ClassNK is pleased to announce the release of its new Guideline for SCR (Selective Catalytic Reduction) Systems and Reductant Agent Supply Systems. The new guidelines address the strengthening of nitrogen oxide (NOx) emission regulations as stipulated in amendments to Annex VI of the International Convention for the Prevention of Pollution from Ships 1973 (MARPOL) which entered into force on 1 July 2010.

With these amendments to MARPOL requiring 80% reductions in NOx emissions from diesel engines from 2016, a number of new technologies and alternative fuels are currently being investigated for their emission reduction potential. As SCR systems already have a proven track record in Europe as aftertreatment systems, and as even a single SCR unit can independently reduce NOx emissions by more than 80%, these systems are expected to find wide use in the maritime industry in the near future. As with any new maritime technology, however, clear guidelines and safety protocols for installing, maintaining, and certifying these systems are essential to bringing this exciting new technology into practical use.

ClassNK’s new Guidelines for SCR Systems and Reductant Agent Supply Systems have been developed in order to support the industry wide effort to safely implement these systems on commercial vessels. “In developing this guideline, we conducted a study of all relevant equipment, including reductant agent tank arrangements and piping specifications of SCR systems, in order to determine which measures are necessary for the safe operation of such systems” says Yukihito Fujinami, General Manager of ClassNK’s Machinery Rules Development Department. “In addition to summarizing standard design specifications based on the IBC Code, IGC Code and Rules for Cargo Refrigerating Installations, the guideline also provides specific requirements for systems using reduction agents that require safe storage specifications, such as urea and ammonia, and we believe the guidelines will be an incredibly useful tool for manufacturers, shipyards, and owners looking to install such systems on their vessels.”