More than 85,000 vessels compose the world’s merchant fleet. Their continued expansion brings with it gaseous and particulate air pollutant emissions. Abt Associates is supporting the United States Army Corps of Engineers in developing an Excel-based model to estimate vessel emissions, with an emphasis on deep-draft or ocean-going vessels.

The Excel-based tool contains two modules:

The first module estimates fuel consumption based on varying operating conditions over the entire voyage for different vessel types – such as containerships, liquid tankers, bulk carriers, LNG tankers, LPG tankers, general cargo, car carrier, and refrigerated.

The operating conditions accounted for in the model include:

• Whether the ship is using its main or auxiliary engine;
• The type of engine, fuel, and load on the engine;
• Whether the ship is operating inside or outside Emission Control Areas; and
• Installed emission controls.

The second module uses the outputs of the fuel consumption module to estimate air pollutant emissions, including greenhouse gases (CO, CO2, NOx, SOx CH4, NH3, PM10, PM2.5, ROG, BC, and O2). The model estimates cumulative emissions by aggregating segment specific emissions for each voyage.