Aromatic Separated From Other Aromatic Patents (Class 585/828)
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Patent number: 6841714Abstract: A process for co-production of paraxylene, metaxylene and/or orthoxylene from a hydrocarbon feedstock (1) that comprises [1] a separation stage of the feedstock in a simulated moving bed in a chromatographic column (9) that contains a number of beds of an adsorbent, interconnected in a loop, is described, whereby said column comprises an injection (3) of the feedstock, a draw-off (10) of an extract that consists of paraxylene and desorbent, an intermediate fraction (11) (extract or raffinate) that contains ethylbenzene, and a raffinate (12) that contains a mixture of metaxylene and orthoxylene that is virtually free of ethylbenzene and paraxylene and [2] a crystallization stage (27) of the metaxylene and/or orthoxylene fraction. Upstream from the adsorption zone and/or upstream from the crystallization zone, it is possible to distill the entering mixture to produce an orthoxylene-enriched fraction at the bottom and a metaxylene-enriched fraction at the top.Type: GrantFiled: September 20, 2002Date of Patent: January 11, 2005Assignee: Institut Francais du PetroleInventors: Philibert Leflaive, Luc Wolff, Gérard Hotier, Alain Methivier
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Patent number: 6838588Abstract: A process is described for co-producing metaxylene and paraxylene from a hydrocarbon feed comprising two separation steps. The first step of the process is a counter-current simulated moving bed system in a chromatographic column containing at least five zones, comprising injecting the feed and injecting a desorbent and delivering an extract, a raffinate and an intermediate raffinate either continuously or discontinuously. The extract is distilled to obtain a paraxylene with a purity of at least 99.7%. The raffinate, which is richer in metaxylene, is distilled to extract the desorbent and injected into a counter-current simulated moving bed continuously delivering an extract and a raffinate. One of these two streams is enriched in metaxylene. The most metaxylene-rich stream is distilled to obtain metaxylene with a purity of more than 99%.Type: GrantFiled: March 29, 2002Date of Patent: January 4, 2005Assignee: Institut Francais du PetroleInventors: Philibert Leflaive, Alain Methivier, Gérard Hotier
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Patent number: 6828470Abstract: A coproduction process for ortho-xylene and para-xylene starting with a batch of hydrocarbons comprises a simulated counter-current fluidized bed system in a chromatographic column (6) containing at least five zones, comprising injection (1) of the batch and injection (2) of desorption agent and delivering an extract (3), a refined product (5), and an intermediate refined product (4). Refined product (5), richer in ortho-xylene than the intermediate refined product, is distilled (9) to extract desorption agent (15) and is injection, according to the second step of the process, into a simulated counter-current fluidized bed system (17) delivering an extract (18) and a refined product (19) continuously.Type: GrantFiled: December 18, 2002Date of Patent: December 7, 2004Assignee: Institut Francais du PetroleInventors: Philibert Leflaive, Luc Wolff, Alain Methivier, Gérard Hotier
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Patent number: 6706939Abstract: A method for concentrating 2,6-dimethylnaphthalene in a dimethylnaphthalene isomer mixture includes supplying the dimethylnaphthalene isomer mixture to an adsorption column packed with Y-type zeolite. In this instance, by setting the value derived from the expression (u1/3/&egr;)d−5/3 at 14 (m5/3 s−1/3 kg−1) or more, the concentration ratio of 2,6-dimethylnaphthalene to 2,7-dimethylnaphthalene can be 2.0 or more. u here represents the linear velocity (m/s) of the dimethylnaphthalene isomer mixture supplied to an adsorption column, &egr; represents the packing density (kg/m3) of Y-type zeolite, and d represents the grain size (m) of the Y-type zeolite.Type: GrantFiled: July 12, 2002Date of Patent: March 16, 2004Assignee: Kobe Steel Ltd.Inventors: Noboru Nakao, Koji Yamamoto, Masahiro Motoyuki
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Patent number: 6706938Abstract: The performance of an adsorptive separation process recovering para-xylene from a C8 aromatic hydrocarbon feed mixture is improved by operating the process at higher desorbent purity. The improved performance allows for tradeoffs in other operating parameters and rates or improved product rates. The process preferably employs a barium and potassium exchanged zeolitic molecular sieve as the adsorbent and toluene as the desorbent.Type: GrantFiled: March 15, 2002Date of Patent: March 16, 2004Assignee: UOP LLCInventors: Cara M. Roeseler, Santi Kulprathipanja, James E. Rekoske
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Patent number: 6696616Abstract: For co-production of metaxylene and paraxylene from a hydrocarbon feedstock in a simulated moving bed in a chromatographic column (1) that contains a number of beds 1, 2,3, 4 . . . of an adsorbent, interconnected in a loop, the column comprises an injection of the feedstock, a draw-off (14) of a first raffinate, a draw-off (17) of a second raffinate that comprises metaxylene, an injection of desorbent and a draw-off of an extract that delivers paraxylene. The injection positions and the draw-off position of the extract are offset periodically by one bed in the direction of flow of the main flux that circulates in the column. First raffinate (14) that comprises desorbent, orthoxylene, metaxylene and ethylbenzene is drawn off continuously or intermittently, and second raffinate (17) R2 that comprises orthoxylene and metaxylene is drawn off intermittently. The second raffinate is distilled in such a way as to recover orthoxylene and metaxylene separately with at least 99% purity and with an improved yield.Type: GrantFiled: April 26, 2001Date of Patent: February 24, 2004Assignee: Institut Français du PétroleInventors: Didier Pavone, Gerard Hotier
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Patent number: 6689929Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C8 aromatics stream produced by toluene conversion uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the pX and EB giving a pX/EB-rich effluent. A stream of non-adsorbed mX and oX may be obtained before desorbing pX and EB.Type: GrantFiled: July 10, 2001Date of Patent: February 10, 2004Assignee: BP Corporation North America Inc.Inventors: Bryce A. Williams, Jeffrey T. Miller, Ruth Ann Doyle, Giorgio Zoia
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Patent number: 6673979Abstract: A process for separating at least one C8 alkylaromatic hydrocarbon from a mixture containing at least one C8 alkylaromatic hydrocarbon and at least one C9 or C10 alkylaromatic hydrocarbon using dealuminated sodium zeolite Y.Type: GrantFiled: March 1, 2002Date of Patent: January 6, 2004Assignee: UOP LLCInventors: Maureen L. Bricker, Charles P. McGonegal, Herman A. Zinnen
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Patent number: 6627783Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with para-xylene and ethylbenzene, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the para-xylene and ethylbenzene. The process effluent is rich in para-xylene and ethylbenzene. A stream of non-adsorbed meta-xylene and ortho-xylene may be obtained prior to desorption of para-xylene and ethylbenzene.Type: GrantFiled: July 10, 2001Date of Patent: September 30, 2003Assignee: BP Corporation North America Inc.Inventors: Ruth Ann Doyle, Jeffrey T. Miller, Kevin A. Kunz
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Patent number: 6600083Abstract: 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 crystallization 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 crystallized to obtain para-xylene product.Type: GrantFiled: July 10, 2001Date of Patent: July 29, 2003Assignee: BP Corporation North America Inc.Inventors: Ruth Ann Doyle, Jeffrey T. Miller, Richard A. Wilsak, Scott A. Roberts, Giorgio Zoia
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Publication number: 20030130556Abstract: A coproduction process for ortho-xylene and para-xylene starting with a batch of hydrocarbons comprising two separation steps is described. The first step relates to a simulated counter-current fluidized bed system in a chromatographic column (6) containing at least five zones, comprising injection (1) of the batch and injection (2) of desorption agent and delivering an extract (3), a refined product (5), and an intermediate refined product (4). The extract is distilled (7) to obtain para-xylene (10) that is very pure or that can be purified by crystallization. The refined products are withdrawn continuously or discontinuously. Refined product (5), richer in ortho-xylene than the intermediate refined product, is distilled (9) to extract desorption agent (15) and is injected, according to the second step of the process, into a simulated counter-current fluidized bed system (17) delivering an extract (18) and a refined product (19) continuously.Type: ApplicationFiled: December 18, 2002Publication date: July 10, 2003Applicant: Institut Francais du PetroleInventors: Philibert Leflaive, Luc Wolff, Alain Methivier, Gerard Hotier
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Patent number: 6573418Abstract: 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.Type: GrantFiled: July 10, 2001Date of Patent: June 3, 2003Assignee: BP Corporation North America Inc.Inventors: Jeffrey T. Miller, Bryce A. Williams, Ruth Ann Doyle, Giorgio Zoia
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Patent number: 6483002Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single column. Both streams are fractionated to recover desorbent, which is removed at one end of a dividing wall column, while separate extract and raffinate products are removed from the other end of the column.Type: GrantFiled: September 26, 2000Date of Patent: November 19, 2002Assignee: UOP LLCInventor: Dennis E. O'Brien
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Publication number: 20020165419Abstract: An improved process for recovering hydrocarbons from an inlet inert gas-hydrocarbon vapor mixture is provided. The inlet mixture is caused to flow through a first bed of solid adsorbent whereby hydrocarbon vapors are adsorbed on the bed and a residue gas stream comprised of substantially hydrocarbon-free inert gas is produced. The hydrocarbon-free inert gas is vented and a second bed of solid adsorbent having hydrocarbon vapors adsorbed thereon is evacuated with an ejector operated by a motive liquid. A major portion of the hydrocarbon vapors is desorbed from the bed and an inert gas and hydrocarbon-rich vapor mixture commingled with the motive liquid is produced. The inert gas and hydrocarbon-rich vapor mixture is separated from the motive liquid and conducted to a point of additional processing or disposal.Type: ApplicationFiled: May 2, 2001Publication date: November 7, 2002Inventors: Melissa G. Lenhart, Harold L. Dinsmore, Scott J. Fox
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Publication number: 20020143223Abstract: A process is described for co-producing metaxylene and paraxylene from a hydrocarbon feed comprising two separation steps. The first step of the process is a counter-current simulated moving bed system in a chromatographic column containing at least five zones, comprising injecting the feed and injecting a desorbent and delivering an extract, a raffinate and an intermediate raffinate either continuously or discontinuously. The extract is distilled to obtain a paraxylene with a purity of at least 99.7%. The raffinate, which is richer in metaxylene, is distilled to extract the desorbent and injected into a counter-current simulated moving bed continuously delivering an extract and a raffinate. One of these two streams is enriched in metaxylene. The most metaxylene-rich stream is distilled to obtain metaxylene with a purity of more than 99%.Type: ApplicationFiled: March 29, 2002Publication date: October 3, 2002Applicant: Institute Francais du PetroleInventors: Philibert Leflaive, Alain Methivier, Gerard Hotier
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Patent number: 6448459Abstract: 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).Type: GrantFiled: April 24, 2000Date of Patent: September 10, 2002Assignee: Institut Francais du PetroleInventors: Julia Magne-Drisch, Fabio Alario, Jean-François Joly, Ari Minkkinen, Elisabeth Merlen
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Publication number: 20020107427Abstract: 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 crystallization 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 crystallized to obtain para-xylene product.Type: ApplicationFiled: July 10, 2001Publication date: August 8, 2002Inventors: Ruth Ann Doyle, Jeffrey T. Miller, Richard A. Wilsak, Scott A. Roberts, Giorgio Zoia
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Patent number: 6429346Abstract: A simultaneous process for simulated moving-bed dismutation and separation of a toluene feedstock into benzene and xylenes in the presence of a hydrogen-rich desorbent in at least one adsorber-reactor (100) that contains beds of a solid and comprises at least three zones (23, 24, 25) is described. Vapor-phase or supercritical feedstock (1) is introduced at the inlet of a reaction and adsorption zone (25) (zone III), and a raffinate (15) that is high in benzene and desorbent is recovered at the outlet. Desorbent (5, 7) is introduced at the inlet of a desorption zone (23) (zone I), and an effluent from which is drawn off a portion (8) in the form of an extract that is high in xylenes and desorbent is recovered at the outlet. The other portion of the effluent of zone I is introduced at the inlet of a reaction and desorption zone (24) (zone II), and an effluent is recovered at the outlet that is sent back to the inlet of reaction and adsorption zone III.Type: GrantFiled: April 12, 2001Date of Patent: August 6, 2002Assignee: Institut Francais du PetroleInventors: Gérard Hotier, Hugues Dulot, Michel Bailly, Karine Ragil
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Publication number: 20020103408Abstract: The performance of an adsorptive separation process recovering para-xylene from a C8 aromatic hydrocarbon feed mixture is improved by operating the process at higher desorbent purity. The improved performance allows for tradeoffs in other operating parameters and rates or improved product rates. The process preferably employs a barium and potassium exchanged zeolitic molecular sieve as the adsorbent and toluene as the desorbent.Type: ApplicationFiled: March 15, 2002Publication date: August 1, 2002Inventors: Cara M. Roeseler, Santi Kulprathipanja, James E. Rekoske
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Publication number: 20020099251Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics uses a para-selective adsorbent, preferably a, non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with para-xylene and ethylbenzene, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the para-xylene and ethylbenzene. The process effluent is rich in para-xylene and ethylbenzene. A stream of non-adsorbed meta-xylene and ortho-xylene may be obtained prior to desorption of para-xylene and ethylbenzene.Type: ApplicationFiled: July 10, 2001Publication date: July 25, 2002Inventors: Ruth Ann Doyle, Jeffrey T. Miller, Kevin A. Kunz
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Publication number: 20020082461Abstract: 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).Type: ApplicationFiled: April 24, 2000Publication date: June 27, 2002Inventors: Julia Magne-Drisch, Fabio Alario, Jean-Francois Joly, Ari Minkkinen, Elisabeth Merlen
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Patent number: 6410815Abstract: The present invention relates to agglomerated zeolite adsorbents based on faujasite with an Si/Al ratio such that 1≦Si/Al≦1.15, at least 70% exchanged with barium and optionally with potassium, and on a binder, preferably a zeolitizable binder. They are obtained by agglomerating zeolite powder with a binder, followed by exchange of the zeolite ions for barium ions and activation of the adsorbents thus exchanged. These adsorbents are particularly suitable for the adsorption of the para-xylene contained in aromatic C8 hydrocarbon fractions in the liquid phase, in processes of simulated fluid-bed type.Type: GrantFiled: May 10, 2000Date of Patent: June 25, 2002Assignee: Elf Atochem S.A.Inventors: Dominique Plee, Alain Methivier
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Publication number: 20020077519Abstract: 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.Type: ApplicationFiled: July 10, 2001Publication date: June 20, 2002Inventors: Jeffrey T. Miller, Bryce A. Williams, Ruth Ann Doyle, Giorgio Zoia
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Patent number: 6403856Abstract: A process for separating at least one C8 alkylaromatic hydrocarbon from a mixture containing at least one C8 alkylaromatic hydrocarbon and at least one C9 or C10 alkylaromatic hydrocarbon using sodium zeolite Y, dealuminated sodium zeolite Y or dealuminated zeolite Y ion exchanged with a metal selected from the group consisting of calcium, sodium, strontium, a Group IB element, a Group VIII element and mixtures thereof.Type: GrantFiled: May 7, 2001Date of Patent: June 11, 2002Assignee: UOP LLCInventors: Maureen L. Bricker, Charles P. McGonegal, Herman A. Zinnen
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Publication number: 20020068844Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C8 aromatics stream produced by toluene conversion uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the pX and EB giving a pX/EB-rich effluent. A stream of non-adsorbed mX and oX may be obtained before desorbing pX and EB.Type: ApplicationFiled: July 10, 2001Publication date: June 6, 2002Inventors: Bryce A. Williams, Jeffrey T. Miller, Ruth Ann Doyle, Giorgio Zoia
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Patent number: 6395951Abstract: Construction and operational costs of recovering the extract or raffinate product of a simulated moving bed adsorptive separation process units are reduced by employing a dividing wall column to perform the separation. The raffinate or extract stream is passed into the column at an intermediate point on the first side of the dividing wall, with the column delivering the adsorptive separation product as a sidedraw from the opposite side of the dividing wall. A stream of co-adsorbed impurity is removed as an overhead stream and desorbent is recovered as a net bottoms stream.Type: GrantFiled: September 26, 2000Date of Patent: May 28, 2002Assignee: UOP LLCInventor: David A Hamm
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Publication number: 20020055665Abstract: For co-production of metaxylene and paraxylene from a hydrocarbon feedstock in a simulated moving bed in a chromatographic column (1) that contains a number of beds 1, 2, 3, 4 . . . of an adsorbent, interconnected in a loop, the column comprises an injection of the feedstock, a draw-off (14) of a first raffinate, a draw-off (17) of a second raffinate that comprises metaxylene, an injection of desorbent and a draw-off of an extract that delivers paraxylene. The injection positions and the draw-off position of the extract are offset periodically by one bed in the direction of flow of the main flux that circulates in the column. First raffinate (14) that comprises desorbent, orthoxylene, metaxylene and ethylbenzene is drawn off continuously or intermittently, and second raffinate (17) R2 that comprises orthoxylene and metaxylene is drawn off intermittently.Type: ApplicationFiled: April 26, 2001Publication date: May 9, 2002Applicant: Institute Francais du PetroleInventors: Didier Pavone, Gerard Hotier
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Patent number: 6376734Abstract: A process for the production of at least one isomer of xylenes comprising a simulated moving-bed adsorption (8) of a C8-aromatic feedstock (1) that delivers a paraxylene-rich fraction (9) that is optionally purified after a distillation (16) by at least one high-temperature crystallization (5) and a fraction (10) that is low in paraxylene is described. Fraction (10) is distilled and then isomerized (21) in the presence of an EUO-structural-type catalyst. The lightest hydrocarbons are removed from the isomerization effluent in a first distillation (23) then naphthenes in a second distillation (26), and distilled isomerization effluent (2) that results therefrom is recycled at least in part in adsorption (8). A mother liquor (3) that results from the crystallization stage is recycled at least in part in adsorption (8).Type: GrantFiled: June 22, 2000Date of Patent: April 23, 2002Assignee: Institut Francais du PetroleInventors: Julia Magne-Drisch, Gérard Hotier, Alain Methivier, Jean-Francois Joly, Fabio Alario, Elisabeth Merlen
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Patent number: 6369287Abstract: A process for co-production of paraxylene and ethylbenzene comprises: (A) an adsorption stage of a feedstock of xylenes and ethylbenzene in a simulated moving bed that produces an extract of pure paraxylene and an ethylbenzene-rich raffinate; (B) an adsorption stage in a simulated moving bed, of raffinate from which desorbent has been removed that supplies an essentially pure ethylbenzene extract and an orthoxylene and metaxylene raffinate that contains desorbent; (C) a recover stage for the desorbent; (D) an isomerization stage for the orthoxylene and metaxylene raffinate in the presence of a catalyst that comprises an EUO-type zeolite; and (E) a stage for recycling the isomerate that is produced with adsorption.Type: GrantFiled: June 19, 2000Date of Patent: April 9, 2002Assignee: Institut Francais du PetroleInventors: Julia Magne-Drisch, Gérard Hotier, Fabio Alario, Alain Methivier
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Patent number: 6348637Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single column. Both streams are fractionated in the same column to recover desorbent, which is removed at the bottom of the column. The bottom of the column is divided into a reboiler sump section and a bottoms product-desorbent inventory section, with this reducing the equipment required in the overall process.Type: GrantFiled: September 26, 2000Date of Patent: February 19, 2002Assignee: UOP LLCInventor: James W. Harris
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Publication number: 20010031903Abstract: A simultaneous process for simulated moving-bed dismutation and separation of a toluene feedstock into benzene and xylenes in the presence of a hydrogen-rich desorbent in at least one adsorber-reactor (100) that contains beds of a solid and comprises at least three zones (23, 24, 25) is described. Vapor-phase or supercritical feedstock (1) is introduced at the inlet of a reaction and adsorption zone (25) (zone III), and a raffinate (15) that is high in benzene and desorbent is recovered at the outlet. Desorbent (5, 7) is introduced at the inlet of a desorption zone (23) (zone I), and an effluent from which is drawn off a portion (8) in the form of an extract that is high in xylenes and desorbent is recovered at the outlet. The other portion of the effluent of zone I is introduced at the inlet of a reaction and desorption zone (24) (zone II), and an effluent is recovered at the outlet that is sent back to the inlet of reaction and adsorption zone III.Type: ApplicationFiled: April 12, 2001Publication date: October 18, 2001Applicant: Institut Francais du PetroleInventors: Gerard Hotier, Hugues Dulot, Michel Bailly, Karine Ragil
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Patent number: 6281406Abstract: An adsorption process for the recovery of paraxylene from mixed xylenes using a molecular sieve adsorbent comprising SSZ-25, MCM-22, PSH-3, ERB-1, or ITQ-1. A preferred desorbent for the process is benzene. A hybrid adsorption/crystallization PX purification process is also described using the molecular sieve adsorbent.Type: GrantFiled: March 31, 2000Date of Patent: August 28, 2001Assignee: Chevron CorporationInventor: John J. Cain
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Patent number: 6274784Abstract: A process for separating at least one C8 alkylaromatic hydrocarbon from a mixture containing at least one C8 alkylaromatic hydrocarbon and at least one C9 or C10 alkylaromatic hydrocarbon using zeolite Y or zeolite Y ion exchanged with a metal selected from the group consisting of calcium, sodium, strontium, a Group IB element, a Group VIII element and mixtures thereof.Type: GrantFiled: November 1, 1999Date of Patent: August 14, 2001Assignee: UOP LLCInventors: Maureen L. Bricker, Charles P. McGonegal, Herman A. Zinnen
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Patent number: 6177604Abstract: Paraxylene and ethylbenzene are produced from an aromatic hydrocarbon feedstock by using adsorption zones in a simulated fluid bed. The feedstock is first passed into a first adsorption zone to produce a first paraxylene-rich fraction and a second ethylbenzene-rich fraction. The second fraction is then passed into a second adsorption zone to produce a third fraction containing essentially pure ethylbenzene and a fourth fraction containing a majority of orthoxylene and metaxylene. The fourth stream is then passed into an isomerization zone to produce an isomerate which is then recycled back to the first adsorption zone.Type: GrantFiled: December 23, 1998Date of Patent: January 23, 2001Assignee: Institut Francais du PetroleInventors: Gerard Hotier, Fabio Alario, Alain Methivier
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Patent number: 6137024Abstract: A process for separating meta-xylene from a mixture containing meta-xylene, para-xylene, and ortho-xylene has been developed. The process involves contacting the mixture with zeolite Beta to effect the adsorption of the para-xylene, ortho-xylene, and ethylbenzene in preference to the meta-xylene and recovering the meta-xylene.Type: GrantFiled: February 22, 1999Date of Patent: October 24, 2000Assignee: UOP LLCInventors: Herman A. Zinnen, Charles P. McGonegal
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Patent number: 6063978Abstract: 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.Type: GrantFiled: June 30, 1997Date of Patent: May 16, 2000Assignee: Institut Francais du PetroleInventors: Gerard Hotier, Paul Mikitenko, Stuart R MacPherson
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Patent number: 6060634Abstract: Para-xylene is produced from a paraselective toluene disproportionation reactor, effluent (3) is distilled to eliminate toluene and benzene in at least 2 distillation columns (C1), (C2), and the xylenes (8) are crystallized at least once (10) at between +10.degree. C. and -30.degree. C. The separated mother liquor (14) is adsorbed on a zeolitic sieve in the presence of toluene in a simulated moving bed (15). This latter produces a raffinate (16) containing toluene which is depleted in para-xylene which is distilled in a distillation column (C4), and an extract which is enriched in para-xylene and contains toluene, which is recycled to columns (C1, C2). The para-xylene crystals are purified by washing with toluene and distillation or by partial melting (30) followed by washing with molten high purity para-xylene.Type: GrantFiled: August 12, 1998Date of Patent: May 9, 2000Assignee: Institut Francais du PetroleInventors: Paul Mikitenko, Gerard Hotier
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Patent number: 6057487Abstract: 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.Type: GrantFiled: December 30, 1997Date of Patent: May 2, 2000Assignee: Chevron Chemical CompanyInventors: Curtis L. Munson, Patrick C. Bigot, Zunqing Alice He
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Patent number: 5948950Abstract: A process for separating para-xylene from a C.sub.8 feed in a simulated moving bed comprises a step for adsorption on a zeolite and desorption using a desorbent delivering an extract and a raffinate, and an extract crystallization step. A stream of water is introduced into the feed, into the desorbent and/or into the stream for recycling one flux in the column, such that the weighted average of the amounts of water measured in the extract and in the raffinate is in the range 1 to 200 ppm. The ratio S/F of the desorbent flow rate to that of the feed during the adsorption and desorption step is in the range 0.6 to 2.5.Type: GrantFiled: December 18, 1997Date of Patent: September 7, 1999Assignee: Institut Francais du PetroleInventors: Gerard Hotier, Alain Methivier, Annick Pucci
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Patent number: 5912395Abstract: The capacity of a simulated moving bed adsorptive separation process is increased by flushing the contents of the transfer line just previously used to remove the raffinate stream from the adsorbent chamber back into the adsorbent chamber. This step is performed immediately upstream of the point of raffinate withdrawal. Preferably the feed stream to the process is used as the flushing liquid. This flush step eliminates the passage of a quantity of the raffinate material into the adsorbent chamber when the process conduit is subsequently used to charge the feed stream to the adsorbent chamber.Type: GrantFiled: February 9, 1998Date of Patent: June 15, 1999Assignee: UOP LLCInventor: Robert J.L. Noe
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Patent number: 5900523Abstract: Metaxylene is recovered from admixture with other C.sub.8 aromatic hydrocarbons including orthoxylene by liquid phase adsorptive separation using a sodium exchanged Y zeolite as the adsorbent. Performance is improved by maintaining the adsorbent in a narrow range of temperature and hydration. These conditions allow the metaxylene to be recovered in a single raffinate process without costly prefractionation for orthoxylene removal. A novel desorbent, indane, is also disclosed.Type: GrantFiled: August 8, 1997Date of Patent: May 4, 1999Assignee: UOP LLCInventor: Santi Kulprathipanja
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Patent number: 5884777Abstract: Disclosed is a method for the adsorptive separation by utilizing an improved simulated moving bed. This invention provides an improved formula for the calculation of primary flush flowrate by correspondingly associating the primary flush flowrate with each connection line by introducting a volume factor and carring out sequential control so as to reduce the amount of the flush stream and increase product purity and yield.Type: GrantFiled: June 4, 1997Date of Patent: March 23, 1999Assignee: Yangzi Petro-Chemical Corp. SinopecInventors: Weizhong Pan, Yubing Wang, Wen Zhou, Yousong Li, Yusong Xue, Weimin Chen
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Patent number: 5866740Abstract: Para-xylene is produced from a paraselective toluene disproportionation reactor, effluent is distilled to eliminate toluene and benzene in at least 2 distillation columns, and the xylenes are crystallized at least once at between +10.degree. C. and -30.degree. C. The separated mother liquor is adsorbed on a zeolitic sieve in the presence of toluene in a simulated moving bed. This latter produces a raffinate containing toluene which is depleted in para-xylene which is distilled in a distillation column, and an extract which is enriched in para-xylene and contains toluene, which is recycled. The para-xylene crystals are purified by washing with toluene and distillation or by partial melting followed by washing with molten high purity para-xylene.Type: GrantFiled: September 27, 1996Date of Patent: February 2, 1999Assignee: Institut Francais du PetroleInventors: Paul Mikitenko, Gerard Paul Hotier
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Patent number: 5849981Abstract: The cost of separating para-xylene from other xylene isomers and C.sub.9 aromatics by adsorption on zeolitic molecular sieves is reduced by the use of 1,4 diisopropylbenzene as a relatively high boiling desorbent. The desorbent has surprisingly high strength and selectivity characteristics with the preferred desorbent. The preferred adsorbent is an X zeolite containing barium or both barium and potassium ions at exchangeable cationic sites. The para-xylene components are selectively adsorbed onto the adsorbent. The non-adsorbed feed is then removed from the adsorbent and the para-xylene recovered by desorption.Type: GrantFiled: June 25, 1997Date of Patent: December 15, 1998Assignee: UOP LLCInventor: Santi Kulprathipanja
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Patent number: 5763714Abstract: A mixed aromatic stream is hydrotreated to remove olefins and fractionated to separate C.sub.9 + heavies in a distillation column reactor and the C.sub.8 and lighter material is fed to a selective adsorption unit where the para-xylene is removed. The para-xylene depleted raffinate therefrom may be subjected to isomerization to form additional para-xylene. The effluent from the isomerization can be fed to the distillation column reactor for hydrogenation of any olefins formed during the isomerization or directly to the adsorption unit.Type: GrantFiled: January 8, 1997Date of Patent: June 9, 1998Assignee: Catalytic Distillation TechnologiesInventors: Thomas P. Hickey, Dennis Hearn, Hugh M. Putman
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Patent number: 5629467Abstract: 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, with a ratio for the solvent to charge flow rates of 1.2 to 2.5; (2) a stage of purifying and washing the low-purity p-xylene by recrystallization (-25.degree. 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.Type: GrantFiled: March 27, 1995Date of Patent: May 13, 1997Assignee: Institut Francais du PetroleInventors: Gerard Hotier, Claude Roux Guerraz, Than Nguyen Thanh
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Patent number: 5495061Abstract: The cost of separating para-xylene from other xylene isomers and C.sub.9 aromatics by adsorption on zeolitic molecular sieves is reduced by the use of certain relatively high boiling desorbents including 1,4 diisopropylbenzene. Preferably the adsorbent is an X zeolite adsorbent containing barium or both barium and potassium ions at exchangeable cationic sites. The para-xylene components are selectively adsorbed onto the adsorbent. The non-adsorbed feed is then removed from the adsorbent and the para-xylene recovered by desorption. Any C.sub.9 aromatic hydrocarbons and the other xylene isomers in the raffinate can be separated from these heavy desorbents by fractionation of the raffinate and the desorbent can be recycled to the process.Type: GrantFiled: October 11, 1994Date of Patent: February 27, 1996Assignee: UOPInventor: Santi Kulprathipanja
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Patent number: 5453560Abstract: Ethylbenzene is recovered from a mixture of C.sub.8 aromatic hydrocarbons including xylenes by adsorptive separation in a narrow temperature range using a cesium exchanged X zeolite as the adsorbent. A mixture of diethylbenzene and toluene is the preferred desorbent.Type: GrantFiled: May 20, 1994Date of Patent: September 26, 1995Assignee: UOPInventor: Santi Kulprathipanja
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Patent number: 5414191Abstract: According to the method of the invention, it is possible to separate and selectively remove alkyltetralins coexisting in a small amount in a LAB mixture which is an intermediate raw material for surfactants for detergents, the method conveniently being carried out in a continuous manner using a solid adsorbent.Type: GrantFiled: January 14, 1994Date of Patent: May 9, 1995Assignees: NKK Corporation, Vista Chemical CompanyInventors: Seiji Aoki, Tomonori Kato, Hiroaki Taniguchi, Hidetosi Morotomi, Masami Ono
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Patent number: 5382747Abstract: Metaxylene is recovered from a mixture of C.sub.8 aromatic hydrocarbons including other xylenes by liquid phase adsorptive separation using a sodium or sodium and lithium exchanged Y zeolite as the adsorbent. Performance is improved by maintaining the adsorbent in a narrow range of temperature and hydration. Toluene is the preferred desorbent.Type: GrantFiled: August 23, 1993Date of Patent: January 17, 1995Assignee: UOPInventor: Santi Kulprathipanja