US-20260125420-A1 - METHOD AND SYSTEM FOR INCREASING PURITY OF PROTEIN FROM A GRAIN PROTEIN RECOVERY SYSTEM

US20260125420A1US 20260125420 A1US20260125420 A1US 20260125420A1US-20260125420-A1

Abstract

A method and system for increasing the purity of protein from a system that produces protein, such as a high protein meal, from dry milling of grains including, for example, corn and wheat. The purity of the high protein meal, for example, can be increased by back end enzyme treatment of yeast, which has been separated along with protein from whole stillage. The enzyme(s) can breakdown the yeast into its yeast components that can be removed from the protein to provide for an increased purity of a resulting high protein product.

Inventors

David Koziol
Christopher Kempf

Assignees

FLUID QUIP TECHNOLOGIES, LLC

Dates

Publication Date: 20260507
Application Date: 20251029

Claims (20)

1 . A method for increasing the purity of a protein product obtained from a whole stillage byproduct produced in a biochemical production process comprising: separating a whole stillage byproduct into a fiber portion and a filtrate, which includes protein particles and yeast cells; subjecting the filtrate to one or more enzymes to break-up the yeast cells into yeast fragments; separating the enzymatically treated filtrate, including the protein particles and yeast fragments, via density, into a protein portion, including protein particles, and a water soluble solids portion, including yeast fragments and free oil; and drying the protein portion to define a high protein grain meal that includes from 40 wt % protein to 80 wt % protein on a dry basis.
2 . The method of claim 1 further comprising separating the filtrate, via density, into a solids portion, including the protein particles and yeast cells, and a centrate, and subjecting the solids portion to the one or more enzymes to break-up the yeast cells into yeast fragments, and separating the enzymatically treated solids portion, including the protein particles and yeast fragments, via density, into the protein portion, including protein particles, and the water soluble solids portion, including yeast fragments and free oil.
3 . The method of claim 2 wherein the centrate is combined with the enzymatically treated solids portion prior to separating the enzymatically treated solids portion.
4 . The method of claim 1 wherein at least a portion of the one or more enzymes are recovered and recycled from a later step in the method.
5 . The method of claim 1 wherein the one or more enzymes are selected from an amylase, alpha-amylase, glucoamylase, fungal, phytase, protease, cellobiose, cellulase, hemicellulase, xylanase, glucanase, beta-glucanase, transglutaminase, zymolyase, or combinations thereof.
6 . The method of claim 1 further comprising separating the enzymatically treated filtrate, via density, into a solids portion, including the protein particles and yeast fragments, and a centrate, including the one or more enzymes, which are recycled back into the method and reused as at least a portion of the one or more enzymes; and separating the solids portion, including the protein particles and yeast fragments, via density, into a protein portion, including protein particles, and a water soluble solids portion, including yeast fragments and free oil.
7 . The method of claim 6 further comprising separating the centrate, via filtration, into a retentate, which includes residual protein particles and yeast fragments, and a recycled enzyme filtrate, including the one or more enzymes, which are recycled back into the method and reused as at least a portion of the one or more enzymes.
8 . The method of claim 7 wherein the retentate is combined with the solids portion.
9 . The method of claim 7 wherein separating the centrate, via filtration, into a retentate and a recycled enzyme filtrate comprises separating the centrate, via membrane filtration.
10 . The method of claim 9 wherein the membrane filtration includes micro, ultra, or nanofiltration.
11 . The method of claim 1 further comprising, along with subjecting the filtrate to the one or more enzymes, subjecting the filtrate to an acid or base to control pH of the filtrate and/or controlling the temperature of the filtrate.
12 . The method of claim 1 further comprising after separating the enzymatically treated filtrate, separately adding a wash water to the separated protein portion followed by dewatering the protein portion to provide a liquid fraction and a protein wet cake fraction, and drying the protein wet cake fraction to define a high protein grain meal that includes from 40 wt % protein to 60 wt % protein on a dry basis.
13 . The method of claim 12 further comprising utilizing the liquid fraction in a step earlier in the method.
14 . The method of claim 1 further comprising subjecting the water soluble solids portion to evaporation via an evaporator followed by separating free oil from the water soluble solids portion to provide an oil portion.
15 . A method for increasing the purity of a protein product obtained from a whole stillage byproduct produced in a biochemical production process comprising: separating a whole stillage byproduct, via filtration, into a fiber portion and a filtrate, which includes protein particles and yeast cells; separating the filtrate, via density, into a first solids portion, including the protein particles and yeast cells, and a first centrate; subjecting the first solids portion to one or more enzymes to break-up the yeast cells into yeast fragments; separating the enzymatically treated first solids portion, via density, into a second solids portion, including the protein particles and yeast fragments, and a second centrate, including the one or more enzymes, which are recycled back into the method and reused as at least a portion of the one or more enzymes; separating the second solids portion, including the protein particles and yeast fragments, via density, into a protein portion, including protein particles, and a water soluble solids portion, including yeast fragments and free oil; and drying the protein portion to define a high protein grain meal that includes from 40 wt % protein to 80 wt % protein on a dry basis.
16 . The method of claim 15 wherein the one or more enzymes are selected from an amylase, alpha-amylase, glucoamylase, fungal, phytase, protease, cellobiose, cellulase, hemicellulase, xylanase, glucanase, beta-glucanase, transglutaminase, zymolyase, or combinations thereof.
17 . The method of claim 15 further comprising separating the second centrate, via membrane filtration, into a retentate, which includes residual protein particles and yeast fragments, and a recycled enzyme filtrate, including the one or more enzymes, which are recycled back into the method and reused as at least a portion of the one or more enzymes.
18 . The method of claim 15 further comprising, along with subjecting the first solids portion to the one or more enzymes, subjecting the first solids portion to an acid or base to control pH of the first solids portion and/or controlling the temperature of the first solids portion.
19 . The method of claim 15 further comprising after separating the second solids portion, including the protein particles and yeast fragments, via density, into a protein portion, including protein particles, and a water soluble solids portion, including yeast fragments and free oil, separately adding a wash water to the separated protein portion followed by dewatering the protein portion to provide a liquid fraction and a protein wet cake fraction, and drying the protein wet cake fraction to define a high protein meal that includes from 40 wt % protein to 60 wt % protein on a dry basis.
20 . A system for increasing the purity of a protein product obtained from a whole stillage byproduct produced in a biochemical production process comprising: a first apparatus that is configured to receive a whole stillage byproduct produced in a biochemical production process, wherein the first apparatus separates the whole stillage byproduct into a fiber portion and a filtrate, which includes protein particles and yeast cells; an enzyme treatment tank that is situated after the first apparatus and that is configured to receive one or more enzymes and the filtrate from the first apparatus, and whereat the yeast cells in the filtrate are broken-up into yeast fragments via the one or more enzymes; a second apparatus that is situated after the enzyme treatment tank and that is configured to receive the enzymatically treated filtrate from the enzyme treatment tank, wherein the second apparatus separates the enzymatically treated filtrate, including the protein particles and yeast fragments, via density, into a protein portion, including protein particles, and a water soluble solids portion, including yeast fragments and free oil; and a dryer that is situated after the second apparatus and that is configured to receive and dry the protein portion to define a high protein grain meal that includes from 40 wt % protein to 80 wt % protein on a dry basis.

Description

TECHNICAL FIELD The present invention relates to dry grind methods and systems of alcohol production and increasing the purity of protein from systems that separate protein from a whole stillage byproduct in a plant that derives a biochemical, such as alcohol (e.g., ethanol), from grain. BACKGROUND Dry milling ethanol plants generally convert corn and/or other grains into three products, i.e., ethanol, distillers grain oil, and distiller's grains with solubles. A typical grain dry milling process consists of four major steps: grain handling and milling, liquefaction and saccharification, fermentation and distillation, and co-product recovery. Grain handling and milling is the step in which the grain is brought into the plant and ground to promote better conversion of starch to glucose. Liquefaction is the step of converting solids, such as starch, to a flowable liquid producing oligosaccharides and saccharification is where the oligosaccharides are converted into single glucose molecules. Fermentation is the process of yeast or bacteria, or as clostridia, for example, converting glucose into a biofuel or a biochemical/biomolecule, such as ethanol. Distillation is the process of removing the biofuel or biochemical/biomolecule, such as ethanol, from the fermentation product. Co-product recovery is the step in which the grain by-products are de-watered and made ready for market. There are many known chemical and biological conversion processes known in the art that utilize yeast, bacteria, or the like to convert glucose/sugar to other biofuels and biochemical/biomolecule components like ethanol, for example. The recovery of alcohol, e.g., butanol, ethanol (a natural co-product), etc., and other similar compounds, generally begins with the beer (spent fermentation broth) being sent to a distillation system. With distillation, ethanol is typically separated from the rest of the beer through a set of stepwise vaporizations and condensations. The beer less the alcohol extracted through distillation is known as whole stillage, which contains a slurry of the spent grains including grain protein, fiber, oil, minerals, sugars, and fermentation agent. This byproduct is too diluted to be of much value at this point and is further processed to provide the distiller's grains with solubles. In typical processing, when the whole stillage leaves the distillation column, it is generally subjected at the back end of the process to a decanter centrifuge to separate insoluble solids or “wet cake”, which includes mostly fiber, from the liquid or “thin stillage”, which includes, e.g., protein, fine fiber, oil, and amino acids. After separation, the thin stillage moves to evaporators to boil away moisture, leaving a thick syrup that contains the soluble (dissolved) solids. The concentrated syrup is typically mixed with the wet cake, and the mixture may be sold to beef and dairy feedlots as distillers wet grain with solubles (DWGS). Alternatively, the wet cake and concentrated syrup mixture may be dried in a drying process and sold as distillers dried grain with solubles (DDGS). The resulting DDGS generally has a crude protein content of about 29% and is a useful feed for cattle and other ruminants due to its protein and fiber content. In addition, in some processes currently used to produce high protein grain meal, including those that separate protein and yeast cells from fiber and germ fragments of a whole stillage stream, the separated protein (and yeast) meal stream can include a total protein concentration that can be hindered by the inclusion of the yeast in the protein meal stream. That is, the presence of yeast negatively impacts the total concentration of the protein and can prevent any resulting protein grain meal product from achieving higher more desirable protein concentrations. While DDGS and DWGS provide a critical secondary revenue stream that offsets a portion of the overall ethanol production cost, it would be beneficial to provide a method and system where a high protein grain product can be obtained, such as with a more desirable or increased purity level, from the whole stillage to be sold at a higher cost per ton than DDGS or DWGS or than other low/lower purity protein grain products. SUMMARY OF THE INVENTION The present invention is directed to a method and system for increasing the purity of protein from a system that produces protein, such as a high protein meal, from dry milling of grains including, for example, corn and wheat. Here, the purity of a high protein meal, for example, can be increased by enzyme treatment of yeast, which has been separated along with protein from whole stillage. The enzyme(s) can breakdown yeast bodies into its yeast components that can be removed from the protein to provide for an increased purity of a resulting high protein product. In one embodiment, a method for increasing the purity of protein from a whole stillage byproduct from a biochemical process includes separating w