<p>The invention relates to a process for treating exhaust gases, preferably flue gases or hot and moist gases from technological processes, a heat pump having a non-azeotropic two-component refrigerant being used. The evaporator arranged in the exhaust gas stream is flushed with some of the condensate arising by collecting it and circulating it. By addition of additives, other toxic gases can be eliminated. The condensation of the refrigerant mixture is carried out in two separate condensors. The more readily boiling refrigerant component is liquefied in a gas-impinged condensor and serves for the secondary heating of the exhaust gas and the second refrigerant component is liquefied in a water-impinged condenser and enables heat to be given off in an external heating circuit.</p>