NYK bulker installs catalytic converter
NYK Line said it has begun shipboard tests of selective catalytic reduction nitrogen oxide removal (SCR NOx) equipment installed on a new bulk coal carrier, Initial Salute. The ship was built by Oshima Shipbuilding.
Shipboard trials of the equipment were conducted, and once it was verified that the equipment met the Tier III nitrous oxide emission controls stipulated by the International Maritime Organization, it was decided to leave the equipment in place to collect more data through tests to be conducted during actual operational voyages.
NYK noted the initial, or tier 1 IMO nitrous oxide regulations came into effect in 2005 and that strengthened Tier II controls came into force last July that aim to decrease nitrous oxide emissions by a further 20 percent. A third tier of regulations for vessels built after 2016 and limited to emission control areas, seeks to reduce nitrous oxide emissions by about 80 percent from the first tier regulations.
NYK said its installation of SCR NOx removal equipment after turbocharging, on board Initial Salute is the world’s first trial on a low-speed marine diesel engine, NYK said.
NYK said it was initially thought that SCR NOx removal equipment would find it difficult to respond to future NOx emission controls because in an atmosphere of low-temperature exhaust gases below 300 degrees Celsius, ammonium hydrogen sulfate generated by the chemical reaction of the sulfur in fuel oil with the ammonia in a reducing agent added to the exhaust “poisons” catalysts. But it said the new SCR NOx removal equipment has been improved to reduce catalyst poisoning to a minimum level by suppressing the sulfur in fuel oil to about 0.1 percent. As a result, in an atmosphere of low-temperature exhaust gases at 250 C after turbocharging, stable denitration effects were observed during a test on land, which led to shipboard tests on an operational vessel with an eye to practical use.
A diagram of the system and additional information can be found here.