Method and system for increasing protein and oil yields from whole stillage produced in an alcohol plant

Abstract

A method for increasing oil and protein yields from a whole stillage byproduct produced in a corn dry-milling process for making alcohol (e.g., ethanol) and / or other biofuels / biochemicals and a system therefor is disclosed. To liberate more oil from the remaining germ fragments in the whole stillage, one or more germ cyclones can be used to separate the germ and / or germ fragments and free corn oil from the whole stillage (or thin stillage). The germ rich light phase stream exiting the germ cyclones can be sent through one or more grind mills, which can reduce the particle size of the germ fragments and liberate additional corn oil therefrom for later recovery. Alternatively, the grain germ fractions may be separated and processed in a manner to separate and / or extract the oil from the germ fractions using other processes in the art.

Description

METHOD AND SYSTEM FOR INCREASING PROTEIN AND OIL YIELDS FROMWHOLE STILLAGE PRODUCED IN AN ALCOHOL PLANTTechnical Field

[0001] The present invention relates generally to grain processing, and more specifically, to a method and system for increasing the yield of protein and oil from a whole stillage byproduct produced in a grain (e.g., corn) processing process for making a biochemical, such as alcohol (e.g., ethanol).Background

[0002] Corn or similar starch-containing grains contain not only starch but also, for example, protein, individual amino acids, fiber, oil, and minerals. The com kernel is typically divided up into three main components. The outer protective layer or pericarp, the endosperm, which is the bulk of the kernel material, and the germ or oil-bearing portion of the kernel. The pericarp contains mostly fiber with a small portion of oil bound in the aleurone layer near the outer seed coat. The endosperm contains homy and floury starch components as well as protein. The protein is mainly storage protein or zein protein. The germ contains the bulk of the kernel oil within oil sacks as well as some proteins and key limiting amino acids, sugar, and minerals. Typically, corn contains about 2.7 to 3.2 lb (dry basis) of germ per bushel of com, and the dry germ has about 50% oil content on a dry basis.

[0003] Grain processing plants, such as dry milling plants, generally convert com and / or other grains into only three products, i.e., ethanol, distillers corn oil, and distiller's grains with solubles. A typical corn dry milling process consists of four major steps: grain handling and milling, liquefaction / cooking and saccharification, fermentation and distillation, and co-product recovery. Grain handling and milling is the step in which the corn is brought into the plant andground to promote better conversion of starch to glucose. Liquefaction is the step of converting solids, such as starch, to a flowable liquid (or slurry stream) producing oligosaccharides while heating (cooking) the slurry, 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, such as ethanol. Distillation is the process of removing the biofuel or biochemical, such as ethanol, from the fermentation product. Co-product recovery is the step in which the com / grains by-products are de-watered and made ready for market. There are many known chemical, mechanical, and biological conversion processes known in the art that utilize yeast, bacteria, or the like to convert glucose to other biofuels and biochemical components like ethanol, for example.

[0004] 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 corn 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.

[0005] 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 slurry can be sent to a centrifuge to separate the oil from the syrup. The oil can be sold as a separate high value product. The oil yield is normally about 0.75 Ib / Bu of com with high free fatty acids content. The free fatty acids content reduces the value of the oil. The de-oil centrifuge only removes less than 50% because the protein and oil make an emulsion, which cannot be satisfactorily separated. Additionally, the oil can be bound within the genn particles, which tends to separate into the wet cake fraction when the whole stillage stream is centrifuged. The concentrated syrup is then 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.

[0006] Various attempts have been made in the dry grinding industry to desirably recover high value co-products, such as oil and protein. Some success has been realized with processes recovering oil after fermentation and from the evaporation stages of the dry mill process. However, the process of mixing and fermentation, coupled with low solids content, emulsifies the oil, and this makes it very difficult to remove. As a result, oil yields have been relatively low. Other attempts have been made to recover oil directly from com but the cost, for example, is too high for commercial use.

[0007] 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 for increasing protein and oil yields from grains and / or grain components used for biochemical and / or biofuel production, such as alcohol production in a com dry-milling process.Summary of the Invention

[0008] The present invention relates to a method and system for increasing protein and oil yields from a whole stillage byproduct produced in a com (or similar carbohydrate-containing grain) dry-milling process for making alcohol (e.g., ethanol) and / or other biofuels / biochemicals. The corn includes protein and oil that can be eventually recovered therefrom as products of the dry-milling process, such as an alcohol dry-milling process.

[0009] To liberate more oil, for example, from the remaining germ fragments in the whole stillage, one or more germ cyclones, as are known in the art, can be used to separate the germ and / or germ fragments and free corn oil from the whole stillage. In another example, to liberate more oil, for example, one or more germ cyclones, as are known in the art, can be used to separate the germ and / or germ fragments and free com oil from the thin stillage. The germ rich light phase stream exiting the top of the germ cyclones can be sent through one or more grind mills, which can reduce the particle size of the germ fragments and liberate additional com oil (as well as protein) therefrom for later recovery. Alternatively, the grain germ fractions may be separated and processed in a manner to separate and / or extract the oil from the germ fractions using other processes known in the ait. To help facilitate the release of more germ and / or germ fragments, and / or grain oil, additives such as a surfactant, flocculant, enzyme, extractant, oil, chemicals, or combinations thereof may be introduced prior to and / or during use of the germ cyclone(s). Surfactants, flocculants, enzymes, extractants, oil, and chemicals can help coagulate the oil and oil bodies together resulting in greater density separation through the germ cyclone, for example. Additionally, these additives can help facilitate oil release from the germ / germ fragments, where proteins can be removed or broken apart to aid further oil / oil body release.

[0010] The milled germ slurry stream may be reintroduced to the whole stillage stream (pre or post the germ cyclone(s)), which ultimately can be subjected to further processing such as a protein and oil recovery process, for example. The existing and / or new equipment in this method can capture this newly liberated oil and protein along with the oil and protein that would have previously been available for recovery thereby increasing total oil and protein yields from the whole stillage.

[0011] In one embodiment, a method for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process includes separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, into a protein and fiber stream and a germ and / or germ fragments stream including free oil, followed by milling the germ and / or germ fragments in the germ and / or germ fragments stream to release additional oil and protein. Next, the milled stream, including the free oil, released oil and protein, and milled germ and / or germ fragments, are combined with the protein and fiber stream, and then the combined stream is separated into a fiber portion, including the milled germ and / or germ fragments, and a protein and oil portion, including the free oil and released oil and protein. Thereafter, the protein and oil portion is separated into an oil portion, including the free and released oil, and a protein portion, including the released protein and the free and released oil is recovered from the oil portion and / or protein, including the released protein, from the protein portion.

[0012] In another embodiment, a method for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process includes separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, into a protein and fiber stream and a germ and / or germ fragments stream including free oil followed by millingthe germ and / or germ fragments in the germ and / or germ fragments stream to release additional oil and protein. Next, the milled stream is dewatered to provide a dewatered solids portion, including the milled germ and / or germ fragments, and a liquid portion, including the free oil and released oil and protein, and then oil is extracted from the dewatered solids portion including the milled germ and / or germ fragments. Thereafter, the liquid portion, including the free oil and released oil and protein, is combined with the protein and fiber stream, and the combined stream separated into a fiber portion and a protein and oil portion, including the free oil and released oil and protein. Then, the protein and oil portion is separated into an oil portion, including the free and released oil, and a protein portion, including the released protein, and the free and released oil recovered from the oil portion and / or protein, including the released protein, from the protein portion.

[0013] In yet another embodiment, a method for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process includes separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, into a protein and fiber stream and a germ and / or germ fragments stream including free oil, followed by milling the germ and / or germ fragments in the germ and / or germ fragments stream to release additional oil and protein. Then, the free and released oil is separated out from the milled germ and / or germ fragments and the protein and fiber stream, which includes oil, is separated into a fiber portion and a protein and oil portion. Thereafter, the protein and oil portion is separated into an oil portion and a protein portion, and the oil is recovered from the oil portion and / or the protein from the protein portion.

[0014] In still another embodiment, system for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process includes a first apparatus thatreceives a whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, wherein the first apparatus separates the whole stillage byproduct into a protein and fiber stream and a germ and / or germ fragments stream including free oil, and a milling device that is situated after the first apparatus and that receives the germ and / or germ fragments stream from the first apparatus, wherein the milling device mills the germ and / or germ fragments to release additional oil and protein. The system further includes a second apparatus that is situated after the first apparatus and the milling device and that receives the protein and fiber stream and the milled stream to define a combined stream, wherein the second apparatus separates the combined stream into a fiber portion, including the milled germ and / or germ fragments, and a protein and oil portion, including the free oil and released oil and protein, and a third apparatus that is situated after the second apparatus and that receives the protein and oil portion, wherein the third apparatus separates the protein and oil portion into an oil portion, including the free and released oil, and a protein portion, including the released protein, whereby the free and released oil from the oil portion and / or protein, including the released protein, from the protein portion can be recovered.Brief Description of the Drawings

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description given below, serve to explain the principles of the invention. Similar reference numerals are used to indicate similar features throughout the various figures of the drawings.

[0016] Fig. 1 is a flow diagram of a prior art dry-milling process and system for producing ethanol and distiller’s grains with solubles;

[0017] Fig. 2 is a flow diagram of a method and system for increasing protein and oil yield from a whole stillage byproduct produced via a corn dry-milling process for making alcohol, e.g., ethanol, in accordance with an embodiment of the invention;

[0018] Fig. 3 is a flow diagram of a method and system for increasing protein and oil yield from a whole stillage byproduct produced via a corn dry-milling process for making alcohol, e.g., ethanol, in accordance with another embodiment of the invention;

[0019] Fig. 4 is a flow diagram of a method and system for increasing protein and oil yield from a whole stillage byproduct produced via a corn dry -milling process for making alcohol, e.g., ethanol, in accordance with another embodiment of the invention;

[0020] Fig. 5 is a flow diagram of additional processing of the fiber portion and protein and oil portion of Figs. 2-4 to recover protein and oil in combination with producing a high protein meal, in accordance with an embodiment of the invention;

[0021] Fig. 6 is a flow diagram of a method and system for increasing protein and oil yield from a whole stillage byproduct produced via a corn dry -milling process for making alcohol, e.g., ethanol, in accordance with another embodiment of the invention; and

[0022] Fig. 7 is a flow diagram of a method and system for increasing protein and oil yield from a whole stillage byproduct produced via a corn dry-milling process for making alcohol, e.g., ethanol, in accordance with another embodiment of the invention.Detailed Description of the Drawings

[0023] The present invention is directed to a method and system for increasing protein and oil yield from a whole stillage byproduct produced in a corn (or similar carbohydrate-containing grain) dry-milling process for making alcohol (e.g., ethanol) and / or other biofuels / biochemicals.In this method and system, which is described in greater detail below, a fractionated germ streamcan be produced, via a germ cyclone(s), from a whole (or thin) stillage byproduct produced in a com or grain dry-milling process for making a biochemical, such as ethanol. In one example, at the back end of the biochemical (e.g., ethanol) process, a high protein meal and an oil rich stream can be produced from a whole stillage byproduct. In general, the method and system can include a milling step that is utilized on the separated germ fragment stream along with additional processing steps to further separate oil and protein from the whole stillage byproduct to increase the oil and protein yield therefrom.

[0024] Fig. 1 shows a flow diagram of a typical dry grind alcohol (e.g., ethanol) production process 10. Although virtually any type and quality of grain, such as but not limited to sorghum, wheat, triticale, barley, rye, tapioca, cassava, potato, peas and other starch and oil containing grains and / or legumes can be used to produce ethanol, for example, the feedstock for this process is typically corn referred to as "No. 2 Yellow Dent Com." Also, as a general reference point, the dry grind method 10 can be divided into a front end and a back end. The part of the method 10 that occurs prior to distillation 24 is considered the "front end," and the part of the method 10 that occurs after distillation 24 is considered the "back end." To that end, the front end of the dry grind process 10 begins with a milling step 12 in which dried whole corn kernels can be passed through hammer mills for grinding / milling into meal or a fine powder. The screen openings in the hammer mills or similar devices typically are of a size 6 / 64 to 9 / 64 inch, or about 2.38 mm to 3.57 mm, but some plants can operate at less than or greater than these screen sizes. The resulting particle distribution yields a very widely spread, bell type curve, which includes particle sizes as small as 45 microns and as large as 2 mm to 3 mm. The majority of the particles tend to be in the range of 500 to 1200 microns, which is the "peak" of the bell curve. Otherscreen openings larger and smaller can be deployed in the hammer mills. Other milling devices such as roller mills or pin mills can also be utilized in the dry grain grinding step.

[0025] After the milling step 12, the ground meal is mixed with cook water and / or thin stillage to create a slurry at the slurry tank 14 and a commercial enzyme called alpha- amylase is typically added (not shown). Creating the slurry at the slurry tank 14 is followed by a liquefaction step 16 whereat the pH can be adjusted to about 4.8 to 5.8 and the temperature maintained between about 50°C to 105°C so as to convert the insoluble starch in the slurry to soluble starch. The stream after the liquefaction step 16 has about 30% dry solids (DS) content, but can range from about 29-36%, with all the components contained in the corn kernels, including starch / sugars, protein, fiber, starch, germ, grit, oil, and salts, for example. Higher solids are achievable, but this requires extensive alpha amylase enzyme to rapidly breakdown the viscosity in the initial liquefaction step. There generally are several types of solids in the liquefaction stream: fiber, germ, and grit.

[0026] Liquefaction 16 may be followed by separate saccharification and fermentation steps, 18 and 20, respectively, although in most commercial dry grind ethanol processes, saccharification and fermentation can occur simultaneously. This single step is referred to in the industry as "Simultaneous Saccharification and Fermentation" (SSF). Both saccharification and SSF can take as long as about 50 to 60 hours. In the saccharification step 18, the liquefied mash is cooled and a commercial enzyme, such as gluco-amylase, is added to hydrolyze the maltodextrins and short-chained oligosaccharides into single glucose sugar molecules. In the fermentation step 20, a common strain of yeast (Saccharomyces cerevisiae)' can be added to metabolize the glucose sugars into ethanol and CO2. Other fermentation agents such as bacteria and clostridia can be utilized to produce other biomolecules / biochemicals. Upon completion,the fermentation mash ("beer") will contain about 17% to 18% ethanol (volume / volume basis), plus soluble and insoluble solids from all the remaining grain components, including fiber, protein, and oil, for example. Yeast can optionally be recycled in a yeast recycling step (not shown) either during the fermentation process or at the very end of the fermentation process. In addition to gluco-amylase, other enzymes can be added to the fermentation step 20 (as well as before or after fermentation), such as but not limited to phytase, protease, cellulase, hemicellulase, xylanase, beta-glucanase, and the like to further enhance the protein and / or oil recovery downstream. Subsequent to the fermentation step 20 is the distillation (and dehydration) step 24, which utilizes a still to recover the alcohol.

[0027] Finally, a centrifugation step 26 involves centrifuging the residuals, i.e., "whole stillage", which includes the non-fermentable grain components (protein, oil, fiber, ash, minerals, etc.) and yeast yielded from the distillation and dehydration step 24 in order to separate the insoluble solids ("wet cake") from the soluble liquid ("thin stillage"). However, some fine insoluble solids and germ fragments can be present in the “thin stillage” stream. The liquid from the centrifuge contains about 5% to 12% DS. The "wet cake" includes fiber, of which there generally are three types: (1) pericarp, with average particle sizes typically about 1 mm to 3 mm; (2) tipcap, with average particle sizes about 500 micron; (3) and fine fiber, with average particle sizes of about 250 microns. There may also be proteins and yeast bodies with a particle size of about 45 microns to about 300 microns. The fiber and other fractions may contain bound protein that is chemically and or physically attached to the fiber and other fraction.

[0028] The thin stillage typically enters evaporators in an evaporation step 28 in order to boil or flash away moisture, leaving a thick syrup which contains the soluble (dissolved) solids(mainly protein and starches / sugars) from the fermentation step 20 (25 to 40% dry solids) alongwith residual oil and fine fiber. The concentrated slurry can be sent to a centrifuge to separate the oil from the syrup in an oil recovery step 29. In one example, the centrifuge used at the oil recovery step 29 can include a stacked disc centrifuge, a solid bowl two or three phase centrifuge, or the like. The oil can be sold as a separate high value product. The oil yield is normally about 0.7 Ib / bu of com with elevated free fatty acids content compared to traditional wet mill com oil. This oil yield recovers only about 1 / 3 of the oil in the com, with part of the oil passing with the symp stream and the remainder being lost with the fiber / wet cake stream.About one-half of the oil inside the com kernel remains inside the germ after the distillation (and dehydration) step 24, which cannot be separated in the typical dry grind process using centrifuges as the oil is bound, not free. The free fatty acids content, which is created when the oil is heated and exposed to oxygen throughout the front and back-end process, reduces the value of the oil. The (de-oil) centrifuge only removes less than 50% because the protein and oil make an emulsion, which cannot be satisfactorily separated without the use of chemicals or added mechanical separation unit operations.

[0029] The syrup, which typically has more than 10% oil, can be mixed with the centrifuged 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 step 30 and sold as Distillers Dried Grain with Solubles (DDGS) to dairy and beef feedlots. This DDGS has all the com and yeast protein and about 67% of the oil in the starting com material. But the value of DDGS is low due to the high percentage of fiber, and in some cases the oil is a hindrance to animal digestion and lactating cow milk quality.

[0030] In accordance with the present invention, Fig. 2 shows an embodiment of a method and system for increasing oil yield, collectively 100, from the whole stillage byproduct such asproduced in a typical corn dry-milling process 10, like that just described in Fig. 1 . While a typical whole stillage byproduct is utilized here, it should be understood that the whole stillage from any com (or similar carbohydrate-containing grain or bean / legume) dry-milling process may be utilized with the same or similar results. Again, the whole stillage byproduct contains a slurry of soluble and insoluble solids, i.e., the spent grains from the distillation and dehydration step 24, which can include protein, amino acids, fiber, and oil, for example, that can be processed in accordance with embodiments of this invention to increase the yield of oil and protein. The recovered oil, which may be further processed, can be sold and / or used as or in, for example, cooking oil, animal feed, renewable diesel feed stock, etc. The recovered protein, which may be recovered as a high protein meal, as further discussed below, may be sold as pig or chicken feed, or further processed, for example.

[0031] With continuing reference to Fig. 2, in one example, the whole stillage byproduct can be piped from the typical com dry mill distillation and dehydration step 24 and subjected to one or more germ cyclones 110, as are known in the art, to separate whole stillage byproduct into a germ and / or germ fragments portion / stream, which includes oil, and a protein and fiber portion slurry / stream. To help facilitate the release of more germ and / or germ fragments, and / or grain oil, additives such as a surfactant, flocculant, enzyme, extractant, oil, chemicals, or combinations thereof may be introduced prior to and / or during use of the germ cyclone(s) 110. Surfactants, flocculants, enzymes, extractants, oil, and chemicals can help coagulate oil and oil bodies together resulting in greater density separation through the germ cyclone, for example.

[0032] A germ cyclone is a hydrocyclone typically used in the corn wet milling industry to separate com germ and germ fragments from a slurry of com kernel fragments produced in the wet milling operation. The germ cyclone 110 utilizes centrifugal and pressure differential typeforces to separate the lighter density germ and / or germ fractions from the remaining spent grain material of the whole stillage by-product. The germ and / or germ fractions contain the majority of the grain oil and thus has a lower density compared to the other grain components, such as fiber, protein, ash, and carbohydrates. The germ cyclone 110 uses pressure from the feeding whole stillage stream to create a centrifuge type flow within the conical shaped cyclone device 110, where lighter, less dense materials (i.e., germ or germ fraction) will tend to gravitate to the top of the conical device and the heavier more dense materials will come out the bottom of the germ cyclone 110. More specifically, the flow into the germ cyclone enters tangentially into a barrel of the cyclone. The centrifugal force of the slurry circling the barrel of the cyclone forces the denser particles of protein and fiber to an outer wall of the cyclone while the less dense germ fragments and free oil droplets collect in a center of the cyclone. The hydraulic flow entering the cyclone displaces the light germ particles and oil and they exit a light phase port in a top center of the cyclone. The denser protein and fiber particles that have been collected near the wall of the cyclone settle due to gravity and exit out a bottom heavy phase port of the cyclone. The germ cyclone device 110 may have a control valve on the discharge of either the overflow (lighter dense flow) or underflow (heavier dense flow) that controls the pressure and flow rate out the device. In addition, although a single germ cyclone 110 is depicted, it should be understood that a plurality of germ cyclones 110 may be situated in-line, either in series and / or parallel. One such suitable germ cyclone is the GS6” model available from Fluid Quip, Inc. of Springfield, Ohio.

[0033] Continuing with the flow from the germ cyclones 110, the overs / lighter, dense material or germ and / or germ fragments stream can then be optionally sent to a paddle screen 120 (or similar solids / liquid separation device) whereat the solids (e.g., germ and / or germ fragments) can be separated from the liquid or centrate portion, which includes the oil (free oil).The solids or germ cake then can be sent to a milling step 130 for grinding via a grind mill, for example. Other milling devices such as a disc mill, a roller mill, an attrition mill, a hammer mill, a rotor- stator style mill, a pin mill, and the like, can be utilized here to release additional oil and protein therefrom from the germ cake. In addition, although a single grind mill 130 is depicted, it should be understood that a plurality of grind mills 130 may be situated in-line, either in parallel and / or in series, and utilized for grinding the germ and / or germ fragments. The separated liquid or centrate from paddle screen step 120 bypasses around the grind mill 130 and is combined with the ground solids material to produce a ground germ and oil stream.Additionally, a portion of the liquid or centrate can be used as backset, for example, as discussed further below with respect to Fig. 5. Optionally, the liquid or centrate, which is used as backset, can be processed through an oil separation device (not shown), like as discussed above with respect to oil recovery step 29, prior to combining the centrate stream with a slurry stream, for example, to recover additional oil. In one example, the oil separation device can include a stacked disc centrifuge, a solid bowl two or three phase centrifuge, or the like. The combined ground germ and oil stream then can be further combined with the underflow or protein and fiber stream from the germ cyclone step 110.

[0034] The paddle screen 120 (or similar liquid separation device) can be utilized to separate the solids from liquids, as the grind mill 130 is set up to generally just grind solids and not the liquid stream to preserve electrical consumption on this unit operations. In one example, one such suitable paddle screen is the MZSA-135OS model available from Fluid Quip, Inc. of Springfield, Ohio. One other suitable paddle screen is the FQ-PS32 available from Fluid-Quip, Inc. of Springfield, Ohio. In an alternate embodiment, the paddle screen 120 may be replaced with a pressure screen or decanter centrifuge, or other like device. One such suitable pressurescreen is the PS-Triple available from Fluid Quip, Inc. of Springfield, Ohio. One such suitable decanter centrifuge is the SG-806 available from Alfa Laval of Lund, Sweden. In addition, although a single paddle screen 120 is depicted, it should be understood that a plurality of paddle screens 120 may be situated in-line, either in parallel and / or in series, and utilized for filtering the overflow.

[0035] The protein and fiber stream, which now includes the ground germ and oil stream, can then be sent to one or more pressure screens 140, as are known in the art, whereat the stream can be further processed by known techniques / technologies such as to separate the protein, fiber, and oil to ultimately provide, for example, a fiber (rich) portion, and oil / corn oil (rich) portion, and a protein (rich) portion (See, e.g., Fig. 5, which is discussed in detail further below). As shown here, the pressure screen 140 initially separates out a fiber / insoluble solids portion from the protein and oil to provide a separate protein and oil portion. One such suitable pressure screen 140 is the PS-Triple available from Fluid Quip, Inc. of Springfield, Ohio. In an alternate embodiment, the pressure screen 140 may be replaced with a standard paddle screen or decanter centrifuge, or other like solid / liquid separation device. In one example, the paddle screen is a standard type paddle screen as is known in the art. One such suitable paddle screen is the FQ- PS32 available from Fluid-Quip, Inc. of Springfield, Ohio. One such suitable decanter centrifuge is the SG-806 available from Alfa Laval of Lund, Sweden. In addition, although a single pressure screen 140 is depicted, it should be understood that a plurality of pressure screens 140 may be situated in-line, either in parallel and / or in series, and utilized for filtering the underflow.

[0036] With reference to Fig. 3, another embodiment of a method and system for increasing oil and protein yield, collectively numeral 200, from a whole stillage byproduct such as producedin a typical corn dry-milling process 10, is shown. In this embodiment, the whole stillage byproduct can be piped from the typical com dry mill distillation and dehydration step 24 and subjected to the one or more germ cyclones 110, as discussed above in Fig. 2, to separate whole stillage byproduct into a germ and / or germ fragments portion / stream, which includes oil, and a protein and fiber portion / stream. The overs or germ and / or germ fragments stream can then be optionally sent directly to the grind mill 130 whereat the solids (e.g., germ and / or germ fragments) can be ground. Other milling devices such as a disc mill, a roller mill, an attrition mill, a hammer mill, a rotor-stator style mill, a pin mill, and the like, can be utilized here to reduce the particle size of the solid type material, such as the germ and / or germ fragments, and release additional oil and protein therefrom.

[0037] After the optional milling step 130, the now ground or not ground (if the grind mill step is absent) germ and / or germ fragments stream can be sent to an optional dewater device 205, such as a decanter centrifuge. Dewatering the now ground or not ground germ and / or germ fragments can lessen the impact on further downstream processing by removing any excess water / liquid from the stream. In one example, one such suitable decanter centrifuge is the SG- 806 available from Alfa Laval of Lund, Sweden. In an alternate embodiment, the decanter centrifuge 205 may be replaced with a pressure screen, paddle screen, filter press, germ press, or other like device(s). One such suitable pressure screen is the PS-Triple available from Fluid Quip, Inc. of Springfield, Ohio. One such suitable paddle screen is the MZSA-135OS model or the FQ-PS32 available from Fluid Quip, Inc. of Springfield, Ohio. In addition, although a single decanter centrifuge / dewater device 205 is depicted, it should be understood that a plurality of decanter centrifuges / dewater devices 205 may be situated in-line, either in parallel and / or in series, and utilized for filtering the overflow.

[0038] Following the optional dewater device 205, the separated liquid stream can be joined up with the protein and fiber stream from the germ cyclone 110 and the dewatered cake, or germ cake if the dewater device 205 is not present, can be subjected to a dryer 210. At the dryer 210, the germ and / or germ fragments stream can be further processed by being dried using a typical dryer, for example, which may include a rotary direct fire dryer, a steam tube dryer, a fluidize bed dryer, a spray dryer, a flash dryer, a ring dryer, an air classifier dryer, or a crystallizer, and the like, as are known in the art, that removes water from the germ and germ fragments stream. After the dryer / dryer step 210, dried germ and / or germ fragments can be further subjected to an oil extraction step 220 whereat bound oil within the dried germ and / or germ fragments may be removed. Oil extraction via solvent(s), such as n-hexane and / or hexane, and / or other known extractants, such as carbon dioxide, is a well-known process in the art. In one example, oil can be recovered from the dried germ and / or germ fragments using alcohol from the distillation and dehydration step 24, which is added to the dried germ and / or germ fragments to extract oil therefrom. In another embodiment, the solvent / oil extraction step 220 can be replaced by an oil press step in which the dried germ and / or germ fragments is sent to an oil press, as are well known in the art, whereat oil can be pressed and recovered from the dried germ and / or germ fragments. In one example, the recovered oil product here can include between about 20 wt% to about 60 wt% of the total corn oil in the com kernel. More or less oil recovery may be obtained as many factors can impact the total oil recovery potential here. The remaining dried germ and / or germ fragments or solvent extracted meal can be utilized as animal feed and / or in or as dried distillers grains (with or without solubles).

[0039] The protein and fiber stream (along with the liquid from the dewater device 205 if present) can be sent to the one or more pressure screens 140, like in Fig. 2, whereat the streamcan be further processed by known techniques / technologies such as to separate the protein, fiber, and oil contained therein to ultimately provide, for example, a fiber portion, and oil / com oil portion, and a protein portion (See, e.g., Fig. 5, which is discussed in detail further below). As shown here, the pressure screen 140 initially separates out a fiber / insoluble solids portion from the protein and oil to also provide a separate protein and oil portion.

[0040] With reference to Fig. 4, another embodiment of a method and system for increasing oil and protein yield, collectively numeral 300, from a whole stillage byproduct such as produced in a typical corn dry-milling process 10, is shown. In this embodiment, the whole stillage byproduct can be piped from the typical com dry mill distillation and dehydration step 24 and subjected to the one or more germ cyclones 110, as discussed above in Fig. 2, to separate whole stillage byproduct into a germ and / or germ fragments portion / stream, which includes oil, and a protein and fiber portion / stream. The overs or germ and / or germ fragments stream can then be optionally sent to the paddle screen 120 and / or to the grind mill 130 whereat the solids (e.g., germ and / or germ fragments or germ cake) can be ground. The separated liquid or centrate from paddle screen step 120 can bypass around the grind mill 130 and is combined with the ground solids material to produce a ground germ and oil stream, as discussed above with respect to Fig. 2. Additionally, a portion of the liquid or centrate can be used as backset, for example, as discussed further below with respect to Fig. 5, and / or sent back to the protein / fiber stream from the germ cyclone 110. Optionally, the liquid or centrate, which is used as backset, can be processed through an oil separation device (not shown), like as discussed above with respect to oil recovery step 29, prior to combining the centrate stream with a slurry stream, for example, to recover additional oil. In one example, the oil separation device can include a stacked disc centrifuge, a solid bowl two or three phase centrifuge, or the like. And instead of combining anyground germ and oil stream (or ground germ and / or germ fragments stream) with the underflow or protein and fiber stream from the germ cyclone step 110, as in Fig. 2, the stream can be sent directly to an oil separation step 310 whereat oil can be removed / recovered therefrom. Optionally, prior to the oil separation step 310, the stream can be sent to an oil separation preconditioning step (not shown) whereat the stream can be preheated to a desired temperature prior to oil separation. Alternatively or additionally, the stream can be subjected to an emulsion breaking pre-conditioning step (not shown) whereat chemicals, surfactants, flocculants, enzymes, extractants, oil, other processing aids, or combinations thereof can be added to increase oil recovery rates at the oil separation step 310.[00411 Here, the oil separation step 310 can include an oil (recovery) centrifuge, as are known in the art, which may be a standalone / separate device or other device (not shown) that is processing another stream, such as the syrup stream, that can be situated after the evaporation step 28 in Fig. 1, for example. In one example, the recovered oil product can include between about 10 wt% to about 60 wt% of the total corn oil in the corn kernel. More or less oil recovery may be obtained as many factors can impact the total oil recovery potential here. One such suitable oil recovery centrifuge is the ORPX 617 available from Alfa Laval of Lund, Sweden. It should be understood that the oil recovery centrifuge may be replaced with other types of oil recovery devices, e.g., a press, an extruder, a tricanter, a decanter centrifuge, and the like, or combinations thereof, which can perform the desired oil recovery function. The remaining liquid underflow stream from the oil separation step 310 can be used as backset, for example, as discussed further below with respect to Fig. 5. Optionally, the liquid or centrate, which is used as backset, can be processed through an oil separation device (not shown), like as discussed above with respect to oil recovery step 29, prior to combining the centrate stream with a slurrystream, for example, to recover additional oil. In one example, the oil separation device can include a stacked disc centrifuge, a solid bowl two or three phase centrifuge, or the like. In another example, the stream from the grind mill 130 can be added directly to (existing) oil recovery centrifuge 29, like as shown in Fig. 1, which here would define the oil separation step 310. In another example, the stream from the grind mill 130 can be added directly to a thin stillage stream, which can be sent to evaporators / evaporation step 28, like as shown in Fig. 1, and oil recovery can occur at the oil recovery centrifuge 29, which again would define the oil separation step 310. Still further, in yet another example, instead of sending the ground germ and oil stream from the grind mill 130 (or ground germ and / or germ fragments stream from the paddle screen 120) to the oil separation step 310, the ground germ and oil stream (or ground germ and / or germ fragments stream) can be sent to an evaporation step, which can include its own standalone / dedicated evaporator(s) then followed by the oil separation step 310 or which can utilize an existing evaporator(s), such as evaporation step 28 of Fig. 1, whereat the stream can be joined with the thin stillage and may be further processed as shown in Fig. 1, including being subjected to oil recovery centrifuge 29 for oil recovery. With these various configurations, the oil recovery step 29 / oil separation step 310 may include one or more unit operations that can be situated in a series and / or parallel configuration.

[0042] With respect to the use of a tricanter as the oil recovery device at oil separation step 310, it should be understood that three streams can be produced instead of the two (oil and liquid) as shown in Fig. 4. The three resulting streams can include the oil, the liquid, and a protein / fine fiber stream. In one example, the protein / fine fiber stream can be sent to the fiber portion / stream of Fig. 5, such as to produce the DWG(S) or DDG(S), as is discussed in detail below.

[0043] The protein and fiber stream, prior to being sent to a stillage decanting step 320 that includes one or more decanter centrifuges, can be subjected to another or second set of one or germ cyclones 330 to further separate additional germ and / or germ fragments from the protein and oil stream. The resulting germ and / or germ fragments can be returned to the whole stillage stream. Although a single germ cyclone 330 is depicted, it should be understood that a plurality of germ cyclones 330 may be situated in-line, either in series and / or parallel. One such suitable germ cyclone is the GS6” model available from Fluid Quip, Inc. of Springfield, Ohio. From here (whether or not the second set of germ cyclones 330 are present), the protein and fiber stream can be sent to the one or more decanter centrifuges 320 whereat the stream can be further processed by known techniques / technologies such as to separate the protein, fiber, and oil contained therein to ultimately provide, for example, a fiber portion, and oil / com oil portion, and a protein portion (See, e.g., Fig. 5, which is discussed in detail further below). As shown here, the decanter centrifuge 320 initially separates out a fiber / insoluble solids portion from the protein and oil to also provide a separate protein and oil portion. In one example, one such suitable decanter centrifuge is the SG-806 available from Alfa Laval of Lund, Sweden. In an alternate embodiment, the decanter centrifuge 320 may be replaced with a pressure screen or paddle screen, or other like device. One such suitable pressure screen is the PS-Triple available from Fluid Quip, Inc. of Springfield, Ohio. One such suitable paddle screen is the MZSA-135OS model or the FQ-PS32 available from Fluid Quip, Inc. of Springfield, Ohio. In addition, although a decanter centrifuge 320 is depicted, it should be understood that a plurality of decanter centrifuges 320 may be situated in-line, either in parallel and / or in series, and utilized for filtering the overflow.

[0044] With reference now to Fig. 5, additional processing of the fiber portion and protein and oil portion is shown, in accordance with an embodiment of the invention, in which the processing begins with the pressure screen 140 of Figs. 2 and 3 or decanter centrifuge 320 of Fig.4 being generally depicted here as separation / screening step 400. Here, as indicated above, a fiber portion and protein and oil portion are produced via the separation step 400, which again can include use of the pressure screen 140 of Figs. 2 and 3 or decanter centrifuge 320 of Fig. 4. Next, the protein and oil portion are sent and subjected to one or more centrifuges 402 (e.g., a nozzle centrifuge), as is known in the art. The centrifuge 402 can be provided with washing capabilities so that water, or similar aqueous solutions, along with the protein and oil portion, can be supplied to the centrifuge 402. At this step, the additional water or aqueous solution allows for easier separation of the protein and oil portion into its protein portion and a water-soluble solids or oil portion. The heavier protein portion, which can include com and yeast protein, separates from the lighter oil portion, which includes water soluble solids, and is removed as the underflow whereas the lighter oil portion, which includes oil, carbohydrates, and other water soluble solids, can be removed as the overflow. One such suitable centrifuge 402 is the FQC- 950 available from Fluid-Quip, Inc. of Springfield, Ohio, which is a nozzle centrifuge. In an alternate embodiment, the centrifuge 402 can be replaced with a standard cyclone apparatus or other like device, as are known in the art, to separate the protein and oil portion into the underflow protein portion and overflow water-soluble solids / oil portion. One such suitable cyclone apparatus is the RM- 12-688 available from Fluid-Quip, Inc. of Springfield, Ohio. In addition, although a single centrifuge 402 is depicted, it should be understood that a plurality of centrifuges 402 may be situated in-line, either in parallel and / or in series.

[0045] The underflow protein portion from the centrifuge 402 can be collected in a tank and then be sent and subjected to a decanter centrifuge 404. Water can be added to the tank to help dilute the protein portion and aid in separating the protein from non-protein solids thereby increasing the purity of any final protein meal. At the decanter centrifuge 404, the protein portion, which can include grain (e.g., corn) and yeast protein, is dewatered to provide a dewatered protein portion. The decanter centrifuge 404 is standard and known in the art. One such suitable decanter centrifuge 404 is the SG-806 available from Alfa Laval of Lund, Sweden. Other like devices are contemplated. In addition, although a single decanter centrifuge 404 is depicted, it should be understood that a plurality of decanter centrifuges 404 may be situated inline, either in series or parallel, and utilized for filtering the protein portion. The separated liquid portion or centrate from the decanter centrifuge 404 may be recycled back, for example, as backset to the slurry tank 14, the liquefaction step 16, and / or the fermentation step 20 for reuse in the dry mill process or used in further biochemical, algae, or other applications. Optionally, the liquid or centrate, which is used as backset, can be processed through an oil separation device (not shown), like as discussed above with respect to oil recovery step 29, prior to combining the centrate stream with a slurry stream, for example, to recover additional oil. In one example, the oil separation device can include a stacked disc centrifuge, a solid bowl two or three phase centrifuge, or the like. In another example, the centrate from the decanter centrifuge 404 may be recycled back to one or more of the germ cyclone 110, pressure screen 140, or decanter centrifuge 320. In an alternate embodiment, the decanter centrifuge 404 may be replaced with a standard filter press or rotary vacuum, or other like device, as are known in the art, to dewater the protein portion.

[0046] The dewatered protein portion from the decanter centrifuge 404 can be further optionally dried, such as by being sent to dryer 406, e.g., a rotary dryer, spray dryer, flash dryer, ring dryer, an air classifier dryer, or a crystallizer, or the like, as is known in the art. In another embodiment, the dewatered protein portion can be subjected to vacuum filtration, a crystallizer, or other drying methods, as are known in the art. The dewatered (and optionally dried) protein product defines a high protein meal that includes at least 40 wt% protein on a dry basis and which may be sold as pig or chicken feed, for example. In another embodiment, the high protein meal includes at least 40 wt% protein on a dry basis. In another embodiment, the high protein meal includes at least 45 wt% protein on a dry basis. In yet another embodiment, the high protein meal includes at least 50 wt% protein on a dry basis. In yet another embodiment, the high protein meal includes at least 60 wt% protein on a dry basis. In still another embodiment, the high protein meal includes about 56 wt% protein on a dry basis. The protein in the high protein meal includes grain (e.g., com) protein and may also contain yeast protein and / or yeast bodies. The amount of yeast protein in the protein of the high protein meal can vary and, in one example, can include less than 5% of the total protein content. In another example, the yeast protein can be from 0.1% to 5% of the total protein content. In another example, the yeast protein can include at least 5% total protein content. In another example, the yeast protein can include from about 5% to 40% of the total protein content. And in another example, the yeast protein can include 40% or more of the total protein content. The resulting high protein meal may be sold at a much higher cost per ton than DDGS or DWGS.

[0047] Returning now to the separated oil portion or filtrate from the centrifuge 402, as shown in Fig. 5, the overflow oil portion, which includes oil as well as minerals and soluble proteins, can be sent from the centrifuge 402 and subjected to a set of three evaporators 460a,460b, and 460c, as are known in the art, to begin separating soluble solids from the water-soluble solids portion. In one embodiment, at least a portion of the oil portion may be recycled back or combined with the centrate from the decanter centrifuge 404 and recycled back, for example, as backset to the liquefaction step 16 or the fermentation step 20 for reuse in the dry mill process. Returning again to the evaporators, the evaporators 460a-c evaporate the liquid portion of the water-soluble solids in the oil portion. Thereafter, the oil portion can be sent and subjected to an oil recovery centrifuge 461, as is known in the art, so that oil can be removed therefrom. The oil recovery centrifuge 461 can include a stacked disc centrifuge, a decanter centrifuge, a screen centrifuge, and the like, or combinations thereof. It should be understood that the oil recovery centrifuge 461 may be replaced with other types of oil recovery devices, e.g., a press, an extruder, and the like, or combinations thereof, which can perform the desired oil recovery function. One such suitable oil recovery centrifuge 461 is the ORPX 617 available from Alfa Laval of Lund, Sweden. In one example, the final recovered oil product or total overall yield can include between about 40 wt% to about 60 wt% of the total com oil in the corn. In comparison to typical oil recovery in a standard dry-milling process, oil recovery centrifuge 461 can function at a higher capacity because the oil portion, which is subjected to the oil recovery centrifuge 461, includes less liquid and less protein and fiber than normal thin stillage or evaporated thin stillage.

[0048] Further, in one embodiment, additives such as a surfactant, flocculent, enzyme, extractant, oil, chemicals, or combinations thereof can be added at and / or prior to the oil recovery centrifuge 461 to help further increase oil yield recovery. Because bound oil can be released due to the recycled oil, the amount of emulsion breaker or surfactant or other additives used may be decreased as compared to a process without the introduction of the recycled oil before the oil recovery centrifuge 461. The final oil recovered from the oil recovery centrifuge461 may be further processed and can be sold and / or used as or in, for example, cooking oil, for conversion to biodiesel or renewable diesel, aviation fuel, or an animal feed.

[0049] With further reference to Fig. 5, the remainder of the oil portion, particularly including the remaining soluble solids, from the oil recovery centrifuge 461 can be sent and subjected to another set of three evaporators 460d, 460e, and 460f whereat the liquid portion is further evaporated from the oil portion to ultimately yield a soluble solids portion. While the oil portion is shown subjected to two sets of three evaporators 460a-c, 460d-f, it should be understood that the number of evaporators and sets thereof can be varied, i.e., can be more or less, from that shown depending on the particular application and result desired.

[0050] In one example, the resulting soluble solids portion may be combined with the fiber portion received from the separation step 400 (e.g., the pressure screen 140 of Figs. 2 or 3 or decanter centrifuge 320 of Fig. 4) to provide DWGS, which may be further dried by a drier 462, as is known in the art, to provide DDGS, both of which can be sold to dairy and beef feedlots, as well as other monogastric species such as swine and poultry. In another example, the soluble solids portion may be used as a natural fertilizer and / or herbicide. In another example, the soluble solids portion may be used as a raw material feed source for conversion to simple sugar, which can be further converted to bioethanol or used in other biochemical and / or fermentation based processes. In another example, the soluble solids portion may be used as a raw material feed source for a digestion or conversion process to process single cell proteins.

[0051] In another embodiment, the resulting oil and protein stream and the fiber stream from the pressure screen 140 of Figs. 2 and 3 or the decanter centrifuge 320 of Fig. 4 can be processed as shown on the back end of Fig. 1. That is, the fiber stream / portion can be processed like thewet cake of Fig. 1 and the protein and oil stream / portion similarly can be processed like the thin stillage of Fig. 1.

[0052] With reference now to Fig. 6, another embodiment of a method and system for increasing oil and protein yield, collectively numeral 500, from a whole stillage byproduct such as produced in a typical corn dry-milling process 10, is shown, which is a variation of the method and system of Fig. 4. In this embodiment, the whole stillage byproduct first is subjected to a decanter centrifuge 505 instead of being sent directly to the one or more germ cyclones 110. The whole stillage decanter centrifuge 505 can be configured to separate coarse fiber and solids into a “wet cake” or insoluble solids portion / stream and a centrate or thin stillage portion / stream with liquid, oil, germ, fine solids, and protein. In one example, one such suitable decanter centrifuge is the SG-806 available from Alfa Laval of Lund, Sweden. In an alternate embodiment, the decanter centrifuge 505 may be replaced with a pressure screen or paddle screen, or other like devices. One such suitable pressure screen is the PS-Triple available from Fluid Quip, Inc. of Springfield, Ohio. One such suitable paddle screen is the MZSA-135OS model or the FQ-PS32 available from Fluid Quip, Inc. of Springfield, Ohio. In addition, although a single decanter centrifuge 505 is depicted, it should be understood that a plurality of decanter centrifuges 505 may be situated in-line, either in parallel and / or in series, and utilized for filtering the overflow.

[0053] The centrate or thin stillage stream next can be subjected to the one or more germ cyclones 110, like as discussed above in Fig. 4, to separate the thin stillage stream (as compared to the whole stillage) into a germ and / or germ fragments portion / stream, which includes oil, and a protein and fine fiber portion / stream. From here, the overs or germ and / or germ fragments stream can be treated in the same / similar manner as discussed above with respect to Fig. 4. Inaddition, while Fig. 4 has been modified and discussed herein as incorporating a decanter centrifuge 505 just prior to the germ cyclones 110 to provide the method and system of Fig. 6, it should be understood that one or more decanter centrifuges 505 and the like also similarly may be incorporated into the methods and systems of Figs. 2 and 3 as well, just prior to the germ cyclones 110. In one example, at least a portion of the protein and fine fiber stream can be returned to the whole stillage stream. In one example, the recovered oil product via oil separation step 310 here can include between about 40 wt% to about 60 wt% of the total corn oil in the com kernel. More or less oil recovery may be obtained as many factors can impact the total oil recovery potential here.[00541 With further reference to Fig. 6, the protein and fine fiber stream, prior to being sent to the one or more decanter centrifuges 320, can be subjected to the optional second set of one or germ cyclones 330 to further separate any additional germ and / or germ fragments from the protein and fine fiber stream, like as discussed above with Fig. 4. The resulting germ and / or germ fragments can be returned to the whole stillage stream. Although a single germ cyclone 330 is depicted, it should be understood that a plurality of germ cyclones 330 may be situated inline, either in series and / or parallel. One such suitable germ cyclone is the GS6” model available from Fluid Quip, Inc. of Springfield, Ohio. From here (whether or not the second set of germ cyclones 330 are present), the protein and fine fiber stream can be sent to the one or more decanter centrifuges 320 whereat the stream can be further processed to separate the fine fiber (along with any germ and germ fragments and / or residual protein) from oil and protein contained therein to provide a fine fiber portion / stream and a protein and oil portion / stream. The decanter centrifuge 320 can dewater the fine fiber slurry to produce a fine fiber cake / stream that can be combined with the fiber / coarse solids or wet cake from the whole stillage decanter 505 toultimately produce distillers grains, such as DWG(S), which can be optionally dried at dryer 510 to produce DDG(S), like as discussed above in Fig. 5, and sold as animal feed as is common practice. In another example, all or a portion of the fine fiber stream can be returned to the whole stillage stream. At least a portion of the centrate produced from decanter centrifuge 320, which contains liquid and soluble solids, protein, and oil, can be combined with the ground solids material from the grind mill 130 to produce a ground germ and oil / protein stream, which can be sent directly to the oil separation step 310 whereat oil can be removed / recovered therefrom. Optionally, prior to the oil separation step 310, the stream can be sent to an oil separation pre-conditioning step (not shown) whereat the stream can be preheated to a desired temperature prior to oil separation. Alternatively or additionally, as discussed above, the stream can be subjected to an emulsion breaking pre-conditioning step (not shown) whereat chemicals, surfactants, flocculants, enzymes, extractants, oil, other processing aids, or combinations thereof can be added to increase oil recovery rates at the oil separation step 310.

[0055] In another example, the now combined stream from the grind mill 130 and decanter centrifuge 320 can be added directly to (existing) oil recovery centrifuge 29, like as shown in Fig. 1, which here would define the oil separation step 310. In another example, the combined stream can be added directly to a thin stillage stream, which can be sent to evaporators / evaporation step 28, like as shown in Fig. 1, and oil recovery can occur at the oil recovery centrifuge 29, which again would define the oil separation step 310. Still further, in yet another example, instead of sending the combined stream to the oil separation step 310, it can be sent to an evaporation step, which can include its own standalone / dedicated evaporator(s) then followed by oil separation step 310, or it can be sent to an evaporation step, which can utilize an existing evaporator(s), such as evaporation step 28 of Fig. 1, whereat the stream can be joined with thethin stillage and may be further processed as shown in Fig. 1 , including being subjected to oil recovery centrifuge 29 for oil recovery.

[0056] In yet another embodiment, the resulting oil and protein stream and the combined fine fiber / coarse fiber stream from the decanter centrifuge 320 can be processed as shown on the back end of Fig. 1 . That is, the fiber stream / portion can be processed like the wet cake of Fig. 1 and the protein and oil stream / portion similarly can be processed like the thin stillage of Fig. 1. Still further, the oil and protein stream from the decanter centrifuge 320 also can be processed as shown in Fig. 5. That is, the protein and oil stream / portion similarly can be processed beginning with the nozzle centrifuge 402 and proceeding from there to produce the high protein meal and oil product.

[0057] With reference now to Fig. 7, another embodiment of a method and system for increasing oil and protein yield, collectively numeral 600, from a whole stillage byproduct such as produced in a typical corn dry-milling process 10, is shown, which is another variation of the method and system of Fig. 4. In this embodiment, the whole stillage byproduct can be piped from the typical corn dry mill distillation and dehydration step 24 and subjected to the one or more germ cyclones 110, as discussed above in Fig. 2, to separate whole stillage byproduct into a germ and / or germ fragments portion / stream, which includes oil, and a protein and fiber portion / stream. The overs or germ and / or germ fragments stream can then be optionally sent to a tricanter centrifuge 610 (or the like) instead of paddle screen 120, for example, whereat three streams can be produced instead of the two (centrate and germ cake) like as shown in Fig. 4.The three resulting streams can include an oil stream, a liquid / centrate stream, which can include residual oil, and a germ and / or germ fragments (germ cake) stream, which can include residual protein and fine fiber. In addition, although a single tricanter centrifuge 610 is depicted, itshould be understood that a plurality of tricanter centrifuges 610 may be situated in-line, either in parallel and / or in series, and utilized for filtering the overflow. In one example, a portion of the liquid or centrate from the tricanter centrifuge 610 can be used as backset and sent back to the slurry tank 14, the liquefaction step 16, and / or the fermentation step 20 for reuse in the dry mill process or used in further biochemical, algae, or other applications. Optionally, the liquid or centrate, which is used as backset, can be processed through an oil separation device (not shown), like as discussed above with respect to oil recovery step 29, prior to combining the centrate stream with a slurry stream, for example, to recover additional oil.

[0058] Here, in Fig. 7, the optional grind mill 130 of Fig. 4 is shown absent, with the centrate from the tricanter centrifuge 610 being sent directly to an evaporator 615 to evaporate liquid from the centrate stream to produce a syrup stream. The syrup stream is then sent to the oil separation step 310 whereat oil can be removed / recovered therefrom to produce a de-oiled liquid or syrup stream. The oil separation step 310 can include an oil (recovery) centrifuge or the like, as are known in the art. In one example, the oil centrifuge can include a stacked disc centrifuge, a solid bowl two or three phase centrifuge, or the like. One such suitable oil recovery centrifuge is the ORPX 617 available from Alfa Laval of Lund, Sweden. Optionally, prior to the oil separation step 310, the stream can be sent to an oil separation pre-conditioning step (not shown) whereat the stream can be preheated to a desired temperature prior to oil separation.Alternatively or additionally, the stream can be subjected to an emulsion breaking preconditioning step (not shown) whereat chemicals, surfactants, flocculants, enzymes, extractants, oil, other processing aids, or combinations thereof can be added to increase oil recovery rates at the oil separation step 310.

[0059] The recovered oil portion can be combined with the oil stream from the tricanter centrifuge 610. In one example, the final recovered and combined oil product or total overall yield can include between about 40 wt% to about 60 wt% of the total corn oil in the corn. More or less oil recovery may be obtained as many factors can impact the total oil recovery potential here. Further, in one embodiment, a surfactant, flocculent, enzyme, extractant, oil, chemicals, or combinations thereof can be added at and / or prior to the oil separation step 310 to help further increase oil yield recovery.

[0060] Returning now to the protein and fiber stream from the germ cyclone(s) 110, prior to being sent to the one or more decanter centrifuges 320, this stream can be subjected to the second set of one or germ cyclones 330 to further separate additional germ and / or germ fragments from the protein and oil stream, like as shown in Fig. 4. The resulting germ and / or germ fragments can be returned to the whole stillage stream. Although a single germ cyclone 330 is depicted, it should be understood that a plurality of germ cyclones 330 may be situated in-line, either in series and / or parallel. One such suitable germ cyclone is the GS6” model available from Fluid Quip, Inc. of Springfield, Ohio. From here (whether or not the second set of germ cyclones 330 are present), the protein and fiber stream can be sent to one or more decanter centrifuges 320 whereat the stream can be further processed such as to separate the protein, fiber, and oil contained therein to ultimately provide, for example, a fiber portion, and oil / com oil portion, and a protein portion. As shown here, the decanter centrifuge 320 initially separates out a fiber / insoluble solids portion / stream from the protein and oil to also provide a separate protein and oil portion / stream. In one example, one such suitable decanter centrifuge is the SG-806 available from Alfa Laval of Lund, Sweden. In an alternate embodiment, the decanter centrifuge320 may be replaced with a pressure screen or paddle screen, or other like device. One suchsuitable pressure screen is the PS-Triple available from Fluid Quip, Inc. of Springfield, Ohio. One such suitable paddle screen is the MZSA-135OS model or the FQ-PS32 available from Fluid Quip, Inc. of Springfield, Ohio. In addition, although a decanter centrifuge 320 is depicted, it should be understood that a plurality of decanter centrifuges 320 may be situated inline, either in parallel and / or in series.

[0061] With continuing reference to Fig. 7, the germ cake stream from the tricanter centrifuge 610 and the de-oiled syrup stream from the oil separation step 310 can be combined with the fiber portion / stream from the decanter centrifuge 320 to ultimately produce distillers grains, such as DWG(S), which can be optionally dried at a dryer 620, e.g., a rotary dryer, spray dryer, flash dryer, ring dryer, an air classifier dryer, or a crystallizer, or the like, to produce DDG(S), like as discussed above in Fig. 5, and sold as animal feed as is common practice. In one example, at least a portion of the germ cake stream from the tricanter centrifuge 610 can be sent to a dryer 630, e.g., a rotary dryer, spray dryer, flash dryer, ring dryer, an air classifier dryer, or a crystallizer, or the like, to produce a protein meal / product, which may be sold as pig or chicken feed, for example. And the centrate or protein and oil stream produced from the decanter centrifuge 320, which contains liquid and soluble solids, protein, and oil, can be combined with the germ and / or germ fragments stream from the first germ cyclone(s) and subjected therewith to the tricanter centrifuge 610.

[0062] In yet another embodiment, the resulting protein and oil stream from the decanter centrifuge 320 can be processed as shown on the back end of Fig. 1. That is, the protein and oil stream / portion can be processed like the thin stillage of Fig. 1. Still further, the protein and oil stream from the decanter centrifuge 320 also can be processed as shown in Fig. 5. That is, theprotein and oil stream / portion similarly can be processed beginning with the nozzle centrifuge 402 and proceeding from there to produce the high protein meal and oil products.

[0063] In another embodiment, the density of the whole (or thin) stillage entering the germ cyclones 110 can be increased by the addition of syrup / soluble solids such as from the evaporation / evaporators 40, 460a-c, 460d-f, like as shown in Figs. 1 or 5, or by the addition of other higher density fluids. This increased density may aid in the separation of the light density germ and / or germ fragments in the whole (or thin) stillage as it passes through the germ cyclones 110. Additionally, the density can be changed, such as decreased by the addition of at least a portion of a separated oil stream from the various steps discussed above. This may also include the addition of at least a portion of a grain (e.g., corn) oil stream produced from a separate, unrelated process.

[0064] Further yet and with respect to Figs. 1-7, one or more feed / storage tanks and corresponding pumps may be utilized to store / collect any of the various streams and pump the same therefrom within the above described methods and systems. For example, such feed tanks and pumps may be situated prior to the germ cyclones 110, 330, including between distillation and dehydration step 24 and the germ cyclone 110 or between the first germ cyclone 110 and second germ cyclone 330, as well as prior to or after the pressure screen 140, decanter centrifuge 320, the tricanter centrifuge 610, or the oil separation step 310.

[0065] While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in anycombination. Additional advantages and modifications will readily appear to those skilled in the art. For example, while the protein and oil streams of Figs. 2-4 and 6 and 7 are shown as being further optionally processed by the means and methods disclosed in Figs. 1 or 5, in one example, at least a portion of the protein and oil streams can be returned the whole stillage stream, the protein and fiber or fine fiber stream, the germ and germ fragments stream, or combinations thereof instead of or in combination with being optionally processed in accordance with Figs. 1 and 5, as discussed above. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicant’ s general inventive concept.

[0066] What is claimed is:

Claims

1 . A method for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process comprising: separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, into a protein and fiber stream and a germ and / or germ fragments stream including free oil; milling the germ and / or germ fragments in the germ and / or germ fragments stream to release additional oil and protein; combining the milled stream, including the free oil, released oil and protein, and milled germ and / or germ fragments, with the protein and fiber stream; separating the combined stream into a fiber portion, including the milled germ and / or germ fragments, and a protein and oil portion, including the free oil and released oil and protein; separating the protein and oil portion into an oil portion, including the free and released oil, and a protein portion, including the released protein; and recovering the free and released oil from the oil portion and / or protein, including the released protein, from the protein portion.

2. The method of claim 1 wherein separating the whole stillage byproduct comprises separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, via a germ cyclone, into a protein and fiber stream and a germ and / or germ fragments stream including free oil.

3. The method of claim 2 wherein the germ cyclone is a hydrocyclone.

4. The method of claim 2 wherein separating the combined stream comprises separating the combined stream, via a pressure screen or centrifuge, into a fiber portion, including the milledgerm and / or germ fragments, and a protein and oil portion, including the free oil and released oil and protein.

5. The method of claim 1 further comprising separating the germ and / or germ fragments stream into a solids portion, including germ and / or germ fragments, and a centrate, which includes the free oil, and milling the solids portion to release additional oil and protein, followed by recombining at least a portion of the centrate with the milled solids portion and then combining the milled stream, including free oil, released oil and protein, and milled germ and / or germ fragments, with the protein and fiber stream.

6. The method of claim 5 further comprising separating the germ and / or germ fragments stream, via a paddle screen, into a solids portion, including germ and / or germ fragments, and a centrate, which includes the free oil.

7. The method of claim 1 wherein additives including a surfactant, flocculant, enzyme, extractant, oil, chemical, or combinations thereof are introduced prior to and / or during separating the whole stillage byproduct.

8. A method for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process comprising: separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, into a protein and fiber stream and a germ and / or germ fragments stream including free oil; milling the germ and / or germ fragments in the germ and / or germ fragments stream to release additional oil and protein;dewatering the milled stream to provide a dewatered solids portion, including the milled germ and / or germ fragments, and a liquid portion, including the free oil and released oil and protein; extracting oil from the dewatered solids portion including the milled germ and / or germ fragments; combining the liquid portion, including the free oil and released oil and protein, with the protein and fiber stream; separating the combined stream into a fiber portion and a protein and oil portion, including the free oil and released oil and protein; separating the protein and oil portion into an oil portion, including the free and released oil, and a protein portion, including the released protein; and recovering the free and released oil from the oil portion and / or protein, including the released protein, from the protein portion.

9. The method of claim 8 further comprising drying the dewatered solids portion, including the milled germ and / or germ fragments, following by extracting oil from the dried and dewatered solids portion.

10. The method of claim 8 wherein extracting oil from the dewatered solids portion comprises extracting oil, via solvent extraction, from the dewatered solids portion including the milled germ and / or germ fragments.

11. The method of claim 8 wherein extracting oil from the dewatered solids portion comprises extracting oil, via an oil press, from the dewatered solids portion including the milled germ and / or germ fragments.

12. The method of claim 8 wherein separating the whole stillage byproduct comprises separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, via a germ cyclone, into a protein and fiber stream and a germ and / or germ fragments stream including free oil.

13. The method of claim 12 wherein the germ cyclone is a hydrocyclone.

14. The method of claim 8 wherein dewatering the milled stream comprised dewatering the milled stream, via a centrifuge, pressure screen, paddle screen, filter press, or germ press, to provide a dewatered solids portion, including the milled germ and / or germ fragments, and a liquid portion, including the free oil and released oil and protein.

15. The method of claim 8 wherein additives including a surfactant, flocculant, enzyme, extractant, oil, chemical, or combinations thereof are introduced prior to and / or during separating the whole stillage byproduct.

16. A method for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process comprising: separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, into a protein and fiber stream and a germ and / or germ fragments stream including free oil; milling the germ and / or germ fragments in the germ and / or germ fragments stream to release additional oil and protein; separating out the free and released oil from the milled germ and / or germ fragments; separating the protein and fiber stream, which includes oil, into a fiber portion and a protein and oil portion;separating the protein and oil portion into an oil portion and a protein portion; and recovering the oil from the oil portion and / or the protein from the protein portion.

17. The method of claim 16 further comprising separating the germ and / or germ fragments stream into a solids portion, including germ and / or germ fragments, and a centrate, which includes the free oil, and milling the solids portion to release additional oil and protein, followed by separating out the released oil from the milled germ and / or germ fragments.

18. The method of claim 17 further comprising recombining at least a portion of the centrate, including free oil, with the milled germ and / or germ fragments followed by separating out the free and released oil from the milled germ and / or germ fragments.

19. The method of claim 17 further comprising recombining at least a portion of the centrate with the protein and fiber stream, which includes the free oil and oil, followed by separating the combined stream into a fiber portion and a protein and oil portion, which includes the free oil and oil, and separating the protein and oil portion into an oil portion, including the free oil and oil, and a protein portion, including protein, and recovering the free oil and oil from the oil portion and / or the protein from the protein portion.

20. The method of claim 16 further separating out residual germ and / or germ fragments from the protein and fiber stream and returning the separated out genii and / or germ fragments to the whole stillage byproduct.

21. The method of claim 16 wherein separating the whole stillage byproduct comprises separating the whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, via a germ cyclone, into a protein and fiber stream and a germ and / or germ fragments stream including free oil.

22. The method of claim 21 wherein the germ cyclone is a hydrocyclone.

23. The method of claim 16 wherein additives including a surfactant, flocculant, enzyme, extractant, oil, chemical, or combinations thereof are introduced prior to and / or during separating the whole stillage byproduct.

24. A system for increasing protein and / or oil yields from a whole stillage byproduct produced from a biochemical process comprising: a first apparatus that receives a whole stillage byproduct, which includes germ and / or germ fragments, protein, and fiber, wherein the first apparatus separates the whole stillage byproduct into a protein and fiber stream and a germ and / or germ fragments stream including free oil; a milling device that is situated after the first apparatus and that receives the germ and / or germ fragments stream from the first apparatus, wherein the milling device mills the germ and / or germ fragments to release additional oil and protein; a second apparatus that is situated after the first apparatus and the milling device and that receives the protein and fiber stream and the milled stream to define a combined stream, wherein the second apparatus separates the combined stream into a fiber portion, including the milled germ and / or germ fragments, and a protein and oil portion, including the free oil and released oil and protein; and a third apparatus that is situated after the second apparatus and that receives the protein and oil portion, wherein the third apparatus separates the protein and oil portion into an oil portion, including the free and released oil, and a protein portion, including the released protein, whereby the free and released oil from the oil portion and / or protein, including the released protein, from the protein portion can be recovered.

25. The system of claim 24 wherein the first apparatus is situated after a distillation column and receives the whole stillage byproduct produced via a grain dry-milling process.

26. The system of claim 24 wherein the first apparatus is a germ cyclone.

27. The system of claim 24 further comprising; a fourth apparatus that is situated between the first apparatus and the milling device and that receives and separates germ and / or germ fragments stream into a solids portion, including germ and / or germ fragments, and a centrate, which includes the free oil, wherein the milling device receives the solids portion, including germ and / or germ fragments from the second apparatus and wherein the milling device mills the solids portion to release additional oil and protein, and wherein the second apparatus receives the protein and fiber stream, at least a portion of the centrate, and the milled solids portion to define a combined stream, and wherein the second apparatus separates the combined stream into a fiber portion, including the milled germ and / or germ fragments, and a protein and oil portion, including the free oil and released oil and protein28. The system of claim 27 wherein the fourth apparatus is a paddle screen.

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