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

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: 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: Disclosed is a method for separating aromatic compounds using a simulated moving bed adsorptive chromatography, comprising a sulfolan process that is a non-aromatic compound removing process, a benzene/toluene fractionation process, an aromatic compound fractionation process, a selective toluene disproportionation process, a transalkylation process, a simulated moving bed para-xylene separation process and a xylene isomerization process, wherein the method is characterized by further comprising a simulated moving bed xylene mixture pre-treatment process and an additional xylene isomerization process. The separation method of aromatic compounds according to the present invention can make significant improvement in para-xylene and benzene production in the overall process, as compared to the conventional aromatic compound separation process.

Abstract: The apparatus includes at least two adsorptive separation zones to separate para-xylene from a feed stream comprising C8 aromatic hydrocarbons and at least one C9 aromatic hydrocarbon component. The first adsorptive separation zone delivers a raffinate stream to a raffinate distillation zone and an extract stream to an extract distillation zone. The raffinate distillation zone delivers a stream to the second adsorptive separation zone and at least one of the extract distillation zone and raffinate distillation zone delivers a recycle stream to the first adsorptive separation zone.

Abstract: Disclosed is a method for separating aromatic compounds using a simulated moving bed adsorptive chromatography and a crystallization process, comprising a sulfolan process that is a non-aromatic compound removing process, a benzene/toluene fractionation process, an aromatic compound fractionation process, a selective toluene disproportionation process, a transalkylation process, a crystallization process for para-xylene separation, a simulated moving bed para-xylene separation process and a xylene isomerization process, wherein the method is characterized by further comprising a simulated moving bed xylene mixture pre-treatment process and an additional xylene isomerization process. The separation method of aromatic compounds according to the present invention can make significant improvement in para-xylene and benzene production in the overall process, as compared to the conventional aromatic compound separation process.

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: The apparatus includes at least two adsorptive separation zones to separate para-xylene from a feed stream comprising C8 aromatic hydrocarbons and at least one C9 aromatic hydrocarbon component. The first adsorptive separation zone delivers a raffinate stream to a raffinate distillation zone and an extract stream to an extract distillation zone. The raffinate distillation zone delivers a stream to the second adsorptive separation zone and at least one of the extract distillation zone and raffinate distillation zone delivers a recycle stream to the first adsorptive separation zone.

Abstract: One exemplary embodiment can include an aromatic production apparatus. The aromatic production apparatus can include a first fractionation zone, a second fractionation zone, and a third fractionation zone. Generally, the first fractionation zone can provide a stream rich in an aromatic C8? and a stream rich in an aromatic C9, the second fractionation zone can separate at least one of benzene and optionally toluene from a transalkylation zone effluent and provide a feed to the first fractionation zone, and the third fractionation zone can receive the stream rich in the aromatic C8? from the first fractionation zone. An effluent from the third fractionation zone can be directly comprised in a para-xylene-separation zone feed to a para-xylene-separation zone.

Abstract: Disclosed is a method for separating aromatic compounds using a simulated moving bed adsorptive chromatography and a crystallization process, comprising a sulfolan process that is a non-aromatic compound removing process, a benzene/toluene fractionation process, an aromatic compound fractionation process, a selective toluene disproportionation process, a transalkylation process, a crystallization process for para-xylene separation, a simulated moving bed para-xylene separation process and a xylene isomerization process, wherein the method is characterized by further comprising a simulated moving bed xylene mixture pre-treatment process and an additional xylene isomerization process. The separation method of aromatic compounds according to the present invention can make significant improvement in para-xylene and benzene production in the overall process, as compared to the conventional aromatic compound separation process.

Abstract: One exemplary embodiment can include a method of altering a feed to a transalkylation zone by changing a destination of a stream rich in an aromatic C9 for increasing production of at least one of benzene, toluene, para-xylene, and an aromatic gasoline blend. The method can include providing the stream rich in an aromatic C9 from a first fractionation zone that receives an effluent from a second fractionation zone. The second fractionation zone may produce a stream rich in at least one of benzene and toluene. The stream rich in the aromatic C9 can be at least partially comprised in at least one of the feed to the transalkylation zone and the aromatic gasoline blend.

Abstract: A process for co-producing para-xylene and styrene from a feed (1) of hydrocarbons containing xylenes and ethylbenzene is described, the process comprising the following succession of steps: a step for separating the feed in a simulated moving bed in an adsorption column (6) containing beds of an adsorbent, from which an extract that is rich in para-xylene (7a) of at least 99.7% purity and at least one raffinate (7b) containing ethylbenzene, ortho-xylene, meta-xylene and a very small quantity of para-xylene is withdrawn; a step for dehydrogenating (10) the ethylbenzene contained in the raffinate (7b) to styrene; at least one step for primary separation of the stream (11) from the dehydrogenation step (10), to eliminate by-products; a step for separating the purified mixture (18) derived from the stream (11) containing styrene, unconverted ethylbenzene, meta-xylene and ortho-xylene, from which a stream (21a) that is rich in styrene of at least 99.

Abstract: The invention concerns a process for producing high purity meta-xylene, comprising a step for separation by simulated moving bed adsorption starting from an aromatic C8 feed delivering a fraction which is rich in meta-xylene and a fraction which is depleted in meta-xylene, and a step for crystallization of the meta-xylene rich fraction. The purity of the meta-xylene produced is at least 99.5%.

Abstract: A complete new process for producing p-xylene is provided to solve the problems in the prior arts of the great amount of benzene as a by-product and the requirement of low content of C10+ heavy aromatics in the feedstock. The process comprises first subjecting benzene and C9+ aromatics to alkyl transfer reaction to produce toluene and C8 aromatics, then conducting toluene selective disproportionation, and molecular sieve adsorptive separation and isomerization of C8 aromatics, to obtain p-xylene.

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: The system and method for optimizing para-xylene production from a feed stream containing para-xylene, ortho-xylene, meta-xylene, ethylbenzene and non-aromatics propose directing the feed stream into an isomerization unit of the system rather than to a separator of the system to avoid causing a bottleneck at the separator and to initially remove ethylbenzene and non-aromatics from the feed stream. This system and method may further provide a reactor in the feed stream used in a pretreatment step, the reactor containing an isomerization catalyst in an amount sufficient to convert substantially all the ethylbenzene in the feed stream to benzene, which is immediately removed and to convert and remove non-aromatics therefrom to optimize equilibrium isomer concentration in the isomerization unit and substantially eliminate coking therein.

Abstract: A process for production of paraxylene from a charge containing C7-C9 aromatic hydrocarbons in which a first fraction is enriched to at least 30% weight with paraxylene and this fraction is purified by at least one high-temperature crystallization in at least one crystallization zone. Said first fraction is crystallized in a crystallization zone at high temperature T1 and advantageously between +10 and −25° C., crystals in suspension in a mother liquor are recovered, the crystals are separated from the mother liquor in at least a first separation zone, the crystals obtained are partially melted in at least a zone for partial melting and a suspension of crystals is recovered, the crystals in suspension are separated and washed in at least one separation and washing zone and pure paraxylene crystals and washing liquor are recovered, and pure crystals are optionally completely melted and a liquid stream of melted paraxylene is collected.

Abstract: The method for removing ethylbenzene from a feed stream for use in producing para-xylene product, the stream containing para-xylene, ortho-xylene, meta-xylene and ethylbenzene. The method incorporates provision of a reactor unit used in a pretreatment step, the reactor containing an isomerization catalyst in an amount sufficient to convert substantially all the ethylbenzene in the feed stream to benzene, and provides for removal of the converted benzene from the stream prior to cyclic retreatments of the stream by a para-xylene separator and an isomerization unit, respectively.

Abstract: For isomerising aromatic compounds containing eight carbon atoms in the presence of hydrogen, a mixture containing compounds with a boiling point of about 80° C. to 135° C. comprising at least one paraffin containing eight carbon atoms, at least one naphthene containing eight carbon atoms, at least benzene and at least toluene is added to the feed before introducing it into the isomerisation reactor R via line 1. These additions are made by a recycle via line 6 or by adding fresh compounds via line 11, or be a combination of fresh and recycled compounds via lines 6 and 11. Hydrogen is added via line 15.

Abstract: A process for producing paraxylene of very high purity from a charge containing a mixture of aromatic hydrocarbons having 7 to 9 carbon atoms in which at least a portion of the charge is made to circulate in a zone suited to enrich a first fraction of paraxylene and at least a portion of said first fraction is purified by at least one high-temperature crystallization in at least one crystallization zone, the process being characterized in that said first paraxylene-enriched fraction is crystallized in a crystallization zone comprising at least two crystallization stages (50,70) at high temperature, and advantageously between +10 and -25 .degree. C.The paraxylene enriching zone can be a crystallization at very low temperature, a selective adsorption or a toluene disproportionation zone.

Abstract: A process for production of paraxylene from a charge containing C7-C9 aromatic hydrocarbons in which a first fraction is enriched to at least 30% weight with paraxylene and this fraction is purified by at least one high-temperature crystallization in at least one crystallization zone. Said first fraction is crystallized in a crystallization zone at high temperature T1 and advantageously between +10 and -25.degree. C., crystals in suspension in a mother liquor are recovered, the crystals are separated from the mother liquor in at least a first separation zone, the crystals obtained are partially melted in at least a zone for partial melting and a suspension of crystals is recovered, the crystals in suspension are separated and washed in at least one separation and washing zone and pure paraxylene crystals and washing liquor are recovered, and pure crystals are optionally completely melted and a liquid stream of melted paraxylene is collected.

Abstract: There are disclosed an industrially advantageous process for efficiently producing highly pure 2,6-dimethylnaphthalene (DMN) in high yield from a mixture of DMN by carrying out in turn, the steps of isomerizing a mixture of DMN in the presence of a catalyst; crystallizing the isomerization reaction product in the presence of a solvent (e.g.

Abstract: A process for separating paraxylene at very high purity from a charge of xylene isomers, comprising a selective adsorption of a fraction that is rich in paraxylene, at least one high-temperature crystallization of this fraction, and an isomerization of the fraction depleted of paraxylene, recycling the mother liquor to the selective adsorption optionally via a clay treatment followed optionally by a distillation of the treatment effluent, and optionally introducing the mother liquor into a distillation unit, wherein the crystallization can comprise several high-temperature stages.

Abstract: A method is disclosed to produce 2,6-dimethylnaphthalene (2,6-DMN), used for the production of polyethylene naphthalate, at high purity and high yield from a mixture of dimethylnaphthalene isomers without limitation to the specific isomers present in the feed by a series of fractionation, crystallization and adsorption steps.

Abstract: In a process for the separation of p-xylene from a feed to be treated containing a mixture of xylenes and olefinic impurities, at least a portion of the feed is circulated in an enrichment zone (14) to enrich a first fraction (15) in p-xylene and provide a second fraction (18) which is depleted in p-xylene. The second fraction is circulated in an isomerisation zone (19) and an isomerate (20) is recovered which is recycled to the enrichment zone. At least a portion of the feed to be treated, the isomerate, or a mixture thereof is circulated in at least one selective hydrogenation zone (3) to partially remove the olefinic impurities and thereafter in at least one clay tretment zone (8) to remove additional olefinic impurities. An effluent is recovered which is sent to the enrichment zone.

Abstract: A method for increasing the efficiency of xylene isomerization by using a two stage isomerization process. In the first stage of the process, a C.sub.9.sup.+ aromatics feedstock is subjected to ethylbenzene conversion and xylene isomerization. Non-C.sub.8 aromatics are removed from the effluent, which is then processed in a second stage of the process to remove para-xylene and isomerize the para-xylene depleted effluent. The effluent from the second stage isomerization unit is then recycled into the inlet of the second stage of the process and a slip stream from the para-xylene separator is recycled to the feedstock and to the effluent of the ethylbenzene conversion unit. In this way, the production of para-xylene is maximized. In a preferred embodiment, toluene is co-fed into the feedstock to minimize the loss of xylenes during the ethylbenzene conversion reaction.

Abstract: A process for producing highly pure 2,6-dimethylnaphthalene in a high yield from a mixture of dimethylnaphthalene isomers in the presence of a solvent, such as an aliphatic or alicyclic saturated hydrocarbon. Highly pure 2,6-dimethylnaphthalene can be produced steadily for a long time by filtering the 2,6-dimethylnaphthalene crystal precipitated by the crystallizing by using a filtration apparatus, such as a rotary vacuum filter, peeling-off the filtered cake from a filter cloth and cleaning the filter cloth with a solvent, at a temperature not lower than a filtration temperature.

Abstract: To continuously produce and separate high purity p-xylene from a C.sub.8 aromatic hydrocarbon charge, successive use is made in combination of (1) a stage of separating low-purity p-xylene (75 to 98%) by simulated moving bed adsorption chromatography; (2) a stage of purifying and washing the low-purity p-xylene by recrystallization (-25 to +10.degree. C.); (3) a stage of catalytic isomerization of the charge which has been p-xylene-depleted by the separating stage (1); and recovering an isomerate which is then recycled to the charge. The solvent for desorption in stage (1) and washing in stage (2) is advantageously toluene.

Abstract: A process for producing alkylnaphthalene from a feedstock comprising isomers of dialkylnaphthalene and naphthalene by contacting the feedstock with a catalyst composition, in which the process comprising transalkylation between isomers of dialkylnaphthalene and naphthalene to produce monoalkylnaphthalene, and isomerization of dialkylnaphthalene, wherein the catalyst composition comprising a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing as set forth in Table A of the specification.

Abstract: The eutectic limit of para-xylene crystallization is overcome by enriching the concentration of para-xylene of the crystallization feed. This is accomplished by passing the crystallization feed stream through a selective adsorption zone to produce a para-xylene-enriched stream and a para-xylene-depleted stream. The para-xylene-depleted stream is passed to an isomerization zone to re-equilibrate the xylene mixture, thereby producing additional para-xylene. The para-xylene-enriched stream is passed to a crystallization zone to produce high purity para-xylene. The result is an increase in the overall para-xylene recovery.

Abstract: Dimethylnaphthalenes are isomerized into 2,6-dimethylnaphthalene by utilizing hydrogen fluoride as a catalyst and straight chain saturated aliphatic hydrocarbons having carbon atoms in the range from 5 to 12 as the solvent. Isomerization to other undesirable isomers such as 2,7-dimethylnaphthalene and side reactions such as disproportionation are suppressed and a very high degree of the isomerization to 2,6-DMN can be attained.

Abstract: Isomerization of xylene in admixture with ethylbenzene by contact with a zeolite catalyst such as ZSM-5 is improved by use of a zeolite having a catalyst particle size of at least 1 micron and having incorporated thereon two metals such as platinum and magnesium.

Abstract: A method is disclosed for promoting isomerization of sym-octahydrophenanthrene (s-OHP) to sym-octahydroanthracene (s-OHA) in the presence of a catalyst provided by aluminum chloride or aluminum bromide, or a mixture of these two compounds. The rate of isomerization is increased by having the reaction run in the presence of an aryl phenone such as benzophenone.