EK Motor Mar 2018 (Q1)

With reference to diesel engine NOx emissions and control:  

(a)  Explain how exhaust gas recirculation and direct water injection reduce engine NOx emissions but result in increased specific CO2 emissions (6)  

(b)  Describe, with the aid of a sketch, a Selective Catalytic Reduction system, stating with reasons, the monitoring and control system (10)

Mar 2018 (Q1)