NOx pollution occurs when nitrogen oxides are released as a gas into the atmosphere during the high-temperature combustion of fossil fuels. NOx molecules interact with volatile organic compounds (VOC) and form ground-level ozone, which is a serious pollutant. In the presence of rain, nitrogen oxides form nitric acid, contributing to the problem of acid rain. Additionally, nitrogen oxide, nitric acid, and ground-level ozone can all readily severe respiratory problems.

The International Maritime Organization’s (IMO) NOx regulations first came into effect in 2000, and the new IMO Tier 3 regulations came into play from the 1st January 2021. Tier III requires a reduction of 80% in NOx emissions compared to the previous values. Tier III control only applies for specified ships while operating in Emission Controlled Area’s (ECA). Outside the ECAs Tier II applies for all engines.

Selective Catalytic Reduction (SCR) is generally considered as the most feasible technology for NOX reduction. Selective catalytic reduction is a means of converting nitrous oxides in the exhaust with the help of a catalyst into molecular nitrogen and water.

The SCR system consists of a NOx-removal catalyst, reactor, ammonia injection system, ammonia dilution system, and ammonia storage and supply tanks. We provide the SCR reactor and mixer, enable the ships to meet IMO Tier III NOx emission standards, and improve operational efficiency.