A numerical simulation for droplet distribution at the exhaust duct with static mixer and injection location was performed for marine selective catalyst reduction. Through the experiment in this auxiliary marine UREA-SCR system the ammonia slip, pressure drop of SCR system and NOx reduction rate in accordance with space velocity (which of meaning is engine load) was performed. At the experimental condition of step by step and random the ammonia slip of this UREA-SCR system is below about 2ppm and this system is satisfied with the regulations of IMO Tier III.

selective catalyst reduction (SCR), space velocity, specific fuel consumption, NOx reduction, ammonia slip.