Abstract: A method for recovering paraxylene from a mixture of aromatic hydrocarbons. The process uses a pressure swing adsorption zone followed by a paraxylene recovery zone. The invention provides for lower throughput through the paraxylene recovery zone, resulting in lower capital costs and operating costs.

Abstract: The present invention describes a process for obtaining para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, said process comprising a single stage A of separation in a simulated moving bed carried out with a zeolite as adsorbent and a desorbent and making it possible to obtain at least three fractions, a fraction A1 comprising a mixture of para-xylene and of desorbent and two fractions A21, A22 comprising ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent, said stage is carried out at a temperature between 20° C. and 250° C., under a pressure between the bubble pressure of the xylenes at the operating temperature and 2.0 MPa, and with a ratio by volume of the desorbent to the feedstock in the unit for separation 2 in a simulated moving bed is between 0.4 and 2.

Abstract: The present invention describes a process for the production of high-purity paraxylene from a xylenes cut containing xylenes and ethylbenzene, a process using two simulated moving bed separation units and two isomerization units.

Abstract: A process for the isomerization of a para-xylene depleted, meta-xylene rich stream under at least partially liquid phase conditions using ZSM-23 with an external surface area of at least 75 m2/g (indicating a small crystallite size), and a SiO2/Al2O3 ratio between 15 and 75 that produces a higher than equilibrium amount of para-xylene, i.e., more than about 24 wt % of para-xylene, based on the total amount of xylenes.

Abstract: Methods are provided for the treatment of a feed stream containing C9 aromatic components to produce mesitylene-containing products. The methods include hydrodealkylating the feed stream to remove C2 and higher alkyl groups from the aromatic components and transalkylating the feed stream to rearrange the distribution of methyl groups among the aromatic components. Disclosed methods also include the treatment of a hydrocarbon feedstock by hydrodealkylation and/or transalkylation in order to produce a hydrocarbon product having an increased mass percentage of mesitylene.

Abstract: Methods and systems for reforming and transalkylating hydrocarbons are disclosed. A method for processing a hydrocarbon stream includes the steps of separating para-xylene from a first mixed-xylene and ethylbenzene-containing stream to produce a first non-equilibrium xylene and ethylbenzene stream and isomerizing the first non-equilibrium xylene and ethylbenzene stream to produce additional para-xylene. The method further includes transalkylating a toluene stream to produce a second mixed-xylene and ethylbenzene-containing stream, separating para-xylene from the second mixed-xylene and ethylbenzene-containing stream to produce a second non-equilibrium xylene and ethylbenzene stream, and isomerizing the second non-equilibrium xylene and ethylbenzene stream using an ethylbenzene dealkylation type xylene isomerization process to produce additional para-xylene.

Abstract: The invention is directed to a process to produce para-xylene and optionally, ortho-xylene, including coupling a C9+-aromatics-removal system with an isomerization system or with a parallel configuration of two isomerization systems to reduce xylenes recycle for energy savings and/or productivity increases.

Abstract: Methods and systems are provided for producing a desired xylene isomer. The method includes adsorbing the desired xylene isomer from a mixed xylene stream in an adsorbent chamber. The desired xylene isomer is desorbed with a desorbent to produce an extract stream with the desired xylene isomer and the desorbent, where the desorbent has a lower boiling point than the desired xylene isomer. The extract stream is fractionated in an extract fractionator to produce a low pressure extract overhead stream with gaseous desorbent. The low pressure extract overhead stream is pressurized to produce a high pressure extract overhead stream with a temperature greater than an extract reboiler temperature.

Abstract: Methods and systems are provided for separating a selected xylene isomer. The method includes separating a feed stream including a plurality of aromatic hydrocarbons into a first stream including toluene and isomers of xylene, and a second stream including isomers of xylene. The method further includes separating the first stream into a third stream including toluene and a fourth stream including isomers of xylene. The method further includes combining the second stream and the third stream in an adsorptive separation unit including an adsorbent configured to adsorb the selected xylene isomer from the second stream. The third stream desorbs the selected xylene isomer to produce a fifth stream including the selected xylene isomer and toluene and a sixth stream including non-selected xylene isomers and toluene. Still further, the method includes separating the sixth stream into a seventh stream including the non-selected xylene isomers and the third stream including toluene.

Abstract: Methods and systems are provided for producing a xylene product. The method includes fractionating a feed stream in a feed fractionator to produce a feed bottoms stream and a feed overhead stream. The feed stream includes aromatic compounds and non-aromatic compounds, and more than 5 weight percent of the non-aromatic compounds have a boiling point above 105° C. at one atmosphere of pressure. The feed bottoms stream is de-ethylated in a heavy aromatics conversion zone to produce a de-ethylated aromatics stream and a light gases stream, where non-aromatic compounds are converted to light gases in the light gases stream. The de-ethylated aromatics stream is fractionated to produce a heavy aromatics stream and an intermediate aromatics stream, and a desired isomer stream is recovered from the intermediate aromatics stream and an isomerized stream in an isomer recovery process.

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: The invention is directed to a process to produce para-xylene and optionally, ortho-xylene, including coupling a C9+-aromatics-removal system with an isomerization system or with a parallel configuration of two isomerization systems to reduce xylenes recycle for energy savings and/or productivity increases.

Abstract: The invention concerns a process for the production of paraxylene and an apparatus suitable for said process. The process separates the overhead from a xylenes re-run into a xylene-rich stream and a xylene-lean stream. The xylene-lean stream is isomerized under conditions such that the xylenes are in the liquid phase.

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 producing a PX-rich product, the process comprising: (a) providing a PX-depleted stream; (b) isomerizing at least a portion of the PX-depleted stream to produce an isomerized stream having a PX concentration greater than the PX-depleted stream and a benzene concentration of less than 1,000 ppm and a C9+ hydrocarbons concentration of less than 5,000 ppm; and (c) separating the isomerized stream by selective adsorption.

Abstract: The invention concerns a process for the production of paraxylene and an apparatus suitable for said process. The process separates the overhead from a xylenes re-run into a xylene-rich stream and a xylene-lean stream. The xylene-lean stream is isomerized under conditions such that the xylenes are in the liquid phase.

Abstract: A process for producing a PX-rich product, the process comprising: (a) providing a PX-depleted stream; (b) isomerizing at least a portion of the PX-depleted stream to produce an isomerized stream having a PX concentration greater than the PX-depleted stream and a benzene concentration of less than 1,000 ppm and a C9+ hydrocarbons concentration of less than 5,000 ppm; and (c) separating the isomerized stream by selective adsorption.

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: The invention concerns a process for the production of paraxylene and an apparatus suitable for said process. The process separates the overhead from a xylenes re-run into a xylene-rich stream and a xylene-lean stream. The xylene-lean stream is isomerized under conditions such that the xylenes are in the liquid phase.

Abstract: Liquid phase isomerization technology is employed in a manner to increase efficiency and reduce energy in paraxylene recovery.

Abstract: A process for producing a PX-rich product, the process comprising: (a) providing a PX-depleted stream; (b) isomerizing at least a portion of the PX-depleted stream to produce an isomerized stream having a PX concentration greater than the PX-depleted stream and a benzene concentration of less than 1,000 ppm and a C9+ hydrocarbons concentration of less than 5,000 ppm; and (c) separating the isomerized stream by selective adsorption.

Abstract: A process for producing a PX-rich product, the process comprising: (a) providing a PX-depleted stream; (b) isomerizing at least a portion of the PX-depleted stream to produce an isomerized stream having a PX concentration greater than the PX-depleted stream and a benzene concentration of less than 1,000 ppm and a C9+ hydrocarbons concentration of less than 5,000 ppm; and (c) separating the isomerized stream by selective adsorption.

Abstract: The invention relates to a process for the preparation of m-substituted alkyltoluenes of the formula (I) in which R1 is C1-C5-alkyl, wherein a p-substituted alkyltoluene of the formula (II) in which R1 has the meaning given under formula (I), is isomerized in the presence of ionic liquids to give an m-substituted alkyltoluene of the formula (I). The m-substituted alkyltoluenes obtainable according to the invention are starting compounds for the preparation of fragrances and aroma substances.

Abstract: A process for producing a PX-rich product, the process comprising: (a) providing a PX-depleted stream; (b) isomerizing at least a portion of the PX-depleted stream to produce an isomerized stream having a PX concentration greater than the PX-depleted stream and a benzene concentration of less than 1,000 ppm and a C9+ hydrocarbons concentration of less than 5,000 ppm; and (c) separating the isomerized stream by selective adsorption.

Abstract: One exemplary embodiment can be a process for the isomerization of a non-equilibrium alkylaromatic feed mixture. The process can include contacting the non-equilibrium alkylaromatic feed mixture in a C8 isomerization zone. The C8 isomerization zone may include a first isomerization stage and a second isomerization stage. At the first isomerization stage, at least a portion of the non-equilibrium alkylaromatic feed mixture can be contacted at a first isomerization condition in a liquid phase in the substantial absence of hydrogen to obtain an intermediate stream. At the second isomerization stage, at least part of the intermediate stream and at least a part of a stream rich in at least one naphthene can be contacted at a second isomerization condition to obtain a concentration of at least one alkylaromatic isomer that is higher than a concentration of that at least one alkylaromatic isomer in the non-equilibrium feed mixture.

Abstract: The invention concerns a process for the production of paraxylene and an apparatus suitable for said process. The process separates the overhead from a xylenes re-run into a xylene-rich stream and a xylene-lean stream. The xylene-lean stream is isomerized under conditions such that the xylenes are in the liquid phase.

Abstract: Meta-xylene is recovered from admixture with other C8 aromatic hydrocarbons including ortho-xylene by liquid phase adsorptive separation. Performance is improved by reducing the concentration of ortho-xylene through adding a sidecut to a prefractionator preparing the feedstock to adsorptive separation.

Abstract: One exemplary embodiment can be a process for the isomerization of a non-equilibrium alkylaromatic feed mixture. The process can include contacting the non-equilibrium alkylaromatic feed mixture in a C8 isomerization zone. The C8 isomerization zone may include a first isomerization stage and a second isomerization stage. At the first isomerization stage, at least a portion of the non-equilibrium alkylaromatic feed mixture can be contacted at a first isomerization condition in a liquid phase in the substantial absence of hydrogen to obtain an intermediate stream. At the second isomerization stage, at least part of the intermediate stream and at least a part of a stream rich in at least one naphthene can be contacted at a second isomerization condition to obtain a concentration of at least one alkylaromatic isomer that is higher than a concentration of that at least one alkylaromatic isomer in the non-equilibrium alkylaromatic feed mixture.

Abstract: Meta-xylene is recovered from admixture with other C8 aromatic hydrocarbons including ortho-xylene by liquid phase adsorptive separation. Performance is improved by reducing the concentration of ortho-xylene through adding a sidecut to a prefractionator preparing the feedstock to adsorptive separation.

Abstract: A process for converting ethylbenzene, by which ethylbenzene in a feedstock containing C8 aromatic hydrocarbon is converted to benzene at a high degree of conversion is disclosed. The process for converting ethylbenzene includes bringing a C8 aromatic hydrocarbon mixed feedstocks containing ethylbenzene into contact with an acid type catalyst containing at least one metal selected from the group consisting of the metals belonging to Group VII and Group VIII in the presence of H2 to convert ethylbenzene to benzene. The feedstock contains C9-C10 aromatic hydrocarbons including ethyltoluene, and the ethyltoluene is converted to toluene together with the conversion of ethylbenzene.

Abstract: Recent experimental work with currently available adsorbents indicates that operating the adsorption section at lower temperatures improves the para-xylene productivity. As a result, an aromatics complex and heat recovery network for a low temperature adsorptive separation-isomerization loop is disclosed resulting in adsorbents savings in combination with higher capacity thereby enabling smaller adsorbents chambers, a smaller total heat exchanger area and a lower heat exchanger shell count.

Abstract: A process for producing a PX-rich product comprises (a) separating a feedstock containing C8 hydrocarbons to produce a C8 hydrocarbons rich stream; (b) separating at least a first portion of the C8 hydrocarbons rich stream to produce a first PX-rich stream and a first PX-depleted stream; (c) isomerizing at least a portion of the first PX-depleted stream to produce a first isomerized stream having a higher PX concentration than the first PX-depleted stream; (d) separating a second portion of the C8 hydrocarbons rich stream and/or at least a portion of the first isomerized stream to produce a second PX-rich stream and a second PX-depleted stream; (e) isomerizing at least a portion of the second PX-depleted stream to produce a second isomerized stream having a higher PX concentration than the second PX-depleted stream; (f) recovering at least a portion of at least one of the first and second PX-rich streams as PX-rich product; and (g) supplying at least a portion of at least one of the first isomerized stream, t

Abstract: One exemplary embodiment can be a process for the isomerization of a non-equilibrium alkylaromatic feed mixture. The process can include contacting the non-equilibrium alkylaromatic feed mixture in a C8 isomerization zone. The C8 isomerization zone may include a first isomerization stage and a second isomerization stage. At the first isomerization stage, at least a portion of the non-equilibrium alkylaromatic feed mixture can be contacted at a first isomerization condition in a liquid phase in the substantial absence of hydrogen to obtain an intermediate stream. At the second isomerization stage, at least part of the intermediate stream and at least a part of a stream rich in at least one naphthene can be contacted at a second isomerization condition to obtain a concentration of at least one alkylaromatic isomer that is higher than a concentration of that at least one alkylaromatic isomer in the non-equilibrium alkylaromatic feed mixture.

Abstract: Process for the production of paraxylene from a C8 aromatic feedstock that comprises the following stages: A stage for separation by adsorption in a simulated moving bed SMB that produces an extract that contains at least 95% paraxylene and at least one raffinate R that contains ethylbenzene, A recycling of raffinate to the SMB separation stage after isomerization, in which R is separated in membrane separation means to obtain a first fraction F1 that is relatively high in ethylbenzene, which is purged, and an additional fraction F2 that is relatively low in ethylbenzene, which is recycled to the SMB after a single isomerization, preferably in the liquid phase.

Abstract: In an isomerization process where the isomerization effluent (108) is fractionated in a deisohexanizer (116) to provide an overhead (118) containing dimethylbutanes and a higher boiling fraction (122) containing normal hexane, the higher boiling is contacted with a selectively permeable membrane (124) to provide a retentate containing methylcyclopentane (128). If desired, the normal hexane-containing permeate can be recycled for isomerization. The preferred membranes are sieving membranes having a C6 Permeate Flow Index of at least 0.01 and a C6 Permeate Flow Ratio of at least 1.25:1.

Abstract: A process for producing a PX-rich product comprises (a) separating a feedstock containing C8 hydrocarbons to produce a C8 hydrocarbons rich stream; (b) separating at least a first portion of the C8 hydrocarbons rich stream to produce a first PX-rich stream and a first PX-depleted stream; (c) isomerizing at least a portion of the first PX-depleted stream to produce a first isomerized stream having a higher PX concentration than the first PX-depleted stream; (d) separating a second portion of the C8 hydrocarbons rich stream and/or at least a portion of the first isomerized stream to produce a second PX-rich stream and a second PX-depleted stream; (e) isomerizing at least a portion of the second PX-depleted stream to produce a second isomerized stream having a higher PX concentration than the second PX-depleted stream; (f) recovering at least a portion of at least one of the first and second PX-rich streams as PX-rich product; and (g) supplying at least a portion of at least one of the first isomerized stream, t

Abstract: Processes are disclosed for production of purified products from a fluid mixtures of C8 aromatics by means of integration of perm-selective separations with purified product recovery operations. The perm-selective separations of the invention comprise of one or more devices using polymeric perm-selective membrane devices to separate a meta-xylene enriched stream from fluid mixtures of C8 aromatics thereby producing a fluid comprising the remaining aromatic compounds which advantageously includes para-xylene. Processes of the invention are particularly useful for recovery of very pure meta-xylene and para-xylene co-products from liquid mixtures even containing ethylbenzene as well as the three xylene isomers.

Abstract: In processes for recovering one or more xylene isomers and isomerizing the remaining isomers for recycle, the isomerate is distilled to provide a toluene-containing overhead, a mid-boiling fraction containing C8 aromatics and a bottoms fraction containing C8 aromatics and C9+ aromatics. The mid-boiling fraction is recycled to the unit for recovering the sought xylene isomers and has sufficiently low content of C9+ aromatics that the separation feed to the unit for recovering the sought xylene isomers contains up to about 500 ppm-mass C9+ aromatics. The processes provide a high quality xylene isomer product while achieving at least one of debottlenecking, energy savings and capital savings.

Abstract: Processes and apparatus are disclosed for recovery of purified products from a fluid mixture by means of integrated perm-selective separations with purified product recovery operations. More particularly, integrated processes of the invention comprise separations by means of one or more devices using polymeric membranes coupled with recovery of purified products by means of fractional crystallization and/or selective sorption. Processes of the invention are particularly useful for recovery of a very pure aromatic isomer when processing aromatic starting materials, for example, a pure para-xylene product from liquid mixtures even containing ethylbenzene as well as the three xylene isomers.

Abstract: A process for producing a PX-rich product comprises (a) separating a feedstock containing C8 hydrocarbons to produce a C8 hydrocarbons rich stream; (b) separating at least a first portion of the C8 hydrocarbons rich stream to produce a first PX-rich stream and a first PX-depleted stream; (c) isomerizing at least a portion of the first PX-depleted stream to produce a first isomerized stream having a higher PX concentration than the first PX-depleted stream; (d) separating a second portion of the C8 hydrocarbons rich stream and/or at least a portion of the first isomerized stream to produce a second PX-rich stream and a second PX-depleted stream; (e) isomerizing at least a portion of the second PX-depleted stream to produce a second isomerized stream having a higher PX concentration than the second PX-depleted stream; (f) recovering at least a portion of at least one of the first and second PX-rich streams as PX-rich product; and (g) supplying at least a portion of at least one of the first isomerized stream, t

Abstract: Disclosed herein is an improved method for making and obtaining para-xylene from a mixture of xylene isomers, and various embodiments of the method. The method generally includes contacting a mixture comprising xylene isomers and ethylbenzene with a para-xylene selective adsorbent to obtain a para-xylene depleted raffinate, and a desorption effluent comprising a para-xylene enriched product. The method also includes isomerizing the para-xylene depleted raffinate. The contacting step is carried out in a manner such that the raffinate need not be pressurized prior to isomerization, thus advantageously obviating expensive compression steps.

Abstract: A process and a system for increasing para-xylene production from a C8 aromatic feedstream by coupling at least one xylene isomerization reactor with at least one pressure swing adsorption unit or temperature swing absorption unit to produce a product having a super-equilibrium para-xylene concentration. This product is then subjected to para-xylene separation and purification.

Abstract: A process and a system for increasing para-xylene production from a C8 aromatic feedstream by coupling at least one xylene isomerization reactor with at least one pressure swing adsorption unit or temperature swing absorption unit to produce a product having a super-equilibrium para-xylene concentration. This product is then subjected to para-xylene separation and purification.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with simulated moving bed adsorption (SiMBAC) to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is subjected to SiMBAC to obtain para-xylene product.

Abstract: The invention relates to a process for the production of at least one isomer of xylenes, preferably paraxylene, as well as benzene, starting from a C8-aromatic fraction, whereby said process comprises a zone for separation of xylenes, a zone for isomerization of aromatic compounds with 8 carbon atoms used in the presence of a catalyst that comprises at least one EUO-structural-type zeolite that is selected from among the EU-1, TPZ-3, ZSM-50 zeolites and at least one metal of group VIII of the periodic table, and finally a transalkylation zone of C7- and C9-aromatic compounds. The invention makes it possible to produce paraxylene and benzene with a high yield, starting from a C8-aromatic fraction that comprises a large amount of ethylbenzene with improved performance levels of the isomerization stage and a good conversion of ethylbenzene in the transalkylation stage.

Abstract: A process for the production of at least one xylene isomer, paraxylene, metaxylene or orthoxylene from an aromatic feedstock that has 7 to 10 carbon atoms per molecule. The process comprises a stage for transalkylation of C7- and C9-aromatic compounds, a stage for separation of xylenes and a stage for isomerization of xylenes. The isomerization catalyst used in the process comprises at least one EUO zeolite composition whose crystals are grouped in aggregates that have a grain size with a value of Dv,90 less than or equal to 500 microns and at least one element of group VIII.

Abstract: The invention concerns novel organometallic complexes comprising cationic heterocyclic carbenes. It also concerns a method for preparing said complexes from dicationic heterocyclic precursor compounds. It further concerns the use as catalysts of said organometallic complexes for a certain number of chemical reactions.

Abstract: A process for the production of paraxilene comprises an adsorption stage (18) using toluene as a desorbent in a simulated moving bed of a feedstock previously depleted in ethylbenzene by distillation (3) or by adsortion, an isomerization stage (26) without hydrogen in liquid phase diluted with toluene from the raffinate produced, a distillation stage (27) of the raffinate that is isomerized to recover the toluene (29) that is recycled. The separated isomerate is introduced into a xylene distillation column (9). The separated ethylbenzene is isomerized separately in gas phase with hydrogen at higher temperature and is distilled (5, 2, 9) in the presence of a catalyst that comprises an EUO-structural-type zeolite, then recycled to adsorption stage (18).

Abstract: A process for the production of paraxylene is described that comprises an adsorption stage (18) that uses toluene as a desorbent in a simulated moving bed of a feedstock whose ethylbenzene was separated by distillation (line 3) or by adsorption, an isomerization stage (26) without hydrogen in liquid phase that is diluted with toluene from the raffinate produced, a distillation stage (27) of the raffinate that is isomerized to recover the toluene (line 29) that is recycled. The separated isomerate is introduced into a xylene distillation column (9) then recycled, in adsorption. The separated ethylbenzene is isomerized separately in gas phase with hydrogen at higher temperature and is distilled (5, 2, 9) in the presence of a catalyst that comprises an EUO-structural-type zeolite, then recycled in adsorption column (18). The pure paraxylene is collected as extract (line 22) then optionally purified by crystallization (17).

Abstract: A process for producing 2,6-dialkylnaphthalene from a hydrocarbon feedstock that contains at least one component selected from the group consisting of dialkylnaphthalene isomers, monoalkylnaphthalene isomers, polyalkylnaphthalenes, and naphthalene, is provided that includes the following steps: I. separating the hydrocarbon feedstock and/or a dealkylation product fed from step III into a naphthalene fraction, a monoalkylnaphthalene fraction, a dialkylnaphthalene fraction and a remaining products fraction; II. separating and purifying 2,6-dialkylnaphthalene from the dialkylnaphthalene fraction of step I; III. dealkylating the hydrocarbon feedstock and/or the remaining products fraction of step I and feeding the dealkylation product to step I; and IV. alkylating the naphthalene and monoalkylnaphthalene fractions of step I; wherein the hydrocarbon feedstock is fed to step I or step III.