It requires high energy and cost to separate specific components from alkane + alkene mixtures, especially for mixtures with similar physical properties. Although some studies have reported hydrate-based processes to replace existing separation/recovery technologies in petroleum refining and petrochemical fields, as the latter are too costly due to their high energy consumption, they mainly focused on macroscopic results regarding stability regions at various concentrations of gas mixtures. In this study, three-phase (liquid-vapour-hydrate) equilibria for (CH4 + C2H4) and (C2H6 + C2H4) gas mixtures with various compositions were investigated. 13C solid-state NMR spectroscopy was also used in order to obtain quantitative information of the guest behaviours of mixed components after the hydrate formation. Experimental and calculated results obtained in this study can provide useful information when applying a hydrate-based process to separate or recover a specific component from gas mixtures having similar physical properties such as (C2H6 + C2H4).
