Various processes have been presented to sweeten natural gas so far. In this study carbon dioxide solubility in diethyl ethanolamine (DEEA) solvent with and without the presence of calcium carbonate nanoparticles at concentrations of 10, 15 and 20 wt% solvent in the pressure range of 5, 10 and 15 bar and titanium oxide, respectively. At concentrations of 0.05 and 0.1 wt% were measured at ambient temperature. The results show that at constant pressure (10 bar) and without the presence of nanoparticles, the solubility for the concentration of 10 to 15 wt% of the solvent increases from 25.8 v/v* to 42.4 v/v*. Increasing the pressure also increases the solubility. For a constant concentration (15 wt% of the solvent), the solubility increases from 31.6 v/v* to 36.7 v/v* by increasing the pressure from 10 to 15 times. However, increasing the concentration of nanoparticles has little effect on increasing solubility. So that for the constant concentration of solvent (10%) and constant pressure (15 bar) the solubility of carbon dioxide for the nanoparticles increases from 0 to 0.1 wt% from 32.6 v/v* to 36.7 v/v*.