Tier 4 i/ Stage III B technologies
The Atlas Copco Portable Energy division has evaluated two technologies that can achieve Tier 4A compliance: Selective Catalytic Reduction (SCR), and the four-step Exhaust Gas Recirculation (EGR) combined with a particulate filter (DPF).
• SCR – higher combustion temperature + SCR
SCR avoids the creation of particulate matter by optimizing combustion. As this results in an increase in NOx, Diesel Exhaust Fluid (DEF, also known as urea) must be added to turn the NOx into harmless nitrogen.
• Cooled EGR – lower combustion temperature + filters
Cooled EGR avoids the formation of NOx by lowering the peak combustion temperature. This process generates more particulate matter, which is then filtered out with a DPF.
Atlas Copco has selected the NOx Reduction System with Clean Emission Module, using EGR/DPF technology, as the best solution.
It offers customers better fuel economy and avoids the need for DEF refills.