Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/3408—Regenerating or reactivating of aluminosilicate molecular sieves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J29/00—Catalysts comprising molecular sieves
  • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
  • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
  • B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
  • B01J29/7038—MWW-type, e.g. MCM-22, ERB-1, ITQ-1, PSH-3 or SSZ-25
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C7/00—Purification; Separation; Use of additives
  • C07C7/12—Purification; Separation; Use of additives by adsorption, i.e. purification or separation of hydrocarbons with the aid of solids, e.g. with ion-exchangers
  • C07C7/13—Purification; Separation; Use of additives by adsorption, i.e. purification or separation of hydrocarbons with the aid of solids, e.g. with ion-exchangers by molecular-sieve technique
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G25/00—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents
  • C10G25/02—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents with ion-exchange material
  • C10G25/03—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents with ion-exchange material with crystalline alumino-silicates, e.g. molecular sieves
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G25/00—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents
  • C10G25/02—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents with ion-exchange material
  • C10G25/03—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents with ion-exchange material with crystalline alumino-silicates, e.g. molecular sieves
  • C10G25/05—Removal of non-hydrocarbon compounds, e.g. sulfur compounds
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G25/00—Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents
  • C10G25/12—Recovery of used adsorbent
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1088—Olefins
  • C10G2300/1092—C2-C4 olefins
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1096—Aromatics or polyaromatics
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/02—Gasoline
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Definitions

• This invention relates to a method for the regeneration of guard bed sorbents and catalysts used in light olefin polymerization and alkylation processes for the production of gasoline boiling range motor fuel.
• the first catalytic polymerization process used a sulfuric acid catalyst to polymerize isobutene selectively to dimers which could then be hydrogenated to produce a branched chain octane for blending into aviation fuels.
• Other processes polymerized isobutylene with normal butylene to form a co-dimer which again results in a high octane, branched chain product.
• An alternative process uses phosphoric acid as the catalyst, on a solid support and this process can be operated to convert all the C 3 and C 4 olefins into high octane rating, branched chain polymers.
• This process may also operate with a C 4 olefin feed so as to selectively convert only isobutene or both n-butene and isobutene.
• This process has the advantage over the sulfuric acid process in that propylene may be polymerized as well as the butenes and at the present time, the solid phosphoric acid [SPA] polymerization process remains the most important refinery polymerization process for the production of motor gasoline. [0006] In the SPA polymerization process, feeds are pretreated to remove hydrogen sulfide and mercaptans which would otherwise enter the product and be unacceptable, both from the view point of the effect on octane and upon the ability of the product to conform to environmental regulations.
• a feed is washed with caustic to remove hydrogen sulfide and mercaptans, after which it is washed with water to remove organic bases and any caustic carryover.
• caustic to remove hydrogen sulfide and mercaptans
• water to remove organic bases and any caustic carryover.
• oxygen promotes the deposition of tarry materials on the catalyst
• both the feed and wash water are maintained at a low oxygen level.
• Additional pre- treatments may also be used, depending upon the presence of various contaminants in the feeds.
• the water content of the feed needs to be controlled carefully because if the water content is too high, the catalyst softens and the reactor may plug. Conversely, if the feed is too dry, coke tends to deposit on the catalyst, reducing its activity and increasing the pressure drop across the reactor.
• the distribution of water between the catalyst and the reactants is a function of temperature and pressure which vary from unit to unit, and for this reason different water concentrations are required in the feeds to different units.
• Petroleum Processing Principles And Applications R. J. Hencksterbeck McGraw-Hill, 1959.
• the unit may be classified as having chamber reactors or tubular reactors.
• the chamber reactor contains a series of catalyst beds with bed volume increasing from the inlet to the outlet of the reactor, with the most common commercial design having five beds.
• the catalyst load distribution is designed to control the heat of conversion.
• butene and lighter olefins are employed as feeds to polymerization processes as heavier olefins up to about Cio or Cn can be directly incorporated into the gasoline.
• propylene and butylene are satisfactory feedstocks and ethylene may also be included, to produce a copolymer product in the gasoline boiling range.
• Limited amounts of butadiene may be permissible although this diolefin is undesirable because of its tendency to produce higher molecular weight polymers and to accelerate deposition of coke on the catalyst.
• the process generally operates under relatively mild conditions, typically between 150° and 200 0 C, usually at the lower end of this range between 150° and 180°C, when all butenes are polymerized.
• the olefin feed together with paraffinic diluent is fed to the reactor after being preheated by exchange with the reaction effluent.
• the solid phosphoric acid catalyst used is non-corrosive, which permits extensive use of carbon steel throughout the unit.
• the highest octane product is obtained by using a butene feed, with a product octane rating of [R+M]/2 of 89 to 91 being typical.
• product octane is typically about 91 and with propylene as the primary feed component, product octane drops to typically 87.
• 11/362,256, 11/362,255 and 11/362,139 in the process set out in these applications, a gasoline boiling range product of low benzene content is produced using light refinery olefins to alkylate reformate streams containing significant levels of benzene.
• Application Serial No. 11/362,139 describes a number of integrated process schemes which combine the polymerization process with the benzene alkylation process.
• the gasoline manufacturing processes described in these patent application use feedstocks produced in the petroleum refinery, usually a light olefinic stream form the FCCU as a source of olefins, either alone or combined with a reformate stream in the processes using aromatics alkylation.
• These olefinic streams from the cracking unit usually contain significant levels of contaminants, especially sulphur compounds including mercaptans, thiophenes and substituted thiophenes, as well as compounds containing other heteroatoms such as nitrogen. Many of these contaminants will act as catalyst poisons for the molecular sieve catalysts used in the olefin upgrading process.
• guard beds are frequently used, containing either a non- reactive sorbent for the contaminants or a reactive material which undergoes a reaction with the contaminant(s). Which ever, is used, the guard bed material eventually requires regeneration itself when loaded with the contaminant(s). Conventionally, a single guard bed is used, making it necessary either to cease operation during regeneration or to send the feed directly to the reactor without separation of the contaminant(s), so shortening catalyst life commensurately.
• Processes of this type include the olefin conversion processes referred to above for the manufacture of gasoline boiling range motor fuels, either using a light olefin feed on its own or with a reformate co-feed to produce a low-benzene alkylaromatic gasoline.
• Other olefin conversion processes using refinery light olefin streams which may use these guard bed regeneration techniques include the well-established aromatics alkylation processes for making cumene or ethylbenzene.
• the guard bed regeneration step is integrated with the olefin conversion to ensure continuous operation of the olefin conversion without sending the feedstock containing the contaminant(s) to the reactor.
• the process uses reaction products from the olefin conversion process to regenerate the guard bed material and so is economically attractive since it does not require the use of separate purge, regeneration feed and separation systems.
• an olefin conversion process which converts olefinic refinery streams to other, higher boiling hydrocarbon products by polymerization (oligomerization) or aromatics alkylation over a molecular sieve catalyst utilizes a plurality of guard beds containing a material which removes catalyst poisons.
• the guard beds are operated on a swing system in which one or more beds is kept on stream to remove the contaminant(s) while one or more of the remaining beds is being purged or regenerated. In this way, continuity of operation is assured.
• the regeneration medium is a product stream from the olefin conversion process.
• Figure 1 shows a process schematic for the olefin polymerization unit for converting light refinery olefins to motor gasoline by the present process.
• the present process is for the conversion of light cracking olefins or the alkylation of aromatics by light cracking olefins to produce higher boiling liquid hydrocarbon products, for example, motor gasoline and other motor fuels such as road diesel blend stock as well as alkylaromatic petrochemical products such as ethylbenzene and cumene.
• the present guard bed regeneration technique will be described below with reference to the olefin polymerization process and the aromatics alkylation processes described in the earlier filed applications cited above but its is more generally applicable, to other similar processes using molecular sieve catalysts and requiring a guard bed to remove contaminants form the feed stream which would otherwise deactivate the catalyst.
• the olefin conversion process when used to produce gasoline boiling range product is intended to provide a replacement for the SPA polymerization process, using a molecular sieve catalyst which can be used as a direct replacement for SPA and so enables existing SPA units to be used directly with the new catalyst, so allowing the advantages of the new catalyst and process to be utilized while retaining the economic benefit of existing refinery equipment.
• the aromatic alkylation process is similar in operation and again, is used to convert light refinery olefins to higher value, higher boiling liquid products.
• the gasoline boiling range products can be produced by the polymerization (oligomerization) of a light refinery olefin stream.
• An alternative to the straightforward polymerization process is an aromatics alkylation process of the type described in Serial Nos. 11/362,256, 11/362,255, 11/362,139, which may be combined with the polymerization process as described in Serial No. 11/362,139. Reference is made to these prior applications for descriptions of the basic olefin upgrading processes.
• the present guard bed regeneration technique is, as noted, capable of use with other processes using molecular sieve catalysts which are subject to poisoning by contaminants in the feed, including processes for converting olefins into lubricants as described in U.S. Patent No. US 4956514 which describes the use of zeolite MCM-22 as an olefin oligomerization catalyst for making lube range materials by the oligomerization of low molecular weight olefins such as propylene and FCC off gas streams.
• Other processes to which it can be applied are the well-established processes for manufacturing aromatics such as ethylbenzene or cumene, using reactions such as alkylation and transalkylation.
• Figure 1 shows an simplified illustrative configuration for an olefin upgrading unit operating on the principle of aromatics alkylation.
• Figure 1 in which the dotted lines show the needed modifications for a conventional Polygas unit.
• the quench circuit used in the olefins polymerization version of the process is omitted for clarity.
• the reactors can be tubular or chamber type. The number of reactors changes from unit to unit, in this example the configuration has three reactors and this potentially enables the rejuvenation can be practiced in one of the reactors while keeping the others in operation.
• the feed to be used as the rejuvenation stream is the olefin-depleted stream from the overhead of the fractionation tower. In this configuration, some piping is needed, and an additional pump to boost the recycle stream to the reactor operating pressure; this pump is needed in any event if the recycle is used as quench as described in Serial No. 11/362257.
• a mixed light olefin feed from a catalytic cracking unit is introduced through line 10 and passes through guard bed 11 which operates on a swing reactor system with a matching guard bed 12.
• the feed then passes to feed drum 13 and on through line 14 to reactors 15A, 15B, 15C.
• the olefins in the feed are polymerized in reactors 15A, 15B and 15C.
• the effluent from .the reactors passes to fractionator 20 by way of line 16.
• the reactor effluent is fractionated in the fractionator to produce the desired product fractions.
• the heavy product fraction leaves fractionator 20 through line 26 as product.
• a portion of the light product fraction with unreactive paraffins from the feed is removed from the top of the fractionator and passed by way of line 21, pump 22, line 23, pump 24 and line 25 to second guard bed 12 which is in the regeneration phase, desorbing the contaminants which have been removed from the feed.
• the guard bed vessels are switched alternately between feed treatment and regeneration by means of conventional valving (not shown) which may also direct effluent from the guard bed during the regeneration portion of the cycle to recovery facilities by way of line 27 so as to permit removal of the desorbed contaminants.
• the beds can be switched so that bed 11 is in the regeneration phase, receiving product from fractionator 20 to desorb contaminants and bed 12 is put into the feed treatment phase with the feed passing from bed 12 to reactors 15 A, 15B and 15C.
• the reaction in reactors 15 is the olefin/aromatics alkylation reaction, using a mixed refinery olefin/reformate stream as the feed, the contaminant desorption stream will usually be a light stream with a heavier alkylaromatic fraction going to recovered product.
• the guard beds may be operated on the swing cycle with two beds, 11 and 12 as described above. If desired, a purge phase may be added before a regenerated bed is returned to feed treatment although this will not always be necessary since the bed contains at that point only innocuous reaction products which can be recycled to the reaction.
• a three-bed guard bed system may be used with the two beds used in series for contaminant removal and the third bed on regeneration. With a three guard system used to achieve low contaminant levels by the two-stage series sorption, the beds will pass sequentially through a three-phase cycle of: regeneration, second bed sorption, first bed sorption.
• the compressed fraction from pump 24 may also be sent through branch lines 29A, 29B and 29C to the reactors to rejuvenate the catalysts, as described in co-pending patent application No. 60/ , filed concurrently,
• the light olefins and aromatic feeds as well as the actual conditions used for converting them to gasoline boiling range products and the products themselves will be as described in the prior applications referred to above.
• the conditions used in other alkylaromatics processes will be those appropriate to the selected process and therefore chosen according to conventional criteria.
• the olefinic feeds are generally obtained from a catalytic cracking unit operating on a hydrocarbon feed such as vacuum gas oil or a resid fraction.
• the olefins will normally be the light olefins in the FCC off-gas in the range C2 to C4 as the higher olefins will be removed by the fractionation for separate use directly as gasoline.
• the aromatics will normally be derived from a reformate stream. More extended descriptions of both streams in their application to the production of olefin polymer and alkylaromatic fuels are given in the prior applications such as those described.
• a light olefin stream such as ethylene, propylene, optionally with butylene and possibly other light olefins, is polymerized or reacted with an aromatic compound or compounds to form a gasoline boiling range [C 5 + - 200° C] [C 5 + - 400°F] product.
• the process is carried out in the presence of a molecular sieve catalyst which is usually a member of the MWW family of zeolites, a family which includes zeolites PSH 3, MCM-22, MCM-49, MCM-56, SSZ 25, ERB-I and ITQ-I although other sieves such as ZSM-5 or ZSM-Il may be used, especially in the vapor phase alkylation process described in Serial No.
• polymerized is used here consistent with the petroleum refinery usage although, in fact, the process is one of oligomerization (which term will be used in this specification interchangeably with the conventional term) in which a low molecular weight polymer is the desired product.
• the process is carried out in a fixed bed of the catalyst, in the case of the straightforward polymerization process, with feed dilution, normally a hydrocarbon diluent, or added quench to control the heat release which takes place.
• the preferred catalysts used in the present process contain, as their essential catalytic component, a molecular sieve of the MWW type, as described in the prior applications referred to above.
• a matrix material or binder in order to give adequate strength to the catalyst as well as to provide the desired porosity characteristics in the catalyst.
• High activity catalysts may, however, be formulated in the binder-free form by the use of suitable extrusion techniques, for example, as described in U.S. 4,908,120.
• matrix materials suitably include alumina, silica, silica alumina, titania, zirconia, and other inorganic oxide materials commonly used in the formulation of molecular sieve catalysts.
• the level of MCM-22 in a finished matrixed catalyst of the preferred type will be typically from 20 to 70 % by weight, and in most cases from 25 to 65 % by weight.
• Catalyst formulation techniques are described in the prior applications, to which reference is made for a description of them.
• the catalyst used in the guard bed may be a reactive material, that is one, which undergoes a surface reaction with the contaminants in the feed stream so as to hold the contaminants on the exterior or interior surfaces of the material.
• Materials of this kind may conveniently be the same catalyst used in the polymerization or alkylation reactor as a matter of operating convenience but this is not required: if desired another catalyst or sorbent to remove contaminants from the feed may used, typically a cheaper guard bed sorbent, e.g a used catalyst from another process.
• a non-reactive sorbent such as alumina or silica-alumina may be used.
• the objective of the guard bed is to remove the contaminants from the feed before the feed comes to the reaction catalyst and provided that this is achieved, there is wide variety of choice as to guard bed catalysts and conditions useful to this end.
• the contaminants which are normally encountered are sulfur compounds such as thiols, sulfides, thiophenes and disulfides; in processing light aromatics stream, nitrogen contaminants may also be encountered, for example, nitrogen-based organic species derived from aromatics extraction operations using solvents such as N- methylpyrrolidone (NMP), dimethylformamide (DMF), N-formyl morpholine (NFM) and similar materials. These contaminants may adversely affect catalyst performance and accordingly, should be removed from the feedstream before it encounters the catalyst in the main reactor.
• the volume of the guard bed will normally not exceed about 20% of the total catalyst bed volume of the unit.
• the guard bed is regenerated at periodic intervals when necessary by switching the on-line bed in the feed treatment phase to regeneration. This can be done by valving in the conventional manner for swing reactor operation. Because the regeneration is carried out using a portion of the product stream, no purging of the feed is necessary before switching to the regeneration phase nor is purging of the regeneration stream necessary before reverting to the feed treatment phase although, if purging is not carried out, care should be taken to see that the contaminants are substantially completely removed from the bed prior to the bed switching.
• the guard bed regeneration is carried out using product from the reactor. Normally, it will be adequate to divert only a portion of the product volume to the guard bed in order to regenerate the bed over an acceptable period of time and so the regeneration gas can be taken as a slip stream from the product stream. A fraction of the product stream will normally be used, selecting the fraction with the most favorable desorption characteristics for the contaminants which actually become sorbed onto the guard bed material.
• the regeneration is preferably carried out using a light paraffinic fraction (C4- C6) from the product fractionator since this fraction is reasonably inert and has good desoiption characteristics for the most common contaminants sorbed onto zeolite guard beds, e.g. MCM-22 or MCM-49.
• the reaction is the aromatic alkylation reaction, the regeneration can be carried out with a light alkylaromatic fraction, for example, the C8-C10 fraction.
• the regeneration is carried out an elevated temperature, typically above ambient with a temperature of at least IOOC being customary and usually in the range of 150-300C, preferably 150-250C.
• High pressures are not necessary and, in fact relatively low pressures may assist desorption. Pressure will therefore normally be in the range of 1000 kPag to 4000 kPag (about 145 to 580 psig) with pressures of 1000 to 2000 kPag (about 145 to 290 psig) being preferred, although in many cases, the pressures imposed by existing equipment will dictate as a practical matter the pressure actually used.
• Space velocity through the bed is not an important factor provided that the regeneration phase is continued long enough to secure the desired degree of contaminant desorption- Normally, the space velocity of the regeneration gas will be in the range of 0.1 to 10 LHSV (hr '1 ) relative to the volume of the guard bed material and in most cases from 0.5 to 5 LHSV, with velocities of about 0.5 to 2.0 LHSV representing typical operation.

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• General Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
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• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
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• 2007
  • 2007-06-19 US US11/812,485 patent/US20080029437A1/en not_active Abandoned
  • 2007-08-01 BR BRPI0714652-3A patent/BRPI0714652A2/pt not_active Application Discontinuation
  • 2007-08-01 WO PCT/US2007/017173 patent/WO2008016636A2/en not_active Ceased
  • 2007-08-01 CA CA002659115A patent/CA2659115A1/en not_active Abandoned
  • 2007-08-01 EP EP07836394A patent/EP2046497A2/en not_active Withdrawn
  • 2007-08-01 RU RU2009104324/04A patent/RU2009104324A/ru not_active Application Discontinuation
  • 2007-08-01 JP JP2009522860A patent/JP2009545650A/ja active Pending

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