US 12,264,302 B2
Process to improve protein recovery in stillage processing streams
Lan Xiao, Naperville, IL (US)
Assigned to Ecolab USA Inc., St. Paul, MN (US)
Filed by Ecolab USA Inc., St. Paul, MN (US)
Filed on Feb. 3, 2021, as Appl. No. 17/166,094.
Claims priority of provisional application 62/976,921, filed on Feb. 14, 2020.
Prior Publication US 2021/0253984 A1, Aug. 19, 2021
Int. Cl. C12F 3/10 (2006.01); A23K 10/38 (2016.01); B01D 21/00 (2006.01); B01D 21/01 (2006.01); C02F 1/24 (2023.01); C02F 1/56 (2023.01); C02F 101/32 (2006.01); C02F 101/38 (2006.01); C02F 103/32 (2006.01); C12P 7/06 (2006.01)
CPC C12F 3/10 (2013.01) [A23K 10/38 (2016.05); B01D 21/0084 (2013.01); B01D 21/01 (2013.01); C02F 1/24 (2013.01); C02F 1/56 (2013.01); C12P 7/06 (2013.01); C02F 2101/32 (2013.01); C02F 2101/38 (2013.01); C02F 2103/32 (2013.01)] 7 Claims
 
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.