Summary of advancements in diesel emission control technology.

As seen from the Fig 6.20, the engine technologies have been able to reduce emissions to Euro IV emission levels. The technologies employed progressively included;

• Turbocharging with inter-cooling
• Variable geometry turbocharging
• Improved fuels esp. low sulphur in addition to  low final boiling point and closer control on density, viscosity etc.
• High injection pressures
• Optimization of combustion bowl geometry and air motion
• EGR

Aftertreatment Technology for Euro V and beyond:

The second stage is the exhaust after treatment. In some engine models even to meet Euro IV standards diesel oxidation catalysts and SCR de-NOx catalysts were employed. However, for Euro V and later standards some form of exhaust treatment is almost essential. Most engines would employ:

• Diesel particulate filters:  DPF or  CRT
• de -NOx catalysts: SCR or other types