Improvement of the process of cleaning exhaust gases of marine diesels from sulfur oxides

The object research is the process of cleaning exhaust gases of marine diesel engines from sulfur oxides, which is associated with the need to fulfill the requirements of Annex VI MARPOL. The research results on reducing emissions of sulfur oxides with exhaust gases of marine diesel engines by additional fuel treatment are presented. It is determined that during the operation of marine diesel engines, it is mandatory to ensure their environmental performance in terms of emissions of harmful substances, including sulfur oxides. Scrubber cleaning is considered as a method that ensures the cleaning of exhaust gases from sulfur-containing components. At the same time, additional fuel treatment using its ultrasonic irradiation is proposed. The results of research carried out on a Bulk Carrier class vessel with deadweight of 82,000 tons are presented. The ship's power plant included the main engine STX-MAN B&W 6S60ME-C and three auxiliary diesel generators Yanmar 6EY18ALW2, the exhaust gases of which were subjected to scrubber cleaning. At the same time, ultrasonic fuel treatment was additionally used in the diesel fuel preparation system. For various operating modes of the ship's power plant, it was found that the relative reduction in emissions of harmful substances when using additional ultrasonic fuel treatment is: for sulfur dioxide SO2 emissions 12.24–24.12%; for the ratio of sulfur dioxide emissions to carbon dioxide emissions SO2/СO2 10.56–22.54%. It is noted that the use of additional ultrasonic treatment is more effective when ships are inside special ecological areas, i. e. in coastal waters. Ultrasonic fuel treatment is possible for any types of liquid marine fuel, regardless of its viscosity, density and component composition.