WO2014009350A1

WO2014009350A1 - Performing a hydrocarbon conversion or processing a hydrocarbon conversion in devices having a surface made of nonmetallic materials

Info

Publication number: WO2014009350A1
Application number: PCT/EP2013/064452
Authority: WO
Inventors: Steffen Tschirschwitz; Joni JONI; Daniel Pfeiffer; Stefan Bitterlich; Michael HÜBNER
Original assignee: Basf Se; Basf Schweiz Ag
Priority date: 2012-07-11
Filing date: 2013-07-09
Publication date: 2014-01-16

Abstract

The invention relates to a method for performing a hydrocarbon conversion or processing an output from a hydrocarbon conversion in the presence of an acidic ionic liquid. The hydrocarbon conversion, preferably an isomerization process, is performed in devices in which the surfaces that come in contact with the acidic ionic liquid are made entirely or at least in part of at least one nonmetallic material. The nonmetallic material is applied to at least one other material that is different from the nonmetallic material.

Description

Carrying out a hydrocarbon conversion or treatment of a hydrocarbon conversion in devices with surfaces of non-metallic materials Description

The present invention relates to a process for carrying out a hydrocarbon conversion or treatment of a hydrocarbon conversion in the presence of an acidic ionic liquid. The hydrocarbon conversion itself, which is preferably an isomerization, and / or subsequent process steps used to process hydrocarbon conversion are carried out in devices whose surfaces that come into contact with the acidic ionic liquid completely or at least partially from at least one non-metallic material are made. The non-metallic material in turn is applied to at least one other material that is different from the non-metallic material.

Ionic liquids can be used in various hydrocarbon conversion processes, in particular they are suitable 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. 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.

US-A 201 1/0155632 discloses a process for the preparation of products having a low hydrogen halide content, wherein in at least two separation stages 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. In one embodiment of the process described in US-A 201 1/0155632, the ionic liquid used as a catalyst is recycled to an alkylation reactor from a downstream phase separator, from a first distillation column downstream of the phase separator is hydrogen chloride and from a further downstream second distillation column is a Isobutane-containing stream is returned to the alkylation reactor. The devices used to carry out, in particular, for the treatment of the process according to US-A 201 1/0155632 are made of one or more metals such as aluminum, iron or steel, which have a poor corrosion resistance to hydrogen chloride. A Corresponding disclosure as in US-A 201 1/0155632 is contained in US-A 201 1/0155640, however, the method described therein relates to a hydrocarbon conversion. 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. In WO 2010/075038, however, no specific information is provided on the materials from which the surfaces of the devices are produced, which are used in the local work-up procedure.

The object underlying the present invention is in the

Providing a new procedure for carrying out a

Hydrocarbon conversion or treatment of hydrocarbon conversion in the presence of an acidic ionic liquid.

The object is achieved by a method for carrying out a hydrocarbon conversion or processing a discharge of a hydrocarbon conversion in the presence of an acidic ionic liquid using at least one device (V1), characterized in that the surfaces of the device (V1) with the acidic ionic Liquid come into contact, completely or at least partially made of at least one non-metallic material (W1), wherein the non-metallic material (W1) on at least one material (W2) is applied, which is different from the non-metallic material (W1).

By means of the process according to the invention, it is advantageously possible to carry out a hydrocarbon conversion in the presence of acidic ionic liquids and / or to process the discharge of such a hydrocarbon conversion. Due to the use of non-metallic materials to produce the surfaces that come in contact with the acidic ionic liquid in the respective devices, the corrosion caused by the acidic ionic liquid can be significantly reduced or even completely suppressed. In this way, costs can be saved because due to the significantly increased corrosion resistance, the corresponding devices can be operated longer, until a repair or even a complete replacement of the corresponding devices must be performed. In addition, by Corrosion products caused impairment of the process reduced or avoided altogether.

Since, according to the invention, the complete device (V1) does not have to be made of non-metallic materials, but only (completely or at least partially) the surfaces which come into contact with the acidic ionic liquid, additional costs can be saved by adding to the corresponding parts of the device (V1), where the acidic ionic liquid can not cause corrosion, cheaper and / or more mechanically stable materials can be used.

The abovementioned advantages come into play in the method according to the invention in particular when an oxidic material, preferably glass, or a polymer, preferably a fluorine-containing polymer, is used as the non-metallic material (W1) and steel as the material (W2). If the non-metallic material (W1) is glass, the non-metallic material (W1) and the material (W2) particularly preferably form an enamel.

A further advantage of the method according to the invention is the fact that it is not absolutely necessary that the surfaces of the device (V1) which come into contact with the acidic ionic liquid must be made completely from the non-metallic material (W1). Thus, portions of these surfaces may also be made of a material (W2) other than non-metallic materials (W1) and / or of a metallic material (W3) containing tantalum. The metallic material (W3) containing tantalum is used in particular when a corresponding device (V1) has been used for a long period of time and, for example, cracks have formed in the surfaces made of the non-metallic material (W1). The metallic material (W3) containing tantalum can be used in a simple and inexpensive manner for repairing / repairing such imperfections in the surfaces made of the non-metallic material (W1). Of course, it is conceivable that even before the start-up of a corresponding device (V1) partial areas of the surfaces which come into contact with the acidic ionic liquid, only from the metallic material (W3) containing tantalum, are produced and / or that this material (W3 ) is applied to corresponding portions / points, which are made of the non-metallic material (W1).

In the following, the process according to the invention for carrying out a hydrocarbon conversion or treatment of a discharge of a hydrocarbon conversion which is carried out in the presence of an acidic ionic liquid in devices with surfaces of non-metallic materials is defined in more detail. In the context of the present invention either a hydrocarbon conversion can be carried out or a discharge of a hydrocarbon conversion can be prepared. In the context of the present invention, preference is given to carrying out both a hydrocarbon conversion and a corresponding processing of an order for the corresponding hydrocarbon conversion.

Hydrocarbon conversions as such are known to those skilled in the art. For example, a chemical reaction or chemical reaction can be carried out with the hydrocarbon to be considered, ie the hydrocarbon can be chemically reacted, modified or changed in any other way with respect to its composition or structure. Preferably, the hydrocarbon conversion is selected from alkylation, polymerization, dimerization, oligomerization, acylation, metathesis, polymerization or copolymerization, isomerization, carbonylation, or combinations thereof. Alkylations, isomerizations, polymerizations, etc. are known in the art. Particularly preferred in the context of the present invention, the hydrocarbon conversion is an isomerization.

In the context of the present invention, the preparation of a hydrocarbon conversion reaction is understood to mean that the product obtained in a hydrocarbon conversion, preferably the isomerization product, is removed completely or partially, preferably completely, from the corresponding device for carrying out the hydrocarbon conversion. This discharge is subsequently subjected to one or more preparation stages. Preparation steps as such are known to the person skilled in the art, for example purification steps such as phase separations and / or distillations, by means of which the discharge of the hydrocarbon conversion, for example of educts, solvents, by-products and / or catalysts, is freed. Preferably, in the context of the present invention, by processing the discharge of the hydrocarbon conversion, a separation of the acidic ionic liquid from the hydrocarbons, ie from the product of the hydrocarbon conversion, is carried out.

In the present invention, the hydrocarbon conversion is carried out in the presence of an acidic ionic liquid having the composition K1Al _n X _{(3n + 1)} , wherein K1 is a monovalent cation, X is halogen and 1 <n <2.5. Such acidic ionic liquids are known to the person skilled in the art, they are disclosed (in addition to other ionic liquids), for example in WO 201 1/069929. For example 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. More preferably, the acidic ionic liquid contains as cation an at least partially alkylated ammonium ion or a heterocyclic cation and / or as an anion a chloroalumination with the composition Al _n Cl _{(3n +} i ₎ with 1 <n <2.5. Preferably, 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.

Particularly preferably, 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. Examples of such particularly preferred acidic ionic liquids are trimethylammonium chloroaluminate and triethylammonium chloroaluminate.

The acidic ionic liquid used in the present invention is preferably used as a catalyst in hydrocarbon conversion, especially as an isomerization catalyst.

In principle, any hydrocarbons may be used in the context of the present invention, with the proviso that at least one of the hydrocarbons used in the presence of the above-described acidic ionic liquids of a hydrocarbon conversion, in particular an isomerization, can be subjected. The person skilled in the art, on the basis of his general knowledge, knows which hydrocarbons can be subjected to a hydrocarbon conversion by acidic ionic liquids, in particular which hydrocarbons are isomerizable. For example, mixtures of two or more hydrocarbons can be used, but it can also be used only one hydrocarbon. Thus, it is possible in the context of the present invention that in a mixture containing two or more hydrocarbons only one of these hydrocarbons a Subjected to hydrocarbon conversion, in particular isomerized. If appropriate, compounds which are themselves non-hydrocarbon but miscible with them can also be present in such mixtures. In the hydrocarbon conversion, preference is given to using methylcyclopentane (MCP) or a mixture of methylcyclopentane (MCP) with at least one further hydrocarbon selected from cyclohexane, n-hexane, isohexanes, n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes ,

More preferred is 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, the proportion of branched hydrocarbons in the mixture being greater than 50 % By weight (based on the sum of all hydrocarbons) used.

According to the invention, the method is carried out so that in the context of carrying out a hydrocarbon conversion or treatment of the discharge of the hydrocarbon conversion at least one device (V1) is used. The device (V1) is designed in such a way that the surfaces of the device (V1) which come into contact with the acidic ionic liquid are completely or at least partly made of at least one non-metallic material (W1). The non-metallic material (W1) in turn is applied to at least one material (W2), which is different from the non-metallic material (W1).

The corresponding devices (V1) as such are known to the person skilled in the art, depending on the respective intended use. For example, it may be a reactor, a (stirred) boiler, a conduit and / or a distillation device. The specific embodiment of the corresponding device in the context of the method according to the invention is selected by the expert on the basis of his expertise for the particular application. If, for example, an isomerization is to be carried out, the person skilled in the art preferably selects a stirred tank or a stirred tank cascade as device (V1) for this purpose. Rührkesselkaskade means that two or more, for example, three or four, stirred tanks are connected in series (in series). In other words, this means that the stirred tank represents a device (V1), which is used in the context of the inventive method for carrying out a hydrocarbon conversion, in particular an isomerization. For the treatment of the discharge from a hydrocarbon conversion, in particular an isomerization, according to the invention as device (V1), however, not such a stirred tank is used, but it is for example (as explained in more detail below) a phase separator and / or a flash device used. However, for each device (V1), it is a prerequisite that (as already explained above) the surfaces of the device (V1) which come into contact with the acidic ionic liquid be completely or at least partially composed of at least one non-metallic material ( W1) are produced, wherein the non-metallic material (W1) is applied to at least one material (W2), which is different from the non-metallic material (W1). On the other hand, those surfaces or parts of the device (V1) which do not come into contact with the acidic ionic liquid, for example a housing outer wall or a fastening device, can be made of any materials. It is equally possible that such surfaces or parts of the device (V1) are also made of a non-metallic material (W1) and / or a material (W2). According to the invention, it is not absolutely necessary for any surface which comes into contact with the acidic ionic liquid within the scope of the corresponding process step to be produced from at least one non-metallic material (W1) within such a device (V1). Thus, it is conceivable that within such a device (V1) at least 50% of the surfaces to be considered, which come into contact with the acidic ionic liquid, are made of the non-metallic material (W1). Preferably, the surfaces of the device (V1) which come into contact with the acidic ionic liquid are at least 80%, more preferably at least 95%, in particular 100%, made of the non-metallic material (W1). The above percentages relate to the total surface area (within) of the respective device (V1) to be considered, which comes into contact with the acidic ionic liquid.

If the surfaces of the device (V1) which come into contact with the acidic ionic liquid are not completely made of the non-metallic material (W1), portions of these surfaces can also be made of a material (W2) made of non-metallic material (W1). is different, and / or made of a metallic material (W3) containing tantalum. Preferably, a maximum of 20%, in particular a maximum of 5% of the surfaces of the device (V1) which come into contact with the acidic ionic liquid, from a material (W2), which is different from non-metallic materials (W1), and / or from a metallic material (W3) containing tantalum.

Preferably, the surfaces of the device (V1) which come in contact with the acidic ionic liquid are made of a metallic material (W3) containing tantalum at the locations where they are not made of the non-metallic material (W1). In particular, the ratio of the subareas (surfaces) of non-metallic material (W1) to metallic material (W3) containing tantalum greater than 95 to 5. The non-metallic material (W1), the material (W2) and the metallic material (W3) containing tantalum are further defined in the text below. In the context of the method according to the invention, it is preferred that two or more, for example three, four or five, of such devices (V1) are used, which may be different in terms of their intended use and / or nature. For example, the first device (V1) to be considered is a stirred tank, the second device (V1) to be considered a phase separator, the third device (V1) to be considered a flash device, which are connected to each other at least one line, these lines may also be devices (V1) in the context of the present invention. Thus, it is also conceivable that in the above example the first device (V1) to be considered is based on another non-metallic material (W1) in comparison to the second device (V1) and / or the lines which interconnect the respective devices connect.

Preferably, the device (V1) is a reactor, a stirred tank, a conduit, a phase separation unit or a separation apparatus. Furthermore, it is preferred that the phase separation unit is a phase separator or the separation apparatus is an evaporator, a rectification column, a flash device or a stripping device, preferably a flash device.

In the context of the present invention, the term "flashing", which is carried out in a corresponding flash device (V1) and can also be referred to as flash evaporation, means the following: In the flash evaporation (flashing), a liquid mixture without external heat or The liquid mixture can originate, for example, from a reaction stage operated at a higher pressure, but it can also be preheated in a preheater the pressure in the preheater must be higher than the pressure in the downstream separator The steam produced during the expansion has a higher proportion of lower-boiling components compared with the mixture entering the separator, so that the flash evaporation ensures a partial separation of the perm aufenden mixture.

In a preferred embodiment of the present invention, the hydrocarbon conversion is carried out in a reactor or stirred tank, wherein the reactor or stirred tank is connected via a line to a phase separation unit and the phase separation unit in turn via a line with a Separating apparatus is connected. Preferably, the individual (aforementioned) devices or lines are each configured as a device (V1) in which the surfaces which come into contact with the acidic ionic liquid are completely made of at least one non-metallic material (W1), which is at least one Material (W2) is applied, which is different from the non-metallic material (W1). Furthermore, it is preferred that the phase separation unit is connected via a return line for the acidic ionic liquid with the reactor or stirred tank, in which the hydrocarbon conversion is carried out. In principle, all non-metallic materials known to the person skilled in the art for the corresponding intended use (for example isomerization or distillation) can be used as the non-metallic material (W1). For example, only a single non-metallic material (W1) can be used, but if appropriate combinations of two or more different non-metallic materials (W1) can also be used, preferably a non-metallic material (W1) per device (V1) is used. A combination of two (or more) different non-metallic materials (W1) means that within the same device (V1) portions of the corresponding surfaces of a first non-metallic materials (W1), while other portions of a different (non-first) non-metallic material ( W1) are produced.

The term "surfaces of the device (V1), which come into contact with the acidic ionic liquid, completely or at least partially made of at least one non-metallic material (W1)" is understood in the context of the present invention, that for the production of contains at least 80%, more preferably at least 90%, in particular 100%, of at least one non-metallic material (W1), which means that, if appropriate, mixtures of at least one non-metallic material (W1) may also be used to produce the corresponding surfaces. and at least one further compound (material) which does not fall under the definition of a non-metallic material (W1) Preferably, the non-metallic material (W1) is an oxidic material or a polymer be used s, which are based on compounds of non-metals, especially silicon, possibly also boron, with oxygen, provided that the material is suitable for the production of surfaces due to its chemical and mechanical properties. In the context of the present invention, silicon is considered as non-metal. The oxidic material is particularly preferably glass. If a polymer is used as the non-metallic material (W1), this is preferably a fluorine-containing polymer, in particular polytetrafluoroethylene (PTFE) or a perfluoroalkoxy polymer (PFA). PFA is a copolymer of tetrafluoroethylene (TFE) and perfluoroalkoxyvinyl ethers such as perfluorovinylpropyl ether. As material (W2), it is possible in principle to use all materials known to the person skilled in the art for the corresponding intended use (for example isomerization or distillation). The material (W2) may be a metallic or a non-metallic material. If the material (W2) is a non-metallic material, this is different in terms of its chemical composition of the non-metallic material (W1). Preferably, the material (W2) is a metallic material, for example in the form of metal alloys, more preferably the material (W2) is steel, in particular stainless steel (stainless steel).

In the context of the present invention, it is preferred that the non-metallic material (W1) is applied in the form of a layer or layer on the material (W2) acting as a lower layer or underlay. If the non-metallic material (W1) is a glass, the non-metallic material (W1) and the material (W2) preferably form (together) an enamel. Particularly preferably, the enamel is formed of glass as a non-metallic material (W1) and steel as a material (W2). Such enamel is also called steel enamel.

In one embodiment of the present invention, the non-metallic material (W1) is a polymer with which the device (V1) is coated or lined. Furthermore, it is preferred that the non-metallic material (W1) is a polymer with which the device (V1) is lined and the materials (W1) and (W2) are glued together. Preferably, the bonding of the materials (W1) and (W2) by a resin-based adhesive.

The metallic material (W3) containing tantalum is included in the definition of the material (W2) if it is a metal. The metallic material (W3) preferably contains at least 95 wt.% Tantalum (Ta), the remaining fractions are preferably also metals, in particular tungsten (W), niobium (Nb), hafnium (Hf) and / or silver (Ag). , The metallic material (W3) containing tantalum is preferably used for repairing cracks formed in the surfaces made of the non-metallic material (W1). Such cracks or other imperfections can occur, for example, if a corresponding device (V1) was used over a longer period of time. In other words, this means that the metallic material (W3) is wholly or partially applied to a layer or layer of the non-metallic material (W1) or wholly or partially replaced, wherein the non-metallic material (W1) turn on the lower layer or supporting material (W2) is or was applied, provided that the metallic material (W3) replaced the non-metallic material (W1). Preferably, in the hydrocarbon conversion which can be carried out in the context of the present invention, at least one hydrogen halide (HX) is present in addition to the acidic ionic liquid. However, the presence of a hydrogen halide in addition to the acidic ionic liquid is not mandatory in the context of the process according to the invention. In principle, all conceivable hydrogen halides can be used as hydrogen halide (HX), for example hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr) or hydrogen iodide (HI). Optionally, 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. Preferably, 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. Preferably, the hydrogen halide (HX) is hydrogen chloride (HCl) or hydrogen bromide (HBr). Most preferably, the hydrogen halide (HX) is hydrogen chloride (HCl). Preferably, the hydrogen halide (HX) is used as cocatalyst.

As already explained above, due to the hydrocarbon conversion in the presence of an acidic ionic liquid and optionally a hydrogen halide (HX), the chemical structure of at least one of the hydrocarbons used changes. The hydrocarbons obtained in the hydrocarbon conversion ("product of hydrocarbon conversion" or "hydrocarbon product") thus differ in terms of the (chemical) composition and / or amount of hydrocarbons contained therein from the corresponding hydrocarbon composition, prior to the hydrocarbon conversion, in particular prior to isomerization , is present. Since in such hydrocarbon conversions, especially in Isomerisierungsprozessen, the hydrocarbon conversion to be carried out often does not run to 100% (ie completely), in the product usually also the hydrocarbon with which the hydrocarbon conversion was carried out (in smaller amounts than before the hydrocarbon conversion) still contain. If, for example, MCP is to be isomerized to cyclohexane, the isomerization product often contains a mixture of cyclohexane and (in less amount than before the hydrocarbon conversion) MCP. With the hydrocarbon product described above, the processing of the hydrocarbon conversion is carried out in the context of the present invention.

Preferably, the product of the hydrocarbon conversion as a hydrocarbon cyclohexane or a cyclohexane-containing mixture. More preferably, the hydrocarbon conversion product contains cyclohexane as a hydrocarbon or a mixture of cyclohexane with at least one other Hydrocarbon selected from methylcyclopentane (MCP), n-hexane, iso-hexanes, n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes.

The product of the hydrocarbon conversion as a hydrocarbon particularly preferably contains a mixture of cyclohexane, MCP and at least one further hydrocarbon. Preferably, the further hydrocarbon is selected from n-hexane, iso-hexanes, n-heptane, iso-heptanes, methylcyclohexane or dimethylcyclopentanes. If the hydrocarbon conversion is carried out as isomerization, the proportion of branched hydrocarbons in the product of the hydrocarbon conversion is preferably less than 5 wt .-% (based on the sum of all hydrocarbons). In the context of the present invention, methylcyclopentane (MCP) is particularly preferably isomerized to cyclohexane. Furthermore, it is preferred that after the hydrocarbon conversion during the treatment of cyclohexane is isolated. The isolation of the cyclohexane is carried out by methods known in the art from the discharge of the hydrocarbon conversion.

In a preferred embodiment of the present invention, the product of the hydrocarbon conversion i) as hydrocarbon contains 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 which has as cation at least partially alkylated ammonium ion and as the anion a chloroaluminum having the composition Al _n Cl _{(3n +} i ₎ with 1 <n <2.5.

In the context of the present invention, if the hydrocarbon conversion is an isomerization, the isomerization is preferably carried out as follows. Carrying out an isomerization of hydrocarbons in the presence of an ionic liquid as catalyst and optionally a hydrogen halide as cocatalyst is known to the person skilled in the art. Preferably, 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 next to it 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. Optionally, there may also be a solid phase containing components in solid form from which the ionic liquid is formed, such as AICI ₃ . In this case, 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.

The present invention will be illustrated below by way of examples. The chemical resistance of various materials to a mixture consisting of the acidic ionic liquid trimethylammonium heptachlorodialuminate and cyclohexane in a volume ratio of 5 is tested to verify their use in a process for carrying out a hydrocarbon conversion in the presence of an acidic ionic liquid. Here, once an oxidic materials and as an optional material tantalum and once a polymer is tested as possible coating materials for stainless steel.

example 1

Corrosion test of commercially available enamel E 91 15 (vitreous, oxidic material) and tantalum in an acidic ionic liquid ((CH ₃ ) ₃ NH Al _n Cl _{3n + 1} with n = 1,)

The corrosion behavior of specimens consisting of alloy-free steel coated with a 50 μm thick enamel layer and pure tantalum are examined in an anhydrous mixture of trimethylammonium heptachlorodialuminate in a 4 × 7 day continuous immersion test at 100 ° C. The mixture is constantly stirred, rendered inert with nitrogen and changed weekly. Two corrosion samples per material in the liquid, in the liquid-vapor phase boundary and in the vapor space are investigated. The medium is placed in the test vessel under careful exclusion of moisture under a nitrogen atmosphere, which was previously rinsed for 30 minutes with dried nitrogen (CaCl 2 drying tower). The following results were obtained:

Table 1: Corrosion resistance measurement of tantalum and enamel in TMA-AI ₂ CI ₇ at 100 ° C.

The specified technical limit values for corrosion resistance amount to 0.05 mm / year for the enamel coating without roughening and v1 = 0.02 mm / year for the tantalum without local corrosion and, as a result, enamelled steel in anhydrous trimethylammonium Heptachloroaluminat is corrosion resistant at 100 ° C. Tantalum is also corrosion resistant under the conditions mentioned and can thus serve for repair work on the intended devices. Example 2

Determination of the chemical resistance of FEP (tetrafluoroethylene-hexafluoropropylene) over a mixture of trimethylammonium heptachlorodialuminate and cyclohexane

The chemical resistance of the plastic materials to TMA-AL2CI7 is determined at 50 ° C.

The following plastic is being tested:

- Symalit FEP (tetrafluoroethylene-hexafluoropropylene) From sheet material corresponding tensile specimens (DI N EN ISO 527-2, type 1 BA) are milled out. The specimens thus produced are stored in the liquid phase of the medium TMA-AL ₂ CI ₇ / cyclohexane. Storage takes place at 50 ° C. in a glass vessel with reflux cooling and N ₂ overlay. The medium is not changed during the test. After 28, 56 and 1 12 days of storage, the dimensional, mass and hardness changes of the samples are determined and after 56 and 12 days tensile tests (ISO 527) to determine the strength characteristics. The evaluation for determining the chemical resistance is based on ISO 4433-2 or 4433-4. The results are summarized in the following tables.

Table 2: Determination of the chemical resistance of FEP to TMA-AI ₂ CI ₇ at 50 ° C

The tested thermoplastic FEP is classified as chemically resistant to the medium TMA-AL ₂ CI ₇ at 50 ° C in accordance with ISO 4433-2.

Claims

claims

1 . A process for carrying out a hydrocarbon conversion or treatment of a hydrocarbon conversion in the presence of an acidic ionic liquid using at least one

Device (V1), characterized in that the surfaces of the device (V1) coming into contact with the acidic ionic liquid are made wholly or at least partly from at least one non-metallic material (W1), the non-metallic material (W1) at least one material (W2) is applied, the non-metallic

Material (W1) is different.

2. The method according to claim 1, characterized in that the non-metallic material (W1) is an oxide material or a polymer and / or that the material (W2) is steel.

3. The method according to claim 2, characterized in that the oxidic material is glass and / or the polymer is a fluorine-containing polymer, preferably polytetrafluoroethylene (PTFE) or a perfluoroalkoxy polymer (PFA).

4. The method according to any one of claims 1 to 3, characterized in that the non-metallic material (W1) is glass and with the material (W2) forms an enamel.

5. The method according to any one of claims 1 to 3, characterized in that the non-metallic material (W1) is a polymer with which the device (V1) is coated or lined.

6. The method according to claim 5, characterized in that the non-metallic material (W1) is a polymer, with which the device (V1) is lined and the materials (W1) and (W2) are glued together, preferably by an adhesive on synthetic resin -Base.

7. The method according to any one of claims 1 to 6, characterized in that the device (V1) is a reactor, a stirred tank, a conduit, a

Phase separation unit or a separation apparatus is.

8. The method according to claim 7, characterized in that the phase separation unit is a phase separator or the separation apparatus is an evaporator, a rectification column, a flash device or a stripping

Device, preferably a flash device is. Method according to one of claims 1 to 8, characterized in that the surfaces of the device (V1), which come into contact with the acidic ionic liquid, at least 80%, preferably at least 95%, in particular 100%, of the non-metallic Material (W1) are made.

A method according to any one of claims 1 to 9, characterized in that the surfaces of the device (V1) which come into contact with the acidic ionic liquid at the points where they are not made of the non-metallic material (W1), from a metallic material (W3) containing tantalum are produced.

Process according to any one of Claims 1 to 10, characterized in that the hydrocarbon conversion is carried out in a reactor or stirred tank, the reactor or stirred tank being connected via a line to a phase separation unit and the phase separation unit in turn being connected by a line to a separation apparatus.

A method according to claim 1 1, characterized in that the individual devices or conduits are each configured as a device (V1) in which the surfaces which come into contact with the acidic ionic liquid are made entirely of at least one non-metallic material (W1) which is applied to at least one material (W2) other than the non-metallic material (W1).

A method according to claim 1 1 or 12, characterized in that the phase separation unit is connected via a return line for the acidic ionic liquid with the reactor or stirred tank, in which the hydrocarbon conversion is carried out.

A process according to any one of claims 1 to 13, characterized in that the hydrocarbon conversion is carried out in the presence of at least one hydrogen halide (HX), preferably hydrogen chloride (HCl).

A method according to any one of claims 1 to 14, characterized in that the acidic ionic liquid has the composition K1Al _n X _{(3n + 1)} , wherein K1 is a monovalent cation, X is halogen and 1 <n <2.5, preferably acidic ionic liquid as a cation at least partially alkylated ammonium ion or a heterocyclic cation and / or as anion a chloroalumination having the composition Al _n CI _{(3n + 1)} with 1 <n <2.5. A process according to any one of claims 1 to 15, characterized in that the hydrocarbon conversion is selected from alkylation, polymerization, dimerization, oligomerization, acylation, metathesis, polymerization or copolymerization, isomerization, carbonylation or combinations thereof.

A process according to claim 16, characterized in that the hydrocarbon conversion is an isomerization, preferably an isomerization of methylcyclopentane (MCP) to cyclohexane.

A process according to any one of claims 1 to 17, characterized in that the hydrocarbon conversion is carried out with a hydrocarbon mixture comprising methylcyclopentane (MCP) or a mixture of MCP and at least one further hydrocarbon selected from n-hexane, iso-hexanes, n-heptane , iso-heptanes, methylcyclohexane or dimethylcyclopentanes.

Method according to one of Claims 1 to 18, characterized

that following the hydrocarbon conversion in the context of

Reprocessing cyclohexane is isolated.