Combustion Characteristics of Partially Premixed Prevaporized Palm Methyl Ester and Jet A Fuel Blends

Abstract

Palm methyl ester (PME) is an attractive alternate biofuel produced by the transesterification of palm oil with methanol. This paper is a sequel to our earlier papers on the comparison of the flame structure and emission characteristics of neat PME with those of petroleumderived fuels (No. 2 diesel and neat Jet A). Blends of prevaporized Jet A fuel and PME (25%, 50%, and 75% by volume) were studied in a laminar flame environment at burnerexit equivalence ratios of 2, 3, and 7. The global combustion characteristics including flame length, CO and NO emission indices, radiative heat fraction, and inflame profiles of species concentration (CO, CO2, NO, and O2), temperature, and soot volume concentration were measured. The global CO emission index decreased significantly with the PME content in the blend at an equivalence ratio of 7; a 30% reduction was observed with the addition of 25% PME by volume, and a further reduction of 25% was observed with the addition of another 25% PME. The global NO emission index of the neat PME flame was 35% lower than that of the Jet A flame at an equivalence ratio of 2. The nearburner homogeneous gasphase reaction zone increased in length with the addition of PME at all equivalence ratios. The concentration measurements highlighted the nonmonotonic variation of properties with the volume concentration of PME in the fuel blend. The fuelbound oxygen and hydrogen of PME affected the combustion properties significantly.