Abstract: A process for the conversion of a hydrocarbon feedstock to produce xylene compounds. The feedstock is selectively hydrocracked and introduced into a transalkylation zone with a hydrocarbonaceous stream rich in benzene, toluene and C9+ hydrocarbons.

Abstract: Product purity from or capacity of a simulated-moving-bed adsorptive separation process is increased by flushing the contents of the transfer line previously used to remove the raffinate stream away from the adsorbent chamber, preferably into the raffinate column used to separate desorbent from raffinate product. Preferably a stream from the adsorbent chamber at an intermediate point between the feed entry point and raffinate withdrawal is used as the flushing liquid. This flush step eliminates the passage of a quantity of the raffinate material into the adsorbent chamber in the transfer-line flush period or when the process conduit is subsequently used to charge the feed stream to the adsorbent chamber.

Abstract: A process for the selective hydrogenation of olefins contained in a hydrocarbonaceous feedstock comprising olefins and aromatic compounds.

Abstract: Fluctuations, such as perturbations in the quality of the extract and/or raffinate streams removed from the circuit in a simulated moving bed (SMB) adsorptive process having at least one discrete non-separating section are eliminated or significantly reduced. This is accomplished by increasing the fluid flow rate in a portion of the circuit in response to the location of a discrete non-separating section and changing the flow rate of at least one stream that is in fluid communication with the circuit consistent with the increased flow rate in the portion of the circuit. Multiple adjustments to the flow rates of the input and/or output streams and multiple increases in the fluid flow rates in portions of the circuit may be used simultaneously when for example there is more than one discrete non-separating section.

Abstract: A catalytic distillation process for producing high purity ethyl tertiary butyl ether that contains less than 0.6 weight percent ethanol, and preferably less than 0.07 weight percent ethanol, has been developed. The high purity ethyl tertiary butyl ether is withdrawn directly from a catalytic distillation column; no downstream processing is necessary to remove excess ethanol from the ether product. A stream containing largely normal butane is generated by a C.sub.4 distillation column along with a stream containing isobutane. The stream containing isobutane is dehydrogenated to form a stream containing isobutylene. Ethanol, the stream containing isobutylene, and the stream containing largely normal butane are introduced to an etherification zone containing a catalytic distillation column. The catalytic distillation column is operated under conditions which result in the reaction of the ethanol with the isobutylene to form ethyl tertiary butyl ether.

Abstract: A reactivation process is disclosed for a catalyst formulated to selectively upgrade naphtha to obtain an isoparaffin-rich product for blending into gasoline. The process utilizes a solid strong-acid catalyst comprising an anion-modified metal oxide, preferably comprising a sulfated support of an oxide or hydroxide of a Group IVB (IUPAC 4) metal, and a platinum-group metal component.

Abstract: A low pressure catalytic distillation process for producing high purity ethyl tertiary butyl ether that contains less than 0.6 weight percent ethanol, and preferably less than 0.07 weight percent ethanol, has been developed. The high purity ethyl tertiary butyl ether is withdrawn directly from a catalytic distillation column. No downstream processing is necessary to remove excess ethanol from the ether product. A stream containing a significant amount of one or more inert azeotropic agents such as normal butane, isopentane, and isobutane is introduced along with the isobutylene and ethanol reactants into an etherification zone containing a catalytic distillation column. The catalytic distillation column is operated under low pressure conditions which result in the reaction of the ethanol with the isobutylene to form ethyl tertiary butyl ether.

Abstract: A light hydrocarbon stream, such as a C.sub.3 -C.sub.5 stream recovered from an FCC unit, is catalytically treated for the selective hydrogenation of dienes and for the removal of mercaptans by thioetherification. The effluent of the reaction zone is fractionated to remove light ends and thioethers in a dual section fractionation zone, with the interconnection of the sections facilitating a reduction in capital and operating costs.

Abstract: A light hydrocarbon stream, such as a C.sub.3 -C.sub.5 stream recovered from an FCC unit, is catalytically treated for the selective hydrogenation of dienes and for the removal of mercaptans by thioetherification. The effluent of the reaction zone is fractionated to remove light ends and thioethers in a dual section fractionation zone, with the interconnection of the sections facilitating a reduction in capital and operating costs.

Abstract: A highly integrated process for concurrently producing diisopropyl ether and an isopropyl tertiary alkyl ether has been developed. Optionally, high purity isopropyl alcohol may also be collected as a product. In a first reactor, propylene and water are reacted to form isopropyl alcohol, a portion of which is further reacted to form diisopropyl ether. After removing unreacted propylene, the effluent of the first reactor is separated into an ether rich stream, a water rich stream and an alcohol rich stream. The alcohol rich stream is dried to provide dry isopropyl alcohol. A portion of the dry isopropyl alcohol may be removed and collected as a product. A portion of the dry isopropyl alcohol and isobutylene, isoamylene or a mixture thereof are reacted to form an isopropyl tertiary alkyl ether in a second reactor. Unreacted iso-olefins and inert compounds are then removed from the second reactor effluent.

Abstract: A highly integrated process for concurrently producing diisopropyl ether and an isopropyl tertiary alkyl ether has been developed. In a first reactor, propylene and water are reacted to form isopropyl alcohol, a portion of which is further reacted to form diisopropyl ether. After removing unreacted propylene, the effluent of the first reactor is separated into an ether rich stream, a water rich stream and an alcohol rich stream. The alcohol rich stream and isobutylene, isoamylene or a mixture thereof are reacted to form an isopropyl tertiary alkyl ether in a second reactor. The water present in the alcohol rich stream also reacts with the iso-olefin to form tertiary alcohol. The effluent from the second reactor is water washed to produce an oxygenate product stream and an aqueous alcohol recycle stream. Some tertiary alcohol is recycled to the first reactor where it is reacted with propylene to form additional isopropyl tertiary alkyl ether.

Abstract: A process is directed to the removal of impurities such as sulfur compounds, oxygenates, and/or olefins from a light paraffin hydrocarbon feedstock such as a C.sub.4 -C.sub.6 fraction, which may be used subsequently in an isomerization process in an integrated complex for the production of ethers such as MTBE and TAME. The hydrocarbon feedstream is passed to a removal zone wherein the hydrocarbon feedstream is contacted with a selective solvent for the removal of the impurities comprising at least one of sulfur compounds, oxygenates and olefins to provide a rich solvent stream and a treated hydrocarbon stream. The rich solvent comprising the trace impurities is contacted with a stripping medium stream to regenerate the selective solvent in a stripping zone. The removal zone may be a liquid-liquid extraction zone or a gas absorption zone.

Abstract: A process is disclosed for improving catalyst performance and yields in the manufacture of motor gasoline components. More particularly the process is directed to the removal of trace amounts of acetonitrile or acetone or propionitrile from a hydrocarbon feedstock such as a C.sub.4 -C.sub.6 product fraction from a fluid catalytic cracking unit, which may be used subsequently in an etherification process for the production of ethers such as MTBE and TAME. The hydrocarbon feedstock is passed to a water wash zone for the removal of the trace amounts of acetonitrile or acetone or propionitrile and the spent water comprising the nitriles is contacted with a nitrile-lean stream to regenerate the wash water. A portion of the spent water stream is withdrawn to reduce the nitrile level in the nitrile-lean water stream.

Abstract: Mercaptans and olefins are removed from paraffin-rich feed streams through the use of dual zone catalytic distillation in the substantial absence of hydrogen. The mercaptans are reacted with the olefins using a first catalyst such as a sulphonated resin to form less volatile thioethers removed as part of a net bottoms stream. The remaining olefins are oligomerized in a higher catalyst zone preferably employing a catalyst, such as a dealuminated Y zeolite, having a higher oligomerization activity at the imposed conditions.

Abstract: The present invention relates to a cyclic process for the preparation of ethyl tert.-alkyl ethers by the reaction of an alcohol, such as ethanol, with an iso-olefin such as isobutylene or isoamylene wherein an effluent from the reaction zone is first separated in a distillation column to provide an overhead effluent stream and a bottoms effluent stream comprising ethyl tert.-alkyl ether and unreacted ethanol, and the ether product is passed to an adsorption zone to remove the unreacted ethanol. When the reaction occurs in the presence of water, a tert. alcohol (e.g., TBA or TAA) is produced and, if returned to the reaction zone, the tertiary alcohol builds up in the process and reduces efficiency.

Abstract: A process is disclosed for improving catalyst performance and yields in the manufacture of motor gasoline components. More particularly the process is directed to the removal of trace amounts of acetonitrile or acetone or propionitrile from a hydrocarbon feedstock such as a C.sub.4 -C.sub.6 product fraction from a fluid catalytic cracking unit, which may be used subsequently in an etherification process for the production of ethers such as MTBE and TAME. The hydrocarbon feedstock is passed to a water wash zone for the removal of the trace amounts of acetonitrile or acetone or propionitrile and the spent water comprising the nitriles is contacted with a nitrile-lean stream to regenerate the wash water. A portion of the spent water stream is withdrawn to reduce the nitrile level in the nitrile-lean water stream.

Abstract: A process is directed to the removal of impurities such as sulfur compounds, oxygenates, and/or olefins from a light paraffin hydrocarbon feedstock such as a C.sub.4 -C.sub.6 fraction, which may be used subsequently in an isomerization process in an integrated complex for the production of ethers such as MTBE and TAME. The hydrocarbon feedstream is passed to a removal zone wherein the hydrocarbon feedstream is contacted with a selective solvent for the removal of the impurities comprising at least one of sulfur compounds, oxygenates and olefins to provide a rich solvent stream and a treated hydrocarbon stream. The rich solvent comprising the trace impurities is contacted with a stripping medium stream to regenerate the selective solvent in a stripping zone. The removal zone may be a liquid-liquid extraction zone or a gas absorption zone.

Abstract: The present invention is a cyclic process for the preparation of ethyl tert.-alkyl ethers by the reaction of an alcohol, ethanol, with an iso-olefin such as isobutylene or isoamylene wherein an effluent from the reaction zone is separated in a distillation column to provide an overhead effluent stream and a bottoms effluent stream comprising ethyl tert.-alkyl ether and unreacted ethanol. The unreacted ethanol is recovered in an adsorption zone comprising a selective adsorbent selected from the group consisting of zeolite 13X, sodium zeolite Y, alumina, silicalite and mixtures thereof. The invention is useful in recovering unreacted ethanol from the bottoms effluent stream and returning the unreacted ethanol to the reaction zone. The invention reduces the cost of this separation which is complicated by the formation of an azeotrope between the unreacted alcohol and the ether.

Abstract: In a process for the production of tertiary ethers by the reaction of an alcohol and isoalkene, a sidecut stream is selected from the etherification separation zone and recycled back to the etherification reaction zone. When this sidecut stream is characterized by an isoalkene to tertiary ether molar concentration ratio that is greater than the isoalkene to tertiary ether molar concentration ratio of the etherification reaction effluent (which is normally at equilibrium conditions), the conversion of isoalkene to tertiary ether is increased.

Abstract: The present invention relates to a process for the separation of ethanol from a mixture thereof with ethyl tert.-alkyl ether employing a selective adsorbent comprising a mixture of sodium zeolite Y in combination with alumina wherein the percentage of the sodium zeolite Y ranges between 10 and 40 wt-%. The invention reduces the cost of this separation which is complicated by an azeotrope formation between the alcohol and the ether.