Process for Integrating Cellulose and Starch Feedstocks in Ethanol Production
The present invention is directed to process integrating cellulose and starch feedstocks to produce ethanol.
1 . A method of producing ethanol, comprising:
(1) providing a fermented beer from a cellulose fermentation;
(2) mixing said fermented beer with a starch source to form a mixed mash;
(3) mixing said mixed mash with a starch enzyme composition and yeast; and
(4) incubating for a period of fermentation time at a first temperature between 20 to 78° C. to produce ethanol.
2 . The method according to claim 1 , wherein said starch enzyme composition is produced with the Aspergillus phoenicis deposited as NRRL 50090.
3 . The method according to claim 1 , wherein said starch enzyme composition is produced by growing a fungus on a solid state substrate.
4 . The method according to claim 1 , wherein said cellulose fermentation comprises:
(a) providing a cellulostic feedstock that is adjusted to pH 4 to 6;
(b) mixing said cellulostic feedstock with a cellulase enzyme composition and yeast; and
(c) incubating for a period of fermentation time under a second temperature between 20 to 40° C. to produce said fermented beer.
5 . The method according to claim 4 , wherein said cellulase enzyme composition is produced with the Trichoderma reesei strain ATCC 56765.
6 . The method according to claim 4 , wherein said cellulase enzyme composition is produced by growing a fungus on a solid state substrate.
7 . The method according to claim 4 , wherein said incubating is conducted at pH 4.5 to 5.0.
8 . The method according to claim 1 , wherein said fermented beer contains less than 7% (w/w) ethanol.
9 . The method according to claim 8 , wherein said fermented beer contains about 2.5 to 6% (w/w) ethanol.
10 . The method according to claim 1 , wherein said first temperature is about 35° C.
11 . The method according to claim 1 , wherein said method is carried at a temperature lower than the boiling point of ethanol.
12 . The method according to claim 1 , wherein said ethanol produced is less than 15% (w/w).
13 . The method according to claim 1 , wherein said method further comprising collecting said ethanol.
14 . The method according to claim 13 , further comprises distilling said ethanol.
15 . The method according to claim 1 , wherein said starch source is un-gelatinized.
16 . The method according to claim 1 , wherein said starch source is gelatinized.