Technology

Benefits

Limitations

References

Direct Water Injection (DWI)

· Potential reduction of NOx by an amount of 60%

· Can be applied for medium speed marine diesel engine

· Increase the fuel consumption by 2% to achieve the same output

[24] [26] [27]

Exhaust Gas Recirculation (EGR)

· Low operating cost

· Allows significant NOx reduction by an amount of 30%

· Cannot be employed at high loads because it will reduce the peak power output

· Increase the creation of PM

· Drop in engine efficiency

[32]

Miller Cycle

· Increase the efficiency of the DE

· Allows potential reduction of NOx by an amount of 40% - 60%

· High cost engine

· Requires more maintenance

[28] [29] [30]

Scavenge Air Temperature

· Reduce the number and size of exhaust ports

· Allows a potential reduction of NOx by an amount of 60%

· Cylinder head complex

· Requires periodical maintenance

[33]

Selective Catalytic Reduction (SCR)

· Potential reduction of NOx by an amount of 95%

· Relatively simple installation

· May suffer from erosion

· High efficiency turbocharger is required to overcome the pressure drop

· Require space for urea storage and a good surface for installation

[36] [37] [38]