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, comprising:
pretreating corn grain to produce a pretreated corn grain that facilitates separation of at least a portion of soft endosperm from the corn grain;
separating a first stream comprising soft endosperm from the pretreated corn grain resulting in a second stream suitable for use as feedstock in a fermentation process, wherein the second stream comprises fiber, germ, and starch;
exposing at least a portion of the second stream to fermentation conditions to produce ethanol; and
providing the first stream to a non-ethanol process, wherein the non-ethanol process comprises producing one or more non-ethanol bio-products.
2 . The process of claim 1 , further comprising processing starch in the first stream into sugar.
3 . The process of claim 2 , 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.
4 . The process of claim 1 , further comprising saccharifying the starch in the first stream into sugar.
5 . The process of claim 4 , further comprising, after saccharifying starch in the first stream, producing one or more non-ethanol bio-products.
6 . The process of claim 1 , further comprising:
saccharifying starch in the second stream into sugar; and
fermenting sugar in the second stream into ethanol.
7 . The process of claim 6 , wherein saccharifying is performed before fermenting.
8 . The process of claim 6 , wherein saccharifying and fermenting are performed simultaneously.
9 . The process of claim 6 , further comprising processing the second stream through a grinding operation prior to saccharifying starch into sugar.
10 . The process of claim 6 , further comprising:
distilling ethanol to form whole stillage;
separating thin stillage from whole stillage; and
evaporating water from thin stillage to form syrup.
11 . The process of claim 1 , wherein producing one or more non-ethanol bio-products 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.
12 . The process of claim 1 , wherein producing one or more non-ethanol bio-products 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.
13 . The process of claim 1 , wherein the one or more non-ethanol bio-products comprise starch.
14 . 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.
15 . The process of claim 1 , wherein the one or more non-ethanol bio-products comprise sugar.
16 . The process of claim 1 , wherein the first stream comprises at least 88% starch on a dry basis.
17 . The process of claim 1 , wherein the first stream comprises at least 90% starch on a dry basis.
18 . The process of claim 1 , wherein the first stream comprises at least 94% starch on a dry basis.
19 . The process of claim 1 , wherein pretreating corn grain comprises milling corn grain.
20 . The process of claim 1 , wherein pretreating corn grain comprises milling corn grain with a pin mill.