Abstract: A process for separating para-xylene from a plurality of aromatic compounds, wherein the process introduces a mixed xylene feed stream comprising a plurality of xylene isomers into a first separation assembly to produce a first para-xylene enriched stream and a first raffinate stream. The process further feeds the raffinate stream into an isomerization unit to convert the raffinate stream into an isomerization reactor product stream, and introduces the isomerization reactor product stream into to a second para-xylene adsorptive separation unit to produce a second para-xylene enriched stream and a second raffinate stream.

Abstract: A process for separating para-xylene from aromatic compounds is presented. The process introduces throughout a first step-time interval a first mixed xylene stream into a first feed input on a first adsorptive separation unit comprising multiple bed lines. The process further introduces throughout the first step-time interval a second mixed xylene stream into a second feed input on the first adsorptive separation unit. During a first portion of the first step-time interval, the process introduces material from a feed stream used during the first step-time interval into a bed line not used to deliver a stream into, or withdraw a stream from, the first adsorptive separation unit during the first step time interval. During a second portion of the first step-time interval, the process introduces material from a purification zone into the feed stream used during the first step-time interval.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex through heat exchange in associated xylene recovery facilities.

Abstract: A process for separating para-xylene from aromatic compounds is presented. The process introduces throughout a first step-time interval a first mixed xylene stream into a first feed input on a first adsorptive separation unit comprising multiple bed lines. The process further introduces throughout the first step-time interval a second mixed xylene stream into a second feed input on the first adsorptive separation unit. During a first portion of the first step-time interval, the process introduces material from a feed stream used during the first step-time interval into a bed line not used to deliver a stream into, or withdraw a stream from, the first adsorptive separation unit during the first step time interval. During a second portion of the first step-time interval, the process introduces material from a purification zone into the feed stream used during the first step-time interval.

Abstract: An apparatus according to various approaches includes separating a component from a feed stream using adsorption separation. The process further includes directing one of the extract stream and the raffinate stream to a high pressure distillation column. In addition, the process includes pumping the one of the extract stream and the raffinate stream to increase the pressure in the stream to flow the one of the extract stream and the raffinate stream into an inlet of the distillation column.

Abstract: A process according to various approaches includes separating a component from a feed stream using adsorption separation. The process further includes directing one of the extract stream and the raffinate stream to a high pressure distillation column. In addition, the process includes pumping the one of the extract stream and the raffinate stream to increase the pressure in the stream to flow the one of the extract stream and the raffinate stream into an inlet of the distillation column.

Abstract: A method of operating a rotary valve using a variable dome seating pressure to provide a minimum seating force for each position of the valve is described.

Abstract: A process for separating para-xylene from aromatic compounds is presented. The process introduces throughout a first step-time interval a first mixed xylem stream into a first feed input on a first adsorptive separation unit comprising multiple bed lines. The process further introduces throughout the first step-time interval a second mixed xylene stream into a second feed input on the first adsorptive separation unit. During a first portion of the first step-time interval, the process introduces material from a feed stream used during the first step-time interval into a bed line not used to deliver a stream into, or withdraw a stream from, the first adsorptive separation unit during the first step time interval. During a second portion of the first step-time interval, the process introduces material from a purification zone into the feed stream used during the first step-time interval.

Abstract: A process for separating para-xylene from a plurality of aromatic compounds, wherein the process introduces a first mixed xylene stream comprising a plurality of xylene isomers into a first adsorptive separation unit to produce a first para-xylene enriched stream and a first raffinate stream. The process further introduces a second mixed xylene stream comprising a plurality of xylene isomers into a second adsorptive separation unit to produce a second para-xylene enriched stream and a second raffinate stream. The process further feeds both the first raffinate stream and the second raffinate stream into a shared raffinate column.

Abstract: A process for separating para-xylene from a plurality of aromatic compounds, wherein the process introduces a mixed xylene feed stream comprising a plurality of xylene isomers into a first separation assembly to produce a first para-xylene enriched stream and a first raffinate stream. The process further feeds the raffinate stream into an isomerization unit to convert the raffinate stream into an isomerization reactor product stream, and introduces the isomerization reactor product stream into to a second para-xylene adsorptive separation unit to produce a second para-xylene enriched stream and a second raffinate stream.

Abstract: A process for separating para-xylene from a plurality of xylene isomers, wherein the process introduces at a first feed point a first mixed xylene stream comprising a plurality of xylene isomers into a first adsorptive separation unit to produce a first para-xylene enriched stream and a first raffinate stream, and introduces a second mixed xylene stream comprising a plurality of xylene isomers into a second adsorptive separation unit to produce a second raffinate stream. The process feeds both the first raffinate stream and the second raffinate stream into a raffinate column. The process further introduces an extract stream from the second adsorptive separation unit into a first input of a split extract column comprising an internal partition defining a first distillation zone and a second distillation zone.

Abstract: Processes for increasing overall aromatics and xylenes yield in an aromatics complex are provided. A C8+ aromatics stream from an aromatics-rich reformate is separated into a C8 aromatics fraction and a C9+ aromatics fraction comprising higher alkyl group-substituted C9 and C10 aromatics. The C9+ aromatics fraction is separated into a lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction and a heavier boiling, C10+ or C11+ aromatics fraction. The lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction is isomerized to convert a portion of the higher alkyl group-substituted C9 or C9/C10 aromatics therein into methyl-enriched C9 aromatics or methyl-enriched C9/C10 aromatics. The methyl-enriched C9+ aromatics stream comprising the methyl-enriched C9+ aromatics stream or the methyl-enriched C9/C10 aromatics is transalkylated with a toluene-containing stream.

Abstract: Purge fluid from a vessel head in an adsorption process is distributed to recovery processes according to the purity of product contained in the fluid. Extract-rich fluid thus is routed directly to recovery of the extract product. Distribution preferably is determined by internal positioning of feed, desorbent and product streams in the adsorption vessel.

Abstract: Improved processing of an oxygenate-containing feedstock for increased production or yield of light olefins is provided. Such processing involves oxygenate conversion to olefins and subsequent cracking of heavier olefins wherein at least a portion of the C4+ hydrocarbon stream resulting from such oxygenate conversion processing and at least a portion of a cracked olefins effluent stream resulting from such olefin cracking processing are processed with a dividing wall fractionation column to form process streams containing: a) C3?hydrocarbons, b) C6+ hydrocarbons, and c) C4 and C5 hydrocarbons, including C4 and C5 olefins, respectively.

Abstract: Processes and systems are disclosed that relate to the removal of impurities and separation the light olefins from an MTO product vapor stream. Specifically, the processes and systems relate to recovery of light olefins during regeneration of an adsorber in an oxygenate removal unit. Processes and systems for recovering light olefins during regeneration of an adsorber in an oxygenate removal unit can include recycling residual effluent stream to an upstream operation unit upstream of the oxygenate removal unit. Processes and systems for recovering light olefins during regeneration of an adsorber in an oxygenate removal unit can also include recycling residual effluent gas produced by depressurizing residual effluent in the first adsorber, as well as preferably venting an effluent gas from the first adsorber to a compressor upstream of the oxygenate removal unit.

Abstract: A process is presented for the regeneration of adsorbent beds in the light olefin recovery process. The process uses gas generated in the methanol to olefins process to regenerate adsorbent beds. The gas removes the need for external gases, and the gas can be used in the periodic purging of the methanol to olefins reactor.

Abstract: Processes for increasing overall aromatics and xylenes yield in an aromatics complex are provided. A C8+ aromatics stream from an aromatics-rich reformate is separated into a C8 aromatics fraction and a C9+ aromatics fraction comprising higher alkyl group-substituted C9 and C10 aromatics. The C9+ aromatics fraction is separated into a lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction and a heavier boiling, C10+ or C11+ aromatics fraction. The lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction is isomerized to convert a portion of the higher alkyl group-substituted C9 or C9/C10 aromatics therein into methyl-enriched C9 aromatics or methyl-enriched C9/C10 aromatics. The methyl-enriched C9+ aromatics stream comprising the methyl-enriched C9+ aromatics stream or the methyl-enriched C9/C10 aromatics is transalkylated with a toluene-containing stream.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex through heat exchange in associated xylene recovery facilities.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex.