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 corn grain to produce a milled stream, wherein the milled stream comprises starch, fiber and germ;
(b) downstream from dry milling, separating starch into a first stream, wherein the separating forms a second stream comprising fiber, germ and starch;
(c) providing the first stream to a non-ethanol process, wherein the non-ethanol process comprises producing one or more non-ethanol bio-products from starch in the first stream; and
(d) exposing at least a portion of the starch, the fiber, and the germ from the second stream to fermentation conditions to produce ethanol from starch.
2. The process of claim 1 , further comprising:
(a) saccharifying starch in the second stream into sugar; and
(b) fermenting sugar in the second stream into ethanol.
3. The process of claim 2 , wherein saccharifying is performed before fermenting.
4. The process of claim 2 , wherein saccharifying and fermenting are performed simultaneously.
5. The process of claim 2 , further comprising processing the second stream through a grinding operation prior to saccharifying starch into sugar.
6. The process of claim 1 , further comprising processing starch in the first stream into sugar.
7. The process of claim 6 , wherein processing starch in the first stream comprises:
enzymatically hydrolyzing starch into one or more dextrins; and
enzymatically hydrolyzing one or more dextrins into one or more sugars.
8. The process of claim 2 , further comprising:
distilling ethanol to form whole stillage;
separating thin stillage from whole stillage; and
evaporating water from thin stillage to form syrup.
9. A process according to claim 1 , wherein the first stream comprises up to about 50% of the soft endosperm in the corn.
10. A process according to claim 1 , wherein dry milling results in at least a portion of soft endosperm having a size of 500 microns or less to facilitate separating the portion of soft endosperm from the corn grain by size.
11. The process of claim 1 , wherein dry milling comprises milling corn grain with a pin mill.
12. The process of claim 1 , further comprising:
a) saccharifying starch in the first stream into sugar; and
b) after saccharifying starch in the first stream, producing one or more non-ethanol bio-products.
13. The process of claim 1 , wherein the first stream comprises at least 88% starch on a dry basis.
14. The process of claim 1 , wherein the first stream comprises at least 90% starch on a dry basis.
15. The process of claim 1 , wherein the first stream comprises at least 94% starch on a dry basis.
16. The process of claim 1 , wherein producing one or more non-ethanol bio-products from starch in the first stream comprises refining the first stream to increase purity of starch in the first stream, and wherein the one or more non-ethanol bio-products comprise starch.
17. The process of claim 1 , wherein producing one or more non-ethanol bio-products from starch in the first stream comprises providing the first stream to a fermentation process to produce a non-ethanol bio-chemical, wherein the one or more non-ethanol bio-products comprise the bio-chemical.
18. The process of claim 1 , wherein the one or more non-ethanol bio-products comprise starch.
19. The process of claim 1 , wherein the one or more non-ethanol bio-products comprise one or more non-ethanol bio-chemicals produced via fermentation.
20. The process of claim 1 , wherein the one or more non-ethanol bio-products comprise sugar.