Many unaware of rules slashing NOx emissions as of 2020

By Robert Wielaard

ALBLASSERDAM – MarQuip, a Dutch specialist in superyacht exhaust systems, rings an alarm bell. It says many builders are unaware of rules slashing nitrogen oxide emissions from yachts that take effect in 2020.

“The year 2021 is a big one for our industry,” says the company.

On Jan. 1, International Maritime Organization rules take effect mandating cuts in NOx emissions of up to 75% on 24m+ boats with a propulsion power of more than 750 kW. Those rules apply to vessels whose keels were laid after Jan. 1, 2021.

NOx is produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures. It is a major source of pollution from cars in cities, but also from yachts as most burn diesel fuel.

As of 2020, the IMO’s Tier III requirements will apply to vessels in Nitrogen Emission Control Areas, i.e. the east and west coasts of Canada and the USA, the US Caribbean and the Baltic and North seas. They target new boats and boats undergoing a refit that involves installing a new, more powerful engine.

The IMO NOx emission rules took effect in 2016 for +500GT vessels. As of Jan. 1, they’ll apply to +24m yachts regardless of GT volume. This is no minor matter. Fitting exhaust gas cleaning gear “is already proving to be quite a challenge on some of the current newbuilds,” says Amsterdam-based SuperYacht Times in its 2019 market survey of the global superyacht industry.

Space and size limitations on future, smaller  boats will  inevitably lead to a mix of techniques and technologies to cut NOx emissions.

“After-treatment units are heavy and bulky,” says Jeroen van der Matten, MarQuip’s general manager of operations. “On larger boats, engine manufacturers make engines with standardized after-treatment. This has the added value of allowing producers to deal with a single supplier, and facilitates certification, servicing and warranty issues.”

Under-500 GT vessels, however, often lack space for standard solutions. Marquip markets custom solutions for small engine rooms combining a silencer and an after-treatment system.

Van der Matten says engine makers tend to deliver engines and after-treatment units in big box. “This may work for tankers or large commercial vessels but is a far cry from what many owners of smaller yachts need,” he says.