M) were introduced during 2011 International Pittsburgh Coal Conference. Since then, the development of C3M has progressed significantly. The new features of C3M will be discussed in this presentation. Specifically, the new modifications in C3M's kinetic expressions and its CFD compatibility will be discussed. Currently, coal/biomass/petcoke gasification process simulation is linked to computational fluid dynamic (CFD) software programs such as such as Multiphase Flow with Interphase Exchanges (MFIX) developed at NETL, ANSYS-Fluent by ANSYS Inc. and Barracuda by CPFD Software with chemical kinetics and laboratory data. These kinetic expressions describe the fundamental steps taking place in the gasification of coal/petcoke/biomass, namely, devolatilization, tar-gas chemistry, soot formation, and the subsequent heterogeneous and homogeneous gasification and combustion reactions. For this purpose, the kinetic data generated through a number of detailed models such as METC Gasifier Advanced Simulation (MGAS), PC Coal Lab (PCCL), Chemical Percolation Model for Coal Devolatilization (CPD), Solomon's Functional-Group, Depolymerization, Vaporization, Cross-linking (FGDVC) model, or experimental data currently being generated at NETL can be used as input. C3M provides the option to select the fuel type that includes a wide variety of coals, biomass and petcoke. The kinetic packages used to generate the kinetic expressions for various reactions along with fuels are: • Devolatilization: MGAS (coal), PCCL (coal/biomass/petcoke), CPD (coal), FGDVC (coal), experimental data (coal/biomass). • Tar cracking: MGAS (coal), PCCL (coal/petcoke), FGDVC (coal), experimental data (coal/biomass). • Char gasification: MGAS (coal), PCCL (coal/petcoke/biomass), experimental data (coal/biomass). • Char oxidation: MGAS (coal), PCCL (coal/petcoke/biomass). • Soot formation: PCCL (coal/petcoke/biomass), CPD (coal). • Soot oxidation and gasification: PCCL (coal/petcoke/biomass). The C3M graphical user interface (GUI) has been modified to allow users to run the various kinetic models and evaluate graphically the effect different fuels and/or gasifier operating conditions have on gasification kinetics along with the yield of product species. After displaying the data, the C3M GUI allows the user to select kinetic information from a particular kinetic model and then correctly formats the data and seamlessly integrates it into the CFD input files thus allowing the user to run the CFD code without extensive development effort for implementing the governing reactions. Uncertainty Quantification (UQ) analysis for coal gasification process is a unique feature provided by C3M. With the UQ analysis capability, a user can better understand the effect of variations in operating conditions and fuel properties in the product yields and reaction rates. This is achieved through a Monte Carlo type simulation consisting of many sampling runs on the kinetic packages available in C3M by randomly drawing values for input parameters and statistically analyzing the output. The fact that computational cost per sample is very cheap, direct Monte Carlo simulation is possible as opposed to a surrogate model based sampling approach, which is commonly used when the computational cost per sample is high. This UQ work is on-going and will be extended to the CFD packages in the future.