Exhaust emissions of a diesel engine using ethanol-in-palm oil/diesel microemulsion-based biofuels

Abstract

The use of palm oil and diesel blended with ethanol, known as a microemulsion biofuel, is gaining attention as an attractive renewable fuel for engines that may serve as a replacement for fossil-based fuels. The microemulsion biofuels can be formulated from the mixture of palm oil and diesel as the oil phase; ethanol as the polar phase; methyl oleate as the surfactant; alkanols as the cosurfactants. This study investigates the influence of the three cosurfactants on fuel consumption and exhaust gas emissions in a direct-injection (DI) diesel engine. The microemulsion biofuels along with neat diesel fuel, palm oil-diesel blends, and biodiesel-diesel blends were tested in a DI diesel engine at two engine loads without engine modification. The formulated microemulsion biofuels increased fuel consumption and gradually reduced the nitrogen oxides (NOx) emissions and exhaust gas temperature; however, there was no significant difference in their carbon monoxide (CO) emissions when compared to those of diesel. Varying the carbon chain length of the cosurfactant demonstrated that the octanol-microemulsion fuel emitted lower CO and NOx emissions than the butanol-and decanol-microemulsion fuels. Thus, the microemulsion biofuels demonstrated competitive advantages as potential fuels for diesel engines because they reduced exhaust emissions.

Effect of alcohol on the properties of water‐in‐diesel microemulsion fuels

“…Microemulsification technique is known to have been used for reducing the viscosity of vegetable oil. For example, (palm oil)‐diesel microemulsions with methyl oleate, ethanol, and butanol have shown a considerable reduction in viscosity . Even though the viscosities of microemulsions were lower than the volume‐fraction weighted averages, they were within the range of ASTM‐specifications, and therefore would not affect atomization of the fuel in the engine.…”

The Recent Progress of Natural Sources and Manufacturing Process of Biodiesel: A Review

“…The experiment conducted by Charoensaeng et al [79] used butanol, octanol, and decanol as cosurfactant in microemulsion biofuel. The effect of that cosurfactant on fuel consumption and emission was compared as they vary in the carbon chain length.…”

Comprehensive Review on Biodiesel Production from Palm Oil Mill Effluent

“…Charoensaeng et al [47] studied the combustion characteristics of palm-biodiesel blends using ethanol as a microemulsifier, methyl oleate as a surfactant, and alkanols as a cosurfactant. The evaluated microemulsion enhanced the burning of fuel and decreased the NO x emissions and exhaust gas temperature.…”