Physical Solubility of Carbon Dioxide in Decane (C10H22) Solvent from a CO2/CH4 System

An investigation of the potential removal of Carbon Dioxide (CO2) from a gas stream containing CO2 and methane (CH4) using n-decane (C10H22) as the physical solvent is presented. Physical absorption has been identified as one of the most effective ways to capture CO2 from natural gas streams as it can handle high pressures and high concentrations of CO2. The study is divided into two parts – the solubility experiment, and a simulation of the process in Aspen HYSYS. The solubility experiments were conducted to predict the solubility of CO2/CH4 at different temperatures and pressures using a high pressure gas solubility cell. The simulation was carried out at different pressures up to 60 bar, for various gas compositions. Two thermodynamic models were selected and analyzed, the PR-EOS and the SRK-EOS. Subsequently, the data obtained was used to estimate Henry’s constant for CO2. The simulation results for n-decane showed an increase in CO2 capturing capacity at lower temperatures and at higher pressures, which is in agreement with Henry’s law, and the absorption capacity was found to be selectively higher for CO2 than for CH4. Based on the experiment results; there was more absorption of CO2 and CH4 at lower temperatures and at a higher pressure, and that the absorption was selectively higher for CO2 than it was for CH4. Therefore, the simulation and the solubility experiment findings show that n-decane is a potential candidate as a physical solvent for the application of the removal of CO2 from natural gas.