High purity starch stream methods and systems
Methods and systems for isolating a high purity starch stream are provided. The methods provide an initial treatment step in advance of traditional grinding or fractionation operations (such as dry milling or wet milling operations) that facilitate separation of starch from other components of starch-based grains, for example facilitate separation of soft endosperm from other components of corn kernels including hard endosperm. The systems include a first treatment system for separating a high purity starch stream from other components of the grain stream, wherein the system can be configured as a bolt on for traditional milling operations such as wet milling and dry milling operations.
1. A process for producing starch streams in a dry mill ethanol fermentation facility, the process comprising:
(a) dry milling a corn grain to produce a first treated stream including soft endosperm, hard endosperm, and other corn grain components; wherein the other corn grain components comprise bran and germ;
(b) separating the first treated stream into a second stream and a third stream, the second stream being a high starch stream comprising soft endosperm;
(c) providing the second stream to a non-ethanol process, wherein the non-ethanol process comprises producing one or more non-ethanol bio-chemicals from the second stream; and
(d) processing the third stream in a fermentation process into ethanol;
wherein the third stream comprises hard endosperm and other corn grain components; wherein the other corn grain components comprise bran and germ;
wherein the dry mill ethanol fermentation facility is the facility for producing the first, second and third streams;
and wherein the third stream produces an ethanol titer similar to an ethanol titer produced by the same ethanol facility without the step of separating the first treated stream into a second and third stream.
2. A process according to claim 1 , wherein milling comprises milling the corn grain with a pin mill.
3. A process according to claim 1 , wherein the separating the first treated stream into the second stream and the third stream produces the second stream comprising up to about 50% of the soft endosperm in the corn grain.
4. A process according to claim 1 , wherein milling the corn grain results in at least a portion of the soft endosperm having a sufficiently small enough size to facilitate separating the portion of soft endosperm from the first treated stream by size.
5. A process according to claim 4 , wherein the size is about 500 microns or less.
6. A process according to claim 1 , wherein the separating the first treated stream into the second stream and the third stream produces the second stream comprising at least about 90% starch on a dry basis.
7. A process according to claim 1 , wherein the separating the first treated stream into the second stream and the third stream produces the second stream comprising at least about 94% starch on a dry basis.
8. A process according to claim 1 , wherein milling the corn grain comprises increasing the amount of corn milled to provide starch to the third stream to counteract the loss of starch removed in forming the second stream.
9. A process according to claim 8 , further comprising removing at least a portion of additional non-starch components present in the first or third stream as a result of increasing the amount of corn milled to achieve a ratio of fermentable to non-fermentable components in the third stream sufficiently equivalent to that of a corn fermentation process for which soft endosperm has not been removed.
10. A process according to claim 1 , wherein the separating the first treated stream into the second stream and the third stream produces the second stream comprising substantially free of hard endosperm.
11. A process according to claim 1 , wherein the separating the first treated stream into the second stream and the third stream produces the second stream comprising at least about 88% starch on a dry basis.
12. A process according to claim 1 , further comprising, prior to milling, moisture adjusting the corn grain.
13. A process according to claim 1 , further comprising, prior to milling, temperature adjusting the corn grain.