Patent Application
20120301597
The subject disclosure relates to systems and methods for producing a composition of fiber from corn and also relates to the composition of fiber from corn.
Ethanol traditionally has been produced from grain-based feedstocks (e.g., corn, sorghum/milo, barley, wheat, soybeans, etc.), or from sugar (e.g., sugar cane, sugar beets, etc.).
In a conventional ethanol plant, corn, sugar cane, other grain, beets, or other plants are used as a feedstock and ethanol is produced from starch contained within the corn or other plant feedstock. In the case of a corn facility, corn kernels are cleaned and milled to prepare starch-containing material for processing. Corn kernels can also be fractionated to separate the starch-containing material (e.g., endosperm) from other matter (such as fiber and germ). Initial treatment of the feedstock varies by feedstock type. Generally, however, the starch and sugar contained in the plant material is extracted using a combination of mechanical and chemical means.
After the extraction, the fiber and germ portions of the corn kernel remain available for other purposes. Often, germ material may be added to animal feed, or sold as a valuable co-product. Similarly, the fiber from a fractionation ethanol plant may be ideally suited for processing in order to derive a food grade product.
The corn fiber may be utilized in food applications, such as, for example, breakfast cereal, cereal bars, muffins, breads, and other baked goods. Fiber utilized in these applications should have a high dietary fiber content (e.g., above about 80 percent), a low starch content, a low moisture content to retard microbial growth, and a low sulfur (e.g., sulfite and/or sulfide) content.
Conventionally, corn fiber is derived from wet mill ethanol plants. The process of wet milling the corn kernels can generate excessive sulfur content in the resulting fiber. Dry fractionation, however, does not add sulfur to the fiber and does not use long steep times that foster bacterial growth.
The disclosed aspects relate to systems and methods for generating a composition of fiber. The various aspects disclosed herein are unique due to codependence on a fractionation ethanol production facility. In particular, the raw fiber utilized in such aspects may be derived from a dry fractionation mill. The remaining components of the corn may be utilized at the ethanol production facility to generate ethanol (endosperm component) or as an animal feed co-product (germ component).
In some embodiments, the raw fiber can be washed with de-starched water to generate a first wash fiber. Wash can be at between about 60° F. and about 200° F. and may last between approximately 5 and 20 minutes with mechanical mixing. A heat exchanger may be utilized to control the wash temperature. The first wash fiber may be dewatered using a screw press or other suitable apparatus.
The dewatered fiber cake can be washed a second time using process water. The same (or substantially the same) mixing, time, and temperature ranges of the first wash can be applicable to the second wash. The process water may be potable grade water in some cases. The washed fiber can be again dewatered and dried. The dried fiber can be then milled to generate the processed fiber.
The liquid recovered from the dewatering step may be collected as starch water. The starch water may be processed by a starch concentrator to generate high solid starch water and the de-starched water (useable in the first wash as wash water). The high solids starch water can be provided to a fermentation system of the ethanol production facility for production of additional ethanol.
The final fiber product may have a composition of less than about 10% moisture, at least about 85% fiber on a dry weight basis, less than about 2-4% fat on a dry weight basis, less than about 1.5% ash on a dry weight basis, less than about 9% starch on a dry weight basis, and a low sulfite content. The fiber may also include less than about 2% starch. Additionally, the fiber may contain low mycotoxin levels, such as less than about 0.1 ppb Aflatoxin, less than about 0.1 ppm Fumonison, less than about 0.2 ppm Deoxynivalenol, and less than about 75 ppb Zearalenone.
Note that the various features described above may be practiced alone or in combination. These and other features will be described in more detail below in the detailed description and in conjunction with the following figures.
In order that the disclosed aspects may be more clearly ascertained, some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:
TABLE 1 provides example data for the composition of raw fiber on a dry weight basis, in accordance with some embodiments;
TABLE 2 provides example data for the composition of processed fiber on a dry weight basis, in accordance with some embodiments; and
TABLE 3 provides example data for mycotoxin levels before and after washing the fiber, in accordance with some embodiments.
Various aspects will now be described in detail with reference to several embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the various aspects. It will be apparent, however, to one skilled in the art, that embodiments may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the various aspects. The features and advantages of embodiments may be better understood with reference to the drawings and discussions that follow.
To provide for fiber that has low sulfur content, and to obtain benefits of generating food grade fiber from an ethanol production facility, the disclosed aspects relate to systems and methods that produce a low sulfur, food grade fiber composition from a dry fractionation corn ethanol production facility. Such systems and methods can provide a valuable co-product to existing ethanol production facilities and can provide a high quality fiber product for human consumption.
Further, the disclosed aspects relate to the composition of fiber from corn. Corn can be fractionated into a fiber component, an endosperm component, and a germ component. The fiber component can be refined to produce the composition of fiber with a high total dietary fiber (TDF) content (e.g., in a range of about 80 to 90 percent dry weight), a low starch content (e.g., in a range of around 0.5 to 5 percent dry weight), a low sulfite content (e.g., less than about 5 parts per million dry weight), and a low concentration of microbial contaminants (e.g., no more than about 1000 colony forming unit per gram). Various processes may be employed to refine corn fiber, including: a washing process and a mechanical separation process. The washing process can be configured to produce corn fiber with improved total dietary fiber concentration.
Generally, there can be significant economic benefits if the fiber production facility that generates fiber from corn is part of, or co-located with, an ethanol production facility. This is because the fiber component of the corn may be utilized to generate the fiber product, while the endosperm (starch) portion of the corn may be utilized to generate ethanol and other co-products (such as Dried Distillers Grains). Further, dry milled fiber, such as that generated at a fractionation ethanol plant can have lower microbial contamination and sulfur content than traditional fiber sources.
Referring to
Referring to
The thin stillage, that results when solids are removed from the whole stillage, can be used as a backset during the fermentation process and can also be used to increase the nutrient content of DDGS (Distillers Dried Grains with Solubles).
Referring now to
In this example fiber processing system 300, raw fiber 302 may be received from fractionated corn of an ethanol production facility fractionation mill (e.g., fractionation milling 210). The raw fiber 302 can be dry milled raw fiber, according to an aspect. In some embodiments, the raw fiber 302 may include corn bran; however, in some embodiments, the raw fiber may be derived from some other feedstock, such as sorghum bran, rice bran, or other suitable bran source.
The raw fiber 302 may be provided to a first wash tank 304 where heated de-starched water can be provided, and, through mechanical agitation, the fiber can be washed a first time. Fiber may be slurried in the wash tank at varying concentrations, but between about 5 and 25% solids are desirable. Further, the water may be heated to between around 60 and 200 degrees Fahrenheit. The washed fiber may be provided to a first dewatering system 306 for substantial removal of the liquids. The first dewatering system 306 may include a screw press, centrifuge, or other known dewatering device. In the case of a screw press, dewatering may be performed using a 0.015 inch screen and a 10 kilogram weight on the screw press, for example.
The dewatered fiber 308 may be provided to a second wash tank 310. Additionally, heated process water 312 may be provided to the second wash tank 310. Process water 312 may be from a municipal water source, or may be from another process system from the ethanol plant (e.g., cooling tower water). Generally, the process water needs to meet some threshold for purity, as the wash water quality affects the composition of the processed fiber.
The process water 312 may be heated via a heat source 314 prior to being added to the second wash tank 310. The heat source 314 may include a water heater, heat exchanger, or other suitable heat source. Being co-located with an ethanol production facility provides an added benefit of a readily available heat source (in the form of steam and heat exchanger devices).
Once the heated process water 312 has been added to the dewatered fiber 308 in the second wash tank 310, it may be mechanically agitated in order to perform the second wash on the fiber. The fiber may then be dewatered by a second dewatering system 316. Any suitable system for dewatering, such as a screw-press or centrifuge, may be utilized.
The dewatered fiber 318 may be provided to a fiber dryer 320. Fiber may be dried to a suitable moisture content in order to prevent the growth of contaminants. In accordance with some aspects, the fiber can be dried to a moisture of less than about 10%. The fiber may be milled to a suitable consistency at a fiber mill 322 to generate processed fiber 324. Processed fiber may be sold for any number of downstream food additive purposes.
Returning to the dewatering systems 306 and 316, the starch water 326 removed from the fiber can be conveyed to a starch water tank 328 for storage. The starch water may be supplied to a starch water concentrator 330 for concentrating the starch water. This may be performed using screens and membranes, centrifuge systems, and reverse osmosis systems, for example. The concentrated high solids starch water 332 may be supplied to the ethanol plant fermentation system (e.g., fermentation system 222) for conversion of the starch to ethanol. The de-starched water 334 may be heated by a heat source 336 and supplied to the first wash tank 304 for the washing of a next batch of raw fiber 302.
In accordance with some aspects, the processed fiber can be a composition of fiber comprising: at least 85% fiber on a dry weight basis, less than about 4% fat on a dry weight basis, less than about 1.5% ash on a dry weight basis, less than about 9% protein on a dry weight basis, and less than about 40 ppm sulfite. In some aspects, the composition of fiber comprises less than about 2% starch on a dry weight basis. In another aspect, the composition of fiber comprises less than about 1.5% starch on a dry weight basis. In a further aspect, the composition of fiber comprises less than about 2% fat on a dry weight basis. According to some aspects, the composition of fiber comprises less than about 0.1 ppb Aflatoxin. In another aspect, the composition of fiber comprises less than about 1 ppm Fumonison. In a further aspect, the composition of fiber comprises less than about 0.2 ppm Deoxynivalenol (DON). In another aspect, the composition of fiber comprises less than about 75 ppb Zearalenone. In yet another aspect, the composition of fiber comprises about 15 ppm sulfite.
It is readily understood by those skilled in the art that such a system could be readily expanded, if desired, to include greater numbers of wash stages. For example, it is conceivable that a three stage wash system may be desired whereby the final stage can be washed with process water, and the used wash water may be de-starched and provided to the second stage as the wash water. The resulting twice-used wash water may again be de-starched and supplied to the first wash stage as a wash water component. In such a way, less process water can be utilized to clean (or fully clean) the fiber, thereby reducing the water demands of the fiber production process.
The raw fiber can be washed with heated de-starched water (at 404). In an implementation, washing the raw fiber can be performed with the de-starched water at a temperature of about 60 to 200° F. For example, a heat exchanger can be utilized to increase the temperature of the de-starched water. The de-starched water can be recovered after a second wash, according to an aspect. In another example, washing the raw fiber can be performed with mechanical agitation for about 5 to 20 minutes. The washed fiber can be dewatered (at 406) to generate a first fiber cake. In an implementation, dewatering the washed fiber can include utilizing a screw press.
The first fiber cake can be washed (at 408) with substantially clean, heated water. In an implementation, the first fiber cake can be washed with process water. In an implementation, the process water can be at a temperature of about 60 to 200° F. For example, a heat exchanger can be utilized to increase the temperature of the process water. In another implementation, washing the dewatered first fiber cake can be performed with mechanical agitation for about 5 to 20 minutes. In an example, the process water can be potable grade water.
The fiber can be dewatered a second time (at 410) to generate a second fiber cake. In an implementation, dewatering the fiber a second time can include utilizing a screw press. The fiber cake may be dried (at 412) and milled (at 414) to generate a processed fiber product. For example, the fiber cake can be dried to a moisture of less than about 10%.
In a further implementation, the process can include recovering starch water from the fiber that is dewatered the second time and from the dewatered first fiber cake. The process can also include concentrating starch in the starch water to generate a high solid starch water and the de-starched water. Additionally, the process can include supplying the high solid starch water to a fermentation system at the fractionation ethanol production facility.
A series of limited examples were conducted according to an exemplary embodiment of a system (as shown in
In this example, samples for collection and analysis were produced by back calculating how much water would be needed to produce a 5% mixture of a known amount of fiber from a fractionation ethanol plant. The fiber concentration calculation took into account the moisture of the fiber. A 200 gallon tank was filled with the calculated amount of recycle water, including all solids, from the second screw press as described above with respect to
Eight samples were collected over a four-day period and compositions were analyzed pre-processing and post-processing. TABLE 1 provides example data for the composition of raw fiber on a dry weight basis. In contrast, TABLE 2 provides example data for the composition of processed fiber on a dry weight basis. The processing resulted in a dramatic reduction in starch content, reduction of fat and protein. Total fiber content is increased to around 90% after processing. In fact, as compared to specifications, all samples were shown to perform better than required.
Further, the processing of the raw fiber resulted in a reduction of mycotoxins in the product. TABLE 3 provides example data for mycotoxin levels (before and after washing) in the fiber. This reduction in toxins was unexpected because many of these toxins are not considered water soluble. A possible explanation for this reduction in toxins is the material that is being washed out has a higher amount of mycotoxin present, or these toxins are mostly on the surface of the removed starch and other components, so even though the toxins themselves are not water soluble they can be removed by washing off the components to which they are bound. This result is different from what traditionally has been experienced in washing processes with wet milled fiber. This could be due to the steeping process (used in wet milling) causing the mycotoxins to be driven into the fiber and making the rinsing less effective.
The embodiments as disclosed and described in the application (including the FIGURES and Examples) are intended to be illustrative and explanatory. Modifications and variations of the disclosed embodiments, for example, of the apparatus and processes employed (or to be employed) as well as of the compositions and treatments used (or to be used), are possible; all such modifications and variations are intended to be within the scope of the disclosed aspects.
The word “exemplary” is used to mean serving as an example, instance, or illustration. Any embodiment or design described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Rather, use of the word exemplary is intended to present concepts in a concrete fashion, and the disclosed subject matter is not limited by such examples.
The term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” To the extent that the terms “comprises,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, for the avoidance of doubt, such terms are intended to be inclusive in a manner similar to the term “comprising” as an open transition word without precluding any additional or other elements.
This application claims the benefit of U.S. Provisional Application Ser. No. 61/489,635, filed May 24, 2011, and entitled “SYSTEMS AND METHODS FOR PRODUCING A COMPOSITION OF FIBER”, the entirety of which is expressly incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61489635 | May 2011 | US |
