Key fuel properties of palm oil alkyl esters

Methyl esters of vegetable oils have been successfully evaluated as diesel substitute. In the present study, other alkyl esters, namely ethyl and isopropyl esters of crude palm oil and crude palm stearin were synthesized via chemical transesterification reactions and subsequently evaluated for their fuel properties. Generally, these alkyl esters exhibit higher viscosity (4.4 X 10(-6) m(2)/s-5.2 X 10(-6) m(2)/s) compared to that of petroleum diesel (4.0 X 10(-6) m(2)/s). However, compared to petroleum diesel, these alkyl esters exhibit acceptable gross heat of combustion (39-41 MJ/kg). Originated from renewable origin, the low sulfur content in alkyl esters emits much lower SO2. These alkyl esters are much safer than petroleum diesel in terms of safety for storage and transportation as they possess high flash points. They may find applications in the fuel industry besides utilization as oleochemicals. (c) 2005 Elsevier Ltd. All rights reserved.