Methods and devices for low contamination energy generation

A method for low-contamination generation of energy comprising: (a) forming a gas mixture by mixing a treated gaseous effluent stream and air; (b) introducing the gas mixture and fuel at a given gas to fuel ratio into at least one diesel engine (3); (c) burning the fuel in the diesel engine to generate energy and a flue gas stream comprising particulate matter (PM), and nitrogen oxides (NOx); (d) treating at least a portion of the flue gas stream with an aqueous stream in a cyclone unit (27) comprising a housing defined by a cylindrical peripheral wall (2) and provided with at least one inlet opening (10) for receiving flue gas and at least one inlet opening for receiving fluids thereinto and with at least one swirling means, whereby a treated gaseous effluent stream and an aqueous effluent stream are formed; (e) emitting a portion of the treated gaseous effluent stream to form an emitted portion; (f) using a portion of the treated gaseous effluent stream to form the gas mixture, and (g) repeating steps (a) through (f) multiple times.