Abatement of Greenhouse Gas Emissions from Ventilation Air Methane (VAM) Using Ionic Liquids: A Review of Experimental Methods and Modelling Approaches.

Ventilation Air Methane (VAM) refers to the release of fugitive methane (CH₄) emissions into the atmosphere during underground coal mining operations. Growing concerns regarding the greenhouse effects of CH₄ have led to a worldwide effort in developing efficient and cost-effective methods of capturing CH₄. Among these, absorption-based processes, particularly those using Ionic Liquids (ILs) are appealing due to their advantages over conventional methods. In this study, the solubility of CH₄ in various ILs, expressed by Henry's law constant, is first reviewed by examining a wide range of experimental techniques. This is followed by a review of thermodynamic modelling tools such as the extended Henry's law model, extended Pitzer's model, Peng–Robinson (PR) equation of state, and Krichevsky−Kasarnovsky (KK) equation of state as well as computational (Artificial Neural Network) modelling approaches. The comprehensive analysis presented in this paper aims to provide a deeper understanding of the factors that significantly influence the process of interest. Furthermore, the study provides a critical examination of recent advancements and innovations in CH₄ capture by ILs. ILs, in general, have a higher selectivity for methane compared to conventional solvents. This means that ILs can remove methane more effectively from VAM, resulting in a higher purity of the recovered methane. Overall, ILs offer several advantages over conventional solvents for the after treatment of VAM. They are more selective, less volatile, have a wider temperature range, are chemically stable, and can be made from renewable materials. As a result of their many advantages, ILs are becoming increasingly popular for the after treatment of VAM. They offer a more sustainable, efficient, and safe alternative to conventional solvents, and they are likely to continue gaining market share in the coming years. [ABSTRACT FROM AUTHOR]