Combined ReaxFF and Ab Initio MD Simulations of Brown Coal Oxidation and Coal–Water Interactions

Citations Over Time

Abstract

In this manuscript, we use a combination of Car-Parrinello molecular dynamics (CPMD) and ReaxFF reactive molecular dynamics (ReaxFF-MD) simulations to study the brown coal-water interactions and coal oxidation. Our Car-Parrinello molecular dynamics simulation results reveal that hydrogen bonds dominate the water adsorption process, and oxygen-containing functional groups such as carboxyl play an important role in the interaction between brown coal and water. The discrepancy in hydrogen bonds formation between our simulation results by ab initio molecular dynamics (CPMD) and that by ReaxFF-MD indicates that the ReaxFF force field is not capable of accurately describing the diffusive behaviors of water on lignite at low temperatures. The oxidations of brown coal for both fuel rich and fuel lean conditions at various temperatures were investigated using ReaxFF-MD simulations through which the generation rates of major products were obtained. In addition, it was observed that the density decrease significantly enhances the generation of gaseous products due to the entropy gain by reducing system density. Although the ReaxFF-MD simulation of complete coal combustion process is limited to high temperatures, the combined CPMD and ReaxFF-MD simulations allow us to examine the correlation between water adsorption on brown coal and the initial stage of coal oxidation.

Related Papers

• → ReaxFF reactive molecular dynamics simulations to study the interfacial dynamics between defective h-BN nanosheets and water nanodroplets(2021)84 cited
• → ReaxFF reactive force field for molecular dynamics simulations of liquid Cu and Zr metals(2019)20 cited
• → Combined ReaxFF and Ab Initio MD Simulations of Brown Coal Oxidation and Coal–Water Interactions(2021)12 cited
• → Interatomic potential parameters for molecular dynamics simulations of RDX using a reactive force field: A validation study(2012)2 cited
• → Comparison of molecular dynamics simulation methods of methane shockwave compression(2020)2 cited