Separating a mixture of CO2 and H2S into two products through distillation is both difficult and complicated because of similar relative volatility between the two gasses, particularly when a CO2 concentration exceeds 80%. Therefore, the separation process can involve many separating stages. However, adding a solvent (agent) to the distillation column during the separation process makes this procedure easier.In this study, different solvents (ethylbenzene, o-xylene, m-xylene, and toluene) and operating conditions (temperature, pressure, and reflux ratio) for separating CO2 from H2S have been simulated through distillation using Aspen HYSYS software. Furthermore, four different aromatic compounds (solvents) for different concentrations (from 0 to 40mol%) have been evaluated to increase the CO2/H2S relative volatility, reducing the quantity of the solvent required and energy consumption.m-xylene was found to be the best solvent for separating CO2 from H2S because of the significant effect on relative volatility, the low quantity required for high CO2 recovery, and the low energy for generating the solvent.