Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
211 words
A process for obtaining anhydrous ethanol from a dilute aqueous ethanol feed containing one or more low boiling impurities in an amount which would perceptibly interfere with the proper operation of a decanter employing a heads stripping column for removal of at least as much of the low boiling impurities in the ethanol feed as is necessary to provide proper operation of the decanter, a rectifying column for concentrating the ethanol, an anhydrous column for drying the ethanol substantially to completeness using an azeotrope-forming agent, and a decanter for separating an upper phase rich in azeotrope-forming agent from a lower phase made up largely of water, which comprises: (a) providing means for obtaining said anhydrous ethanol consisting essentially of said heads stripping column, said rectifying column and said anhydrous column; (b) stripping the dilute ethanol feed in the heads stripping column operated with thermal values contained in sidestream vapor withdrawn from the rectifying column; (c) concentrating the stripped dilute ethanol feed in the rectifying column; and, (d) azeotropically distilling the concentrated ethanol in the anhydrous column operated under substantially superatmospheric pressure to provide substantially anhydrous ethanol with thermal values recovered from the anhydrous column overhead being used to satisfy part or all of the thermal operating requirements of the rectifying column.
Claim 2
Dependent Claim
211 words
A process for obtaining anhydrous ethanol from a dilute aqueous ethanol feed containing one or more low boiling impurities in an amount which would perceptibly interfere with the proper operation of a decanter employing a heads stripping column for removal of at least as much of the low boiling impurities in the ethanol feed as is necessary to provide proper operation of the decanter, a rectifying column for concentrating the ethanol, an anhydrous column for drying the ethanol substantially to completeness using an azeotrope-forming agent, and a decanter for separating an upper phase rich in azeotrope-forming agent from a lower phase made up largely of water, which comprises: (a) providing means for obtaining said anhydrous ethanol consisting essentially of said heads stripping column, said rectifying column and said anhydrous column; (b) stripping the dilute ethanol feed in the heads stripping column operated with thermal values contained in sidestream vapor withdrawn from the rectifying column; (c) concentrating the stripped dilute ethanol feed in the rectifying column; and, (d) azeotropically distilling the concentrated ethanol in the anhydrous column operated under substantially superatmospheric pressure to provide substantially anhydrous ethanol with thermal values recovered from the anhydrous column overhead being used to satisfy part or all of the thermal operating requirements of the rectifying column.
Claim 3
Dependent Claim
31 words
The process of claim 1 wherein prior to introduction into the heads stripping column, the dilute ethanol feed is preheated with thermal values recovered from the heads stripping column overhead vapor.
Claim 4
Dependent Claim
32 words
The process of claim 1 wherein prior to introduction into the heads stripping column, the dilute ethanol feed is preheated with thermal values recovered from the rectifying column overhead vapor and/or bottoms.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein the azeotrope-forming agent is cyclohexane.
Claim 6
Dependent Claim
26 words
The process of claim 1 wherein the ethanol feed contains high boiling impurities which are removed therefrom as a liquid sidestream taken from the rectifying column.
Claim 7
Dependent Claim
15 words
The process of claim 1 wherein the ethanol feed is obtained from a fermentation process.
Claim 8
Dependent Claim
20 words
The process of claim 1 wherein the anhydrous column is operated at from about 60 to about 150 psig pressure.
Claim 9
Dependent Claim
20 words
The process of claim 7 wherein the anhydrous column is operated at from about 80 to about 130 psig pressure.