CROSS-REFERENCE TO RELATED APPLICATION

This application is a national phase of International Patent Application No. PCT/US2018/037200 filed Jun. 13, 2018, the entirety of which is incorporated by reference herein.

FIELD OF INVENTION

The disclosed technology generally described hereinafter provides for a composition and method for improved corn oil extraction/separation from syrup streams, and more specifically, a composition and method for using polyglycerol fatty acid esters (PGE) for improving corn oil extraction during the corn milling process, especially in the corn ethanol process.

BACKGROUND OF THE INVENTION

Over the past few decades, ethanol has become increasingly important as an alternative fuel. One advantage to use of ethanol fuel is that it can be produced from corn. Ethanol from corn is produced by either the wet-milling or dry-milling process. During the wet-milling process, the corn kernels are ground, and the main constituents (starch, gluten, germ, and fiber) are separated and the starch is further processed to make ethanol. In dry corn milling, the corn kernels are ground and without additional separation, mixed with water and the mixture is further processed to make ethanol. The residue of the ethanol process is referred to as stillage or whole stillage. Whole stillage from dry corn milling contains a mixture of solids, oil, and water soluble components.

Whole-stillage is further processed into several different by-products. Typically whole stillage is centrifuged to separate most of the solids from the liquid phase. The recovered solids are referred to as distillers grains (DG), and if thermally dried, as dried distillers grains (DDG). Both DG and DDG are utilized as animal feed. The liquid phase is referred to as thin stillage. This stillage is further processed by thermal action to reduce the moisture content from >90% to <60-65%. The evaporated thin stillage is referred as syrup, or condensed corn distillers solubles (CCDS). The syrup contains majority of the corn oil originally present in the feedstock corn for the ethanol process.

Incorporated corn oil is separated from syrup using thermal, mechanical, and/or chemical methods. The primary method for corn oil extraction from syrup is the use of centrifuges. However, centrifugation can only separate the free oil by destabilizing the stable emulsion through coalescence of the dispersed oil droplets. The rest of the oil, bound and trapped, remain with the syrup stream and is not available for sale as a valuable commodity. Therefore, what is needed in the art is a composition and method for improved corn oil separation from syrup streams during the corn ethanol production process.

SUMMARY OF THE INVENTION

The disclosed technology generally described hereinafter provides for a composition and method for improved corn oil extraction/separation from syrup streams. According to one aspect of the disclosed technology, an oil separation treatment composition is provided, the composition comprising a process stream mixture from a corn to ethanol process, and one or more polyglycerol esters of fatty acids (PGE) or mixture of PGE.

In some embodiments, the process stream mixture is present in a whole stillage process stream, a thin stillage process stream, an evaporator, a syrup stream, or at any time after the distillation stage but prior to the oil separation process.

In some embodiments, the PGE is a member or members selected from the group consisting of polyglycerol-3-monooleate, polyglycerol-3-dioleate, polyglycerol-3-monostearate, polyglycerol-6-distearate, polyglycerol-10-caprylate/caprate, polyglycerol-10-dipalmitate, polyglycerol-10-monostearate, polyglycerol-10-monooleate, polyglycerol-10-dioleate, polyglycerol-10-tetraoleate or polyglycerol-10-decaoleate.

In some embodiments, the PGE is non-toxic and digestible. In some embodiments, the PGE is polyglycerol-3-monooleate. In some embodiments, the PGE is a blend of polyglycerol-3-monooleate, polyglycerol-10-monooleate and polyglycerol-10-dioleate. In some embodiments, the PGE is a blend of polyglycerol-10-monooleate and polyglycerol-10-dioleate.

In some embodiments, about 50 ppm to about 1000 ppm of the oil separation treatment composition is added to the process stream based upon one million parts of the process stream mixture. In some embodiments, the oil separation treatment composition has an HLB of about 5 to about 15. In some embodiments, the oil separation treatment composition has an HLB of about 6 to about 12.

In yet another aspect of the disclosed technology, a method for recovering oil in a corn to ethanol process wherein oil and solids are present in a process stream mixture is provided, wherein the method comprises adding to the process stream mixture an oil separation treatment, the oil separation treatment comprises polyglycerol esters of fatty acids (PGE) or mixture of PGE.

In some embodiments of the present method, the PGE is a member or members selected from the group consisting of polyglycerol-3-monooleate, polyglycerol-3-dioleate, polyglycerol-3-monostearate, polyglycerol-6-distearate, polyglycerol-10-caprylate/caprate, polyglycerol-10-dipalmitate, polyglycerol-10-monostearate, polyglycerol-10-monooleate, polyglycerol-10-dioleate, polyglycerol-10-tetraoleate or polyglycerol-10-decaoleate.

In some embodiments of the present method, the PGE is polyglycerol-3-monooleate. In some embodiments of the present method, the PGE is a blend of polyglycerol-3-monooleate, polyglycerol-10-monooleate and polyglycerol-10-dioleate. In some embodiments of the present method, the PGE is a blend of polyglycerol-10-monooleate and polyglycerol-10-dioleate.

In some embodiments of the present method, about 50 ppm to about 1000 ppm of the oil separation treatment composition is added to the process stream based upon one million parts of the process stream mixture.

In some embodiments of the present method, the process stream mixture is present in a whole stillage process stream, a thin stillage process stream, an evaporator, a syrup stream, or any time after the distillation stage but prior to the oil separation process.

In some embodiments of the present method, the oil separation process further includes centrifuges, decanters, settling-tanks, clarifiers, filters, dissolved or induced air flotation devices, and any other thermal or mechanical device that separates the corn oil from the process stream mixture. In some embodiments of the present method, the PGE is non-toxic and digestible.

