Urea SCR heavy duty engine NO{sub}x Reduction for Eruo IV

摘要

The different steps of european heavy duty Diesel emissions standards are represented Figure 1, showing that PM emissions must be reduced by 5 from Euro 3 to Euro 4, and NO{sub}x emissions are reduced by 30% at the same time. Refining combustion of the engine to maintain PM level below the Euro 4 standards of 0.02 g/kWh, leads to engine out NO{sub}x level in the range of 8-10 g/kWh as illustrated by figure 2. That means that about 70% of NO{sub}x reduction are required to fulfill NO{sub}x Euro 4 legislation taking into account durability aspects, that can be obtained with high potential aftertreament like SCR. This strategy represents a big advantage for the customer as a reduction of fuel consumption of about 4% (on ESC and ETC cycles) compared to Euro 3 is expected.