Exxonmobil Chemical Patents Inc.

Georgia Tech Research Corporation

Other

John Roger Porter

Dana Lynn Pilliod

John Di-Yi Ou

Timothy Paul Bender

Gaurav Agrawal

Michael W Weber

Robert G Tinger

Larry Lee Iaccino

Michael Salciccioli

Anthony Go

Indulis J Eilands

Harold William Helmke

Christopher Lynn Becker

Jeevan Sahib Abichandani

Sankar Nair

John Joseph Monson

Catherine M Dorsi

Yoshiaki Kawajiri

Meha Rungta

Siwei Guo

Jonathan J Watts

Thomas J Waddick

Ke Zhang

Jason Bentley

Harold W Helmke

Albert F Seibert

Para-xylene is separated from a mixture of xylenes and ethylbenzene by a separation process. An ortho-selective adsorbent is used to reduce the ortho-xylene concentration of the xylenes, prior to contact of the xylenes and ethylbenzene with a para-selective adsorbent. The stream rich in ortho-xylene may be isomerized in the liquid phase to increase the amount of para-xylene therein. The para-xylene-depleted stream may be treated in the vapor phase to remove the ethylbenzene and then subjected to isomerization in the liquid phase to produce a stream having a higher than equilibrium amount of para-xylene.

Process for recovering para-xylene

In a process and system for treatment of feed stocks comprising alkylating agent and metal salts, the metal salts are removed from the feedstock by an efficient combination of separations processes. The processes may take place in one or more stages, each stage taking place in one or more vessels. Such treatment processes may remove 99.9% or more of metal salts from a feedstock, while recovering 99.9% or more of the alkylating agent from the feedstock for use in an alkylation reaction, especially of aromatics such as toluene and benzene. Preferred alkylating agents include methanol and mixtures of carbon monoxide and hydrogen, for methylation of toluene and/or benzene. The methylation proceeds over an aluminosilicate catalyst and preferably yields para-xylene with 75% or greater selectivity.

Treatment of aromatic alkylation feedstock

A process to separate paraxylene from a mixture of paraxylene, metaxylene, orthoxylene, and ethylbenzene in a commercial simulated moving bed apparatus in a reduced number of beds is provided, allowing an additional separation to be conducted in the remaining beds. This additional separation may separate another xylene isomer, ethylbenzene, or a non-aromatic Chydrocarbon from the raffinate stream produced by the first separation. A PowerFeed process is used to recover paraxylene in a first adsorption zone containing 8-16 beds of a conventional 24-bed simulated moving bed adsorption apparatus, and then a second separation may be conducted in a second adsorption zone containing the remaining beds.

Xylene separation process

Disclosed herein are processes for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce a paraxylene-rich extract stream that also contains a significant amount of the ethylbenzene and a paraxylene-depleted raffinate stream. Because a significant amount of the ethylbenzene is removed in the paraxylene-rich extract stream (at least enough to limit buildup in the isomerization loop), the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy- and capital-intensive hydrogen recycle loop.

Process for the recovering of paraxylene

A process and a device for removing water and/or oxygen from a crude organic liquid stream using a distillation column with heat input and dry nitrogen stream. A side effluent stream comprising water at a high concentration is drawn from the distillation column. An optional settling drum can be used to separate the aqueous phase from the organic phase in the side effluent stream can be used. The invention can be advantageously used for purifying a crude organic liquid stream comprising one or more of benzene, toluene, xylene, ethylbenzene, cumene, cyclohexane, cyclohexene, cyclohexanol, cyclohexanone, and the like.

Process for removing water and/or oxygen from organic liquid

A process for producing para-xylene (PX) comprises supplying a hydrocarbon feed comprising xylenes and ethylbenzene (EB) to a PX recovery unit, where a PX-rich stream and at least one PX-depleted stream are recovered from the feed. The PX-depleted stream is then separated into an EB-rich stream and an EB-depleted stream in a divided wall column. The EB-depleted stream is then isomerized under at least partial liquid phase conditions to produce a first isomerized stream having a higher PX concentration than the PX-depleted stream, and the EB-rich stream is isomerized under at least partial vapor phase conditions to produce a second isomerized stream having a higher PX concentration than the PX-depleted stream. The first and second isomerized streams are then recycled to the PX recovery unit to recover additional PX and the process is repeated to define a so-called xylene isomerization loop.

Process and apparatus for the production of para-xylene

A simulated moving bed process using dual, parallel rotary valves configured or plumbed to be operated independently in which the step times of the rotary valves are staggered. In embodiments, the second rotary valve is programmed to step about halfway through the step time of the first rotary valve. Staggering the step time of the parallel rotary valves, rather than utilizing simultaneous stepping, results in increased net composite paraxylene concentration of the extract stream, allowing for increased capacity of the simulated moving bed process and/or reduced energy consumption.

Xylene separation process and apparatus

A method for removing sulfolane from hydrocarbon streams by serial separation using raffinate wash column and at least one raffinate wash drum. The separation may be particularly useful in retrofitting existing separation facilities to produce motor fuels meeting the specifications requiring lower sulfolane content. A method is provided for the purification of a hydrocarbon-containing stream having a sulfolane therein. The method includes separating a first sulfolane-depleted stream from a hydrocarbon stream in a first counter-current separation unit and then separating a second sulfolane-depleted stream from the first sulfolane-depleted stream in a second counter-current separation unit. The first and second counter-current separation units are preferably different and chosen from a raffinate wash column or at least one raffinate wash drum. An apparatus for performing the methods is also described.

Method and apparatus for the purification of a hydrocarbon-containing stream

A process is described for separating paraxylene from a multicomponent fluid mixture of Caromatics. A mixture of Caromatics is fed to a simulated moving bed adsorptive apparatus having at least two sieve chambers and at least two rotary valves. Each sieve chamber may be operated individually using the PowerFeed process. The flow rates of the streams to or from the individual sieve chambers may be varied during the step time in an inverse manner such that a substantially constant flow to and from the apparatus is achieved. Alternatively, the flow rates to each sieve chamber may vary during the step time according to the same profile, but the rotary valves may be off-set and step independently in a staggered manner to achieve a substantially constant flow of a stream to or from the apparatus.

A process for producing paraxylene is provided. The process includes separating a first mixture of Caromatic hydrocarbons in a simulated moving bed apparatus using a desorbent to produce (i) an extract comprising &#x2267;50.0 wt % of the paraxylene in the first mixture; (ii) a desorbent-rich raffinate comprising &#x2267;75 wt % of the desorbent withdrawn, and (iii) an desorbent-lean raffinate comprising &#x2266;25 wt % of the desorbent withdrawn in the desorbent-rich and desorbent-lean raffinates. The desorbent-lean raffinate can then, without an intervening separation step, be passed to a refinery process or a vapor phase isomerization reaction to produce an effluent comprising paraxylene in a greater concentration than the desorbent-lean raffinate. The desorbent-rich raffinate can be passed to a liquid phase isomerization reaction to produce an effluent comprising paraxylene in a greater concentration than the desorbent-rich raffinate.

Paraxylene separation process

Process of producing para-xylene by alkylation of benzene and/or toluene including treatment of an alkylating agent to remove metal salts

A process for separating a product from a multicomponent feedstream to an adsorption apparatus or system is described. The apparatus or system may comprise a moving-bed or a simulated moving-bed adsorption means. The product comprises at least one organic compound, such as an aryl compound with alkyl substitutes. In embodiments the conduits used to supply the feedstream to the apparatus or system are flushed with media of multiple grades. The improvement is more efficient use of the desorbent. In embodiments the process achieves improvements in one or more of efficiency of adsorption separation, capacity of adsorption apparatus systems, and purity of product attainable by adsorption process.

Apparatus for conducting simulated countercurrent adsorptive separation of a multi-component feed stream

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

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Friendswood, TX, United States of America

John Roger Porter