Abstract: The present disclosure relates to a flue gas treatment system (e.g. a multi-pollutant flue gas treatment system) for removal of greenhouse gases such as SO2, NO, NO2, H2S, HCl, water and CO2 as well as heavy metals (e.g. mercury, arsenic, bismuth, cadmium, lead and/or selenium) from the flue gases of fossil-fueled utility and industrial plants by reacting the raw flue gas, firstly, with chlorine in a gas-phase oxidation reaction and recovering the resulting products as marketable products, and then, secondly, treating the cleaned gas, which includes CO2, with a Sabatier reaction to produce a hydrocarbon fuel (e.g. methane). The system also includes an electrolytic unit for electrolyzing HCl to produce hydrogen gas for the Sabatier reaction as well as chlorine gas, which may then be recycled into the reactor.

Abstract: The invention is directed to a process for oxidizing gaseous pollutants in a flue gas stream composed of flue gases, water vapour and one or more gaseous pollutants selected from the group consisting of SO2, NO, NO2, H2S, and mercury vapour, the oxidized form of the pollutants being more readily removable from the flue gas stream by water absorption than the non-oxidized form thereof, comprising: (a) injecting sufficient chlorine in a gaseous form, a liquid form, or as a chlorine water solution, into the flue gas stream while the flue gas stream is at a temperature greater than 100° C.