NOVELTY - Treatment of greenhouse gases contained in a polluting flue gas, which is emitted as a result of combusting a fuel and utilization of the treated gases to produce useful products includes pyrolyzing coal to produce a volatile material and a bed of hot char; combusting a fuel to release energy while producing a polluting flue gas containing greenhouse gases; and passing the polluting flue gas through the bed of hot char to reduce oxide(s) contained in the polluting flue gas, resulting in the treatment of the oxide and obtaining a non-polluting gas.    USE - Treatment of greenhouse gases contained in a polluting flue gas, which is emitted as a result of combusting a fuel and utilization of the treated gases to produce useful products i.e. syngas, which is suitable to make into a chemical, which is converted to methanol that is converted into a transport fuel, such as gasoline, and carbon monoxide used as chemical to make fertilizer i.e. oxamide or fuel to generate electric power (claimed) or thermal power.    ADVANTAGE - The hot char filters the mercury through a portion of the char to prevent it from being emitted into the atmosphere. The method converts valuable by-products in an environmentally acceptable manner; reduces capital investment; and lowers operating costs.    DETAILED DESCRIPTION - Treatment of greenhouse gases contained in a polluting flue gas, which is emitted as a result of combusting a fuel and utilization of the treated gases to produce useful products comprises pyrolyzing coal to produce a volatile material and a bed of hot char; combusting a fuel to release energy while producing a polluting flue gas containing greenhouse gases; passing the polluting flue gas through the bed of hot char to reduce oxide(s) contained in the polluting flue gas, resulting in the treatment of the oxide and obtaining a non-polluting gas; converting the non-polluting gas into a useful by-product; and converting the volatile material into valuable by-product(s). The hot char, which is a reductant, is used to convert sulfur dioxide to elemental sulfur, oxides of nitrogen to elemental nitrogen, and carbon dioxide to carbon monoxide.