Techniques to control IC engine exhaust emissions through modification in fuel and intake air - a review

Engine manufacturers worldwide are forced to reduce diesel engine emissions like PM, CO, NOx, etc. Of late post combustion exhaust after-treatment devices viz. SCR, Selective Catalytic Converter, DPF, LNT, etc. have been in use but have negative impact on the performance of engine. Oxygenates biodiesel and alcohols due to high oxygen content and properties almost comparable to diesel are potentially used by researchers as renewable, reliable and a cost-effective alternative to India's ever increasing future energy demands. However, higher NO(x)emission and stability of biodiesel is a deterrent to its market expansion of these fuels. This paper reviews the literature for emission control of blends of biodiesel, diesel and/or ethanol with additives like antioxidants, nanoparticles, etc., and unaltered diesel fuel viz. EGR, control of engine and air/diesel injection parameters and water injection to the inlet air having emphasis on major pollutants like CO, HC, smoke and NOx emissions.