| Marine diesel engines are being investigated thoroughly since many engines in these vessels incorporate older technology that may not have been subjected to emissions regulations and hence produce a significant amount of pollution. The Staten Island Ferry Alice Austen was fitted with selective catalytic reduction (SCR) technology to reduce the emissions of oxides of nitrogen (NOx) to offset the dredging equipment emissions from the Harbor Deepening project. Data logging showed a repeatable route of vessel operation including an idle, acceleration, cruise, and maneuvering mode combined with vessel direction. The SCR system provided 34-64% NOx reduction for a round trip with less than 8ppm ammonia slip. Average NOx reductions during cruise mode were 47-75%. Reductions for the cruise mode during urea injection typically exceeded 94%. From modal analysis of onboard testing, idle, acceleration, and maneuvering produced 20% of the NOx. Cruise produced 80% of the NOx. The oxidation catalyst provided 80-95% reduction in carbon monoxide. |
