Flue gas cleaning approach based on jet reactor prototype research

Abstract

The motivations for developing innovative jet ejector scrubbers, which meet the contemporary requirements for reducing sulfur oxide emissions in marine engineering, are presented in this paper. The proposed jet ejector scrubber was equipped with a cylindrical mixing section. The selected operating conditions enabled the development of a mixing shock process that afforded favourable conditions for sulfur oxide absorption. The first series of experimental investigations were carried out on a laboratory scale for a 40-kW diesel engine equipped with jet ejector scrubbers at a sulfur mass content of 0.35% in the fuel. The tests were conducted for various applied motive nozzles, as well as a nominal mixing section length-to-diameter ratio (L/D) of 25. These tests confirmed the complete reduction of SO2 using the jet reactor, as well as the reduction of other chemical compounds in the exhaust gas without using additional filters, e.g., reduction of heavy metals and transition metals by 85–98% and 71–74%, respectively, and the removal of total organic carbon (TOC) from exhaust gas at a level greater than 46%. The second series of experiments investigated a diesel engine with a maximum power of 250 kW under marine operating conditions. In this case, the effect of the mixing section length was tested. For fuels with 1.0% and 1.5% sulfur mass contents, full reduction of sulfur oxides was obtained for various loads of the engine. A maximum SO2/CO2 ratio of 0.18 was obtained for the ejector with an L/D of 25 and an engine load of 200 kW. However, this is significantly lower than the required limit of 4.3 according to the IMO.