Selective Catalyatic Conversion

Clean cats pay dividends

Initially NOx legislation was a minor irritant which could increase fuel consumption Š now it is set to have a greater impact on shipping economics.

In many parts of the world there was dissatisfaction with IMO`s proposed 30 per cent cut in NOx emissions, from the 1992 level, by 2000, and its 4.5 per cent sulphur cap. The IMO`s legislation has yet to enter into force and the NOx reductions only apply to newbuildings after 2000, so its effect on the global marine production will at best be minimal for the next decade. Even granting the Baltic Special Area Status and the 1.5 per cent sulphur limit that imposes was felt to be too little, too late, by the Swedish administration.

So Sweden devised its own system of differentiated port and fairway dues which makes vessels producing higher levels of NOx and SOx pay more to visit the country`s ports than an environmentally-friendly ship of similar size. Vessels using low sulphur fuel can qualify for a Skr0.9/grt ($0.12/grt) discount. This discount has persuaded the owners of almost 1,000 ships to sign an undertaking to use low sulphur fuel Š 1 per cent and below for merchant vessels and a maximum of 0.5 per cent for ferries.

Fee reductions for low NOx emissions are on a sliding scale, starting from 12g/kWh, with the biggest discount of Skr1.6/grt ($0.21/grt) available to ships with a weighted emission figure of 2 g/kWh. As extra encouragement for owners to fit NOx reducing equipment, the Swedish authorities will rebate up to 40 per cent of the capital cost over a five year period. This rebate has to be paid from the fees collected when the vessel visits its ports.