SCR Systems Installed Aboard Ocean Going Vessels

In 2015, the Environmental Protection Agency began implementing emission regulations for the maritime industry by requiring selective catalytic reductions (SCR) systems and the use of marine urea and diesel exhaust fluid (maritime DEF). Initially, the EPA sought to impact emission levels by focusing on the commercial trucking industry, but later expanded their efforts to include heavy duty equipment such as tractors, combines, and earth movers of various types such as backhoes, dump trucks, cranes, etc. Having now moved from land to sea, commercial water vessels such as barges, freight and cruise liners and ferries must also comply with EPA emission standards for diesel engines and be retrofitted with SCR systems.

Ongoing NOx Emission Reduction

When the regulations were extended to the maritime industry, the goal was to reduce sulfur levels in marine diesel by up to 99% over the period of ten years, ushering in a need for new engine design, the implementation and retrofitting of SCR system technology, and the use of marine urea and maritime DEF. Diesel exhaust fluid, otherwise known as DEF is a non-hazardous aqueous solution of 67.5% deionized water and 32.5% urea. DEF is sprayed into the selective catalytic reduction system of a diesel engine to break down harmful nitrogen oxide emissions. The byproducts of the SCR process are nitrogen and water, considered non-toxic and harmless to the environment. While DEF may be considered a non-toxic substance, when used for maritime applications, it requires special attention in regards to shipping, handling and storage. Marine urea, which is distinct from maritime DEF is a 40% aqueous urea solution combined with 60% deionized water. Depending on where the vessel is located, whether operating along a river corridor, a lake or in the ocean, as well as the quality of diesel fuel being used, different regulations exist around the need to use either maritime DEF or marine urea. It is important to understand environmental the regulations as they pertain to certain types of vessels and the specific location of a vessel, as well as the quality and type of urea reagent required to provide the highest level of performance for an SCR system.

Maritime DEF Storage and Handling

The EPA is especially firm when it comes to fuel or fuel additives being transported over or near water. Maritime DEF and marine urea are no exceptions and must be properly managed to ensure environmental integrity, as well as the integrity of the product with proper storage to ensure maximum efficacy and longevity. For maritime transport, DEF and marine urea must be kept within a proper temperature range and storage conditions must be clean, dry and secure. Heaters may be introduced, but care must be taken to ensure that fluids are kept warm with consistent, evenly distributed heat. Containment must be sealed to prevent contamination from ambient conditions, which may introduce particulates, debris, excess moisture and salt from the marine air.

Maritime DEF for Inland Barges and Additional Waterway Transport

Not all shipping via waterway takes place in the ocean. In the United States, the Mississippi river corridor, for example is a major thoroughfare for the transport of goods and services, as well as for transportation. The Great Lakes region also sees a significant amount of maritime transport via ferries, barges, tug boats and river tankers. Regulation exists for the diesel engines on such watercraft as well, requiring them to comply with SCR technology and the use of maritime DEF and marine urea in an effort to continually reduce NOx emissions from coastal regions.

The Bottom Line

U.S. environmental legislation along with mandates by the International Maritime Organization (IMO) will likely continue to increase in an effort to curb noxious emissions produced from the maritime industry, which impact the air quality in and around coastal communities and ports. Many of these regions are referred to as emission control areas (ECAs) and emission control areas related to nitrogen oxides (NECAs). To impact the air quality in these areas, the maritime industry will be called to continually increase the application and design of SCR systems and the use of maritime DEF and marine urea to reduce NOx emissions both domestically and internationally.

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In a wide range of industrial sectors, SCL is committed to being the number one logistics and solutions provider for the products that protect and optimize the machines that keep our country moving. We pride ourselves on remaining at the forefront of industry trends and technological innovations, and as the market continues to evolve, we are committed to providing extensive product and industry knowledge and total performance satisfaction for our customers. For information on how we can assist your fleet in choosing the optimal products at a competitive price, contact an SCL consultant today.