Recovery of 3,4-epoxy-1-butene by extractive distillation
AssigneeEastman Chemical Company
InventorsScott Donald Barnicki, Robert Sterling Kline
Life of this patent
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Abstract
Disclosed is a process for the recovery and purification of 3,4-epoxy-1-butene (epoxybutene) from mixtures comprising epoxybutene and aliphatic and aromatic hydrocarbons containing five to seven carbon atoms having boiling points between about 20° C. and 115° C. by means of extractive distillation of the epoxybutene using certain extractive distillation solvents.
Claims9
Process for the separation of 3,4-epoxy-1-butene (epoxybutene) from a mixture comprising epoxybutene and at least one aliphatic or aromatic hydrocarbon containing five to seven carbon atoms and having a boiling point of between about 20 and 115° C. which comprises the steps of:
- (1) feeding a mixture comprising epoxybutene and at least one hydrocarbon selected from aliphatic or aromatic hydrocarbons containing five to seven carbon atoms and having boiling points of between about 20 and 115° C., to the mid-section of an extractive distillation column;
- (2) feeding an extractive distillation solvent to the upper section of the extractive distillation column;
- (3) removing from the upper section or top of the extractive distillation column a vapor comprising the hydrocarbon;
- (4) removing from the lower section or base of the extractive distillation column a liquid comprising epoxybutene and extractive distillation solvent;
- and
- (5) separating the liquid of step (4) into epoxybutene and extractive distillation solvent;
- wherein the extractive distillation solvent (i) is inert, (ii) does not form an azeotrope with either epoxybutene or the hydrocarbon, (iii) is miscible with epoxybutene and the hydrocarbon, (iv) has a boiling point at least about 20° C. higher than the higher boiling point of epoxybutene and the hydrocarbon, and (v) creates a large relative volatility difference between epoxybutene and the hydrocarbon;
- and wherein the extractive distillation solvent is selected from the group consisting of C3 to C12 alcohols, C5 to C12 aliphatic ketones;
- alkyl alkanoate esters containing a total of 6 to 12 carbon atoms, C6 to C12 aliphatic and cyclic ethers, glycol ethers containing a total of 4 to 12 carbon atoms, glycol ether esters containing a total of 5 to 12 carbon atoms, polar aprotic solvents, and mixtures thereof.
Process for the separation of 3,4-epoxy-1-butene (epoxybutene) from a mixture comprising epoxybutene and at least one aliphatic or aromatic hydrocarbon containing five to seven carbon atoms and having a boiling point of between about 20 and 115° C. which comprises the steps of:
- (1) feeding a mixture comprising epoxybutene and at least one hydrocarbon selected from aliphatic or aromatic hydrocarbons containing five to seven carbon atoms and having boiling points of between about 20 and 115° C., to the mid-section of an extractive distillation column comprising 7 to 50 theoretical stages;
- (2) feeding an extractive distillation solvent to the upper section of the extractive distillation column;
- (3) removing from the upper section or top of the extractive distillation column a vapor comprising the hydrocarbon;
- (4) removing from the lower section or base of the extractive distillation column a liquid comprising epoxybutene and extractive distillation solvent;
- and
- (5) separating the liquid of step (4) into epoxybutene and extractive distillation solvent;
- wherein the extractive distillation solvent is selected from the group consisting of 4-methyl-2-pentanone, 2-heptanone, 5-methyl-2-hexanone, n-butyl acetate, and propylene glycol monomethyl ether acetate, the temperature at the top stage of the extractive distillation column is from about 10 to 90° C., the temperature at the base of the extractive distillation column is about 100 to 240° C., and the pressure within the extractive distillation column is about 0.1 to 4 bars absolute (bara).
Dependencies are inferred from the claim text.