Molecular scale modeling of coal and its behavior

This chapter focuses on the study of coal through molecular modeling and simulation. The molecular scale is the appropriate level for gaining a detailed understanding of adsorption mechanisms within nanopores. Experimental investigation of mechanics at this scale is highly limited, and molecular simulation offers a complementary approach to experiments, relying on elementary physical interactions between atoms and molecules. The chapter concerns with so-called classical simulations, which are based on empirical interaction potentials between atoms, as opposed to ab initio simulations. However, such simulations remain valuable in coal research, as they help calibrate the empirical interaction potentials used in classical simulations. Classical simulations are, in turn, limited to studying systems no larger than a few tens of nanometers. Molecular approaches enable quantitative predictions of fluid adsorption, both for pure fluids and mixtures in coal, while also helping to understand and model the unusual poro-mechanical couplings.