Exam Question

Selective catalytic Reactors (SCR) are being extensively used in marine diesel engines for the compliance of Tier-III NOx emission requirements. Explain various types of SCRs in use with particular focus on the following: (16)

(a) High-Pressure SCRs (HPSCR) vs Low-Pressure SCRs (LPSCR)

(b) SCRs with static mixers

(c) SCRs installed upstream the turbocharger(s) Vs downstream turbochargers.