Reduction of NOx emissions with low viscous biofuel using exhaust gas recirculation technique

Abstract

The demand of biodiesel as an alternate fuel is increasing due to fossil fuel depletion. The two most common types of biofuels are ethanol and biodiesel. In this study, plant species, Lemongrass (LG) (Cymbopogon flexuous) is discussed as a newer source of oil for biodiesel production. The chemical composition of LG was observed with Fourier Transform Infrared Spectroscopy (FT-IR). The properties of LG were found to be closer to that of neat diesel. In-order to enhance the properties of LG, a cetane enhancer namely Pyrogallol (PY), which acts as an anti-oxidant and Diethyl ether (DEE) which is highly volatile and has higher oxygen content was added. Blends LG+PY, LG+DEE and LG+PY+DEE are mixed with diesel and properties were determined. Test fuels are denoted as BE-1 (75% diesel 20% LG and 5% DEE), BE-2 (80% diesel 20% LG and 500ppm of pyrogallol) and BE-3 (75% diesel 20% LG, 5% DEE and 500ppm of pyrogallol) respectively. NOx formation is highly temperature dependant phenomenon and takes place when the temperature in the combustion chamber exceeds 2000k. Therefore, in order to reduce NOx emission in the exhaust, it is necessary to keep peak combustion temperature under control. Recirculating part of the exhaust gas helps in reducing NOx. So, the work was further extended with the application of Exhaust Gas Recirculation system (EGR) as a post treatment system for the reduction of NOx emission.