Electron beam treatment of simulated marine diesel exhaust gases

The exhaust gases from marine diesel engines contain high SO₂ and NO_x concentration. The applicability of the electron beam flue gas treatment technology for purification of marine diesel exhaust gases containing high SO₂ and NO_x concentration gases was the main goal of this paper. The study was performed in the laboratory plant with NO_x concentration up to 1700 ppmv and SO₂ concentration up to 1000 ppmv. Such high NO_x and SO₂ concentrations were observed in the exhaust gases from marine high-power diesel engines fuelled with different heavy fuel oils. In the first part of study the simulated exhaust gases were irradiated by the electron beam from accelerator. The simultaneous removal of SO₂ and NO_x were obtained and their removal efficiencies strongly depend on irradiation dose and inlet NO_x concentration. For NOx concentrations above 800 ppmv low removal efficiencies were obtained even if applied high doses. In the second part of study the irradiated gases were directed to the seawater scrubber for further purification. The scrubbing process enhances removal efficiencies of both pollutants. The SO₂ removal efficiencies above 98.5% were obtained with irradiation dose greater than 5.3 kGy. For inlet NO_x concentrations of 1700 ppmv the NO_x removal efficiency about 51% was obtained with dose greater than 8.8 kGy. Methods for further increase of NO_x removal efficiency are presented in the paper.