Solubility of Natural Gas Components in Hybrid Solvents of 2-(2-aminoethoxy)ethanol +1-Methylpyrrolidin-2-One/Water

The absorption of hydrocarbons into the solvent during the gas-sweetening process is undesirable since this is a fuel source. To address this issue and improve the process design and efficiency, it is important to have a comprehensive understanding of the solubility characteristics of hydrocarbons. Such knowledge plays a crucial role in optimizing the gas-sweetening process and improving the overall production efficiency. The solubilities of methane and ethane in solvent mixtures of diglycolamine, n-methyl-2-pyrrolidone, and water with amine mass fractions of 0.3 and 0.5 were investigated via the static synthetic technique. The data were measured isothermally at 313.15 K with pressures of up to 2.185 MPa. The experimental data were modeled using either the Soave–Redlich–Kwong or Peng–Robinson equations of state. The experimental results indicate that substituting n-methyl-2-pyrrolidone for water in aqueous diglycolamine solvents results in an undesirable increase in the solubility of key natural gas components. However, compared to the use of pure n-methyl-2-pyrrolidone as in the Purisol process, the results show that incorporating amines into the Purisol process could potentially lead to increased carbon dioxide solubility and decreased methane and ethane solubility.