Can Ammonia Be Used To Enhance the CO2 Sequestration in Methane Hydrates: A Molecular Dynamics Perspective

Abstract

Sequestration of greenhouse gases, like CO2, in methane hydrates reduces both environmental pollution and increases fuel recovery of methane simultaneously. This approach is thermodynamically feasible as a result of the higher stability of carbon dioxide hydrates than methane hydrates. However, a few bottlenecks, like low permeability and the replacement kinetics of CO2 beyond the surface layers of the hydrate, limit this process. Therefore, the objective of this study is to understand this phenomenon at a molecular level by conducting long-scale molecular dynamics simulations for a microsecond. It then tries to verify if the defects caused in the structure with a tertiary molecule, like ammonia, can enhance the process by carrying CO2 beyond the surface layers. Additionally, the impact of ammonia on the methane recovery for the same concentrations of CO2 is also studied. Analysis of properties like hydrogen bonding and changes in the number of cages is conducted, which indicates encouraging results for such an enhancement upon optimizing the concentrations of ammonia.