Abstract: The present invention provides a method for separating conjunct polymers which are formed as byproducts of acid catalyzed isoparaffin-olefin alkylation and sulfolane from a mixture containing conjunct polymers, sulfolane, and hydrofluoric acid comprising the sequential steps of:(a) separating hydrofluoric acid from a mixture containing conjunct polymers, sulfolane, and hydrofluoric acid to provide a first intermediate stream containing less than about 30 percent hydrofluoric acid by weight;(b) mixing said intermediate stream with a nonpolar extraction solvent to provide a second intermediate stream; and(c) gravitationally separating said intermediate stream into a less dense extract stream enriched in conjunct polymers and a more dense liquid stream enriched in sulfolane.

Abstract: Described is a novel process for regenerating an ASO contaminated alkylation catalyst which contains a sulfone component and a hydrogen halide component. The alkylation catalyst undergoes a series of separation steps to remove a significant portion of the hydrogen halide component contained therein followed by a phase separation between an ASO phase and a sulfone phase. The sulfone phase is then contacted with a carbon material to remove a portion of any remaining ASO contained in the sulfone.

Abstract: Disclosed is a process for removing acid soluble oils, produced as an undesirable by-product of an HF catalyzed alkylation reaction, from a liquid containing a sulfone compound. The process includes the use of a solvent to extract the acid soluble oils from a sulfone-containing fluid that has previously been neutralized by a treating step.

Abstract: This invention provides a method for separating ASO from a mixture containing ASO, HF and sulfolane comprising the steps of:(a) contacting said mixture with a sorbent to selectively sorb HF and water from said mixture to evolve an intermediate product containing less than 5 weight percent HF;(b) charging said intermediate product to a gravitational separation zone;(c) holding said intermediate product in said gravitational separation zone for time sufficient to evolve two at least partially immiscible liquid phases in said gravitational separation zone; and(d) withdrawing a less-dense phase enriched in ASO and a more-dense phase enriched in sulfolane from said gravitational separation zone.

Abstract: The present invention provides a method for separating conjunct polymers which are formed as byproducts of acid catalyzed isoparaffin-olefin alkylation and sulfolane from a mixture containing conjunct polymers, sulfolane, and hydrofluoric acid comprising the sequential steps of:(a) separating hydrofluoric acid from said mixture to provide an intermediate stream containing less than about 30 percent hydrofluoric acid by weight;(b) gravitationally separating said intermediate stream into a more dense sulfolane-enriched stream and a less dense conjunct polymer-enriched stream;(c) distilling said more dense sulfolane-enriched stream of step (b) to provide an overhead stream containing a higher sulfolane concentration than said more dense sulfolane-enriched stream of step (b) and a bottom stream enriched in conjunct polymers.

Abstract: The present invention provides a method for separating sulfolane from a mixture containing conjunct polymers, sulfolane, and hydrofluoric acid comprising the sequential steps of:(a) removing HF from said mixture to provide an intermediate stream containing less than about 30 weight percent HF;(b) contacting said intermediate stream with water;(c) contacting said intermediate stream with an aliphatic hydrocarbon co-solvent having from about 3 to about 20 carbon atoms concurrently with said water-contacting step (b);(d) recovering an extract stream enriched in sulfolane and hydrofluoric acid; and(e) recovering a raffinate stream enriched in conjunct polymers.

Abstract: Octene-1 is difficult to separate from several of its isomers by conventional distillation or rectification because of the closeness of their boiling points. Octene-1 can be readily separated from its close boiling isomers by azeotropic or extractive distillation. Effective agents are: for azeotropic distillation, t-amyl methyl ether; for extractive distillation, isophorone.

Abstract: The separation by conventional distillation or rectification of methyl t-butyl ether from close boiling hydrocarbons is difficult because of the closeness of their vapor pressures. Methyl t-butyl ether can be readily separated from these by extractive distillation. Examples of effective agents are: from 1-pentene, dimethylsulfoxide; from cyclopentane, sulfolane and from n-pentane - cyclopentane mixtures, diethyl malonate.

Abstract: A method is provided for the recovery of aromatic hydrocarbons from the extract phase of aromatic-selective solvent extraction process which involves withdrawing a vapor side-cut fraction containing aromatic hydrocarbons and solvent from a stripping zone and passing the side-cut fraction to a rectification zone which can be refluxed with an aqueous condensate. The benefits of the invention are that the introduction of the rectification zone bottoms to the bottom of the stripping section provides an aromatic product comprising less than 100 wt. ppm. solvent, provides improved stripping over prior schemes, and reduces the flowrate of stripping medium throughout the stripping zone which results in energy saving.

Abstract: An extractive distillation process for separation ethers (in particular methyl t-butyl ether or ethyl t-butyl ether), aliphatic hydrocarbons (in particular isobutane and/or isobutene) and alcohols (in particular methanol or ethanol) employs as solvent sulfolane(s) and/or dialkyl sulfone(s), or N-(.beta.-mercaptoalkyl)-2-pyrrolidone(s), or a mixture of N-alkyl-2-pyrrolidone(s) and either sulfolane(s) or glycol compound(s).

Abstract: The separation of alkadienes from close-boiling alkenes by extractive distillation employes as solvent N-methyl-2-thiopyrrolidone, alone or in admixture with unsubstituted sulfolane (cyclotetramethylene sulfone), or a mixture of unsubstituted sulfone and N-methyl-2-pyrrolidone. The separation of cycloalkadienes from close-boiling alkadienes by extractive distillation employs N-methyl-2-thiopyrrolidone as solvent.

Abstract: Raffinate yield from solvent extraction is improved when the extract phase recovered from the solvent extraction process is subjected to a membrane separation step wherein a saturates/1-ring aromatics rich retentate is produced and a 2+ ring aromatics rich permeate are produced and the saturates/1-ring aromatic rich retentate phase is recycled to the solvent extraction process.

Abstract: An extractive distillation process for separatin at least one C.sub.4 -C.sub.10 alkene (monoolefin) from at least one close-boiling alkane employs a solvent mixture of (a) at least one saturated alcohol (preferably cyclohexanol) and either (b1) at least one sulfolane (preferably cyclotetramethylene sulfone) or (b2) at least one glycol compound (preferably tetraethylene glycol) or (b1)+(b2).

Abstract: The yield, raffinate product quality, and throughput of the selective solvent extraction of hydrocarbon feeds is improved by subjecting the hydrocarbon feeds from which aromatic hydrocarbons are to be selectively solvent extracted to a membrane separation process which selectively permeates aromatics through the membranes to produce a permeate rich in aromatics and a retentate rich in saturates and 1-ring aromatics and subjecting this retentate to the selective solvent extraction process.

Abstract: An extractive distillation process for separating at least one C.sub.4 -C.sub.10 alkene (monoolefin) from at least one close-boiling alkane (paraffin) employs as solvent a mixture of (a) at least one N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone and either (b1) at least one sulfolane compound (preferably cyclotetramethylene sulfone) or (b2) at least one glycol compound (preferably tetraethylene glycol) or both (b1) and (b2).

Abstract: Methods are provided for the recovery of aromatic hydrocarbons from the extract phase of aromatic-selective solvent extraction processes which involve withdrawing a vapor side-cut fraction containing aromatic hydrocarbons and solvents from a stripping zone and passing the side-cut fraction to a rectification zone which can be refluxed with aromatic hydrocarbons or aqueous condensate.

Abstract: An extractive distillation process for separating at least one aromatic hydrocarbon from at least one close-boiling alkane employs as solvent a mixture of (a) at least one N-mercaptoalkyl-2-pyrrolidone, preferably N-(.beta.-mercaptoethyl)-2-pyrrolidone and (b) at least one sulfolane, preferably cyclotetramethylene sulfone.

Abstract: Extractive distillation processes for separating aromatic hydrocarbon(s) or cycloalkane(s) or alkene(s) from close-boiling alkane(s) are carried out with a solvent including at least one N-alkyl-2-thiopyrrolidone compound, preferably N-methyl-2-thiopyrrolidone. Optionally, the solvent additionally contains a cosolvent, preferably tetraethylene glycol or N-(.beta.-mercaptoethyl)-2-pyrrolidone or unsubstituted sulfolane.

Abstract: A process for recovering 3-methyl-1-butene from a hydrocarbon stream by treating the stream with a dimethylformamide/sulfolane solvent mixture to remove compounds which form azeotropes with 3-methyl-1-butene and separating the remaining stream.

Abstract: The reaction effluent from an oxydehydrogenation reactor, used in the preparation of t-butylstyrene from t-butylethylbenzene, is subjected to liquid-liquid extraction with a sulfolane-water mixture to separate unreacted t-butylethylbenzene from t-butylstyrene.

Abstract: Dialkenylbenzene compounds, present in t-butylstyrene in small quantities as impurities are removed by liquid/liquid extraction using aqueous sulfolane as solvent.

Abstract: Isopropenylstyrene, present in t-butylstyrene in small quantities as an impurity, is removed by extractive distillation using sulfolane as solvent.

Abstract: A solvent system composed essentially of sulfolane and a ketone, e.g., sulfolane and methyl ethyl ketone is employed in a liquid-liquid extraction operation to separate a low boiling olefin, e.g., pentene-2, hexene-1, octene-1, etc., from a corresponding close boiling paraffin, e.g., n-pentane, n-hexane, and n-octane, respectively, and wherein solvent is recovered by employing a portion thereof in a drying or stripping column.

Abstract: A level-controlled water tank in an extractive distillation system is used to maintain the water concentration in the solvent mixture constant.

Abstract: This invention provides a unique means of effective corrosion inhibition and corrosion inhibitor utilization in a process for the extraction of aromatics from a hydrocarbon mixture using sulfolane. The corrosion inhibitor used is an organic amine. The invention involves introduction of the inhibitor into the overhead receiver of the benzene fractionation column and the recycle of water collected in that receiver to the stripper column overhead receiver. The inhibitor is thus effectively distributed throughout the process.

Abstract: A process for recovering pure benzene from hydrocarbon mixtures containing the same and non-aromatic compounds which are gaseous and difficultly condensible is described in which the feedstock is fed to an initial distillation column operated at atmospheric or sub-atmospheric pressure. Overhead comprising benzene and non-aromatics is obtained and a portion thereof condensed. The condensible material is in part returned to the distillation column and in part subjected to extractive distillation to recover pure benzene. Those components which did not condense, i.e. the non-condensible and difficultly condensible components and entrained aromatics are fed to a reflux vessel such as a scrubber, stripper, or the like for recovery of any benzene or other valuable components which might be soluble in a selective solvent and used for such recovery. The selective solvent can be the same solvent used for the extractive distillation.

Abstract: A process for purifying gaseous effluents containing aldehydes comprises submitting the gaseous effluents to the simultaneous action of SO.sub.2 and NH.sub.3 followed by washing with water. The ratio of the required quantities of NH.sub.3 and SO.sub.2 is between 2:1 and 3:1.When the gas to be purified naturally contains NH.sub.3, as is for instance the case in rendering plants, the quantity of NH.sub.3 to be added to the gas is reduced accordingly. Conversely when the gas to be treated naturally contains SO.sub.2, the quantity of SO.sub.2 to be added to the gas is also reduced accordingly. The most favorable ratio would correspond to a pH of the washing waters of between 7 and 7.5.

Abstract: Indene is separated from close boiling, olefinically unsaturated alkylaromatic compounds by extractive distillation. For example, indene is separated from trans-.beta.-methylstyrene, and from 2-, 3- and 4-methylstyrene by extractive distillation using 1-methyl-2-pyrrolidone as the extracting agent.

Abstract: Cyclohexylbenzene is separated from a cyclohexylbenzene-cyclohexanone-phenol admixture by liquid-liquid extraction with a non-polar solvent such as hexadecane and a polar solvent, such as sulfolane, diethylene glycol, or mixtures with water. Cyclohexylbenzene is separated from the non-polar phase by fractional distillation. Phenol and cyclohexanone are separated from the polar solvent by fractional distillation.

Abstract: A mixture of C.sub.4 -hydrocarbons is extractively distilled with sulfolane and acetone or methylethyl ketone as the selective solvent; the rich solvent containing 1,3-butadiene and vinylacetylene is stripped and a small quantity of the ketone is allowed to leave overhead. Thereby the further fractionation of the stripper overhead results in a very efficient separation of 1,3-butadiene and vinylacetylene.