Process to improve protein recovery in stillage processing streams

Patent metadata

Field	Value
Publication number	US-12264302-B2
Application number	US-202117166094-A
Country	US
Kind code	B2
Filing date	Feb 3, 2021
Priority date	Feb 14, 2020
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

Provided is a method of processing stillage from an ethanol production process. The method comprises treating stillage comprising oil, protein, and water upstream of a separation, concentration or evaporation step with at least one organic coagulant and at least one flocculant, thereby forming treated thin stillage comprising solids which include at least a portion of the oil and protein; and clarifying the treated stillage via a solid/liquid separation process thereby forming clarified stillage and a separated solids phase comprising at least a portion of the protein from the stillage.

First claim

The invention claimed is:

1. A method of recovering protein from stillage produced in an ethanol production process, the method comprising:
treating stillage comprising oil, protein, and water upstream of a separation, concentration or evaporation step with about 50 ppm to about 500 ppm of a coagulant comprising poly(diallyldimethylammonium chloride) (polyDADMAC), epichlorohydrin-diethylamine, or a combination thereof, and about 50 ppm to about 500 ppm of a polymer comprising a monomer unit derived from a monomer selected from 2-acrylamido-2-methylpropane sulfonic acid (“AMPS”), 2-acrylamido-2-methylbutane sulfonic acid (“AMBS”), [2-methyl-2-[(1-oxo-2-propenyl)amino |propyl]-phosphonic acid, methacrylic acid, acrylic acid, salts thereof, and combinations thereof, to produce a treated stillage comprising solids which include at least a portion of the oil and protein; and subjecting the treated stillage to a solid/liquid separation process, to produce a clarified stillage comprising a clarified aqueous phase and a separated solids phase, wherein the separated solids phase comprises at least a portion of the protein from the stillage,
wherein the stillage is whole stillage or thin stillage and the separated solids phase is in the form of a float layer and
the method further comprising separating at least a portion of the oil from the float layer to produce a de-oiled float layer by treating the float layer with an oil recovery agent, comprising a blend of 75-95% castor oil ethoxylate, 5-15% hydrophobic precipitated silica, 10-30% vegetable oil, and <10% propylene glycol.

2. The method of claim 1 , comprising treating the thin stillage with the coagulant and the polymer upstream of the concentration or the evaporation step, to produce a treated thin stillage.

3. The method of claim 1 , further comprising drying the de-oiled float layer to produce distiller dry grain comprising the protein.

4. The method of claim 1 , wherein the solid/liquid separation process comprises dissolved air flotation, induced air flotation, or a combination thereof.

5. The method of claim 1 , wherein the separating at least a portion of the oil from the float layer comprises heating and mechanical processing.

6. An ethanol production process comprising the method of claim 1 , wherein the ethanol production process is an ethanol biofuel process, a spirits distillery process, or a brewery process.

7. The method of claim 1 , further comprising drying the separated solids phase to produce dried grains.

Assignees

• Ecolab Usa Inc

Inventors

• Xiao Lan

Classifications

• C12P7/06

  Ethanol, i.e. non-beverage · CPC title

• C02F2103/32

  from the food or foodstuff industry, e.g. brewery waste waters · CPC title

• C02F2101/38

  containing nitrogen · CPC title

• C02F2101/32

  Hydrocarbons, e.g. oil · CPC title

• C02F1/56

  Macromolecular compounds · CPC title