The reduction of nitrogen oxides (NOx), hydrocarbons and particulate matter emissions has been a large environmental focus for Matson’s engineering department for several years.  Matson’s four newest vessels built at Aker Philadelphia Shipyard, Inc., have modern, fuel efficient diesel engines and include state-of-the-art air emissions reduction technology including slide valves.  The MV Maunalei came equipped with an alpha lubricator system which reduces cylinder oil consumption and has a positive impact on reducing air emissions.  Matson is in the process of installing this system on its three other new ships.  These three vessels have also been retrofitted with fuel oil homogenizers which help to reduce the levels of particulate matter, NOx emissions, and sludge formation.  On the MV R.J. Pfeiffer, which was constructed in 1992, slide valve fuel injectors were installed three years ago to reduce NOx and hydrocarbon emissions.

Matson has also reduced air emissions on its older steamships.  In 2006, the main propulsion boilers on three steamships were retrofitted with internal mix atomizers.  These atomizers optimize combustion, and reduce smoke, particulate matter and NOx emissions.

High efficiency turbo chargers on six ship service diesel generators (SSDGs) have been installed on Matson’s three C-9 vessels.  The exhaust gas driven turbocharger is an efficiency device that utilizes waste heat energy in the exhaust and supplies the engine with pressurized air.  This pressurized and compressed air in the engine intake increases the mean effective pressure in the cylinder without a proportional increase in the maximum pressures in the power cylinder.  The turbo chargers reduce smoke, particulate matter, NOx emissions, and provide greater scavenging (air intake to cylinders) while lowering peak combustion temperatures.  This leads to less fuel used thus maximizing efficiency and creating less pollution. 

Matson is now embarking on an expensive and innovative demonstration project to reduce NOx emissions by at least 90% on an auxiliary engine using selective catalytic reduction (SCR) technology.  As part of this project, the SSDG is being entirely replaced with a more fuel efficient model.  Although SCR has been used for many years at shoreside thermal power plants, its use on marine ocean-going vessels is still uncommon in the United States.  By combining high efficiency SCR with an oxidation catalyst and low sulfur fuel usage, Matson hopes to demonstrate emission reductions of at least 80% compared to using cold ironing during port usage plus the additional benefit of reduction in emissions during voyages to and from ports and along the coast.  The MV Mokihana is being retrofitted with an SCR system designed by Munters of Gothenburg, Sweden.  This system reduces NOx by injecting a small amount of urea and water solution into the hot exhaust gas where it is vaporized and makes contact with the catalyst.  Mixers in the exhaust stream ensure a homogenous flow before entering the SCR converter which consists of different layers of catalyst material placed on elastically mounted shelves.