Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/22—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by isomerisation
  • C07C5/27—Rearrangement of carbon atoms in the hydrocarbon skeleton
  • C07C5/29—Rearrangement of carbon atoms in the hydrocarbon skeleton changing the number of carbon atoms in a ring while maintaining the number of rings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
  • B01D17/02—Separation of non-miscible liquids
  • B01D17/0208—Separation of non-miscible liquids by sedimentation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
  • B01D3/06—Flash distillation
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C7/00—Purification; Separation; Use of additives
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C7/00—Purification; Separation; Use of additives
  • C07C7/005—Processes comprising at least two steps in series
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2527/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
  • C07C2527/06—Halogens; Compounds thereof
  • C07C2527/125—Compounds comprising a halogen and scandium, yttrium, aluminium, gallium, indium or thallium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2531/00—Catalysts comprising hydrides, coordination complexes or organic compounds
  • C07C2531/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
  • C07C2601/14—The ring being saturated

Definitions

• the present invention relates to a process for isomerizing at least one hydrocarbon in the presence of an acidic ionic liquid and at least one hydrogen halide (HX) in a device (V1), wherein in a device (V2) the hydrogen halide (HX) is separated from the isomerization product in gaseous form and at least is partially returned to the device (V1).
• Ionic liquids are suitable, inter alia, as catalysts for the isomerization of hydrocarbons.
• a corresponding use of an ionic liquid is disclosed, for example, in WO 201 1/69929, where a specific selection of ionic liquids in the presence of an olefin is used for the isomerization of saturated hydrocarbons, in particular for the isomerization of methylcyclopentane (MCP) to cyclohexane.
• MCP methylcyclopentane
• An analogous process is described in WO 201 1/069957, although the isomerization is not carried out in the presence of an olefin there, but with a copper (I I) compound.
• hydrogen halides can also be used as cocatalysts in isomerization processes. Frequently, the hydrogen halides are used in gaseous form. In order to be able to make better use of the co-catalytic effect of the hydrogen halides, a partial pressure of 1 to 10 bar of hydrogen halide, in particular of hydrogen chloride, is generally established above the reaction mixture by carrying out the isomerization. However, the hydrogen halide used is dissolved to some extent in the hydrocarbons and thus discharged from the isomerization reaction. This fraction of hydrogen halide, which is dissolved in the hydrocarbons, must be removed from the hydrocarbons again after the isomerization, which is often associated with problems in practice.
• US-A 201 1/0155632 discloses a process for the preparation of products with a low hydrogen halide content, wherein in at least two separation steps by stripping or distillation from a mixture which originates from a reactor and contains an ionic liquid as catalyst, the content Hydrogen halides is reduced.
• the ionic liquid used as catalyst is returned to an alkylation reactor from a downstream phase separator, from a first distillation column downstream of the phase separator Hydrogen chloride and from a second distillation column located downstream of the first distillation column, an isobutane-containing stream is returned to the alkylation reactor.
• US Pat. No. 3,271,467 discloses a method and an associated apparatus for maintaining the hydrogen halide concentration in a hydrocarbon conversion, using as catalyst a metal halide and the hydrogen halide as promoter.
• Suitable metal halides are, for example, aluminum chloride, aluminum bromide, boron trifluoride or halides of zinc, tin, antimony or zirconium, but such compounds are not ionic liquids.
• the hydrocarbon conversion may, for example, be an isomerization of methylcyclopentane (MCP) to cyclohexane. From the hydrocarbon-containing outlet of the hydrocarbon conversion, a stream rich in gaseous hydrogen halide is separated in a (first) stripping device and discharged from the arrangement.
• MCP methylcyclopentane
• a second stream, enriched in hydrogen halide, is passed from the stripping apparatus to an absorber to selectively separate, on a solid absorber, the hydrogen halide contained in that stream.
• the thus separated hydrogen halide is removed from the solid absorber again and returned to the system.
• WO 2010/075038 discloses a process for reducing the content of organic halides in a reaction product formed as a result of a hydrocarbon conversion process in the presence of a halogen-containing acidic ionic liquid-based catalyst.
• the hydrocarbon conversion process is in particular an alkylation, but if appropriate this process can also be carried out as isomerization.
• the organic halides are removed from the reaction product by washing with an aqueous alkaline solution.
• hydrogen halide as cocatalyst of ionic liquids in isomerization processes as well as the associated removal of hydrogen halide from the isomerization product is not disclosed in WO 2010/075038.
• the object underlying the present invention is to provide a novel process for the isomerization of at least one hydrocarbon in the presence of an acidic ionic liquid.
• the object is achieved by a process for the isomerization of at least one hydrocarbon comprising the following steps: a) isomerization of at least one hydrocarbon in the presence of an acidic ionic liquid having the composition K1 Al n X (3n + 1) , where K1 is a monovalent cation, X is halogen and 1 ⁇ n ⁇ 2.5, and at least one hydrogen halide (HX) in a device (V1), b) discharging a mixture (G1) from the device (V1), the mixture (G1) at least one C) feeding the mixture (G1) into a device (V2), a mixture (Gi b) containing at least 50%, preferably at least 70%, of the hydrogen halide (HX) contained in G1 , gaseous from (V2) is withdrawn, d) partial or complete return of the
• hydrogen halide which is / is dissolved in the isomerization product (hydrocarbons) following isomerization, can be removed from the isomerization product in an advantageous manner. Due to the at least partially carried out return of the hydrogen halide, this can be reused in the process.
• a further advantage of the method according to the invention is that according to step c) only a single device (separation step) is required to effectively separate hydrogen halide from the isomerization product, while in the process according to US-A 201 1/0155632 or US-A 201 1/0155640 two such separation stages, in particular distillations, are required in principle.
• a step is less complicated in terms of apparatus and thus less expensive than the compulsory performance of a second distillation.
• a flash device is used as the device (V2) in the context of the method according to the invention, this is associated with further advantages.
• the use of a flash device in step c) is initially less expensive and simpler in terms of apparatus, in particular compared to the use of a rectification column (due to the corrosivity of the hydrogen halide, which has a particularly disadvantageous effect on the complex geometries given in a column).
• the separation effect in the flash device is achieved in an advantageous manner only by a pressure reduction compared to the pressure selected in the isomerization in step a). There is thus no separate energy input necessary, the corrosivity of the hydrogen halide is also less significant.
• step c) is carried out before step c) according to the invention, ie a phase separation unit, in particular a phase separator, is connected upstream of the device (V2), in particular a flash device.
• step a) the isomerization of at least one hydrocarbon takes place in the presence of an acidic ionic liquid having the composition K1Al n X (3n + 1) , where K1 is a monovalent cation, X is halogen and 1 ⁇ n ⁇ 2, 5, and at least one hydrogen halide (HX) in a device (V1).
• the acidic ionic liquid is used as an isomerization catalyst and the hydrogen halide as cocatalyst.
• the acidic ionic liquids which can be used in the context of the present invention and have the composition K1Al n X (3n + 1) , where K1 is a monovalent cation, X is halogen and 1 ⁇ n ⁇ 2.5, are known to the person skilled in the art.
• Such ionic liquids are disclosed (among other ionic liquids), for example in WO 201 1/069929.
• mixtures of two or more acidic ionic liquids can be used, preferably an acidic ionic liquid is used.
• K1 is preferably an unsubstituted or at least partially alkylated ammonium ion or a heterocyclic (monovalent) cation, in particular a Pyridinium ion, an imidazolium ion, a pyridazinium ion, a pyrazolium ion, an imidazolinium ion, a thiazolium ion, a triazolium ion, a pyrrolidinium ion, an imidazolidinium ion or a phosphonium ion.
• X is preferably chlorine or bromine.
• the acidic ionic liquid contains as cation at least a partially alkylated ammonium ion or a heterocyclic cation and / or as an anion a chloroaluminum having the composition Al n Cl (3n + 1) with 1 ⁇ n ⁇ 2.5.
• the at least partially alkylated ammonium ion contains one, two or three alkyl radicals having (each) 1 to 10 carbon atoms. If two or three alkyl substituents with the corresponding ammonium ions are present, the respective chain length can be selected independently of one another, preferably all alkyl substituents have the same chain length. Particularly preferred are trialkylated ammonium ions having a chain length of 1 to 3 carbon atoms.
• the heterocyclic cation is preferably an imidazolium ion or a pyridinium ion.
• the acidic ionic liquid contains as cation an at least partially alkylated ammonium ion and as anion a chloroalumination with the composition Al n Cl (3n + 1) with 1 ⁇ n ⁇ 2.5.
• acidic ionic liquids are trimethylammonium chloroaluminate and triethylammonium chloroaluminate.
• hydrogen halides can be used as hydrogen halide (HX), for example hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr) or hydrogen iodide (HI).
• the hydrogen halides can also be used as a mixture, but preferably only one hydrogen halide is used in the context of the present invention.
• the hydrogen halide is used, the halide part of which is also contained in the above-described acidic ionic liquid (at least partially) in the corresponding anion.
• the hydrogen halide (HX) is hydrogen chloride (HCl) or hydrogen bromide (HBr).
• the hydrogen halide (HX) is hydrogen chloride (HCl).
• any hydrocarbons can be used in the context of the present invention, provided that at least one of the hydrocarbons used can be isomerized in the presence of the acidic ionic liquids described above.
• the skilled person knows, based on his general knowledge, which hydrocarbons are isomerizable by acidic ionic liquids.
• mixtures of two or more hydrocarbons can be used, but it can also be used only one hydrocarbon. That's the way it is Within the scope of the present invention, it is possible for only one of these hydrocarbons to be isomerized in a mixture containing two or more hydrocarbons. If appropriate, compounds which are themselves non-hydrocarbon but miscible with them can also be present in such mixtures.
• methylcyclopentane (MCP) or a mixture of methylcyclopentane (MCP) with at least one further hydrocarbon selected from cyclohexane, n-hexane, iso-hexanes, n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes is isomerized in step a) as hydrocarbon.
• MCP methylcyclopentane
• at least one further hydrocarbon selected from cyclohexane, n-hexane, iso-hexanes n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes, wherein the proportion of branched hydrocarbons in a mixture greater than 50 wt .-% is (based on the sum of all hydrocarbons), isomerized.
• methylcyclopentane (MCP) is particularly preferably isomerized to cyclohexane.
• the isomerization product obtained in the process according to the invention in step a) is subsequently characterized in detail under step b).
• the device (V1) for carrying out the isomerization, it is possible in principle to use all devices known to the person skilled in the art for such a purpose.
• the device (V1) is a stirred tank or a stirred tank cascade.
• Rlickkesselkaskade means that two or more, for example, three or four, stirred tanks are connected in series (in series).
• the hydrocarbons and the ionic liquid each form a separate phase in the isomerization, wherein subsets of the ionic liquid in the hydrocarbon phase and subsets of the hydrocarbons may be contained in the ionic liquid phase.
• the hydrogen halide in particular hydrogen chloride, is preferably introduced in gaseous form into the device (V1) for carrying out the isomerization.
• the hydrogen halide may, at least in part, be contained in the two aforementioned liquid phases, preferably the hydrogen halide forms a separate gaseous phase.
• the isomerization is preferably carried out at a temperature between 0 ° C and 100 ° C, more preferably at a temperature between 30 ° C and 60 ° C. Furthermore, it is preferred that the pressure in the isomerization between 1 and 20 bar abs. (absolute), preferably between 2 and 10 bar abs., Is.
• the isomerization in the apparatus (V1) is preferably carried out such that two liquid phases and one gas phase are present in a stirred tank or a stirred tank cascade.
• the first liquid phase contains at least 90% by weight of the acidic ionic liquid and the second liquid phase contains at least 90% by weight of the hydrocarbons.
• the gas phase contains at least 90% by weight of at least one hydrogen halide, preferably hydrogen chloride.
• the pressure and composition of the gas phase are adjusted so that the partial pressure of the gaseous hydrogen halide, in particular of HCl gas, in the gas phase between 1 and 20 bar abs., Preferably between 2 and 10 bar abs. is.
• a mixture (G1) is discharged from the device (V1), the mixture (G1) containing at least one hydrocarbon and at least one hydrogen halide (HX).
• HX hydrogen halide
• the isomerization product generally also contains the hydrocarbon to be isomerized (in a smaller amount than before the isomerization). If, for example, MCP is to be isomerized to cyclohexane, the isomerization product frequently contains a mixture of cyclohexane and MCP (in less amount than prior to isomerization).
• the mixture (G1) contains at least one hydrogen halide (HX) and optionally further components.
• the hydrogen halide (HX) contained in the mixture (G1) is usually the same hydrogen halide used in the isomerization step a) described above.
• the mixture (G1) preferably contains the ionic liquid used in the isomerization step a) described above.
• the mixture (G1) additionally contains between 10 and 99% by weight, preferably between 50 and 95% by weight, of acidic ionic liquid (the amounts are based on the total weight of hydrocarbons and hydrogen halide in the mixture (G1)).
• the mixture (G1) as a hydrocarbon - that is as an isomerization of step a) - cyclohexane or a cyclohexane-containing mixture. More preferably, the mixture (G1) contains as a hydrocarbon a mixture of cyclohexane with at least one further hydrocarbon selected from methylcyclopentane (MCP), n-hexane, iso-hexanes, n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes.
• MCP methylcyclopentane
• the mixture (G1) particularly preferably contains as hydrocarbon a mixture of cyclohexane, MCP and at least one further hydrocarbon.
• the further hydrocarbon is selected from n-hexane, iso-hexanes, n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes.
• the proportion of branched hydrocarbons in the mixture (G1) is less than 10% by weight (based on the sum of all the hydrocarbons present in the mixture (G1)).
• the mixture (G1) i) contains as hydrocarbon a mixture of cyclohexane with at least one further hydrocarbon selected from methylcyclopentane (MCP), n-hexane, iso-hexanes, n-heptane, iso-heptanes, Methylcyclohexane or dimethylcyclopentanes, ii) hydrogen chloride (HCl) and iii) an acidic ionic liquid containing as cation an at least partially alkylated ammonium ion and as the anion a chloroaluminum having the composition Al n Cl (3n + 1) with 1 ⁇ n ⁇ 2.5 having.
• MCP methylcyclopentane
• HCl hydrogen chloride
• iii) an acidic ionic liquid containing as cation an at least partially alkylated ammonium ion and as the anion a chloroaluminum having the composition Al n Cl (3n + 1) with 1 ⁇ n
• step c) of the process according to the invention the mixture (G1) is fed into a device (V2), a mixture (Gi b) containing at least 50% of the hydrogen halide (HX) contained in G1 being taken off in gaseous form from (V2) ,
• the mixture (Gi b) preferably contains at least 70%, more preferably at least 95%, particularly preferably at least 99%, of hydrogen halide (in each case based on the corresponding amount in G1).
• V2 for carrying out the gaseous removal (separation) of the hydrogen halide (HX) from the mixture (G1)
• devices known to the person skilled in the art for such a purpose, preferably an evaporation device, rectification column, a device for flash evaporation ( Flash device) or a stripping device.
• the device (V2) should preferably be carried out in the context of the inventive method, a separation of the hydrogen halides from the hydrocarbons.
• Particularly preferred V2 is a flash device or a stripping device.
• step c) is to be understood such that when using a flash device as the device (V2), a corresponding flash process (flashing) with the mixture (G1) is carried out.
• a flash device as the device (V2)
• flashing flashing
• G1 mixture
• step c) is to be understood such that when using a flash device as the device (V2), a corresponding flash process (flashing) with the mixture (G1) is carried out.
• the device (V2) listed above such as stripping device or evaporator.
• evaporation which is carried out in a corresponding evaporation apparatus, the following understood:
• evaporation is characteristic that evaporated from the liquid mixture to be separated under heat, a part, and condensed after separation from the residual liquid mixture
• a vapor phase is generated for the original liquid phase in which the lower-boiling mixture components accumulate.
• rectification which is carried out in a corresponding rectification column (rectification apparatus), also called a rectification column or rectification apparatus, is understood as follows: In the rectification, the steam produced by distillation is passed in a rectification column in countercurrent to a In this way, more volatile components in the overhead and heavier volatile in the bottom product of the rectification are enriched.
• flashing which is carried out in a corresponding flash device and can also be referred to as flash evaporation, means the following:
• a liquid mixture is introduced into a suitable device (flash device) ), for example, in a vapor-liquid separating vessel (ie, on a suitable device such as a valve is a lowering of the pressure sufficient to spontaneously evaporate a portion of the liquid mixture)
• flash device a suitable device
• the liquid mixture can, for example, a reaction stage operated at a higher pressure
• it may also be preheated in a preheater, for example at boiling temperature, wherein the pressure in the preheater must be higher than the pressure in the downstream precipitation vessel n higher proportion of lower boiling components.
• the flash evaporation thus provides for a partial separation of the incoming mixture, wherein the separator can act as a single theoretical separation stage.
• the flashing can also be combined with a heat input into the liquid mixture remaining during the flash process, for example, by a circulating evaporator connected to the separating vessel.
• the term "stripping", which is carried out in a corresponding stripping apparatus means the following: during stripping, the depletion of one or more lower-boiling components takes place from a liquid, this being carried out, preferably in a countercurrent column, is contacted with gases such as nitrogen, air or water vapor, so that as a result of the gas caused by the reduction of the partial pressure of the lower-boiling components in the gas phase, their solubility in the liquid decreases.
• step d) of the process according to the invention the partial or complete return of the mixture (Gi b) withdrawn in step c) takes place into the device (V1), if necessary under pressure increase by means of a suitable device, such as e.g. a jet, piston, turbo or screw compressor.
• a suitable device such as e.g. a jet, piston, turbo or screw compressor.
• the mixture (Gi b) withdrawn in step c) is completely returned to the device (V1).
• the excess amounts of mixture (Gi b) are carried out from the process according to the invention and discarded (as a rule).
• step c) is preferably carried out such that a single-stage evaporation, preferably a flash evaporation, takes place in the device (V2).
• the following additional steps e) and f) are carried out, which are defined as follows: e) discharge of a mixture (G2) from the device (V2) in which the mixture (G2) contains at least one hydrocarbon and an amount of at least one hydrogen halide (HX) reduced by at least 50% compared with the mixture (G1), f) washing the mixture (G2) with an aqueous medium to obtain a mixture (G3) containing at least one hydrocarbon and not more than 100 ppm by weight, preferably not more than 10 ppm by weight of hydrogen halide (HX) (based on the total weight of G3)).
• the additional process step f) is carried out so that the laundry according to step f) comprises at least two washing steps, wherein
• the aqueous medium used in a first washing step has a pH> 9, preferably> 12, f2) in a second washing step has a pH between 5 and 9, preferably between 6 and 8.
• the aqueous medium according to the first washing step contains an alkali metal hydroxide, more preferably NaOH.
• the aqueous medium according to the second washing step is water, more preferably demineralized water.
• step f) can be carried out so that step f2) can be carried out before step f1).
• this process variant is therefore washed first with an aqueous medium having a lower pH, then carried out in the wash with an aqueous medium having a higher pH.
• steps f1) and several steps f2) are carried out in two stages, first step f1) and then step f2) being carried out.
• a one-step washing step f) is carried out, wherein the aqueous medium has a pH of 5 to 9, preferably between 6 and 8, and is particularly preferably demineralized water.
• the washing step f) is preferably carried out in a countercurrent extraction column or mixer-settler arrangement.
• step f) is carried out using at least one dispersing and phase separation unit or at least one extraction column per washing stage.
• the dispersing and phase separation unit is a mixer-settler apparatus (combination of a stirred tank with a subsequent phase separator), a combination static mixer with phase separator or a combination of mixing pump with phase separator.
• the mixture (G2) is conducted in countercurrent to the aqueous medium.
• the mixture (G2) discharged from the device (V2) is particularly preferably washed without intermediate steps with the aqueous medium (according to step f)).
• the washing step f) is carried out in a, preferably in countercurrent, multistage mixer-settler apparatus or it is extracted in a countercurrent extraction column with water.
• the mixer-settler apparatus or extraction column in the direction of flow of the mixture (G 2) (containing the hydrocarbons), this is preferably followed by a further washing stage, which is fed with fresh water.
• a further washing stage In its aqueous outlet there is a device for the continuous measurement of the pH or the electrical conductivity so as to monitor the complete removal of the non-hydrocarbon components, in particular HCl.
• the inventive method is illustrated again according to a preferred embodiment.
• the two process steps e) and f) are performed.
• the device (V1) is preferably a stirred tank or a stirred tank cascade, in which Device (V2) is preferably an evaporator, in particular a flash device.
• Device (V2) coming and pointing upward arrow is shown that optionally in the context of the inventive method in step d), only a partial return of the separated in step c) mixture (Gi b) can be performed or that Mixture (Gi b) a further process step, preferably a material separation is supplied. This is particularly advantageous when (V2) is performed as stripping.
• a complete or partial separation of the hydrogen halide from the stripping gas used can be carried out and the hydrogen halide-enriched stream thus obtained can be completely or partially recycled to the apparatus (V1).
• the washing step f) according to FIG. 1 can be one-stage or multi-stage as described above, preferably a multi-stage, in particular two-stage washing of the mixture (G2) in countercurrent to aqueous medium is carried out and / or a dispersing and phase separation unit, in particular a mixer-settler apparatus, is used.
• a further step g) is carried out between step b) and step c), which is defined as follows: g) feeding the mixture (G1) into a phase separation unit, in particular into a phase separator Phase separation unit from the mixture (G1) at least 90%, preferably at least 99% of the acidic ionic liquid is separated and the acidic ionic liquid depleted mixture (G1) is fed into the device (V2).
• the acidic ionic liquid separated from the mixture (G1) in the phase separation unit (according to step g)) is completely or partially returned to the device (V1).
• FIG. 2 the abbreviations, arrows and other symbols have a meaning corresponding to that stated above for FIG. 1;
• PT means phase separation unit,
• IL means acidic ionic liquid.
• cyclohexane is preferably isolated in the context of the present invention. Methods and apparatus for the separation of cyclohexane from the mixture (G3) are known in the art.
• the device (V1) is a stirred tank or a stirred tank cascade and is operated at a pressure (p1) of 1 to 10 bar.
• the device (V2) is a flash device and is operated at a pressure (p2) which is less than the pressure (p1) in the device (V1). Due to the use of the flash device, there is a pressure reduction relative to the pressure which is present in the isomerization according to step a).
• the pressure values (p2) can be chosen arbitrarily (for example 1 to 5 bar), provided that they are lower than the pressure (p1) present in the device (V1) during the isomerization.
• the present invention will be illustrated by way of examples.
• (A) and (B) are mixed so that the resulting mixture after phase separation G1 (-I L) has an HCl content of 1.5% by weight.
• Example 1 is shown schematically in FIG.
• V1 is an isomerization of a hydrocarbon mixture (A) in the presence of an ionic liquid (trimethylammonium chloroaluminate - TMA-IL), which serves as a catalyst, instead.
• the volume ratio of ionic liquid to organic phase is 5 l / l.
• hydrogen chloride gas (B) for stabilizing the IL and the recycle streams Gi b from a flash device V2 and IL are fed from a phase separation.
• an operating pressure of 3.5 bar (abs) and a temperature of 50 ° C are assumed.
• the resulting mixture G1 is passed into a phase separation device PT.
• TMA-IL is completely separated and recycled as a pure IL phase.
• the organic phase G1 (-IL) is led into the flash device V2, where it is expanded to an operating pressure of 1 bar (abs).
• the resulting gas fraction Gi b is returned to the device V1.
• purge refers to the partial streams of G1 or IL which can be removed from the process if appropriate
• the liquid mixture G2 is discharged from V2 and can be treated by washing in a subsequent step (not the subject of this example calculation) Properties and compositions of the streams are shown in Table 1.
• Properties Unit act Value value act. Value act. Value act. Value Value Value
• Comparative Example 2 without HCI Separation or Recycling Comparative Example 2 is shown schematically in FIG.
• a device V1 is an isomerization of a hydrocarbon mixture (A) in the presence of an ionic liquid (trimethylammonium chloroaluminate - TMA-IL), which serves as a catalyst, instead.
• the volume ratio of ionic liquid to organic phase is 5 l / l.
• hydrogen chloride gas (B) is supplied to stabilize the IL.
• an operating pressure of 3.5 bar (abs) and a temperature of 50 ° C are assumed.
• the resulting mixture G1 is passed into a phase separation device PT.
• the organic phase G1 (-IL) is passed into a device V2, which is ineffective compared to Example 1. This should clarify the lack of influence of a flash device.
• the liquid mixture G2, which in this case corresponds to the composition of mixture G1 (-IL), is discharged from V2 and can be treated by washing in a subsequent step.
• the hydrogen halide can be reused in the process due to the recycling to over 75%.
• the gas flow Gi b is completely returned, there are no losses associated with the product of value.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Analytical Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Water Supply & Treatment (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=48748250

Family Applications (1)

Country Status (3)

Families Citing this family (2)

Citations (7)

• 2013
  • 2013-07-09 EP EP13734778.7A patent/EP2872470A1/fr not_active Withdrawn
  • 2013-07-09 WO PCT/EP2013/064426 patent/WO2014009331A1/fr not_active Ceased
  • 2013-07-09 CN CN201380036675.5A patent/CN104470876A/zh active Pending

Patent Citations (7)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events