The specific technological processes occurring in energy systems, the chemical and petrochemical plants release in the environment the waste fluids containing the important fraction of pollutant components (vapours, CO2; SO2, COV etc). A very hard task in the conception of these systems consists to find the adequate layout processes having a high technological efficiency and to produce the low pollution of the surroundings.This paper analyses the ways for an adequate energy recovery system with the capture of pollutant components, especially vapours and CO2. In aim to reduce the negative impact on the environment in the paper is proposed a heat recovery with compression – condensing – expansion system. On this way the vapour fraction from initial waste gas reduces drastically and the secondary effects too (acid rains, corrosion, etc). Also, a partial reduction, of the CO2 is realised by the absorbtion/desorbtion processes. The paper presents the particularities of the proposed system and the amount of heat and compounds recovered from the gas-vapour mixture and the thermal efficiency of this. The proposed system may be easy used for the retrofitting of the actual plants.