A multiple stage apparatus and process using aerodynamic reactors and aero-coalescers in sequence for the selective capture and removal of purified carbon dioxide gas, the sequential capture and removal of mercury, metal and particulate aerosols by a recycling chemical generation-regeneration system using alkali metal chloride solution following multiple oxidations of mercury vapor, and nitric oxide in sequence, selective capture and removal of sulfur dioxide and nitrogen dioxide by two stage absorption by a recycling chemical generation-regeneration system using alkali metal hydroxide-carbonate-bicarbonate solution together with sequential oxidation to alkali metal sulfate and alkali metal nitrate compounds through evaporation and crystallization. Carbon dioxide capture and recovery is achieved in sequence by selective thermal decarbonation from an alkaline liquid followed by recovery as a purified gas stream.