Technologies
NTRD technologies focus on on-road heavy duty vehicles, off-road construction equipment, locomotives and marine vessels. Some typical technologies include exhaust gas recirculation (EGR), selective catalytic reduction (SCR), lean NOx catalyst (LNC) and Lean NOx Trap (LNT).
Exhaust Gas Recirculation (EGR)
- 3 proposals received
- Send up to 30% of the exhaust back into the engine
- Many different options with varying results, broadly applicable
- Limitations: Durability, up to 40% reduction in NOx
Selective Catalytic Reduction (SCR)
- 12 proposals received
- Requires ammonia to be injected into the exhaust stream
- 3 different technologies functional in different temperature ranges
- Limitations: Requires UREA, temperature dependence, up to 85% reduction in NOx
Lean NOx Catalyst (LNC)
- 2 proposals received
- Requires fuel to be injected into the exhaust stream
- Requires at least 260ºC for at least 25% of the time
- Limitations: Sulfur sensitive, temperature dependent, up to 25% reduction in NOx
Lean NOx Trap (LNT)
- 2 proposals received
- Chemically absorbs NOx onto a special catalyst
- At set intervals (~60-90 seconds), fuel is injected into the LNT to react with the stored NOx