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
  • 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
• • 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
  • C10G53/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes
  • C10G53/02—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes plural serial stages only
  • C10G53/08—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes plural serial stages only including at least one sorption step
• • 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
  • C10G70/00—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00
  • C10G70/04—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00 by physical processes
  • C10G70/046—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00 by physical processes by adsorption, i.e. with the use of solids

Definitions

• the invention relates to a method for a special residual removal of C 4 -C 8 -i-alkenes from mixtures of hydrocarbons in which n- and i-alkenes are contained.
• Such mixtures are treated according to the invention with a cation exchanger in the H + form; the material to be treated is then separated by distillation.
• the process is important in the production of pure n-alkenes.
• C 5 cuts (benzene feed) or from higher-boiling fractions after the aromatics removal
• these hydrocarbon cuts primarily contain the 1-alkene corresponding to the respective number of carbon atoms, the as valuable monomer or comonomer and for the preparation of various alkylates is sought.
• the lowest possible content of the associated i-butene is required in order to ensure trouble-free (co) polymerization.
• this maximum permissible content of i-butene is set at less than 200 ppm.
• a distillative separation for example of i-butene and butene-1, fails in many cases due to the boiling points being too close together; this is particularly pronounced in the example of the C 4 -alkenes mentioned. Therefore, attempts have been made to convert i-butene into a higher-boiling substance by chemical conversion, which is then easier to separate by distillation.
• the reaction with methanol or other lower alcohols to form methyl t-butyl ether (MTBE) or its higher homologues in the presence of acidic catalysts lends itself to this.
• MTBE methyl t-butyl ether
• the raffinate with the remaining butene-1 which is formed by distillation from such a reaction mixture, is contaminated by oxygen compounds in the same boiling range, for example by dimethyl ether. Such oxygen compounds then have to be removed again, for example by an ORU system.
• ORU Oxygen Removal Unit
• oxygen compounds are removed from carbon water streams by adsorption on an active material, such as molecular
• the invention relates to a process for removing C 4 -C 8 -i-alkenes from mixtures thereof containing hydrocarbons with essentially the same number of C atoms, which is characterized in that such mixtures at 0-30 ° C. and 1-25 bar, preferably 10-20 ° C. and 10-20 bar, are treated with a cation exchanger in the H + form and the material to be treated is then distilled into a top product largely free of i-alkenes and into the conversion products of the i- Bottom product containing alkenes is separated.
• the mixture of hydrocarbons to be treated is preferably a C 4 -, a C 5 -C 6 - or a C 4 -C 6 distillation fraction.
• the mixture of hydrocarbons to be treated is a C 4 fraction.
• the outflowing mixture of cracked hydrocarbons is subjected to a distillative separation, in which a C 4 hydrocarbon stream is generally collected separately. This C 4 cut is generally subjected to the extraction of the valuable material butadiene.
• the C 4 -hydrocarbon mixture flowing out here is known as raffinate I.
• this raffinate I is subjected to either dimerization, including further oligomerization, or t-alkyl ether formation.
• An i-butene-free distillate is generally referred to as raffinate II.
• Raffinate II is used for the further extraction of the valuable materials butene-1 and butene-2.
• Cation exchangers for the process according to the invention are polymers made from acrylic compounds or styrene which are reacted with crosslinking agents, such as divinylbenzene, to give insoluble resins, or crosslinked phenol-formaldehyde condensates which contain sulfonic acid groups, carboxyl groups or phosphonic acid groups.
• crosslinking agents such as divinylbenzene
• ion exchangers with inorganic carrier material such as functionalized siloxanes can also be used.
• Styrene-divinyl resins with sulfonic acid groups are preferably used.
• Such resins have long been known to the person skilled in the art.
• such resins are present in the H + form at least 50 equivalent%, preferably at least 80 equivalent%, particularly preferably at least 90 equivalent%.
• Such resins are common commercial products, for example for water desalination.
• the process according to the invention can in principle be carried out batchwise or continuously.
• the hydrocarbon mixture containing one or more i-alkenes is mixed with a Cation exchanger of the type described, optionally under such a pressure at which the hydrocarbon mixture is liquid, treated.
• the desired removal of the i-alkenes can be checked by taking samples after specified reaction times.
• the process according to the invention is preferably carried out continuously, using shaft reactors or tubular reactors which are filled with the cation exchanger in the form of a fixed bed.
• i-butene it may be advantageous to separate the major part of i-butene in a first reactor under more stringent reaction conditions, the formation of codimer with loss of butene-1 not yet being too significant, and in a second step under milder conditions to push the remaining i-butene content down to the required specification, and under milder reaction conditions the loss of butene-1 by formation of codimer or by acid-catalytic isomerization to other alkenes can also be adequately avoided.
• the inventive method is carried out at a temperature of 0-30 ° C, preferably 10-20 ° C.
• the pressure at which the process according to the invention is carried out is necessary to the extent that the mixture of hydrocarbons to be treated has to be kept in the liquid state in consideration of the desired reaction temperature; otherwise the pressure is not critical.
• the pressure range to be set according to the invention is therefore 1-30 bar, preferably 10-20 bar; in a particularly preferred manner, work is carried out under the autogenous pressure as it occurs at the desired reaction temperature.
• the reaction mixture can flow through the reactor both from the bottom up and from the top down.
• the material to be treated is then separated by distillation.
• the top product obtained is a hydrocarbon mixture largely freed of i-alkene, which is used in particular for further work-up on alkene-1 can.
• the bottom product obtained is the alkenes with an internal double bond and a higher-boiling mixture which contains the oligomerization products of the removed i-alkenes.
• the distillation can also be carried out in such a way that the alkene-1 and the alkenes with an internal double bond are obtained as the top product and only the higher-boiling oligomerization product remains in the bottom.
• the oligomerization products are essentially C 8 hydrocarbons (dimers) which are 90% by weight and C 12 -, C 16 - or even higher oligomerization products which are at most 10 % By weight are present.
• the composition of the oligomer is strongly dependent on the composition of the feed mixture and the reaction conditions; in general, all possible reaction products arise from the i-alkene with the other alkenes in accordance with the associated reaction rate constants.
• the bottom product obtained can be worked up to pure recyclables.
• the bottom product is only a small amount, the work-up of which is not worthwhile, but which is advantageous to the Feed for the steam cracker or a catalytic cracker can be fed.
• the process according to the invention is carried out at an LHSV (Liquid Hourly Space Velocity) of 0.1-5 liters of hydrocarbon mixture containing i-alkenes per liter of cation exchanger per hour, preferably 1-2 l / l ⁇ h.
• the LHSV and the reaction temperature are set depending on the content of i-alkenes in the hydrocarbon mixture or on the desired residual content of i-alkene in the treatment mixture in such a way that as complete a conversion of i-alkene as possible with as little loss of 1- Alkene is reached.
• a continuous laboratory apparatus consisting of a preheater, a temperature-controlled double-jacket reactor and a separator was filled with 150 ml of cation exchanger in the H + form (Lewatit SPC 118 from Bayer AG).
• a C 4 raffinate II from a steam cracker was passed through the apparatus at a temperature and an LHSV, as indicated in the following Table 1, and at an equal pressure of 15 bar in both experiments, the removal of the i- Butene up to a value of below 200 ppm (below the detectability limit) the slight loss of butene-1 also given in Table 1 occurred.
• the reaction product from the last hour was collected and examined by gas chromatography. This information can also be found in Table 1 below.

Landscapes

• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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Citations (2)

• 1995
  • 1995-09-13 DE DE19533914A patent/DE19533914A1/de not_active Withdrawn
• 1996
  • 1996-09-02 DE DE59603770T patent/DE59603770D1/de not_active Expired - Lifetime
  • 1996-09-02 EP EP96113986A patent/EP0763588B1/fr not_active Expired - Lifetime
  • 1996-09-12 CZ CZ19962685A patent/CZ291045B6/cs not_active IP Right Cessation

Patent Citations (2)

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