Abstract
Natural gas hydrates have been recognized as a promising and sustainable future energy resource.
Deep eutectic solvents (DESs) belong to a family of environmentally friendly and green solvents that have attracted significant attention for hydrate-related applications.
The primary focus of this research is the assessment of green solvents, particularly terpene-based compounds and DESs, for gas hydrate inhibition.
The formation, dissociation, and flow characteristics of gas hydrates in the presence of DESs is currently investigated using the isochoric pressure search method.
This study experimentally evaluates the effectiveness of two DESs, namely choline chloride + 1,4- butanediol (DES1) and choline chloride + 1,3-butanediol (DES2), prepared at a 1:3 molar ratio, in suppressing gas hydrate formation for carbon dioxide (CO₂), methane (CH₄), and a 50:50 CO₂-CH₄ gas mixture.
This are new DESs and there is no hydrate dissociation data available. Hydrate inhibition performance were assessed at various concentrations ranging from 5 to 20 wt%. The primary experimental results provide new insights into the hydrate suppression capabilities of these novel DES systems.
In addition, there is currently a lack of Cubic-Plus-Association (CPA) equation of state parameters for these DES- containing hydrate systems.
Therefore, this study will develop and apply a thermodynamic modelling framework based on the CPA equation of state coupled with the Soave-Redlich-Kwong (SRK) approach to predict hydrate phase equilibria and represent experimental observations.
Furthermore, the Clausius-Clapeyron equation is employed to evaluate the energy requirements associated with hydrate dissociation, and the molar enthalpies of hydrate dissociation were determined using the experimentally measured phase equilibrium data.
The outcomes of this research are expected to contribute to the development of environmentally sustainable hydrate inhibitors and provide valuable thermodynamic parameters and modelling approaches for predicting hydrate behaviour in DES-containing systems involving CH₄, CO₂, and mixed-gas hydrates.