Process for separating organic liquid solutes from their solvent mixtures
First Claim
1. A process for separating an organic liquid from an organic liquid/solvent mixture, comprising the steps of(a) contacting a mixture of an organic liquid solute and a solvent for said solute with an extractant fluid under conditions of temperature and pressure to render said extractant fluid a solvent for said organic liquid solute but substantially less for said solvent, thereby forming a fluid extract of said organic liquid solute in said extractant fluid and a raffinate comprising said solvent with minor amounts of said extractant fluid and organic liquid solute, said extractant fluid being a gas at ordinary ambient conditions of temperature and pressure;
- (b) separating said fluid extract and said raffinate;
(c) providing said fluid extract as a still feed separable into two phases by distillation;
(d) distilling said still feed to produce a still overhead vapor and liquid still bottoms;
(e) compressing said still overhead vapor to provide compressed vapor at an elevated temperature;
(f) effecting indirect heat exchange between said compressed vapor and said still bottoms to provide the thermal energy required in said distilling step, and to form a liquid condensate of said vapor;
12 Assignments
0 Petitions
Accused Products
Abstract
Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.
-
Citations
33 Claims
-
1. A process for separating an organic liquid from an organic liquid/solvent mixture, comprising the steps of
(a) contacting a mixture of an organic liquid solute and a solvent for said solute with an extractant fluid under conditions of temperature and pressure to render said extractant fluid a solvent for said organic liquid solute but substantially less for said solvent, thereby forming a fluid extract of said organic liquid solute in said extractant fluid and a raffinate comprising said solvent with minor amounts of said extractant fluid and organic liquid solute, said extractant fluid being a gas at ordinary ambient conditions of temperature and pressure; -
(b) separating said fluid extract and said raffinate; (c) providing said fluid extract as a still feed separable into two phases by distillation; (d) distilling said still feed to produce a still overhead vapor and liquid still bottoms; (e) compressing said still overhead vapor to provide compressed vapor at an elevated temperature; (f) effecting indirect heat exchange between said compressed vapor and said still bottoms to provide the thermal energy required in said distilling step, and to form a liquid condensate of said vapor; - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
2. (g) recovering a liquid bottoms product comprising said liquid solute;
-
(h) recycling said liquid condensate as extractant fluid in said contacting step; (i) flashing off said extractant fluid from said raffinate to provide a raffinate vapor flash; (j) flashing off residual vapor from said still bottoms to form decompressed still bottoms; and (k) separating liquid organic product from said decompressed still bottoms, thereby recovering said liquid bottoms product and producing a vapor flash.
-
-
23. A process for separating an oxygenated hydrocarbon liquid from an aqueous mixture, comprising the steps of
(a) contacting a mixture of an oxygenated hydrocarbon liquid and water with solvent-condition carbon dioxide fluid at a pressure between about 30 and about 150 atmospheres and a temperature between about 0° - and 150°
C., thereby forming a carbon dioxide fluid extract of said oxygenated hydrocarbon liquid and a raffinate comprising water with minor amounts of said carbon dioxide and oxygenated hydrocarbon liquid;(b) separating said carbon dioxide fluid extract from said raffinate; (c) reducing the pressure on said carbon dioxide fluid extract to form a still feed separable into two phases by distillation; (d) distilling said still feed to produce a still overhead comprising essentially all carbon dioxide vapor and still bottoms; (e) recompressing said carbon dioxide vapor from step (d) to provide recompressed carbon dioxide at a pressure essentially equivalent to that of said solvent-condition carbon dioxide used in step (a) and at a temperature above the boiling point of said still bottoms; (f) effecting indirect heat exchange between said recompressed carbon dioxide and said still bottoms to provide the thermal energy required in said distilling step and to form a carbon dioxide liquid condensate; (g) recovering a liquid bottoms product containing said oxygenated hydrocarbon; (h) recycling said carbon dioxide liquid condensate as said solvent-condition carbon dioxide in step (a); (i) flashing off said carbon dioxide from said raffinate to provide a raffinate carbon dioxide vapor flash; (j) flashing off residual carbon dioxide from said still bottoms to form decompressed still bottoms; (k) separating liquid oxygenated hydrocarbon product from said decompressed still bottoms and producing a carbon dioxide vapor flash; (l) combining said carbon dioxide vapor flashes from steps (i) and (k); (m) converting the combined vapor flashes to solvent-condition carbon dioxide fluid; and (n) combining said carbon dioxide fluid of step (m) with said carbon dioxide fluid condensate of step (f).
- and 150°
Specification