SCR • NOx mass balance • reductant logistics • tank endurance • compliance cost
Marine SCR Urea Consumption & NOx Cost Calculator
Estimate NOx mass entering an SCR system, NOx removed, urea-solution demand, storage endurance and annual compliance cost. Advanced mode separates engine operating segments, Tier-reference limits, dosing reserve, energy/fuel penalty, catalyst replacement and lifecycle cost.
↑Need Tier-reference checks, engine segments, urea tank sizing or catalyst lifecycle cost?Advanced separates operating segments and exposes the assumptions that drive reductant use and annual SCR cost.
NOxBaseline, removed & post-SCR
UreaSolution tonnes & daily demand
CostAnnual & $/t NOx removed
Engine & NOx Basis
Use measured, certified or project-specific engine-out NOx where available. Simple mode is an annual screening calculation, not a certification test.
kW.
% of rated power during SCR operating hours.
Hours relevant to the entered annual screen.
g/kWh before SCR.
% removal while SCR is available.
% of entered operating hours.
Urea & Cost Basis
Mass % pure urea in solution.
kg pure urea / kg NOx removed. Use supplier/certification basis.
Currency / tonne solution.
Annual service, inspection and fixed maintenance allowance.
↑Advanced SCR operating modelBuild NOx and urea demand from multiple engine/load segments. Tier limits are shown as regulatory references only; applicability depends on the engine, ship and operating area.
Regulatory & Reductant Basis
rpm, used only for the selected MARPOL Annex VI Tier reference.
Reference limit only, not an applicability determination.
g/kWh when Custom is selected.
Mass % pure urea.
kg pure urea / kg NOx removed.
% above stoichiometric solution demand.
kg/m³.
m³.
% of gross tank volume.
Engine Operating Segments
Each enabled row creates annual engine work, engine-out NOx, actual SCR-active NOx removal and post-SCR emissions. Segment labels remain screen/export only.
| Use | Engine / segment | Type | Power kW | Load % | Hours/y | NOx g/kWh | SCR active % | Removal % | SFOC g/kWh |
|---|
Energy, Urea & Lifecycle Cost
Currency / t solution.
Currency / t fuel.
% of segment fuel during SCR-active operation.
Average kW while SCR is active.
g/kWh for SCR pumps/heaters/control load.
Service, inspection and routine fixed maintenance.
Installed project cost.
0 disables a scheduled replacement.
Cost in the entered replacement year.
Years.
% nominal planning rate.
Applied to urea, fuel and fixed O&M.
Technical File / Project Readiness
Stress Cases
| Use | Case | Urea price % | NOx factor % | Removal % | SCR availability % |
|---|
ScreenSCR COST BASELINEAnnual NOx and reductant screen.
Annual SCR operating cost$0
Urea plus modeled SCR operating burden.
NOx removed0 t
Post-SCR0 g/kWh
Urea solution0 t
Cost / t NOx$0
Baseline NOx0 tEngine-out annual mass
NOx removed0 tActual modeled removal
Post-SCR NOx0 tAnnual emitted mass
Urea solution0 tAnnual reductant solution
NOx removal0%Mass-based annual reduction
NOx Mass BalanceEngine-out NOx → actual SCR removal → post-SCR NOx.
Engine work0 GWh
Baseline intensity0 g/kWh
Post-SCR intensity0 g/kWh
Reference targetN/A
Urea Consumption & StoragePure urea demand is converted to solution mass using the entered concentration. Advanced adds dosing reserve and tank endurance.
Pure urea0 t/y
Solution / day0 t/d
Usable tankN/A
Tank enduranceN/A
Low storage burdenAdvanced mode adds tank logistics.High storage burden
Annual SCR Cost StackUrea plus modeled fuel/utility burden, fixed O&M and annualized catalyst reserve where applicable.
Urea cost$0
Energy/fuel penalty$0
Fixed O&M$0
Lifecycle PVN/A
Engine Segment NOx ContributionAdvanced mode shows which operating segments create the engine-out NOx and reductant demand.
Urea Price × NOx Demand SensitivityAnnual SCR cost as urea price and engine-out NOx demand move around the base case.
Advanced Stress CasesEditable downside/upside cases recalculate urea demand, post-SCR NOx and annual SCR cost.
Model boundary. This is an operating and cost planning tool. It does not certify compliance, determine Tier applicability, establish an approved dosing map, calculate ammonia slip, replace EIAPP/Technical File requirements, or substitute for engine/SCR maker data and Administration/class procedures.