Method for separating saturated and unsaturated fatty acid esters and use of separated fatty acid esters

Abstract

The present invention provides a composition comprising methyl esters derived from vegetable oils having less than about 3% by weight of saturated fatty acid methyl esters and a cloud point of less than about −30° C. A method for making the lowered cloud point composition is also disclosed in which vegetable derived methyl esters, urea and alcohol are mixed under sufficient heat to form a homogenous mixture. The mixture is then cooled to a temperature where a solid phase and a liquid phase are formed. The solid phase is enriched in saturated fatty acid methyl esters and the liquid phase is enriched in unsaturated fatty acid methyl esters. The solid phase is separated from the liquid phase. Finally, unused urea and methanol are removed from the liquid phase to form a liquid composition having a cloud point of less than about −30° C. and less than about 3% by weight saturated fatty acid methyl esters.

Description

RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 11 / 690,540, filed Mar. 23, 2007, which claims priority to U.S. patent application Ser. No. 11 / 668,865, filed Jan. 30, 2007, now abandoned, which claims priority to U.S. patent application Ser. No. 11 / 068,104, filed Feb. 28, 2005, which claims priority to U.S. Provisional Patent Application Ser. No. 60 / 547,992, filed Feb. 26, 2004, all of which are hereby incorporated by reference in their entirety.BACKGROUND OF THE DISCLOSURE[0002]The present invention generally relates to fatty acid esters, more particularly, to a method for preparation and separation of fatty acid esters. A multitude of energy crises stemming from supply disruption as well as significantly increasing demand for fossil fuels by industrialized nations in the past few decades have spawned motivation for development of alternative fuel sources. Additionally, since there are finite reserves of crude oil from which p...

AI Technical Summary

Benefits of technology

[0047]Embodiments of the present teachings are related to lowering cloud point of a vegetable derived composition h

Problems solved by technology

Biodiesel produced by typical methods suffers from a crystallization phenomenon when temperatures decrease.

The crystallized constituents can clog fuel filters in vehicles using biodiesel and thereby cut off the fuel supply to the engine.

Winterization by itself produces low yields, i.e., a substantial portion of the starting material is lost during the filtration process.

Conversely, solvent based fractionation requires more energy and the solvents are costly, although in many cases they are recovered in solvent recovery schemes.

However, a significant amount of co-crystallization occurs.

Co-crystallization occurs when during the winterization process certain unsaturated components also crystallize and are thus also removed, resulting in high losses of the preferred unsaturated fatty acid methyl esters (FAME).

Additionally, these techniques involve cooling to very low temperatures and require processing times of days.

However, complete removal of saturated methyl esters may not be recommended because doing so would significantly reduce their ignition quality.” P.

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