Although gasoline or diesel are likely to continue fuelling the internal combustion engines for the near future, there is an increasing concern over the emission of greenhouse gases and other environmental pollutants. Alternative fuels such as biofuels are promising as they are renewable, sustainable, and reduce engine emissions. However, they usually emit a higher amount of nitric oxide (NO) and nitrogen dioxide (NO~2~), collectively known as NO~x~ as they contain high oxygen content. There are several attempts to reduce the NOx emissions from biofuels. There are reports on the exhaust gas recirculation, water fuel emulsion, injection timing retardation, reburn, and using different fuel additives. There is abundant literature on the study of the reduction of NO~x~ from hydrocarbon fuels, but analysis on biofuels is very scarce. In the present paper, an acoustic wave excitation is another efficient method that has been investigated for continuous premixed and diffusion flames. Applying acoustic excitation on a biofuel operated engine generated NO~x~ is investigated with and without LPG reburn using a cross tube. Four biofuels, namely Jatropha, Karanja, Palm and neem oils, are burned in a single-cylinder internal combustion engine (ICE). The ICE exhaust gases is then allowed to pass through a well-insulated cross tube that is equipped by the acoustic wave generator. The laboratory-scale, acoustically enhanced apparatus consists of a vertically oriented long tube with a cross acoustic excitation tube. The exhaust gases produced by ICE is supplied to the bottom entrance of the vertical tube. After that, a trace of liquid petroleum gas (LPG) is injected into the exhaust gas before it passes the acoustic cross tube.  Acoustic waves of variable frequency were passed through the setup using a speaker and amplifier. Gas sampling is obtained from the top of the combustion tube; concentrations of NO~x~ were analyzed in a NO~x~ Analyzer. A series of experiments were conducted to investigate the effects of the following three parameters on NO~x~ mitigation: (1) acoustic wave frequency, (2) the LPG reburn, and (3) combination of both acoustic waves and reburn. The combination of acoustic wave excitation and reburn showed the most significant reduction in the NO~x~ concentration. The second-largest NO~x~ reduction was obtained with reburn technology alone. The combination of the acoustic excitation with reburning was found to produce a significant result for NO~x~ reduction at a range of 100-150 Hz for all tested biodiesel fuels. Out of the fuels under consideration, Neem Oil generated the lowest amount of NO~x~ and showed the most substantial reduction in NO~x~.


Investigating Acoustic Excitation and Reburn Interaction on NOx Concentration in Bio-Fuel Engines Exhaust

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

IMECE2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.