Alcohol manufacturing process

Claim 2

A process for the conversion of cellulosic material into fermentable sugars, the process consisting essentially of the following steps: obtaining a feedstock, at least a portion of which is a cellulosic material; contacting the cellulosic material with a concentrated delignifying acid said concentrated delignifying acid being in a liquid phase and having a temperature of less than about 60° F. and having a concentration of from about 60% to about 90% acid by volume, thereby producing a cellulose-containing solution and a solid residue; removing the solid residue from the cellulose-containing solution; precipitating cellulose from the cellulose-containing solution; and hydrolyzing the precipitated cellulose with a dilute hydrolyzing acid, thereby producing fermentable sugars.

Claim 3

A process as defined in claim 1 wherein the cellulosic material is a waste material selected from the group consisting of corn residue, forestry, feedlot, crop, urban, and industrial wastes.

Claim 4

A process as defined in claim 1 wherein the concentrated acid is concentrated sulfuric acid.

Claim 5

A process as defined in claim 1 wherein the dilute hydrolyzing acid has a concentration of about 0.5% to about 10% acid by volume.

Claim 6

A process as defined in claim 4 wherein the dilute hydrolyzing acid is dilute sulfuric acid.

Claim 7

A process as defined in claim 4 wherein during the hydrolyzing step the precipitated cellulose is hydrolyzed at a temperature within the range of about 200° F. to about 400° F. at a pressure from about 15 psi to about 200 psi for a period of about two minutes to about ten minutes.

Claim 8

A process as defined in claim 1 wherein the cellulose is precipitated from the cellulose-containing solution by diluting the cellulose-containing solution with methanol.

Claim 9

A process as defined in claim 1 wherein the cellulosic material comprises cellulose and hemicellulose and wherein the process further comprises the steps of: dissolving at least a portion of the hemicellulose in the cellulosic material with a dilute hemicellulose-dissolving acid prior to treating the cellulosic material in the contacting step, thereby producing a hemicellulose-containing solution and leaving undissolved cellulosic material to be treated in the contacting step; and separating the hemicellulose-containing solution from the undissolved cellulosic material.

Claim 10

A process as defined in claim 8 wherein the concentration of the dilute hemicellulose-dissolving acid is from about 0.5% to about 2.0% acid by volume.

Claim 11

A process as defined in claim 9 wherein the the dilute hemicellulose-dissolving acid is dilute sulfuric acid.

Claim 12

A process as defined in claim 9 wherein during the dissolving step the cellulosic material and the dilute hemicellulose-dissolving acid are heated to a temperature within the range of about 200° F. to about 300° F. at a pressure of about 5 psi to about 50 psi for a period of about two minutes to about ten minutes.

Claim 13

A process for the conversion of cellulosic material to fermentable sugars, the process consisting essentially of the following steps: obtaining a feedstock, at least a portion of which is a cellulosic material; dissolving at least a portion of the cellulosic material with a first dilute sulfuric acid having a concentration of from about 0.5% to about 2.0% sulfuric acid by volume at a temperature of from about 200° F. to about 300° F. at a pressure of about 5 psi to about 50 psi for a period of about two minutes to about ten minutes, thereby producing a hemicellulose-containing solution and leaving undissolved cellulosic material; separating the hemicellulose-containing solution from the undissolved cellulosic material; contacting the undissolved cellulosic material with concentrated sulfuric acid cooled to a temperature of about 30° F. to about 60° F. for a period of about one minute to about ten minutes, thereby producing a cellulose-containing solution and a solid residue; removing the solid residue from the cellulose-containing solution; precipitating cellulose from the cellulose-containing solution by diluting the cellulose-containing solution with methanol; and hydrolyzing the hemicellulose and the precipitated cellulose with a second dilute sulfuric acid having a concentration of about 0.5% to about 10% sulfuric acid by volume at a temperature of about 200° F. to about 400° F. at a pressure of about 15 psi to about 200 psi for a period of about two minutes to about ten minutes.

Claim 14

A process for the conversion of cellulosic material to fermentable sugars, the process consisting essentially of the following steps: obtaining a feedstock, at least a portion of which is a cellulosic material; dissolving at least a portion of the cellulosic material with a first dilute sulfuric acid having a concentration of from about 0.5% to about 2.0% sulfuric acid by volume at a temperature of from about 200° F. to about 300° F. at a pressure of about 5 psi to about 50 psi for a period of about two minutes to about ten minutes, thereby producing a hemicellulose-containing solution and leaving undissolved cellulosic material; separating the hemicellulose-containing solution from the undissolved cellulosic material; contacting the undissolved cellulosic material with concentrated sulfuric acid cooled to a temperature of about 30° F. to about 60° F. for a period of about one minute to about ten minutes, thereby producing a cellulose-containing solution and a solid residue; removing the solid residue from the cellulose-containing solution; precipitating cellulose from the cellulose-containing solution by diluting the cellulose-containing solution with methanol; and hydrolyzing the hemicellulose and the precipitated cellulose with a second dilute sulfuric acid having a concentration of about 0.5% to about 10% sulfuric acid by volume at a temperature of about 200° F. to about 400° F. at a pressure of about 15 psi to about 200 psi for a period of about two minutes to about ten minutes.

Claim 15

A process for the production of alcohol from cellulosic material, the process comprising the steps of: obtaining a feedstock, at least a portion of which is a cellulosic material; contacting the cellulosic material with concentrated delignifying acid said concentrated delignifying acid being in a liquid phase and having a temperature of less than about 60° F. and having a concentration of from about 60% to about 90% acid by volume, thereby producing a cellulose-containing solution and a solid residue; removing the solid residue from the cellulose-containing solution; precipitating cellulose from the cellulose-containing solution; hydrolyzing the precipitated cellulose with a dilute hydrolyzing acid, thereby producing fermentable sugars; introducing the fermentable sugars into a vessel; mixing yeast with the fermentable sugars and fermenting the fermentable sugars to produce alcohol and carbon dioxide; removing alcohol vapor and carbon dioxide from the vessel under a partial vacuum, said removal being aided by sparging a gas throughout the fermentable sugars in the vessel at a rate of about 0.01 to about 0.5 cubic feet per minute per gallon of fermentable sugars in the vessel; concentrating the alcohol vapor by passing the alcohol vapor and carbon dioxide through a distillation column under the partial vacuum while refluxing liquid alcohol through the distillation column, the vessel being in gaseous communication with the distillation column; and condensing the alcohol vapor which has passed through the distillation column, producing liquid alcohol and thereby creating at least a portion of the partial vacuum in the vessel.

Claim 16

A process for the production of alcohol from cellulosic material, the process comprising the steps of: obtaining a feedstock, at least a portion of which is a cellulosic material; contacting the cellulosic material with concentrated delignifying acid said concentrated delignifying acid being in a liquid phase and having a temperature of less than about 60° F. and having a concentration of from about 60% to about 90% acid by volume, thereby producing a cellulose-containing solution and a solid residue; removing the solid residue from the cellulose-containing solution; precipitating cellulose from the cellulose-containing solution; hydrolyzing the precipitated cellulose with a dilute hydrolyzing acid, thereby producing fermentable sugars; introducing the fermentable sugars into a vessel; mixing yeast with the fermentable sugars and fermenting the fermentable sugars to produce alcohol and carbon dioxide; removing alcohol vapor and carbon dioxide from the vessel under a partial vacuum, said removal being aided by sparging a gas throughout the fermentable sugars in the vessel at a rate of about 0.01 to about 0.5 cubic feet per minute per gallon of fermentable sugars in the vessel; concentrating the alcohol vapor by passing the alcohol vapor and carbon dioxide through a distillation column under the partial vacuum while refluxing liquid alcohol through the distillation column, the vessel being in gaseous communication with the distillation column; and condensing the alcohol vapor which has passed through the distillation column, producing liquid alcohol and thereby creating at least a portion of the partial vacuum in the vessel.