Green shipping: Marine engine pollution abatement using a combined catalyst/seawater scrubber system. 1. Effect of catalyst

A marine engine pollution abatement system was constructed and tested on a 1.5 MW auxiliary marine engine. The integrated system, designed to abate all of the currently legislated emissions from marine engines, consisted of a monolithic Pt/Al2O3 oxidation catalyst and a seawater scrubber, both of suitable dimensions for the engine size. The test results obtained showed the general validity of the approach adopted, as significant abatement of emissions was achieved. However, under the conditions used, the system showed some limitations with regard to the sulphur content of the fuel. On the basis of the results obtained, the system can be used with fuel sulphur content of up to 0.4%, while problems were encountered when a fuel with a sulphur content of 2.0% was used. Whereas the catalytic section operated satisfactorily, fine tuning of the scrubber operating conditions is necessary to improve abatement of NOx and increase the range of fuel sulphur which can be used with the system.