Abstract: Advantaged separation of xylene isomers may be realized by separating o-xylene and other components, such as styrene, from an aromatic hydrocarbon mixture comprising m-xylene and p-xylene. Separation of xylene isomers may comprise: providing an aromatic hydrocarbon mixture comprising at least o-xylene, m-xylene, and p-xylene; separating the aromatic hydrocarbon mixture into a first stream enriched in o-xylene and lean in m-xylene and p-xylene relative to the aromatic hydrocarbon mixture, and a second stream enriched in m-xylene and p-xylene and lean in o-xylene relative to the aromatic hydrocarbon mixture; and separating the second stream into a third stream enriched in p-xylene and lean in m-xylene relative to the second stream and a fourth stream comprising m-xylene.

Abstract: Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Abstract: Processes and systems for converting benzene and/or toluene via methylation with methanol and/or dimethyl ether may be performed by contacting an aromatic hydrocarbon feed with a first methylating agent feed in the presence of a methylation catalyst in a series of fixed beds. Between the fixed beds, the product mixture from the upstream bed may be treated by (a) reducing the temperature, (b) adding additional methylating agent feed, (c) optionally removing water, and (d) optionally adding additional aromatic hydrocarbon feed.

Abstract: A membrane separator comprising a membrane is used to separate various streams in processes for separating aromatic hydrocarbons from non-aromatic hydrocarbons. Such streams can be a lean-solvent stream, a rich-solvent stream, or a hydrocarbon stream comprising both aromatic and non-aromatic hydrocarbons. The membrane separator is advantageously used in combination with an extraction sub-system including a liquid-liquid distillation column and/or an extraction distillation column.

Abstract: A liquid phase isomerization process comprising cofeeding molecular hydrogen at a feeding rate ?100 ppm by weight can effectively convert a C8 aromatic hydrocarbon isomerization feed in the presence of an isomerization catalyst with a very low deactivation rate of the catalyst, even at high WHSV ?5 hour?1.

Abstract: Hydrocarbon extraction processes utilizing a cleansing bed to cleanse at least a portion of a lean-solvent stream are disclosed. The cleansing bed can preferentially include abed of activated carbon, abed of alumina, and/or a bed of an ion-exchange resin. The extraction process can use a liquid/liquid extraction column or an extraction distillation column. The process can be particularly advantageous for removing C10-C20 contaminants, among others, from the lean-solvent stream.

Abstract: Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Abstract: Hydrocarbon extraction processes utilizing a cleansing bed to cleanse at least a portion of a lean-solvent stream are disclosed. The cleansing bed can preferentially include abed of activated carbon, abed of alumina, and/or a bed of an ion-exchange resin. The extraction process can use a liquid/liquid extraction column or an extraction distillation column. The process can be particularly advantageous for removing C10-C20 contaminants, among others, from the lean-solvent stream.

Abstract: Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Abstract: Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Abstract: A membrane separator comprising a membrane is used to separate various streams in processes for separating aromatic hydrocarbons from non-aromatic hydrocarbons. Such streams can be a lean-solvent stream, a rich-solvent stream, or a hydrocarbon stream comprising both aromatic and non- aromatic hydrocarbons. The membrane separator is advantageously used in combination with an extraction sub-system including a liquid—liquid distillation column and/or an extraction distillation column.

Abstract: Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Abstract: Processes for producing high-octane-number fuel components, particularly those useful for AvGas blends, can be advantageously produced from hydrocarbon feed streams comprising C8+ aromatic hydrocarbons. Such feed streams may be produced by, among others, separation and other optional post-processing of an effluent produced from a steam cracker (e.g., a liquid feed steam cracker cracking liquid feeds such as naphtha and/or other crude fractions, a gas steam cracker cracking gas feeds such as ethane and/or propane), hydrocarbon reforming of a crude fraction or steam cracker effluent fraction, C6-C7 aromatic hydrocarbon methylation, transalkylation between C6-C7 aromatic hydrocarbons and C9+ aromatic hydrocarbons, isomerization of C8 aromatic hydrocarbons, and toluene disproportionation processes.

Abstract: A process and system for separating paraxylene from a mixture of paraxylene, metaxylene, orthoxylene, and ethylbenzene in a simulated moving bed apparatus using a membrane to separate non-aromatics from a desorbent stream. The lower nonaromatics content in the desorbent improves paraxylene product purity, increases paraxylene production at the same desorbent rate, reduces the desorbent rate, and/or reduces energy consumption in the product tower.

Abstract: A process and system for separating paraxylene from a mixture of paraxylene, metaxylene, orthoxylene, and ethylbenzene in a simulated moving bed apparatus using a membrane to separate non-aromatics from a desorbent stream. The lower nonaromatics content in the desorbent improves paraxylene product purity, increases paraxylene production at the same desorbent rate, reduces the desorbent rate, and/or reduces energy consumption in the product tower.

Abstract: An changeable lead-lag configuration of two isomerization reactors can be used to achieve continuous isomerization operations in an aromatics production complex, even if the isomerization catalyst deactivates over time to require catalyst regeneration and/or replacement. The configuration can be particularly advantageous for two liquid phase isomerization reactors, especially those operated under a high WHSV?5 hour?1 where the isomerization catalyst can deactivate at a high rate.

Abstract: Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Abstract: A liquid phase isomerization process comprising cofeeding molecular hydrogen at a feeding rate ?100 ppm by weight can effectively convert a C8 aromatic hydrocarbon isomerization feed in the presence of an isomerization catalyst with a very low deactivation rate of the catalyst, even at high WHSV ?5 hour?1.

Abstract: Processes for activating precious metal-containing catalysts. The processes can decrease the amount of high purity hydrogen required for starting up a catalytic conversion process such as transalkylation of heavy aromatics, without detrimental impact to the metal activity. The processes can include a low temperature treatment step with a high purity first gas, such as hydrogen generated by electrolysis and/or reformer hydrogen diluted with high purity inert gas, and a high temperature treatment step with a low purity second gas such as the reformer hydrogen. Also, the processes can include mixing a hydrogen gas of high or low purity with a high purity inert gas to form a gas mixture with a proportion of hydrogen no less than 2% and a reduced carbon monoxide concentration relative to the low purity hydrogen, and contacting the catalyst with the gas mixture.

Abstract: Methods for the production of para-xylene include flowing a xylenes-containing stream comprising PX, meta-xylene (MX), and ortho-xylene (OX), to a first crystallization stage. In addition, the methods include lowering a temperature of the xylenes-containing stream to below the eutectic point of the xylenes-containing stream within the first crystallization stage to crystallize at least some of the PX and at least some of one of both of the MX and the OX within the xylenes-containing stream. Further, the methods include separating the xylenes-containing stream into a first crystallization effluent stream and a first filtrate stream.