1.5-2.5 yuan/kg. The treatment cost of chemical waste gas is 1.5-2.5 yuan/kg, that is, the comprehensive cost (operating cost+depreciation cost of treatment system) of recovering solvent per kg is about 1.5-2.5 yuan. Chemical waste gas refers to toxic and harmful gases emitted by chemical plants in chemical production. Chemical waste gas often contains a variety of pollutants with complex physical and chemical properties and different toxicity, which seriously pollutes the environment.