Butoxylation of butyl biodiesel and its impact on cloud point

Abstract

A property of biodiesel that currently limits its use to blends of ≤ 20% is its relatively poor low-temperature properties. Alkoxation of the unsaturated portion of biodiesel offers the potential benefit of improved cloud point without compromising ignition quality or oxidation stability. However, biodiesel was synthesized from canola oil, then epoxidized via the in-situ peroxyacetic acid method with 30% H2O2 at 60°C for 6 hr, with a conversion of 46%. Epoxy butyl biodiesel was alkoxated by acid-catalyzed oxirane ring opening in the presence of butanol. Selectivity for butoxy biodiesel was 85.8% before purification but reduced to 80.6% after purification, corresponding to glycol and keto by-product contents of 3.1 and 5.2%, respectively. The cloud point for butoxy butyl biodiesel increased by 1 K over that measured for butyl biodiesel. The reason for the negative impact on cloud point may be due to the low conversion rate and/or the high by-product content. This is an abstract of a paper presented at the 8th World Congress of Chemical Engineering (Montréal, Quebec, Canada 8/23-27/2009).