US2952630A - Separation of hydrocarbons using zeolitic molecular sieves - Google Patents

Separation of hydrocarbons using zeolitic molecular sieves Download PDF

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US2952630A
US2952630A US622894A US62289456A US2952630A US 2952630 A US2952630 A US 2952630A US 622894 A US622894 A US 622894A US 62289456 A US62289456 A US 62289456A US 2952630 A US2952630 A US 2952630A
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normal
mass
hydrocarbons
hydrocarbon
feed
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Frank T Eggertsen
John W Gibson
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Shell USA Inc
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Shell Oil Co
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/10—Inorganic adsorbents
    • B01D2253/106—Silica or silicates
    • B01D2253/108—Zeolites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/30—Physical properties of adsorbents
    • B01D2253/302—Dimensions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
    • B01D2253/30—Physical properties of adsorbents
    • B01D2253/302—Dimensions
    • B01D2253/308—Pore size
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/24—Hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
    • B01D2257/702—Hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/40—Further details for adsorption processes and devices
    • B01D2259/40083—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption
    • B01D2259/40086—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption by using a purge gas
    • 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
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/20—Capture or disposal of greenhouse gases of methane

Definitions

  • This invention relates to a process for the separation of normal hydrocarbons from branched and/or cyclic hydrocarbons. It relates more particularly to an improved vapor-solid contacting process for the fractionation of hydrocarbon mixtures containing a plurality of both normal, i.e. linear, hydrocarbons and non-normal hydrocarbons.
  • Normal parafiins are frequently undesired components in hydrocarbon fuels and lubricants: they depress the octane number of gasoline, raise the pour point of lubricating oil, and raise the freezing point of diesel and jet fuels.
  • Figure 1 is a schematic flow sheet of one mode of practicing this invention
  • I Figure 2 is a schematic flow sheet of another mode of practicing this invention.
  • Zeolites having rigid three-dimensional anionic net- 2,952,630 Patented Sept. 13, 1960 works and having intracrystalline interstitial channels whose narrowest cross section has essentially a uniform diameter, e.g. about 4 or 5 Angstrom units, are well known to the art. They are commonly designated molecular sieves. The intracrystalline channels are generally designated pores. Such zeolites are described, for example, in a paper, entitled Zeolites as Absorbents and Molecular Sieves, by R. M. Barter in Annual Reports on the Progress of Chemistry for 1944, vol. 61, pp. 31-46, London (1945). Another molecular sieve is described by Black in U.S. 2,442,191.
  • MS-4A More recently certain synthetic molecular sieves have become commercially available from Linde Air Products Company.
  • One such molecular sieve is designated MS-4A. It is a zeolite of average composition 0.96:0.04 Na O, 1.00 A1 0 1.92:0.09 SiO plus an amount of water depending on the degree of dehydration; the crystals are cubic, with unit cells measuring, on an edge, approximately 12.26 Angstrom units, and are characterized by an essentially uniform pore diameter of about 4 Angstrom units.
  • MS-SA Another available sieve is designated MS-SA. This is made from MS-4A by replacement of approximately of the sodium ions with calcium ions by ion exchange. These are also cubic crystals, having the same unit cell dimensions as MS-4A, and are characterized by an essentially uniform pore diameter of about 5 Angstrom units.
  • the crystallites of Lindes sieve materials generally have diameters of from 500 to 5000 Angstrom units.
  • Zeolites become active for selective sorption by a treatment designed to drive ofi the water originally present in the interstitial spaces.
  • the spaces vacated remain and become available for the sorption of compounds of appropriate maximum critical molecular cross section.
  • the zeolites may be subjected to temperatures of 600 C. and, in some cases up to 800 C. or more without destruction of their crystalline structure. In some cases, repeated contact with steam can be tolerated Without substantially affecting their structure.
  • Activated zeolites are generally soft, friable materials. Although they may be used as sorbents in pure form, if carefully handled, they can be made up in the form of particles held in shape bythe addition of ten to twenty percent of an inert binder material such as clay. They may also be used admixed with other solids which are stable at the conditions to be used in the process and which are, preferably, non-adsorbents, or relatively nonselective adsorbents so as not to interfere in the desired separations.
  • pore diameters herein referred to which are determined by physical measurements such as X-ray methods or by the sorptive characteristics of the zeolites,'rnay not be precisely accurate numbers.
  • normal hydrocarbon molecules may enter pores whose smallest diameters are believed to be at least slightly smaller than the apparent maximum critical cross-section diameter of the molecule.
  • reference to zeolites having substantially uniform intracrystalline interstitial channels (or pores) of from about 5 to about 6 Angstrom units diameter includes those above-mentioned zeolites and otherswhich'h'ave the characteristic of selectively sorbing normal hydrocarbons of four or. more carbon atoms per molecule and notsorbing non-normals, by virtue of their crystal structure.
  • These sorbents may also be; referred to as zeolitic molecular sieves of from about 5 to about 6 Angstrom unit maximum pore diameter;
  • the pore volume in molecular sieves is quite substantial. It may be as much as about 50% of the total volume of each crystal of sorbent.
  • the weight of normal hydrocarbons which can be sorbed is a function of the available pore volume, the temperature, pressure and other j conditions including the concentration of the normal hydrocarbon in the mixture and the rate at which the mixture is passed in contact with the sorbent. It may be as high as 14% by weight of the sorbent.
  • the dynamic capacity of a molecular sieve such as Linde MS-SA for normal. hydrocarbons may be in the range from 3 to 6% by weight, or higher, based on the weight of sorbent. The capacity is greater for hydrocarbons of higher molecular weight; it increases at higher pressures but decreases. at higher temperatures and at increasing flow velocities through the bed of sorbent.
  • a mixture of hydrocarbonsrfrom which normal hydrocarbons of at least four carbon atoms per molecule are to be separated is passed in contact with a mass of molecular sieve sorbent having a pore diameter of from about 5 to about 6 Angstroms in'relatively brief pulses, followed by relatively brief periods ofsweeping the mass of sorbent with an inert sweeping gas; the pulses of feed and the conditions of desorption-are so'correlatedthat'no more than one tenth to one half of sorbed normal hydrocarbons is removed in the sweeping periodand the amount of normal hydrocarbons in each pulse of feed is approximately equal to the actual capacity of the mass of sorbent for normal hydrocarbons at the beginning of the feed pulse, i.e. about one tenth to one half of the total capacity of the sorbent.
  • this is a continuous process for the separation of normal hydrocarbons from admixture with non normals in which portions of'feed are intermittently passed in contact with a mass of suitable molecular sieve sorbent which, once the process is in continuous operation, contains from one half to nine tenths of its capacity of normal hydrocarbons at the beginning of each feed pulse and is substantially full of normals at the end of the feed pulse and the beginning of the sweeping gas pulse. 7
  • the non-normal hydrocarbons in the mixture are not delayed in their passage through the sorbent mass and consequently they emerge from the mass very rapidly, depending only on the rate at which the mixture is charged.
  • the concentration of the nonnormal hydrocarbons in the efiluent vapor mixture is higher than in the feed vapor mixture passed to the sorbent since the normal hydrocarbons are being retained in the sorbent mass.
  • the non-normals are, therefore, present in the effluent vapors'in a relatively high concentration and are readily condensed therefrom by conventional condensers operating at suitable temperatures e.g., between 15 and 40 C.
  • the concentration of non-normals in the effiuent decreases very rapidly to essentially zero, as soon as all the non-normals have been swept through the contact mass.
  • norm-a1 hydrocarbons are desorbed irom the contact mass and appear in the efliuent vapors in relatively low concentration compared to the concentration in which the non-normals appeared.
  • the effluent vapors are passed through a condenser operating at a relatively higher temperature during the period when anon-normals are present in the efiluent, which essentially coincides with the feed pulse period, and the effluent vapors are then switched to a different condenser operating at a lower temperature e.g., between 0 and C. 'to recover the normal hydrocarbons present in the efliuent vapors during that period.
  • advantage is taken of the diiference in concentration of the nonnormals and the normals in the effluent vapors by passing the total product mixture continuously through a first condenser which is so adjusted in temperature. that substantially all of the hydrocarbons in the efiiuent are condensed when the non-normals are present but'the normals are not condensed when they are present alone in low concentration during the sweeping portion of the cycle, and the gas mixture leaving the first condenser is then passed through a second condenser operating at a substantially lower temperature to condense all me remaining hydrocarbons from the sweep gas.
  • the receiver for the first condenser collects essentially all the non-normal hydrocarbons and the receiver for the second condenser collects essentially only the normal hydrocarbons passing through when there are no non-normals present, as well as the small amount of uncondensed nonnormals-which pass through the first condenser in the feed pulse of the cycle.
  • This invention takes advantage of .the fact that the rate of sorption of normal hydrocarbons on passage of a hydrocarbon mixture containing them into contact with a molecular sieve is rapid and that the normal hydrocarbons are held bythe sieve'quite tenaciously so that o it is not possible to completely desorb normal hydrocarbons from the sieve when applying only heat and vacuum except by using very high temperatures or extremely long desorption periods, it does appear that the normal hydrocarbons are not entirely held in place on the sieve mass but that they gradually diffuse through the sieve in the direction of lower normal paraffin concentration or in the direction of flow of the vapor mixture. It is, therefore, possible to desorb the normal hydrocarbons from a molecular sieve mass by passing a so-called sweep gas through the contact mass.
  • the normal hydrocarbons are then contained in the total vapor mixture leaving the bed.
  • the amount of time and the amount of sweeping gas required for recovery of a given amount of a sorbed normal hydrocarbon are interchangeable variables.
  • a very small amount of sweeping gas passed slowly through a bed of normal-rich sorbent permits removal of the same amount of normal hydrocarbons as a large amount .of sweeping gas passed through a bed in a much shorter period of time, conditions otherwise being equal.
  • the temperature of the molecular sieve sorbent mass is suitably maintained in the range from 250 to about 600 C. It is better to maintain a temperature of at least 350 and no more than 500 C.; temperatures between 350 and 450 C. are preferred.
  • the temperature is generally chosen sufiiciently high that the ratio of the absolute temperature in the contacting zone to the absolute boiling temperature of the highest boiling component in the feed mixture at the operating pressure is at least 1.1. It is preferably chosen to be below the temperature at which the least stable hydrocarbon in the feed undergoes appreciable thermal cracking at the process conditions. The thermal stability of the sorbent must not be exceeded.
  • the separation process can be carried out isothermally, i.e., the temperature of the sorbent mass can be maintained essen tially unchanged throughout each cycle.
  • the temperature during the adsorption and desorption of normals e.g., up to 100 C.
  • the feed may be relatively cool, thus cooling the sorbent during the charging step, or the heat of sorption of normals from a warm feed may heat the sorbent during the charging step.
  • the temperature of the sorbent may be maintained by indirect heating or cooling means or by control of the feed and stripping gas temperatures.
  • the pressure is suitably in the range from atmospheric pressure to 1000 lbs/sq. in. gauge, and preferably between 100 and 750 p.s.i.g.
  • the efiect of operating at the higher pressures in this range is to increase the capacity of the bed for sorbing normal hydrocarbons, but at the same time to increase the actual quantity of sweeping gas required (measured at standard conditions) in the desorption step. Pressures above 1000 psig. can, therefore, be employed if the amount of sweeping gas required does not become uneconomically high.
  • the amount of 6 normal hydrocarbons sorbed in the mass of molecular sieve sorbent does not fall below of the capacity of the sorbent, once continuous operation has been established. It is preferable to operate with a sieve mass containing at least about two-thirds of its capacity of normal hydrocarbons at all times and the lowest normal hydrocarbon content of the sieve mass in continuous operation may be as high as nine-tenths of its total dynamic capacity.
  • Total dynamic capacity here refers to the amount of normal hydrocarbon which is retained by the sieve when a hydrocarbon mixture of the composition to be charged is passed into contact with activated molecular sieve sorbent, either fresh or regenerated so as to be completely free of normal hydrocarbons, at the conditions of temperature, pressure and gas flow to be employed in the separation process.
  • the amount of feed charged to the sorbent mass in each pulse during continuous operation is determined by the working capacity of the sorbent mass for normal hydrocarbons at the time the feed pulse is started.
  • the length of the feed pulse may be varied by varying the rate at which the feed is added. Feed pulses as short as from one to a few seconds have been found satisfactory in small scale experiments, since selective sorption of normal hydrocarbons is practically instantaneous at the conditions of this process. It is convenient to control the feed pulse such that the feed is added at a LHSV of up to 20 v./v./hr. (measured during the feed pulse). Any lower rate is operative, e.g., down to l v./v./hr.
  • the length of the desorption period is determined according to the extent of desorption desired; it is affected by factors which have already been discussed, e.g., the temperature, sweep gas rate and type of hydrocarbon to be desorbed. It is convenient to fix the desorption period at a value such that the feed rate for the overall process is at a LHSV between 1 and 4 v./v./hr. or higher, preferably between 2 and 4 v./v./l1r.
  • the time during which normal hydrocarbon is desorbed is generally at least as long as the time during which feed is charged and may be up to ten times as long or longer.
  • the time required in the desorption step can be shortened by increasing the flow rate of sweep gas through the sorbent mass during the desorption step. 7
  • Figure 1 illustrates a single mode of practicing the present invention.
  • the molecular sieve sorbent such as Chabazite or Linde molecular sieve type 5A which has been activated by driving off most of the water of hydration, is placed in a fixed bed A. Efiluent from the bed passes to product recovery zone B or C. Zones B and C may each contain a condenser and product receiver or other suitable recovery means, such as a hydrocarbon absorber or adsorber.
  • sweep gas is passed through line 11 controlled by valve 12. The gas passes into sorbent bed A which is maintained at a desired predetermined temperature by the gas or by other means, not shown.
  • the feed pulse is continued until'a sufiicient amount of normal hydrocarbons has been charged to substantially fill the capacity of the molecular sieve mass for normals, as determined by calculation from knowledge of the capacity of'the sieve, the feed rate and the concentration of normals in the feed, or by analysis of the efiiuent in line 15.
  • the feed pulse with recoveryof the efiluent in receiver C and the sweeping step with recovery of the effluent in receiver D are cyclically repeated.
  • The'cyclic operation may continue for many days without requiring further treatment of the sorbent bed, provided the conditions of temperature, pressure, rate and so forth are controlled within the ranges given in this specification and the feed contains no impurities which tend 'to poison the sorbent bed.
  • the product receivers in zones B and C are periodically emptied or may be continuously emptied through valved lines 22 and 23respectively.
  • a'single means may be placed in line 15; zones B and C, in that case, merely provide product accumulators.
  • the recovery means in line 15 may consist ofja single condenser operating at a temperature suf- 8 ficiently low to permit adequate condensation. of normal hydrocarbons during the desorption step, or of a single condenser operating at diiferent temperatures for the recovery of non-normals and of normals,.or it may comprise two condensers operating at difierent temperatures, connected in such manner that the non-normals are recovered at. a relatively higher temperature than the normals.
  • FIG. 2 A preferred modification is illustrated schematically in Figure 2.
  • the apparatus shown in Figure 2 comprises a feed tank E; a sorbentbed F located in a heatable vesselG; a first product condenser H; a product analyzer I adapted to determine the concentration of normal hydrocarbons in a vapor mixture; A means I for recovering. the remaining hydrocarbons from a vapor stream, which may be a condenser or an absorber; productaccumulators K and L, and product receivers M and N. Since the process diagram is schematic in nature, much necessary associated equipment which can be readily supplied by those skilled in. the art is not shown to avoid unnecessary complexity.
  • a flow of inertgas is commenced through line 211'- controlled by'valve 212.
  • This gas passes through bed P, which is brought to a desired temperature by passing heating medium through the jacket, the heating medium entering through line 214 and passing out through line 215.
  • Other means of heating the bed F may be employed, e.g., liquid coils imbedded in the sorbent bed or electrical or other means.
  • the gas may be used as a direct heating medium.
  • the gas passes out of the bed through line 215, through condenser H, line 218, accumulator K, line 219, condenser or'absorber J, line 220, accumulator L and finally through line 221.
  • feed hydrocarbon mixture is passed from tank E through line 226 containing vaporizer 228 and into line 211.
  • feed hydrocarbon mixture is passed from tank E through line 226 containing vaporizer 228 and into line 211.
  • normal hydrocarbons are retained in bed F and nonnormal hydrocarbons are swept out through line 216, condensed in condenser H and recovered in accumulator K.
  • the condenser temperature is maintained by controlling the rate of flow of cooling medium which enters the condenser through line 229 and leaves it through line 231.
  • the flow controlling means is valve 230, which may be manually adjusted or may be regulated from analyzer I once continuous operation is established.
  • Analyzer I may be, for example, a differential refractrometer which continually determines the difierence in refractive index between amixture having the composition corresponding to original feed minus the amount of normal hydrocarbons to be removed therefrom and the actual liquid condensate which has been collected in at least one complete cycle of operation in vessel K; the condensate is sampled through'line 232.
  • the differential reading is used to control valve 230, e.g., by controlling the air-pressure supplied to the valve to open it further and thus lower the temperature of the condenser. for additional hydrocarbon recovery or to open it and raise the condenser temperature, thus keeping the concentration of normals in the recovered liquid in a predetermined range.
  • the flow of feed is continued until the capacity of sorbent bed F for normal hydrocarbons is substantially used up. This may be calculated from a knowledge of bed capacity at the conditions employed, the concentration of normal hydrocarbons inthe feed and feed rate. It may also be determined by analyzing the vapor mixture in line 218, e.g., by passing a continuous sample of the mixture to an analyzer similar to analyzer I.
  • the sieve material may be provided in a suitably sized vessel, generally an upright cylindrical vessel with The material a length from 2 to 10 times the diameter. is suitably supported by a screen grid in the bottom and, if desired, a plurality of suitable screen grids are prov'ided at spaced intervals throughout the column to sup- 7 port the sieve material.
  • the bed of zeolite material may be disposed horizontally instead of upright and it may be provided as a fixed, stationary mass, or it may be adapted to be moved as a mass, as in an elevating system or as annular segmental packing of a rotatable vertical or horizontal contactor providing solid particulate contacting material in the annular space between concentric rotatable cylindrical screens or perforate partitions, suitably provided with means for delivering and removing fluid streams to and from outer and inner surfaces of the mass and periodically to change the nature of the fluid delivered to and removed from any particular segment and to reverse the flow of fluid therethrough.
  • helium hydrogen, nitrogen and methane can be sucessfully used as sweep gases.
  • Other inert gases i.e., gases which do not react with either the sorbent, the vessel or the. reactants, are also suitable.
  • gases which do not react with either the sorbent, the vessel or the. reactants.
  • argon, flue gas (preferably scrubbed to remove reactive impurities), propane and other gases and vapors can be used as sweep gas.
  • the feed may be added to the heated sorbent as a liquid, to be quickly vaporized by contact withsorbent, or it may be added as a vapor. 7
  • sweep gas flow may be maintained through the sorbent mass at all times and the feed added as liquid or as vapor to the sweep gas. It will generally be preferred to maintain a relatively low rate of inert gas flow or no gas flow at all during the time when feed is added,
  • the first sweep gas added after feed is discontinued serves to flush the 7 10 remaining non-sorbed hydrocarbons out of the sorbent mass.
  • the rate of gas flow during this flushing step may diifer from that used during the sweeping step.
  • the process of the present invention is useful in the separation of normal hydrocarbons from mixtures containing normals having a carbon number of at least 4 and generally at least 5. It is particularly suitable for mixtures containing normals from n-pentane or n-hexane through n-decane or n-dodecane and corresponding olefins, but may be used with mixtures containing normals up to n-eicosane.
  • Example I illustrates runs carried out in accordance with the mode described by means of Figure 2
  • Example II a run carried out in accordance with the mode described by means of Figure 1.
  • the feed used throughout these runs was a dehexanized C -C Platformate fraction.
  • This fraction had a refractive index (R. I.) of 1.4538, and contained about 41% wt. saturated compounds, 59% wt. aromatics and 0% wt. olefins.
  • the content of normal parafiins was about 12% wt.
  • Sorbent bed'F consisted of ca. parts by weight of Linde molecular sieve sorbent type 5A, in the form of irregularly shaped particles of average 1-2 mm. diameter, containing about 80% wt. of the actual zeolite and 20% of a clay binder. The bed was placed in an externally heated vertical cylindrical vessel of about 20:1 height to diameter ratio.
  • the bed was maintained at a temperature of about 450 C.
  • a flow of dry nitrogen through the bed was maintained throughout the run at a rate of about volumes (at STP) per bulk volume of sorbent per hour. The nitrogen was passed in at the top of the sorbent bed.
  • Condenser H was maintained at about 18 C. by
  • the feed was added to the flowing nitrogen at the rate of 0.72 liquid volume per bulk volume of sorbent per hour, in portions of 20 parts by weight, each, during a period of 6.7 minutes. After each feed pulse, flow of nitrogen without feed addition was continued for 20 minutes.
  • the non-normal product was separately recovered from receiver K after each feed pulse; it was measured and analyzed for normal paraflins by means of refractive index. The hydrocarbons not recovered in receiver K were recovered in receiver L. This product was measured only at the end of the run, i.e. after several cycles had been completed, and its volume and refractive index then determined.
  • Recovery means B represents a condenser and reactor operating'at 18 C.,'followed by a set of cold traps at --180 C. Almost 98% of the normal-lean product was recovered nated.
  • Sorbent bed A was of the same size and shape as bed F of Example I.
  • the run consisted of 5 0 cycles. In each cycle, dry nitrogen flow was maintained, but the rate was varied from 270 volumes (at STP) per bulk volume in the condenser-receiver.
  • Recovery means C represents a set of cold traps operating at -180 C. followed by a Non-normal product was-removed after each set of ten cycles; it was measured and analyzed for normal parafiins content by means of refractive index. The product in cold traps C was measured and analyzed at the end of the Table III Product, Condenser B Feed Cycle Charged, 7 Normal (pts. Percent Paraflius Satu- Aroma- Olefins, wt. (pts) wt of Content, rates, pertics, perpercent 7 feed percent cent v. cent v. v.
  • a process for the separation of normal hydrocarbons from a mixture of a plurality of normal hydrocarbons of at least four carbon atoms per molecule with non-normal hydrocarbons of similar boiling range which comprises: (1) passing a vapor stream of the hydrocarbon mixture into a particulate fixed mass of a solid zeolitic material having a rigid three-dimensional anionic network and having substantially uniform intracrystalline interstitial channels of from about to about 6 Angstrom units diameter while maintaining a contacting temperature of from 250 C. to 600 C.
  • hydrocarbon mixture is a gasoline boiling range reformate hydrocarbon mixture.
  • a continuous process for the separation of normal hydrocarbons from a feed mixture of a plurality of normal hydrocarbons of at least four carbon atoms per molecule with non-normal hydrocarbons of similar boiling range which comprises: (1) establishing a continuous flow of an inert gas through (a) a particulate mass of a solid zeolitic material having a rigid three-dimensional anionic network and having substantially uniform intracrystalline interstitial channels of from about 5 to about 6 Angstrom units diameter, while maintaining a contact temperature of from 250 to 600 C., (b) a first hydrocarbon recovery means comprising a condenser, and (c) a second hydrocarbon recovery means; (2) periodically adding to said gas, upstream from said mass, a portion of said feed mixture to produce a vapor mixture, which passes into said mass; (3) continuing said addition for a period no longer than that required for those normal paraflins desired to be separated to appear in the vapor mixture at the outlet and of said mass in substantial proportion; (4) recovering hydrocarbons, substantially reduced in content of those normal hydrocarbons desired
  • a continuous process for the separation of normal hydrocarbons from a feed mixture of a plurality of normal hydrocarbons of at least four carbon atoms per molecule with non-normal hydrocarbons of similar boiling range which comprises: (1) establishing a continuous flow of an inert gas through (a) a particulate mass of a solid zeolitic material having a rigid three-dimensional anionic network and having substantially uniform intracrystalline interstitial channels of from about 5 to about 6 Angstrom units diameter, while maintaining a contact temperature of from 250 to 600 C., (b) a first condenser maintained at a first temperature, and (c) a second condenser maintained at a second temperature; (2) periodically adding to said gas, lip-stream from said mass, a portion of said feed mixture to produce a vapor mixture; (3) continuing said addition for a period no longer than that required for those normal paraffins desired to be separately recovered to appear in the vapor mixture at the outlet end of said mass in substantial proportion; (4) recovering hydrocarbons, substantially reduced in content of normal hydrocarbons desired to be
  • a cyclic process for the separation of a normal hydrocarbon from non-normal hydrocarbons, said normal hydrocarbons having from about five to about .ten carbon atoms per molecule which comprises (1) passing a vapor stream of a mixture of said hydrocarbons into a particulate fixed mass of a solid zeolitic material having a rigid three-dimensional anionic network and having substantially uniform intracrystalline interstitial channels of from about 5 to about 6 Angstrom units diameter while maintaining a contacting temperature of from 250 C. to 600 C.

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  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
US622894A 1956-11-19 1956-11-19 Separation of hydrocarbons using zeolitic molecular sieves Expired - Lifetime US2952630A (en)

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NL108276D NL108276C (es) 1956-11-19
DENDAT1067161D DE1067161B (es) 1956-11-19
US622894A US2952630A (en) 1956-11-19 1956-11-19 Separation of hydrocarbons using zeolitic molecular sieves
GB35840/57A GB826089A (en) 1956-11-19 1957-11-18 A process for the separation of normal hydrocarbons from mixtures by selective adsorption
FR1196019D FR1196019A (fr) 1956-11-19 1957-11-18 Procédé de séparation des hydrocarbures normaux de leurs mélanges

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3086065A (en) * 1959-09-21 1963-04-16 Engineers & Fabricators Inc Separation of close boiling components
US3181231A (en) * 1963-08-06 1965-05-04 Union Carbide Corp Molecular sieve-metal agglomerates and their preparation
US3184406A (en) * 1961-11-03 1965-05-18 British Petroleum Co Separation processes
US3201490A (en) * 1961-02-02 1965-08-17 British Petroleum Co Separation of mixtures
US3210267A (en) * 1965-04-20 1965-10-05 Socony Mobil Oil Co Inc Catalytic cracking of hydrocarbons with the use of a crystalline zeolite catalyst containing rare earths and a porous matrix
US3226914A (en) * 1962-09-04 1966-01-04 Union Carbide Corp Pressure cycle for molecular sieve separation of normal paraffins from hydrocarbon mixtures
US3251766A (en) * 1962-02-21 1966-05-17 British Petroleum Co Separation processes
US3251765A (en) * 1962-02-23 1966-05-17 British Petroleum Co Separation processes
US3269989A (en) * 1962-03-14 1966-08-30 Eric T Rayner Intumescent coatings based upon polyesters of aliphatic diyne-diols
US3294858A (en) * 1958-02-12 1966-12-27 Exxon Research Engineering Co Selective conversion of normal paraffins
USRE28300E (en) * 1958-02-12 1975-01-14 Selective conversion of normal paraffins
US4717784A (en) * 1986-12-10 1988-01-05 Shell Oil Company Total isomerization process with mono-methyl-branched plus normal paraffin recycle stream
CN111097368A (zh) * 2018-10-29 2020-05-05 中国石油化工股份有限公司 一种吸附材料及其制备方法和应用

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1291044B (es) * 1962-05-02 1975-07-03

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2306610A (en) * 1941-02-24 1942-12-29 Barrer Richard Maling Fractionation of mixtures of hydrocarbons
US2522426A (en) * 1945-05-30 1950-09-12 Standard Oil Dev Co Method of extrcting hydrocarbons
US2586889A (en) * 1949-08-23 1952-02-26 Standard Oil Dev Co Separation of straight-chain from branched-chain hydrocarbons
US2628933A (en) * 1949-03-21 1953-02-17 California Research Corp Regeneration of solid adsorbents
US2644018A (en) * 1949-12-16 1953-06-30 Sun Oil Co Continuous adsorption process
US2651603A (en) * 1951-05-29 1953-09-08 Standard Oil Dev Co Fractionation with solid adsorbents
US2818455A (en) * 1955-03-28 1957-12-31 Texas Co Desorption of straight chain hydrocarbons from selective adsorbents
US2818137A (en) * 1955-10-24 1957-12-31 Texas Co Adsorptive separation process
US2859173A (en) * 1955-01-25 1958-11-04 Texas Co Method of treating a petroleum fraction with molecular sieve adsorbents
US2859256A (en) * 1955-01-28 1958-11-04 Texas Co Separation process involving adsorption and desorption

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2306610A (en) * 1941-02-24 1942-12-29 Barrer Richard Maling Fractionation of mixtures of hydrocarbons
US2522426A (en) * 1945-05-30 1950-09-12 Standard Oil Dev Co Method of extrcting hydrocarbons
US2628933A (en) * 1949-03-21 1953-02-17 California Research Corp Regeneration of solid adsorbents
US2586889A (en) * 1949-08-23 1952-02-26 Standard Oil Dev Co Separation of straight-chain from branched-chain hydrocarbons
US2644018A (en) * 1949-12-16 1953-06-30 Sun Oil Co Continuous adsorption process
US2651603A (en) * 1951-05-29 1953-09-08 Standard Oil Dev Co Fractionation with solid adsorbents
US2859173A (en) * 1955-01-25 1958-11-04 Texas Co Method of treating a petroleum fraction with molecular sieve adsorbents
US2859256A (en) * 1955-01-28 1958-11-04 Texas Co Separation process involving adsorption and desorption
US2818455A (en) * 1955-03-28 1957-12-31 Texas Co Desorption of straight chain hydrocarbons from selective adsorbents
US2818137A (en) * 1955-10-24 1957-12-31 Texas Co Adsorptive separation process

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE28300E (en) * 1958-02-12 1975-01-14 Selective conversion of normal paraffins
US3294858A (en) * 1958-02-12 1966-12-27 Exxon Research Engineering Co Selective conversion of normal paraffins
US3086065A (en) * 1959-09-21 1963-04-16 Engineers & Fabricators Inc Separation of close boiling components
US3201490A (en) * 1961-02-02 1965-08-17 British Petroleum Co Separation of mixtures
US3184406A (en) * 1961-11-03 1965-05-18 British Petroleum Co Separation processes
US3251766A (en) * 1962-02-21 1966-05-17 British Petroleum Co Separation processes
US3251765A (en) * 1962-02-23 1966-05-17 British Petroleum Co Separation processes
US3269989A (en) * 1962-03-14 1966-08-30 Eric T Rayner Intumescent coatings based upon polyesters of aliphatic diyne-diols
US3226914A (en) * 1962-09-04 1966-01-04 Union Carbide Corp Pressure cycle for molecular sieve separation of normal paraffins from hydrocarbon mixtures
US3181231A (en) * 1963-08-06 1965-05-04 Union Carbide Corp Molecular sieve-metal agglomerates and their preparation
US3210267A (en) * 1965-04-20 1965-10-05 Socony Mobil Oil Co Inc Catalytic cracking of hydrocarbons with the use of a crystalline zeolite catalyst containing rare earths and a porous matrix
US4717784A (en) * 1986-12-10 1988-01-05 Shell Oil Company Total isomerization process with mono-methyl-branched plus normal paraffin recycle stream
CN111097368A (zh) * 2018-10-29 2020-05-05 中国石油化工股份有限公司 一种吸附材料及其制备方法和应用

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FR1196019A (fr) 1959-11-20
DE1067161B (es)
NL108276C (es)

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