Abstract: A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone.

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: A process for separating C.sub.2 -C.sub.4 alkenes from C.sub.1 -C.sub.6 alkanes comprises the presence of water vapor in the alkene/alkane feed and the use of an Ag.sup.+ -exchanged sulfonated copolymer of tetrafluoroethylene and perfluorovinyl ether having been prepared by one of several specific ion-exchange methods.

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 employs as solvent either N-(.beta.-mercaptoethyl)-2-pyrrolidone alone, or a mixture of N-(.beta.-mercaptoethyl)-2-pyrrolidone and either N-methyl-2-pyrrolidone or cyclohexanol, or a mixture of cyclohexanol and tetraethylene glycol. The separation of cycloalkadines from close-boiling alkadienes by extractive distillation employs N-(.beta.-mercaptoethyl)-2-pyrrolidone as solvent.

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: Aromatic hydrocarbons containing 6-10 carbon atoms per molecule are separated from close-boiling olefinic hydrocarbons by extractive distillation employing as solvent either N-methyl-2-thiopyrrolidone alone, or a mixture of N-(.beta.-mercaptoethyl)-2-pyrrolidone and N-methyl-2-thiopyrrolidone, or a mixture of N-(.beta.-mercaptoethyl)-2-pyrrolidone and N-methyl-2-pyrrolidone.

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: 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: An extractive distillation process for separating at least one C.sub.2 -C.sub.4 alkene (preferably propylene) from at least one close-boiling alkane (preferably propane) employs propylene carbonate as solvent, optionally in admixture with a minor amount of water.

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 employs solvent at least one N-mercaptoalkyl-2-pyrrolidone, preferably N-(.beta.-mercaptoethyl)-2-pyrrolidone, optionally in admixture with at least one N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone.

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 mixture of (a) at least one N-alkyl-2-pyrrolidone (preferably N-methyl-2-pyrrolidone) and (b) at least one glycol compound (preferably ethylene glycol or tetraethylene glycol) is used as solvent in the extractive distillation of a feed mixture of cycloalkane(s) (in particular cyclohexane) and close-boiling alkane(s).

Abstract: A mixture of (a) at least one saturated C5-C9 alcohol (preferably cyclohexanol) and (b) at least one sulfolane (preferably unsubstituted sulfolane, cyclotetramethylene sulfone) is used as solvent in the extractive distillation of a feed mixture of cycloalkane(s) in particular cyclohexane) and close-boiling alkane(s). A novel composition of matter contains (a) and (b), as defined above, and optionally also (c) water.

Abstract: A process for cracking hydrocarbon containing feed streams, which have an initial boiling point of at least 400.degree. F. and contain at least about 5 ppmw vanadium, is carried out in the presence of a catalyst composition comprising a physical mixture of (a) zeolite embedded in an inorganic refractory matrix material and (b) at least one oxide of Be, Mg, Ca, Sr, Ba or La, preferably MgO, on a silica containing support material.

Abstract: A process is provided for converting alkanes and cycloalkanes having up to 20 carbon atoms per molecule to a product comprising hydrogen gas and dehydrogenated and/or dehydrocyclized hydrocarbons, in the presence of a catalyst composition comprising vanadium oxide and aluminum phosphate. The preferred product components are aromatics such as ethylbenzene and xylenes. In one embodiment, a substantially deactivated catalyst composition is regenerated by contacting it with a free oxygen containing gas under suitable regeneration conditions.

Abstract: A process for catalytically cracking a hydrocarbon-containing feed stream, preferably having an API.sup.60 gravity of about 5-30, wherein at least a portion of off-gases is treated so as to remove C.sub.2 -C.sub.4 olefins therefrom, and the off-gas stream having a reduced olefin content is then recycled to the catalytic cracking zone.

Abstract: A process for producing anhydrous ethanol from an ethanol-water mixture feedstock comprising subjecting the feedstock to distillation in a first distillation zone to produce an overhead vapor of from about 80 to about 90 weight percent ethanol, subjecting the thus produced overhead vapor to extractive distillation in an extractive distillation zone to produce anhydrous ethanol vapor overhead of about 99.5 weight percent ethanol and a solvent-rich bottom stream, and stripping the solvent-rich bottom stream and recycling the thus produced lean solvent bottom stream to the extractive distillation zone and recycling the thus produced overhead vapor stream to the first distillation zone. Also disclosed is a system for performing the process.

Abstract: A vapor-liquid extractive distillation process utilizing a dialkyl sulfone containing 4 to 8 carbon atoms per molecule and at least one percent water as the solvent. The process according to this invention is of particular applicability in separating aromatics from nonaromatics in a BTX stream. The solvent system operates particularly well with relatively large amounts of water.

Abstract: A process for treating and recovering components from aldol-condensation polyol waste liquor containing sodium formate, water, polyol, and organic by-products comprising A. vacuum crystallizing and removing sodium formate; B. introducing methanol and sulfuric acid; C. distilling to remove and recover methyl formate; D. increasing the pH to about 6.5 to 7.0; E. cooling to precipitate Glauber's salt, polyol and organics; and F. adding water to dissolve and separate the Glauber's salt and recover substantially pure polyol and organics.