Technology | Benefits | Limitations | References |
SCR | · Potential reduction of NOx by an amount of 95% · Relatively simple installation | · Expensive · Catalyst may suffer from erosion caused by flue gases · Requires enough space that can be complex or not feasible for retrofit applications | [38] [39] |
Open loop scrubber | · High Sulphur dioxide (SOx) removal efficiency (up to 98%) · Offers the possibility to use the cheaper bunker fuel than medium or low Sulphur fuel · Reduce the PM by 60% | · Subject to corrosion (seawater) · Requires regular maintenance · Requires additional electric power to run seawater and pumps · Not suitable for vessels operating in fresh water · Increases ship fuel consumption | [34] [35] [36] [37] |
Closed loop scrubber | · Requires storage space to hold waste water and hazardous chemical solutions · High consumption of fresh water · Crews must be trained to manipulate waste water and chemical solutions | [34] [35] [36] [37] | |
Ecospec CSNOx | · Potential reduction of NOx by 65% · Potential reduction of SOx by 99% · Potential reduction of CO2 by 77% · Possibility to continue using heavy fuel oil (HFO) | · High investment cost · Requires additional generator power · Machinery and stacking arrangements: for retrofits, fitting this equipment into existing spaces will be a major challenge | [34] [35] [36] [37] |