A binary liquid mixture system of 2-methylimidazole and ethylene glycol was used to remove carbon dioxide (CO2) from natural gas at room temperature. The measurement on absorption capacity of methane (CH4) and CO2 in this system shows the CO2 solubility about 0.87 mol·L-1 at 0.1 MPa

which is higher than that in most ionic liquids under the same condition

and the absorption capacity of CO2 was greater than that of CH4. Further experimental results demonstrate that the liquid mixture could effectively separate CO2/CH4 gas mixture and could be regenerated and reused. After several cycles of absorption/desorption operations

the absorption capability was found barely changed

indicating good stability and application prospective of this binary system.