Urea (as 32.5 % AdBlue solution) consumption for a selective-catalytic-reduction NOx aftertreatment.
Formula
$$ m_\text{urea} = m_{NO_x} \cdot \frac{60}{46} \cdot \text{NSR}, \quad m_\text{AdBlue} = m_\text{urea} / 0.325 $$Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $m_{NO_x}$ | Mass of NOx reduced | kg | derived |
| $NSR$ | N:NO_x molar ratio | - | SCR controller |
| $60 / 46$ | Urea / NO₂ mole ratio | - | stoichiometry |
Sources
- MEPC.76(40) - SCR system requirements.
- ISO 22241 - AdBlue quality.