SCR Urea Consumption

Urea (as 32.5 % AdBlue solution) consumption for a selective-catalytic-reduction NOx aftertreatment.

EmissionsSCR

Engine powerkWOperating hourshEngine-out NOxg/kWhTarget tailpipe NOx (Tier III)g/kWhN:S ratio - Moles of NH₃ per mole of NOx reduced. 1.0 stoichiometric; 1.05 to avoid slip.

NOx reduced

106.00kg

Pure urea

145.17kg

AdBlue (32.5 %)

446.69kg

Formula, assumptions, and limits

60/46 is the molar mass ratio of urea (60.06) to NO₂ (46.01). AdBlue is 32.5 % urea in demineralised water per ISO 22241. Typical AdBlue consumption ~5 % of fuel mass on Tier III compliance for residual-fuel engines.

Symbol legend

Meaning	Unit	Source
Mass of NOx reduced	kg	derived
N:NO_x molar ratio	-	SCR controller
Urea / NO₂ mole ratio	-	stoichiometry