Fermentable acid hydrolyzates and fermentation process

Claim 3

A method for preconditioning acid hydrolyzates as claimed in claim 1 wherein said acid hydrolyzate provided in step (1) has a pH within the range of 0.5 to 1.5 and is derived from sawdust or newspaper.

Claim 4

A method for preconditioning acid hydrolyzate as claimed in claim 2 wherein prior to subjecting the hydrolyzate to steam, the hydrolyzate is partially neutralized to a pH of about 4 with a sufficient amount of calcium carbonate or ammonium hydroxide and the resulting precipitate is separated therefrom.

Claim 5

A method for preconditioning acid hydrolyzates as claimed in claim 3 wherein the mineral acid employed in step (3) is phosphoric acid.

Claim 6

A method of preconditioning acid hydrolyzates as claimed in claim 1 wherein said hydrolyzate is concentrated in step (4) to a glucose concentration of at least 100 grams per liter but less than 150 grams per liter.

Claim 7

A method for preconditioning acid hydrolyzates as claimed in claim 5 wherein acid hydrolyzate is concentrated by heating to about 35° C. under a vacuum of about 28 to 30 inches Hg.

Claim 10

A process for preconditioning acid hydrolyzate as claimed in claim 7 wherein said hydrolyzate is derived from sawdust or newspaper.

Claim 11

A process for preconditioning acid hydrolyzates as claimed in claim 7 wherein said hydrolyzate is concentrated in step (6) by heating to a temperature of about 35° C. under a vacuum of about 28 to 30 inches hg.

Claim 12

A process for the production of ethyl alcohol from glucose contained in an acid hydrolyzate derived from lignocellulosic materials, comprising the steps of: (1) preconditioning said acid hydrolyzate to negate the effect of substances tending to inhibit the fermentation thereof by subjecting said hydrolyzate to the method of claim 1; (2) inoculating the preconditioned hydrolyzate with yeast inoculum developed from a strain that is capable of growth in the hydrolyzate fermentation medium; (3) permitting said inoculated hydrolyzate to ferment at a pH of about 5 to 7 for a period sufficient to convert glucose to ethyl alcohol; and (4) recovering ethyl alcohol from the fermentation medium.

Claim 13

A process for the production of ethyl alcohol as claimed in claim 10 wherein said yeast is Baker's yeast.

Claim 14

A process for the production of ethyl alcohol as claimed in claim 11 wherein yeast cells are recovered from the fermentation mixture and recycled to a subsequent fermentation medium.

Claim 15

A process for the production of ethyl alcohol from glucose contained in an acid hydrolyzate derived from lignocellulosic materials, comprising the steps of: (1) providing an acid hydrolyzate comprising glucose, furfural and 5-hydroxymethylfurfural and having a pH of about 0.5 to 1.5; (2) preconditioning said hydrolyzate to negate the effect of substances tending to inhibit the fermentation thereof by subjecting said hydrolyzate to the method of claim 4; (3) inoculating the preconditioned hydrolyzate with yeast inoculum developed from a strain that is capable of growth in the hydrolyzate fermentation medium; (4) permitting said inoculated hydrolyzate to ferment at a pH of 5.5 to 7 for a period sufficient to convert glucose to ethyl alcohol; and (5) recovering ethyl alcohol from the fermentation medium.

Claim 16

A process for the production of ethyl alcohol from glucose contained in an acid hydrolyzate derived from lignocellulosic materials, comprising the steps of: (1) providing an acid hydrolyzate comprising glucose, furfural and 5-hydroxymethylfurfural; (2) preconditioning said hydrolyzate to negate the effect of substances tending to inhibit the fermentation thereof by subjecting said hydrolyzate to the steps of (a) steam-stripping furfural and other steam volatile substances therefrom; (b) adding sufficient calcium oxide to said steam-stripping hydrolyzate, at room temperature to adjust the pH to about 10.5 and maintaining said solution at said pH for a period of about 1 hour and separating the resulting precipitate from said hydrolyzate; (c) adjusting the pH of said hydrolyzate to about 5 to 7 with phosphoric acid and separating the resultant precipitate; and (d) adjusting the concentration of the neutralized hydrolyzate to a glucose concentration of at least about 100 grams per liter but less than 150 grams per liter; (3) inoculating said preconditioned hydrolyzate with Baker's yeast inoculum comprising from about 0.7 to about 7 dry weight percent of yeast cells per 100 grams per liter of glucose in said hydrolyzate; (4) fermenting said inoculated hydrolyzate at a pH of 5 to 7 for 20 to 1.5 hours to convert glucose to substantially quantitative amounts of ethyl alcohol; and (5) recovering ethyl alcohol from the fermentation mixture.

Claim 17

A process for the production of ethyl alcohol from glucose contained in an acid hydrolyzate derived from lignocellulosic materials, comprising the steps of: (1) providing an acid hydrolyzate comprising glucose, furfural and 5-hydroxymethylfurfural; (2) preconditioning said hydrolyzate to negate the effect of substances tending to inhibit the fermentation thereof by subjecting said hydrolyzate to the steps of (a) steam-stripping furfural and other steam volatile substances therefrom; (b) adding sufficient calcium oxide to said steam-stripping hydrolyzate, at room temperature to adjust the pH to about 10.5 and maintaining said solution at said pH for a period of about 1 hour and separating the resulting precipitate from said hydrolyzate; (c) adjusting the pH of said hydrolyzate to about 5 to 7 with phosphoric acid and separating the resultant precipitate; and (d) adjusting the concentration of the neutralized hydrolyzate to a glucose concentration of at least about 100 grams per liter but less than 150 grams per liter; (3) inoculating said preconditioned hydrolyzate with Baker's yeast inoculum comprising from about 0.7 to about 7 dry weight percent of yeast cells per 100 grams per liter of glucose in said hydrolyzate; (4) fermenting said inoculated hydrolyzate at a pH of 5 to 7 for 20 to 1.5 hours to convert glucose to substantially quantitative amounts of ethyl alcohol; and (5) recovering ethyl alcohol from the fermentation mixture.

Claim 18

A process for the production of ethyl alcohol as claimed in claim 14 wherein said hydrolyzate is derived from newspaper or sawdust.

Claim 19

A process for production of ethyl alcohol as claimed in claim 14 wherein said hydrolyzate is adjusted to a pH of about 4 with ammonium hydroxide prior to said preconditioning step.

Claim 20

A process for the production of ethyl alcohol as claimed in claim 14 wherein urea is added to said hydrolyzate prior to said inoculation step.

Claim 21

A process for the production of ethyl alcohol as claimed in claim 14 wherein the inoculum added in step (3) comprises from about 3 to 3.5 dry weight percent of yeast cells per 100 grams per liter of glucose in said hydrolyzate.

Claim 22

A process for the production of ethyl alcohol as claimed in claim 18 wherein said fermentation is complete in about 2 to 3 hours.

Claim 23

A process for the production of ethyl alcohol from glucose contained in an acid hydrolyzate derived from a lignocellulosic material which comprises the steps of: (1) introducing into a fermentor an acid hydrolyzate that has been preconditioned to negate the effect of substances tending to inhibit the fermentation thereof by the method of claim 1, said fermentor containing a performed yeast culture capable of growth in said hydrolyzate medium; (2) substantially continuously maintaining said yeast culture in said fermentor at a concentration of about 0.7 to about 7 dry weight percent cells per 100 grams per liter of glucose in said fermentor; (3) permitting said hydrolyzate to ferment at a pH of 5 to 7 for a period sufficient to convert glucose to ethyl alcohol; (4) removing an ethyl alcohol stream from the fermentor; (5) separating yeast cells from said ethyl alcohol stream; and (6) reconcentrating said yeast cells and recycling the concentrated cells to said yeast culture maintained in said fermentor.

Claim 24

A method for preconditioning acid hydrolyzate as claimed in claim 1 wherein said hydrolyzate is separated from precipitate formed in step (2).

Claim 25

A method for preconditioning acid hydrolyzates as claimed in claim 1 wherein said hydrolyzate is separated from precipitate formed in step (3).

Claim 26

A method for preconditioning acid hydrolyzates as claimed in claim 1 wherein said hydrolyzate is separated from precipitate formed in steps (2) and (3).

Claim 29

A fermentable solution produced in accordance with the method of claim 1.

Claim 30

A fermentable solution produced in accordance with the method of claim 7.

Claim 31

A fermentable solution produced in accordance with the method of claim 24.