In December of 2003, the Port Authority of New York and New Jersey (PANYNJ) undertook a project to retrofit the Staten Island Ferry vessel, Alice Austen, with selective catalytic reduction (SCR) and diesel oxidation catalyst (DOC) exhaust aftertreatment. Alice Austen was selected for the first SCR demonstration project as it is one of the fleet’s smallest vessels and it is equipped with four-stroke (as opposed to two-stroke) main engines which exhibit characteristics beneficial for SCR operation, higher exhaust temperatures and lower PM emission rates. The goal of this project was to reduce NOx and PM emissions in the New York City nonattainment area.
M.J. Bradley & Associates acted as technical consultant to the PANYNJ throughout the course of this project, and elected to install a urea-based system, which requires refilling, but achieves significantly higher NOx reductions than other SCR options. Emissions reductions are on the order of 16.5 tons per year NOx, and 0.19 tons per year PM. This project was completed in June of 2006. With a total project cost of $1.2 million, lifetime NOx reductions were achieved at a cost of $7,800/ton.