Abstract: The present invention describes a process for separating xylenes in simulated counter-current (simulated moving bed, SMB) for the treatment of feeds including oxygen-containing aromatic impurities of the phenol type and/or derivatives thereof, by controlled injection of water in the ingoing streams.

Abstract: A process for separating para-xylene from a plurality of aromatic compounds, wherein the process introduces a first mixed xylene stream comprising a plurality of xylene isomers into a first adsorptive separation unit to produce a first para-xylene enriched stream and a first raffinate stream. The process further introduces a second mixed xylene stream comprising a plurality of xylene isomers into a second adsorptive separation unit to produce a second para-xylene enriched stream and a second raffinate stream. The process further feeds both the first raffinate stream and the second raffinate stream into a shared raffinate column.

Abstract: A device (SMB) for separation by simulated moving bed adsorption comprises a plurality of elementary zones Zi in series operating in a closed loop, each of said zones comprising, between two successive fluid injection or extraction points, a unique bed Li of adsorbant solid with volume VAi and a non-selective free volume Vi, in which the majority of the zones are ordinary elementary zones each having an identical volume VA of the same adsorbant S, and a substantially identical non-selective free volume equal to V; the device also comprises at least one particular elementary zone Z0, termed the particular elementary zone, comprising a non-selective free volume V0 which is greater than V, and a unique bed L0 of adsorbant S0 with volume VA0 which is less than VA, S0 having a volume adsorption capacity C0 which is greater than that, C, of S, such that the overall adsorption capacity C0×VA0 of Z0 is closer to the overall adsorption capacity C×VA of each of the ordinary elementary zones than the overall adsorption

Abstract: A process for separating para-xylene from a plurality of xylene isomers, wherein the process introduces at a first feed point a first mixed xylene stream comprising a plurality of xylene isomers into a first adsorptive separation unit to produce a first para-xylene enriched stream and a first raffinate stream, and introduces a second mixed xylene stream comprising a plurality of xylene isomers into a second adsorptive separation unit to produce a second raffinate stream. The process feeds both the first raffinate stream and the second raffinate stream into a raffinate column. The process further introduces an extract stream from the second adsorptive separation unit into a first input of a split extract column comprising an internal partition defining a first distillation zone and a second distillation zone.

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: A device (SMB) for separation by simulated moving bed adsorption comprises a plurality of elementary adsorption zones Zi in series operating in a closed loop, and at least one singular adsorption zone with a dead volume which is greater than the adsorption zones Zi, the solid adsorbant of said singular adsorption zone having a granulometry which is lower than that of the solid adsorbant of the ordinary adsorption zones.

Abstract: A method for separating a xylene from a feed mixture by contacting the feed mixture with a bed of adsorbent comprising metal organic framework crystals selective to the xylene.

Abstract: Helicobacter pylori is closely associated with chronic gastritis, peptic ulcer disease, and gastric adenocarcinoma. Helicobacter pylori neutrophil-activating protein (HP-NAP), a virulence factor of Helicobacter pylori, plays an important role in pathogenesis of Helicobacter pylori infection. Since HP-NAP has been proposed as a candidate vaccine against Helicobacter pylori infection, an efficient way to obtain pure HP-NAP needs to be developed. In the present invention, recombinant HP-NAP expressed in Bacillus subtilis and Escherichia coli was purified through a single step of DEAE SEPHADEX ion-exchange chromatography with high purity. Also, purified recombinant HP-NAP was able to stimulate neutrophils to produce reactive oxygen species. Thus, recombinant HP-NAP obtained from our Bacillus subtilis expression system and Escherichia coli expression system is functionally active.

Abstract: A process for the production of para-xylene by simulated counter-current adsorption with high flexibility with respect to a reference run (100%) uses 2 adsorbers each with 12 beds, said adsorbers being able to be connected in accordance with 3 different modes; the flexibility obtained is 50% to 150%.

Abstract: The present disclosure provides natural gas and petrochemical processing systems including oxidative coupling of methane reactor systems that integrate process inputs and outputs to cooperatively utilize different inputs and outputs of the various systems in the production of higher hydrocarbons from natural gas and other hydrocarbon feedstocks.

Abstract: Embodiments of the present invention provide, for an adsorption separation system for separating normal paraffins from a hydrocarbon feed stream, a process for switching the adsorption separation from a triple split desorbent system to a dual split desorbent system, and vice versa. Switching occurs by separating and/or introducing a second flush material in the adsorption separation system. This switching can occur during normal operations.

Abstract: One exemplary embodiment can be a separation system. The separation system can include an adsorption zone, a rotary valve, a transition zone, and one or more pipes. Usually, the transition zone includes one or more lines communicating the rotary valve with the adsorption zone. The rotary valve alternatively may distribute an input of a feed or a desorbent to the adsorption zone or alternatively can receive an output of a raffinate or an extract from the adsorption zone in a line, and a remnant may remain in the line from a previous input or output. One or more pipes outside the transition zone communicating with the rotary valve can form at least one pipe volume receiving an input for dislodging a remnant or for receiving a remnant from the line. The remnant may be different from the input or output.

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: Methods are disclosed for producing C8 aromatic hydrocarbons. Representative methods comprise fractionating a transalkylation effluent, exiting a transalkylation reaction zone and comprising C8 and C9 aromatic hydrocarbons, to provide a C8 aromatic hydrocarbon-enriched fraction and a C9 aromatic hydrocarbon-enriched fraction. The methods may further comprise (i) recycling the C9 aromatic hydrocarbon-enriched fraction to the transalkylation reaction zone and/or (ii) separating, in a xylene separation zone, isomers of C8 aromatic hydrocarbons in the C8 aromatic hydrocarbon-enriched fraction, into a para-xylene-enriched extract and a para-xylene-depleted raffinate. Performance in the transalkylation reaction zone is improved and/or downstream processing requirements in an aromatics complex are mitigated.

Abstract: A simulated moving bed adsorptive separation process for preparing the separate feed streams charged to naphtha reforming unit and a steam cracking unit has been developed. The feed stream to the overall unit is passed into the adsorptive separation unit. The desorbent in the adsorptive separation is C12 hydrocarbons. The simulated moving bed adsorptive separation separates the components of the feed stream into a normal paraffin stream, which is charged to the steam cracking process, and non-normal hydrocarbons which are passed into a reforming zone. The desorbent is readily separated from the normal paraffin stream and from the non-normal paraffin stream and the simulated moving bed adsorption zone is operated at an A/Fn ratio of from about 0.90 to about 0.92.

Abstract: A process is presented for the selective separation and recovery of large normal paraffins from a heavy kerosene boiling point fraction. The process includes passing the heavy kerosene fraction through an adsorption separation system for separating the normal paraffins from the paraffin mixture. The recovered extract and raffinate streams are mixed with a diluent made up of a lighter hydrocarbon. The subsequent diluted extract and raffinate streams are passed through first fractionation columns to separate the desorbent from the diluent and the heavier paraffins. The mixture of the diluent and heavier paraffins is passed through a second set of fractionation columns to separate the diluent and the heavier paraffins.

Abstract: The invention is an adsorptive separation process for producing a para-xylene product from a feed stream comprising para-xylene, at least one other C8 aromatic, and a C9 aromatic. An adsorbent comprising X or Y zeolite and a desorbent comprising para-diethylbenzene (p-DEB) are used in an adsorptive separation zone to produce an extract stream comprising para-xylene, p-DEB, and the C9 aromatic and a raffinate stream comprising the at least one other C8 aromatic, the C9 aromatic, and p-DEB. The extract stream is separated in an extract distillation zone to produce a second desorbent stream comprising the C9 aromatic and p-DEB and the raffinate stream is separated in a raffinate distillation zone to produce a third desorbent stream comprising the C9 aromatic and p-DEB. At least a portion of at least one of the second desorbent stream and the third desorbent stream is further separated in a desorbent distillation zone to produce a stream comprising the C9 aromatic.

Abstract: The invention relates to an improved absorption-type separation and/or purification processes having dual rotary valves.

Abstract: The invention relates to processes for reducing the sulfur content in hydrocarbon fuels such as gasoline, diesel fuel and jet fuel. The invention provides a method and materials for producing ultra low sulfur content transportation fuels for motor vehicles as well as for applications such as fuel cells. The materials and method of the invention may be used at ambient or elevated temperatures and at ambient or elevated pressures without the need for hydrogen.

Abstract: A process for separating a feed F by simulated moving bed adsorption in a SMB device comprises external bypass lines Li/i+1 which directly connect two successive plates, Pi, Pi+1, the index “i” being either even or (exclusive of the foregoing) odd, along the whole length of the column, allowing said plates to be flushed, in which each of the bypass lines Li/i+1 comprises automated means for regulating the flow rate in the bypass lines, the bypass lines in certain cases being subject to a flushing flow during injection or withdrawal operations.

Abstract: A process for separating a feed F by simulated moving bed adsorption in a SMB device comprises at least one zone 1 for desorption of the compounds produced in the extract, a zone 2 for desorption of the compounds produced in the raffinate, a zone 3 for adsorption of the compounds produced in the extract, a zone 4 located between the raffinate withdrawal and the desorbant supply, the device comprising external by-pass lines Li/i+1 directly connecting two successive plates Pi and Pi+1; in which the degree of opening of means for restricting the flushing flow rate of the by-pass lines Li/i+1 are sequentially modified such that: 1) in an operational zone where there is at least one closed by-pass line, a super-synchronicity of the flushing flow rate is established in all of the by-pass lines which are not closed belonging to the zone under consideration, said super-synchronicity being defined by the following formula: S=a+b(nf/nt) in which the constant a is a constant in the range ?5 to 5 and b is a constant

Abstract: A process for separating a feed F by simulated moving bed adsorption in a SMB device is described, the device comprising external bypass lines Li/i+1 which directly connect two successive plates Pi, Pi+1, the index i being either even or (exclusive of the foregoing) odd, along the whole length of the column, in order to flush said plates, in which each of the bypass lines Li/i+1 comprises automated means for regulating the flow rate in the bypass lines, the degree of opening of said regulating means being defined by the following three rules: a) establishing a flow rate corresponding to an oversynchronicity in the range 15% to 30% in all of the open bypass lines of zone 1; b) establishing a flow rate corresponding to the synchronicity to within plus or minus 8% in all of the open bypass lines of zones 2 and 3; c) establishing a flow rate corresponding to an oversynchronicity in the range 20% to 40% in all of the open bypass lines of zone 4.

Abstract: Ion exchange and hydrophobic interaction chromatographic materials are constructed by tethering a terminal binding functionality to a solid support via a hydrophobic linker. The backbone of the linker typically comprises sulfur-containing moieties. Suitable terminal binding functionalities are tertiary amines, quaternary ammonium salts, or hydrophobic groups. These chromatographic materials possess both hydrophobic and ionic character under the conditions prescribed for their use. The separation of proteins from crude mixtures at physiological ionic strength can be accomplished with a chromatographic material of this type by applying pH or ionic strength gradients, thereby effecting protein adsorption and desorption.

Abstract: An improved process for the production capacity and feedstock handling flexibility of a simulated moving bed adsorptive separation process by introducing a second feed stream to the adsorbent chamber comprising a feed material of a different concentration of the desired compound than the concentration of the desired compound in the first feed material stream. The introduction of this second feed material stream may be performed at any location on the adsorbent chamber between (i) a transfer point located immediately upstream of the point of the raffinate material stream withdrawal from the adsorbent chamber to (ii) a transfer point located immediately downstream of the point of extract material stream withdrawal from the adsorbent chamber. A recycle stream may be introduced into the system at a location having a concentration similar to the concentration of the first feed material stream.

Abstract: A process for the separation of close boiling compounds comprising distilling a hydrocarbon mixture of said compounds in the presence of a high boiling diluent liquid and a solid adsorbent. The high boiling diluent is withdrawn from the bottom of the distillation column and recycled to the column. The process is particularly suitable for the separation of straight-chain isomers from isomerate mixtures, the separation of benzene from hydrocarbon mixtures and the separation of paraffins from olefins.

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: A process is presented for the selective separation and recovery of large normal paraffins from a heavy kerosene boiling point fraction. The process includes passing the heavy kerosene fraction through an adsorption separation system for separating the normal paraffins from the paraffin mixture. The recovered extract and raffinate streams are mixed with a diluent made up of a lighter hydrocarbon. The subsequent diluted extract and raffinate streams are passed through first fractionation columns to separate the desorbent from the diluent and the heavier paraffins. The mixture of the diluent and heavier paraffins is passed through a second set of fractionation columns to separate the diluent and the heavier paraffins.

Abstract: The present invention relates to a process for recycling cyclopentadienyl derivatives of the formulae (I) and (I?), a process for preparing metallocenes of the formula (III) from cyclopentadienyl derivatives of the formulae (I) and (I?) or from bridged biscyclopentadienyl derivatives of the formula (II), in which the cyclopentadienyl derivatives of the formulae (I), (I?) or (II) which are used have been at least partly recovered and purified by means of liquid-solid chromatography, and the use of liquid-solid chromatography for purifying substituted, recovered cyclopentadienyl derivatives of the formulae (I), (I?) or (II).

Abstract: Aromatic by-products are sorbed from mono-olefin-containing feedstocks of olefins having from about 6 to 22 carbon atoms per molecule that contain aromatic by-products having from 7 to 22 carbon atoms per molecule. A benzene-containing regenerant displaces and desorbs the aromatic by-products from the sorbent and a regeneration effluent is provided. The regeneration effluent is treated in a regeneration effluent distillation system to provide a benzene-rich stream and an aromatic by-products-containing stream. The latter is subjected to benzene-forming conditions and recycled to the regeneration effluent distillation system where benzene is recovered.

Abstract: The process 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. An adsorbent comprising X or Y zeolite and a heavy desorbent are used in the first adsorptive separation zone to produce an extract stream comprising para-xylene and a raffinate stream comprising para-xylene depleted C8 aromatic hydrocarbons, the C9 aromatic hydrocarbon, and the desorbent. The raffinate stream is separated in a raffinate distillation zone to produce a stream comprising the first desorbent component and the C9 aromatic hydrocarbon which stream is further separated in a second adsorptive distillation zone to produce a stream comprising the desorbent and a C9 aromatic hydrocarbon stream.

Abstract: Process for separation of metaxylene, with at least 99% by weight of purity of an aromatic feedstock F, in a single adsorption stage in a simulated moving bed in an SMB device that comprises 12, 13 or 15 adsorbent beds with different numbers of beds being employed in zone 1 between the supply of the desorbent D and the draw-off of the extract E; zone 2 between the draw-off of the extract E and the supply of the feedstock F; zone 3 between the supply of the feedstock and the draw-off of the raffinate R; and zone 4 between the draw-off of the raffinate R and the supply of the desorbent D whereby the process is carried out according to a configuration of zones (a, b, c, d), whereby a, b, c, and d represent the number of adsorbent beds that operate respectively in zones 1, 2, 3, 4 in which there is used: Either an SMB of 12 adsorbent beds operating according to the configuration (2, 5, 3, 2), Or an SMB of 13 adsorbent beds operating according to the configuration (2, 5, 4, 2), Or an SMB of 15 adsorbent beds op

Abstract: The present invention relates to a process for recycling cyclopentadienyl derivatives of the formulae (I) and (I?), a process for preparing metallocenes of the formula (III) from cyclopentadienyl derivatives of the formulae (I) and (I?) or from bridged biscyclopentadienyl derivatives of the formula (II), in which the cyclopentadienyl derivatives of the formulae (I), (I?) or (II) which are used have been at least partly recovered and purified by means of liquid-solid chromatography, and the use of liquid-solid chromatography for purifying substituted, recovered cyclopentadienyl derivatives of the formulae (I), (I?) or (II).

Abstract: Process for the separation of close boiling isomeric compounds comprising distilling a dilute solution of isomers in a high boiling compound in the presence of a solid adsorbent. Multi and/or monobranched as well as cyclic isomers are withdrawn at the top of the distillation column, while straight chain and/or mono branched isomers are retained within the solid adsorbent. The diluent solution of the high boiling compound is withdrawn from the bottom of the distillation column and recycled, where it may be combined with the feed isomer mixture or recycled straight to the top of the adsorption column.

Abstract: Process for separating paraxylene with a purity that is at least equal to 99.5% by weight from an aromatic feedstock F in a single adsorption stage in a simulated moving bed (SMB), comprising different numbers of beds, allocated to a zone 1 between the supply of the desorbent D and the draw-off of the extract E; a zone 2 between the draw-off of the extract E and the supply of the feedstock F; a zone 3 between the supply of the feedstock and the draw-off of the raffinate R; a zone 4 between the draw-off of the raffinate R and the supply of the desorbent D, wherein an SMB of 12 adsorbent beds has bed configuration (2, 5, 3, 2), an SMB of 15 adsorbent beds has bed configuration (3, 6, 4 , 2), or an SMB of 19 adsorbent beds has bed configuration (4, 7, 6, 2), wherein the desorbent in this latter case is paradiethylbenzene.

Abstract: Aromatic by-products are sorbed from mono-olefin-containing feedstocks of olefins having from about 6 to 22 carbon atoms per molecule that contain aromatic by-products having from 7 to 22 carbon atoms per molecule. A benzene-containing regenerant displaces and desorbs the aromatic by-products from the sorbent and a regeneration effluent is provided. The regeneration effluent is treated in a regeneration effluent distillation system to provide a benzene-rich stream and an aromatic by-products-containing stream. The latter is subjected to benzene-forming conditions and recycled to the regeneration effluent distillation system where benzene is recovered.

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 separating meta-xylene from a hydrocarbon feed comprising isomers containing 8 carbon atoms, comprising: a step for bringing said feed into contact with a faujasite type zeolite adsorbant, the water content of the adsorbant being in the range 0 to 1% by weight and the adsorption temperature being from 160° C. to 180° C.; a desorption step employing a solvent selected from toluene, indane and mixtures thereof.

Abstract: A method for separating a mixture of hydrocarbons into fractions enriched in linear, mono-branched, or multi-branched hydrocarbons is disclosed. In particular, mono-branched alkanes are separated from a mixture of alkanes containing multi-branched, mono-branched and linear alkanes, by selectively adsorbing the mono-branched alkanes on a zeolitic adsorbent. The zeolitic adsorbent MCM-22 is particularly suitable for carrying out the method.

Abstract: The present invention discloses a means to improve the production capacity and feedstock handling flexibility of a simulated moving bed adsorptive separation process by introducing a second feed stream to the adsorbent chamber, such second feed stream comprising a feed material of a different concentration of the desired compound than the concentration of such desired compound in the first feed material stream. The introduction of this second feed material stream may be performed at any location on the adsorbent chamber between (i) a transfer point located immediately upstream of the point of the raffinate material stream withdrawal from the adsorbent chamber to (ii) a transfer point located immediately downstream of the point of extract material stream withdrawal from the adsorbent chamber. The specific transfer point used for the introduction of the second feed material stream will depend upon the concentration of the desired component in the second feed material stream.

Abstract: A method of managing the valves of a simulated moving bed separation system comprising at least one column of adsorbent beds split into several zones delimited by injection and draw-off points, allowing finer monitoring of a determined concentration profile. The method comprises, during each period between the shift times of the injection and draw-off points, in opening and closing a first valve located at one end of a zone according to a determined law, while opening and closing the valve downstream from the first valve in relation to the direction of flow of the recirculation flow, according to the same law with a lag, referred to as overlap time, in relation to the first valve, which is less than or equal to the period, the law imposing a constant total flow rate for the flow passing through the two consecutive valves throughout the overlap time.

Abstract: A stripping process is provided which continuously strips volatile substances from a dispersion containing a polymer particles through stripping the volatile substances from a dispersion by blowing an inert gas into the dispersion to draw the volatile substances into the inert gas, removing the volatile substances from the gas mixture of the inert gas and the stripped volatile substances and circulating the purified inert gas obtained by removing the volatile substances from the gas mixture, and blowing the purified inert gas into the dispersion. Also provided is a production process for a toner which uses this stripping process.

Abstract: In a process for selectively separating 1-butene from a C4 feed stream comprising at least 1-butene, cis-2-butene and trans-2-butene, the feed stream is passed through a first bed of an adsorbent comprising a crystalline microporous material to form a substantially trans-2-butene-free effluent stream. Then, the substantially trans-2-butene-free effluent stream is passed through a second bed of an adsorbent comprising a crystalline microporous material to form a substantially 1-butene-free effluent stream, whereby the 1-butene is separated from the feed stream. The adsorbed 1-butene is then typically desorbed from the second adsorbent bed either by lowering the pressure or raising the temperature of the bed.

Abstract: A process for separating mixtures of hydrocarbon isomers on molecular sieves, including providing columns which include molecular sieves and function alternatively as secondary adsorption, primary adsorption, and desorption devices, feeding the mixtures of hydrocarbon isomers to a column functioning as the primary adsorption device for adsorbing isomers with greater selectivity towards the molecular sieves, feeding effluent of the mixtures from the column functioning as the primary adsorption device to a column functioning as the secondary adsorption device for adsorbing remaining isomers with greater selectivity, discharging isomers with a lower selectivity from the column functioning as the secondary adsorption device and a desorbing agent therein, feeding a desorbing agent to the column functioning as the desorption device, discharging isomers with a greater selectivity towards the molecular sieves and the desorbing agent in the column functioning as the desorption device.

Abstract: A process of reducing the sulfur content of gasoline product comprising at least three concurrent steps: a) passing input fluid comprising pollutant through at least one adsorber to produce a polluted adsorber and a purified fluid stream which leaves the adsorber, stopping the flow into said adsorber to leave residual fluid therein, and separating said residual fluid therein said adsorber to leave the polluted adsorber of reduced residual fluid content, b) heating a polluted adsorber with a heated regeneration gas to produce a hot adsorber and cooler regeneration gas, c) contacting a heated adsorber with a regeneration gas (of a lower temperature than that of said adsorber) to produce a cooler adsorber and a warmer regeneration gas, which gas is further heated to produce said heated regeneration gas which is pass to step b), said process comprising at least 3 adsorber, at least one of which being subjected to step a) at least one different adsorber to step b) and at least one further different adsorber being

Abstract: The present invention relates to agglomerated zeolitic adsorbents based on zeolite X with an Si/Al ratio such that 1.15<Si/Al?1.5, at least 90% of the exchangeable cationic sites of the zeolite X of which are occupied either by barium ions alone or by barium ions and potassium ions whose Dubinin volume is greater than or equal to 0.240 cm3/g. They are obtained by agglomerating zeolite powder with a binder, followed by the zeolitization of the binder, the exchange of the ions of the zeolite by barium ions (and potassium ions) and the activation of the adsorbents thus exchanged. These adsorbents are particularly suited to the adsorption of the para-xylene present in C8 aromatic hydrocarbon fractions in the liquid phase in processes of simulated moving bed type but also to the separation of sugars, polyhydric alcohols, cresols or substituted toluene isomers.

Abstract: There is provided with a process for separating normal paraffins from hydrocarbons of C5-10 using zeolite molecular sieve 5A, which comprises the steps of (a) selective adsorption (b) cocurrent purge (c) countercurrent desorption. The present process employs butane for purge and desorption step to achieve excellent desorption efficiency and recycles butane in liquid phase to reduce the investment cost. The optimum operating conditions for feedstock change and adsorption capacity reduction are determined by NIR system for on-line monitoring and control. The separated normal paraffins can be efficiently applied to raw material for ethylene production and the separated non-normal paraffins can be efficiently applied to raw material for aromatic hydrocarbons production.

Abstract: The invention comprises a process for removal of carbonyl sulfide from a hydrocarbon, which comprises contacting a hydrocarbon stream containing carbonyl sulfide with an adsorbent and then regenerating the adsorbent by passing a heated gas, containing a hydrolyzing agent. The adsorbent that is regenerated by using this process retains at least 70% of its capacity for adsorption of sulfur as compared to fresh adsorbent.

Abstract: 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.

Abstract: 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%.

Abstract: 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.