LAUSR

NOx emission reduction techniques such as fuel additives used in biodiesel-diesel blends and exhaust gas recirculation method in CI engine have been discussed detailed in this paper. The emission characteristics of the various biodiesel-diesel blends have been summarised and discussed and it is observed that the exhaust gas recirculation method is more efficient. NOx emission is reduced upto 25–75% by EGR method with 5–25% EGR rate in the optimised biodiesel fuelled engine. It is also observed that carbon monoxide, hydrocarbons, and smoke are decreased slightly. This is achieved by controlling combustion peak temperature in combustion chamber and oxygen content in the fuel. In most of the cases, NOx emissions are reduced by compromising brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC). The above drawbacks can be overcome by optimising the parameters suitably in CI engine.