Regeneration method and regeneration system of composite ionic liquid catalyst

Abstract

The invention provides a regeneration method and a regeneration system of a composite ionic liquid catalyst, and the regeneration method comprises the following steps: carrying out selective hydrogenation treatment on an inactivated composite ionic liquid catalyst containing a transition metal element by using a selective hydrogenation catalyst containing a non-noble metal element to obtain hydrogenated tail oil; and separating the hydrogenated tail oil to obtain a regenerated composite ionic liquid catalyst, an intermediate selective hydrogenation catalyst and hydrogenated acid-soluble oil. The regenerated composite ionic liquid catalyst obtained by the method has high catalytic activity.

Description

Technical Field

[0001] This invention relates to the field of catalyst regeneration, and in particular to a method and system for regenerating a composite ionic liquid catalyst. Background Technology

[0002] Alkylated oil is a mixture of isoalkanes produced by the reaction of isobutane and butene under the action of a strong acid catalyst. It possesses advantages such as high octane number, low saturated vapor pressure, no sulfur, and almost no olefins or aromatics, making it an ideal blending component for automotive gasoline. With the continuous upgrading of fuel quality, the C4 alkylation process used to produce alkylated oil has become a key process for achieving gasoline quality upgrades.

[0003] Ionic liquid catalysts are catalysts composed of organic cations and inorganic or organic anions, with the anionic portion being the active component. In recent years, ionic liquid catalyst-catalyzed C4 alkylation technology has been vigorously developed as an alternative to traditional hydrofluoric acid and concentrated sulfuric acid methods. For example, US7285698 discloses a method for producing alkylated oil from isobutane and butene using a composite ionic liquid catalyst. This method feeds isobutane and butene into a reactor, where the reactants are contacted with a composite ionic liquid under alkylation conditions to generate alkylation products. The reactor effluent is separated, the ionic liquid phase is recycled back to the reactor, and the hydrocarbon phase is treated to recover the alkylates. However, it has been found that during the C4 alkylation reaction catalyzed by ionic liquid catalysts, the carbocation undergoes multiple alkylation, cracking, and oligomerization reactions, generating an olefin byproduct—acid-soluble oil (ASO)—with five- or six-membered rings resembling cyclopentadiene. Furthermore, as the reaction proceeds, the unsaturated C=C bonds in the ASO react with the active component [Al2Cl7] in the ionic liquid. - Anionic complexation leads to the deactivation of ionic liquid catalysts and their accumulation in ASO, even forming solids.

[0004] Patent CN104582844 discloses a method for regenerating ionic liquid catalysts, which utilizes fresh ionic liquid to treat metal-containing solids precipitated from deactivated ionic liquids to form regenerated ionic liquid catalysts. This method effectively regenerates the ionic liquid catalyst in the solids and reduces the amount of solids in the reaction system; however, it cannot fundamentally destroy the complexation between ASO and the ionic liquid, thus failing to truly restore the activity of the deactivated ionic liquid catalyst.

[0005] Composite ionic liquid catalysts are ionic liquid catalysts composed of anions formed by the co-coordination of two or more metal salts (such as AlCl3 with CuCl, ZnCl2, etc.) and organic cations. Although existing regeneration methods for composite ionic liquid catalysts can break the complexation between the acid-soluble oil and the anionic active component in the deactivated composite ionic liquid catalyst, during the regeneration process, the transition metal ions contained in the anionic active component of the composite ionic liquid catalyst are easily reduced to transition metal solids and precipitated, resulting in insufficient catalytic activity of the regenerated composite ionic liquid catalyst.

[0006] Therefore, it is necessary to provide a method for regenerating composite ionic liquid catalysts that can selectively hydrogenate unsaturated bonds in ASO without reducing the transition metal ions in the composite ionic liquid. Summary of the Invention

[0007] This invention provides a method for regenerating a composite ionic liquid catalyst. In this method, a selective hydrogenation catalyst containing non-precious metal elements is used to selectively hydrogenate a deactivated composite ionic liquid catalyst containing transition metal elements, which can restore the deactivated composite ionic catalyst containing transition metal elements to a high level of catalytic activity.

[0008] This invention provides a regeneration system for implementing the above-described regeneration method. The regeneration system has a simple structure and is suitable for widespread application.

[0009] A method for regenerating a composite ionic liquid catalyst, wherein a selective hydrogenation catalyst is used to selectively hydrogenate the deactivated composite ionic liquid catalyst to obtain hydrogenated tail oil;

[0010] The hydrotreated tail oil is separated to obtain a regenerated composite ionic liquid catalyst, an intermediate selective hydrotreating catalyst, and a hydrogenated acid-soluble oil.

[0011] The active component in the selective hydrogenation catalyst includes non-precious metal elements;

[0012] The deactivated composite ionic liquid catalyst contains at least two metal elements, one of which is a transition metal element.

[0013] A method for regenerating a composite ionic liquid catalyst, wherein, prior to the selective hydrogenation treatment, the method further includes: mixing the selective hydrogenation catalyst with the deactivated composite ionic liquid catalyst and performing a homogenization treatment.

[0014] A method for regenerating a composite ionic liquid catalyst, wherein the homogenization process is carried out at a temperature of 10~250℃ for a time of 0.1~3600s.

[0015] The homogenization process uses a high-shear homogenizer or a high-pressure homogenizer.

[0016] A method for regenerating a composite ionic liquid catalyst, comprising: using the regenerated composite ionic liquid catalyst to catalyze a C4 alkylation reaction; and / or,

[0017] The intermediate selected hydrogenation catalyst participates in the homogenization process; and / or,

[0018] The hydrogenated acid-soluble oil is used in the homogenization process.

[0019] A method for regenerating a composite ionic liquid catalyst, wherein, in the homogenization process, the mass of the hydrogenated acid solvent accounts for 0.5 to 30% of the mass of the deactivated composite ionic liquid catalyst.

[0020] A method for regenerating an ionic liquid catalyst, wherein the ionic liquid in the regenerated ionic liquid catalyst comprises: ammonium cations and anions;

[0021] The anion includes a complex coordination anion of two or more metal salts; wherein at least one metal salt is an aluminum salt, and the other metal salts are selected from at least one of salts of Group IB elements, Group IIB elements, and other transition metal elements in the periodic table.

[0022] A method for regenerating a composite ionic liquid catalyst, wherein the selective hydrogenation catalyst comprises a support and an active component located in at least a portion of the surface and / or at least a portion of the pores of the support;

[0023] The active component includes at least one of Ni, Co, Mo, and Mn; and / or,

[0024] A method for regenerating a composite ionic liquid catalyst, wherein the selective hydrogenation catalyst is at least one of a non-precious metal sulfide, a non-precious metal carbide, or a non-precious metal oxide.

[0025] A method for regenerating a composite ionic liquid catalyst, wherein the selective hydrogenation treatment is carried out at a temperature of 60~250℃, a time of 0.001~8h, and a hydrogen pressure of 0.2~8MPa.

[0026] A regeneration system for implementing the above-described regeneration method for a composite ionic liquid catalyst includes: a selective hydrogenation unit and a separation unit;

[0027] The selective hydrogenation unit has a feed inlet and a hydrogenation tail oil outlet, and the separation unit has an intermediate selective hydrogenation catalyst outlet, a hydrogenated acid solvent oil outlet, and a regenerated composite ionic liquid catalyst outlet.

[0028] The hydrotreated tail oil outlet is connected to the inlet of the separation unit.

[0029] The regeneration method of the composite ionic liquid catalyst of the present invention includes: selectively hydrogenating the deactivated composite ionic liquid catalyst with a selective hydrogenation catalyst containing non-precious metal elements. This not only breaks the complexation between the C=C bond in the acid-soluble oil and the anionic active component, but also makes it less likely for transition metal elements in the deactivated composite ionic liquid catalyst to precipitate. Thus, the deactivated composite ionic liquid catalyst can be regenerated efficiently, and a regenerated composite ionic liquid catalyst with excellent catalytic activity can be obtained. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a regeneration system for a composite ionic liquid catalyst. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the absence of conflict, the following embodiments and features can be combined with each other.

[0033] While existing regeneration methods for composite ionic liquid catalysts can break the complexation between the acid-soluble oil and the anionic active component in deactivated composite ionic liquid catalysts, the transition metal ions in the anionic active component are easily reduced to solid transition metals during the regeneration process, resulting in insufficient catalytic activity of the regenerated composite ionic liquid catalyst. The inventors discovered that using a selective hydrogenation catalyst containing non-precious metals can not only break the complexation between the acid-soluble oil and the active component of the composite ionic liquid catalyst, but also retain more transition metal ions in the composite ionic liquid catalyst, achieving highly efficient regeneration.

[0034] A method for regenerating a composite ionic liquid catalyst, comprising:

[0035] Selective hydrogenation of a deactivated composite ionic liquid catalyst was performed using a selective hydrogenation catalyst to obtain hydrogenated tail oil.

[0036] The hydrotreated tail oil was separated to obtain a regenerated composite ionic liquid catalyst, an intermediate selective hydrotreating catalyst, and a hydrogenated acid-soluble oil.

[0037] The active components in selective hydrogenation catalysts include non-precious metal elements.

[0038] The composite ionic liquid in the deactivated composite ionic liquid catalyst includes at least two metal elements, one of which is a transition metal element.

[0039] Specifically, selective hydrotreating refers to the selective hydrotreating of feedstocks, including hydrogen and deactivated composite ionic liquid catalysts, using selective hydrotreating catalysts containing non-precious metal elements. Under the action of the selective hydrotreating catalyst, hydrogen will hydrogenate and saturate the C=C bonds in the acid-soluble oil in the deactivated composite ionic liquid, and the C=C bonds will be converted into C=C bonds, resulting in hydrotreated tail oil.

[0040] The hydrotreated tail oil is then separated to obtain a regenerated composite ionic liquid catalyst, an intermediate selective hydrotreating catalyst, and a hydrogenated acid solvent.

[0041] The hydrotreated tail oil is then separated to separate the hydrogenated acid solvent, the regenerated composite ionic liquid catalyst, and the intermediate selective hydrogenation catalyst, thereby obtaining the hydrogenated acid solvent, the regenerated composite ionic liquid catalyst, and the intermediate selective hydrogenation catalyst.

[0042] For composite ionic liquid catalysts containing transition metal ions, such as those containing Cu + For composite ionic liquid catalysts, Cu + The standard reduction potential of Al is +0.52 V. 3+ The standard reduction potential is -1.676 V, indicating that the transition metal ions (such as Cu) in the composite ionic liquid catalyst... + ) far more than Al 3+Ions are more easily reduced during selective hydrogenation, forming reduced elemental substances. This invention uses a selective hydrogenation catalyst containing non-precious metal elements to selectively hydrogenate deactivated composite ionic liquid catalysts. Because the selective hydrogenation catalyst contains non-precious metal elements, which possess moderate hydrogen activation capacity and high reduction temperatures, it does not reduce transition metal ions in the composite ionic liquid catalyst to elemental substances or co-reduce them with the metal components in the selective hydrogenation catalyst to form alloys. This preserves the transition metal ions in the composite ionic liquid catalyst, thereby restoring high catalytic activity to the deactivated composite ionic liquid catalyst. Therefore, the regeneration method of the composite ionic liquid catalyst in this invention not only breaks the complexation between acid-soluble oil and anions but also prevents the precipitation of transition metal ions from the composite ionic liquid catalyst.

[0043] In some embodiments of the present invention, prior to selective hydrogenation, the process further includes mixing the selective hydrogenation catalyst with a deactivated ionic liquid catalyst and performing homogenization.

[0044] The acid-soluble oil in the deactivated composite ionic liquid catalyst has high viscosity and poor dispersibility, leading to localized aggregation within the catalyst. When selectively hydrogenating the deactivated composite ionic liquid catalyst directly with hydrogen, the gas-liquid mass transfer resistance is high. Mixing the selective hydrogenation catalyst with the deactivated ionic liquid catalyst and homogenizing it can improve the dispersion and uniformity of the deactivated composite ionic liquid catalyst and the solid complex (the complexation product of the C=C bond in the acid-soluble oil and the active component in the composite ionic liquid catalyst) in the acid-soluble oil, forming a stable acid-soluble oil suspension. This facilitates uniform mixing and rapid diffusion of hydrogen and the acid-soluble oil suspension during subsequent selective hydrogenation.

[0045] In some embodiments of the present invention, when the homogenization process is carried out at a temperature of 10~250°C and a time of 0.1~3600s, the selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst can be mixed more uniformly while saving energy, thereby improving the efficiency of subsequent selective hydrogenation processes.

[0046] In some embodiments, a high-shear homogenizing pump or a high-pressure homogenizer can be used to homogenize the selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst. The high-shear homogenizing pump, with its strong mechanical shear and impact, can rapidly disperse the high-viscosity acid-soluble oil, allowing for more rapid mixing of the selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst; the high-pressure homogenizer, relying on high-pressure cavitation, can achieve a more uniform mixing of the selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst.

[0047] In some embodiments of the present invention, the method for regenerating the composite ionic liquid catalyst further includes using the regenerated composite ionic liquid catalyst to catalyze the C4 alkylation reaction. The composite ionic liquid catalyst can be reused, thereby reducing the cost of the C4 alkylation reaction.

[0048] Since the obtained intermediate selective hydrogenation catalyst still has a certain catalytic activity, in some embodiments of the present invention, the intermediate selective hydrogenation catalyst can be involved in homogenization treatment to reduce the consumption of selective hydrogenation catalyst during the regeneration of composite ionic liquid catalyst, thereby reducing the regeneration cost of composite ionic liquid catalyst.

[0049] Typically, hydrogenated acid solvents have low viscosity and good compatibility with deactivated composite ionic liquid catalysts. In some embodiments of the present invention, hydrogenated acid solvents can be involved in homogenization treatment, resulting in a lower viscosity of the suspension obtained from homogenization treatment, which improves the effect of homogenization treatment and promotes subsequent selective hydrogenation treatment.

[0050] In some embodiments of the present invention, when the mass of the hydrogenated acid solvent accounts for 0.5 to 30% of the mass of the deactivated ionic liquid catalyst, the viscosity of the suspension can be effectively reduced, allowing the selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst to be mixed uniformly, thereby improving the selective hydrogenation efficiency in the selective hydrogenation process.

[0051] The regeneration method of the composite ionic liquid catalyst of the present invention is applicable to all mixtures containing deactivated composite ionic liquid catalysts in the art. In some embodiments, the ionic liquid in the deactivated composite ionic liquid catalyst includes ammonium cations and anions.

[0052] Anions include complex coordination anions of two or more metal salts; wherein at least one metal salt is an aluminum salt, and the other metal salts are selected from at least one of salts of Group IB elements, Group IIB elements, and other transition metal elements in the periodic table.

[0053] In some embodiments, the ammonium cation can be , , At least one of them; wherein, It is methylammonium. It is ethyl. It is n-butyl.

[0054] In some implementations, the anion can be , , At least one of them.

[0055] When the regeneration method of the composite ionic liquid catalyst of the present invention is used for a deactivated composite ionic liquid catalyst including the above-mentioned components, it can not only regenerate the deactivated composite ionic liquid catalyst, but also retain the transition metal ions in the composite ionic liquid catalyst.

[0056] The selective hydrogenation catalyst can be either supported or unsupported. In some embodiments, when the selective hydrogenation catalyst is a supported catalyst, it includes a support and an active component. The active component can be supported on at least a portion of the surface of the support, or on at least a portion of the pores of the support, or simultaneously on at least a portion of the surface and at least a portion of the pores of the support. The active component includes at least one of Ni, Co, Mo, and Mn.

[0057] When using supported catalysts for selective hydrogenation of deactivated composite ionic liquid catalysts, the catalyst is less likely to be lost from the reactor, and the supported catalysts have a longer service life, reducing the regeneration cost of composite ionic liquid catalysts.

[0058] The present invention does not impose any particular limitation on the support for the selective hydrogenation catalyst. The support can be a redox inert support commonly used in the art. For example, the support can be at least one of Al2O3, SiO2, molecular sieve or carbon material.

[0059] In other embodiments, the selective hydrogenation catalyst may also be an unsupported catalyst. For example, the unsupported catalyst may be at least one of non-precious metal sulfides, non-precious metal carbides, and non-precious metal oxides.

[0060] Unsupported catalysts can mix better with feedstocks in selective hydrogenation and are less affected by mass transfer and diffusion, thus exhibiting higher catalytic activity.

[0061] The present invention does not specifically limit the non-precious metal sulfides. For example, the non-precious metal sulfides can be at least one of NiS, MoS2, and NiMoS.

[0062] The present invention does not specifically limit the non-precious metal carbide. For example, the non-precious metal carbide can be at least one of Ni3C, MoC, and NiMoC.

[0063] The present invention does not specifically limit the non-precious metal oxide. For example, the non-precious metal oxide can be at least one of NiO, MoO2, and NiMoO4.

[0064] In some embodiments of the present invention, when the selective hydrotreating temperature is 60~250℃, the time is 0.001~8h, and the hydrogen pressure is 0.2~8MPa, the efficiency of selective hydrotreating can be improved while saving energy, thereby separating the regenerated ionic liquid catalyst from the hydrotreating tail oil.

[0065] like Figure 1 As shown, the present invention also provides a regeneration system for an ionic liquid catalyst, comprising: a selective hydrogenation unit and a separation unit;

[0066] The selective hydrogenation unit has a feedstock inlet and a hydrogenation tail oil outlet, while the separation unit has an intermediate selective hydrogenation catalyst outlet, a hydrogenated acid solvent oil outlet, and a regenerated ionic liquid catalyst outlet.

[0067] The hydrotreated tail oil outlet is connected to the inlet of the separation unit.

[0068] Specifically, the selective hydrogenation catalyst and the deactivated ionic liquid enter the selective hydrogenation unit through the inlet of the selective hydrogenation unit, and selective hydrogenation treatment is carried out in the selective hydrogenation unit to obtain hydrogenated tail oil including regenerated ionic liquid catalyst, hydrogenated acid solvent oil and intermediate selective hydrogenation catalyst.

[0069] The hydrotreated tail oil is output from the outlet of the selective hydrotreating unit and enters the separation unit through the inlet. In the separation unit, the regenerated ionic liquid catalyst, hydrogenated acid solvent oil, and intermediate selective hydrotreating catalyst in the hydrotreated tail oil are separated to obtain the regenerated ionic liquid catalyst, hydrogenated acid solvent oil, and intermediate selective hydrotreating catalyst. The regenerated ionic liquid catalyst is output from the outlet of the separation unit, the intermediate selective hydrotreating catalyst is output from the outlet of the separation unit, and the hydrogenated acid solvent oil is output from the outlet of the hydrogenated acid solvent oil fine separation unit.

[0070] The regeneration system of the present invention connects a selective hydrogenation unit and a separation unit in series. When regenerating a deactivated composite ionic liquid catalyst, the deactivated composite ionic liquid catalyst can be regenerated, and the transition metal ions in the composite ionic liquid catalyst are not easily reduced and precipitated.

[0071] The present invention does not particularly limit the selective hydrogenation unit. In some embodiments, the selective hydrogenation unit can be a hydrogenation reactor. Exemplarily, the hydrogenation reactor can be any of a reaction vessel, a fixed-bed reactor, or a slurry-bed reactor.

[0072] In some embodiments, the regeneration system further includes a homogenization unit; the homogenization unit has an inlet for a deactivated composite ionic liquid catalyst and an inlet for a selective hydrogenation catalyst; the outlet of the homogenization unit is connected to the feed inlet of the selective hydrogenation catalyst; the outlet of the selective hydrogenation catalyst is connected to the inlet of the homogenization unit, and the inlet of the hydrogenated acid solvent is connected to the inlet of the homogenization unit.

[0073] The present invention does not impose any particular limitation on the homogenization unit. In some embodiments, the homogenization unit may be a high-shear homogenizing pump or a high-pressure homogenizer.

[0074] In some embodiments, when a fixed-bed reactor is used for selective hydrogenation, the homogenization step can be omitted, and the deactivated composite ionic liquid catalyst can be directly introduced into the hydrogenation reactor. The deactivated composite ionic liquid catalyst and hydrogen are in contact in the selective hydrogenation catalyst bed and selective hydrogenation is performed. After the selective hydrogenation is completed, the selective hydrogenation catalyst is retained in the fixed-bed reactor, and only the regenerated composite ionic liquid catalyst and hydrogenated acid solvent are separated from the hydrogenation tail oil.

[0075] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0076] The composite ionic liquid catalyst is composed of triethylamine hydrochloride, aluminum(III) chloride and cuprous(I) chloride, with the chemical formula Et3NHCl-1.6AlCl3-0.2CuCl.

[0077] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0078] Example 1

[0079] The regeneration method of the composite ionic liquid catalyst in this embodiment is as follows:

[0080] (1) Preparation of deactivated composite ionic liquid catalysts

[0081] (a) Isobutane and butene in a molar ratio of 1:1 are continuously fed into the reactor at a rate of 2 kg / h over 5.5 days;

[0082] (b) 30 kg of composite ionic liquid catalyst is fed into the reactor and the composite ionic liquid is kept in circulation in the reaction system.

[0083] (c) During the reaction, isobutane is fractionated in the fractionation tower and recycled back to the reactor. The molar ratio of isobutane to butene is controlled at 6:1 to obtain a mixture.

[0084] (d) During the reaction, hydrocarbons are separated at the top of the settler and recycled back into the reactor to be mixed with the mixture obtained in step (c) to achieve an I / O ratio of 100:1, thus obtaining a hydrocarbon mixture (wherein, the I / O ratio refers to the molar ratio of isobutane to butene in the reaction system).

[0085] (e) During the reaction, the composite ionic liquid catalyst is separated at the bottom of the settler. The separated composite ionic liquid catalyst is mixed with the hydrocarbon mixture obtained in step (d) in equal volume and fed into a reactor equipped with a static mixer for C4 alkylation reaction. The reactor temperature is maintained at 10 °C. The outlet of the reactor is connected to the middle of the settler. The composite ionic liquid catalyst is collected at the bottom of the settler and recycled to the reactor. The hydrocarbon phase is collected at the top of the settler and fed to the reactor and the fractionation tower respectively.

[0086] (f) The composite ionic liquid catalyst collected at the bottom of the settler is the deactivated composite ionic liquid catalyst.

[0087] (2) Preparation of regenerated composite ionic liquid catalyst

[0088] (a) The selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst were homogenized in a homogenization unit using a high-shear homogenizing pump to obtain a suspension; wherein the selective hydrogenation catalyst was a supported catalyst, the support was Al2O3, and the active component supported on the support was elemental Ni, wherein the mass percentage of Ni element in the support was 5%;

[0089] (b) At 120 °C and 3 MPa, the suspension was selectively hydrogenated with hydrogen in a reactor to obtain a hydrogenated tail oil comprising a regenerated composite ionic liquid catalyst, a selective hydrogenation catalyst and hydrogenated acid solvent oil.

[0090] (c) After selective hydrogenation, the regenerated composite ionic liquid catalyst, selective hydrogenation catalyst and hydrogenated acid solvent are separated from the hydrogenation tail oil. The regenerated composite ionic liquid catalyst is used to catalyze the C4 alkylation reaction, and the selective hydrogenation catalyst is recycled to the homogenization unit and reused for the hydrogenation regeneration of the deactivated composite ionic liquid catalyst.

[0091] Example 2

[0092] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 1, except that:

[0093] (2) Hydrogenation regeneration of composite ionic liquid catalysts

[0094] (a) The selective hydrogenation catalyst, the deactivated composite ionic liquid catalyst and the hydrogenated acid oil obtained in Example 1 were homogenized in a homogenization unit using a high-shear homogenizing pump, wherein the mass of the hydrogenated acid oil was 10% of the deactivated composite ionic liquid, and a suspension was obtained.

[0095] (c) After the hydrogenation reaction is completed, the separated hydrogenated acid oil is recycled to the homogenization unit, wherein the mass of the recycled hydrogenated acid oil is 10% of the deactivated composite ionic liquid catalyst.

[0096] Example 3

[0097] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0098] The selective hydrogenation catalyst is a supported catalyst with SiO2 as the support and Ni as the active component supported on the support, wherein the mass percentage of Ni in the support is 5%.

[0099] Example 4

[0100] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0101] The selective hydrogenation catalyst is a supported catalyst, with ZSM-5 molecular sieve as the support. The active component supported on the support is Ni element, and the mass percentage of Ni element in the support is 5%.

[0102] Example 5

[0103] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0104] The selective hydrogenation catalyst is a supported catalyst with activated carbon (AC) as the support. The active component supported on the support is Ni element, and the mass percentage of Ni element in the support is 5%.

[0105] Example 6

[0106] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0107] The selective hydrogenation catalyst is a supported catalyst with Al2O3 as the support. The active component supported on the support is Co, and the mass percentage of Co in the support is 5%.

[0108] Example 7

[0109] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0110] The selective hydrogenation catalyst is a supported catalyst with Al2O3 as the support. The active component supported on the support is Mo, and the mass percentage of Mo in the support is 5%.

[0111] Example 8

[0112] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0113] The selective hydrogenation catalyst is a supported catalyst with Al2O3 as the support. The active component supported on the support is Mn element, and the mass percentage of Mn element in the support is 5%.

[0114] Example 9

[0115] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0116] The selective hydrogenation catalyst is a supported catalyst with Al2O3 as the support. The active components supported on the support are Ni and Mo elements. Ni and Mo elements exist in the selective hydrogenation catalyst in the form of NiMo alloy. The mass percentage of Ni element in the support is 2.5%, and the mass percentage of Mo element in the support is 2.5%.

[0117] Example 10

[0118] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0119] The selective hydrogenation catalyst is nickel sulfide NiS.

[0120] Example 11

[0121] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0122] The selective hydrogenation catalyst is molybdenum sulfide MoS2.

[0123] Example 12

[0124] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0125] The selective hydrogenation catalyst is a nickel-molybdenum bimetallic sulfide NiMoS, in which Ni and Mo elements exist in the form of a NiMo alloy.

[0126] Example 13

[0127] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0128] The selective hydrogenation catalyst is nickel carbide Ni3C.

[0129] Example 14

[0130] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0131] The selective hydrogenation catalyst is molybdenum carbide (MoC).

[0132] Example 15

[0133] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0134] The selective hydrogenation catalyst is a nickel-molybdenum bimetallic carbide NiMoC, in which Ni and Mo elements exist in the form of a NiMo alloy.

[0135] Example 16

[0136] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0137] The selective hydrogenation catalyst is nickel oxide (NiO).

[0138] Example 17

[0139] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0140] The selective hydrogenation catalyst is molybdenum oxide (MoO2).

[0141] Example 18

[0142] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0143] The selective hydrogenation catalyst is a nickel-molybdenum bimetallic oxide, NiMoO4, in which Ni and Mo elements exist in the form of a NiMo alloy.

[0144] Example 19

[0145] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0146] Instead of homogenizing the selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst, the deactivated composite ionic liquid catalyst is directly subjected to selective hydrogenation treatment.

[0147] Example 20

[0148] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0149] The selective hydrogenation catalyst and the deactivated composite ionic liquid catalyst were homogenized in a homogenization unit using a high-pressure homogenizer to obtain a suspension.

[0150] Example 21

[0151] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0152] A fixed bed is used as the hydrogenation reactor. The selective hydrogenation catalyst is directly packed in the fixed bed without the need for homogenization with the deactivated composite ionic liquid catalyst. After the deactivated composite ionic liquid catalyst is introduced into the fixed bed, it contacts hydrogen in the selective hydrogenation catalyst bed and undergoes selective hydrogenation. The selective hydrogenation catalyst does not flow out of the hydrogenation reactor with the regenerated composite ionic liquid catalyst; it only separates the regenerated composite ionic liquid catalyst from the hydrogenated acid solvent.

[0153] Example 22

[0154] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0155] A slurry bed was used as the hydrogenation reactor.

[0156] Example 23

[0157] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0158] The selective hydrogenation treatment temperature is 60 °C.

[0159] Example 24

[0160] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0161] The selective hydrogenation treatment temperature is 250 °C.

[0162] Example 25

[0163] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0164] In selective hydrogenation, the hydrogen pressure is 0.2 MPa.

[0165] Example 26

[0166] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0167] In selective hydrogenation, the hydrogen pressure is 8.0 MPa.

[0168] Example 27

[0169] The regeneration method of the composite ionic liquid catalyst in this embodiment is basically the same as that in Example 2, except that:

[0170] The mass of hydrogenated acid solvent recycled to the homogenization unit is 30% of the deactivated composite ionic liquid catalyst.

[0171] Comparative Example 1

[0172] The regeneration method of the comparative example composite ionic liquid catalyst is basically the same as that in Example 2, except that:

[0173] The selective hydrogenation catalyst is a supported catalyst with Al2O3 as the support. The active component supported on the support is Pt element, and the mass percentage of Pt element in the support is 5%.

[0174] Comparative Example 2

[0175] The comparative example of the composite ionic liquid catalyst is a deactivated composite ionic liquid catalyst.

[0176] Performance testing

[0177] (1) The catalytic activity of the regenerated composite ionic liquid catalysts in the examples and comparative examples was tested using the following methods:

[0178] 10 mL of regenerated composite ionic liquid catalyst and dry dichloromethane were added to a three-necked flask, with a mass ratio of regenerated composite ionic liquid catalyst to dichloromethane of 1:1. Accurately weighed nitrobenzene was added in batches to the mixture of composite ionic liquid catalyst and dichloromethane under continuous stirring. Using nitrobenzene as an indicator, in-situ infrared titration was performed, and the changes in the infrared peaks of the mixture were monitored in real time. The titration was stopped when the infrared spectral signal of unreacted nitrobenzene indicator in the mixture was still detectable, while the infrared peaks of other reactants or products remained stable and showed no significant changes. The activity index (AI) of the regenerated composite ionic liquid catalyst was calculated according to the following formula:

[0179] AI = 1000m1 / (m2·M)

[0180] Wherein, AI is the activity index of the composite ionic liquid catalyst (mol / kg); m1 is the mass of nitrobenzene (g); m2 is the mass of the composite ionic liquid catalyst (g); and M is the molar mass of nitrobenzene (g / mol). The test results are shown in Table 1.

[0181] (2) The alkylation performance of the regenerated composite ionic liquid catalysts in the examples and comparative examples was tested using the following methods:

[0182] 100 mL of regenerated composite ionic liquid catalyst was added to a 500 mL laboratory-scale autoclave. Isobutane and butene in a molar ratio of 1:1 were fed into the autoclave at a rate of 700 mL / h for alkylation reaction. The reaction temperature and stirring speed were maintained at 15 °C and 1300 r / min, respectively. When the autoclave was completely filled with liquid, the reaction was stopped, and the reaction product was taken out. The hydrocarbon phase composition of the product was analyzed by gas chromatography. The selectivity of C8 and the octane number (RON) of the alkylated oil were calculated according to the mass fractions of C5~C7, C8 (i.e., octane, including trimethylpentane and dimethylhexane) and C9+, respectively. The test results are shown in Table 1.

[0183] The selectivity of C8 and RON were detected and calculated by gas chromatography.

[0184] C8 selectivity is the percentage of the mass of the C8 component in the total mass of the alkylate; RON is the sum of the products of the octane number of each component in the alkylate and its corresponding volume fraction.

[0185] Table 1

[0186]

[0187] The following conclusions can be drawn from the analysis of Table 1:

[0188] 1) As can be seen from Examples 1, 2, 27 and Comparative Example 2, the method of the present invention can effectively regenerate the deactivated composite ionic liquid catalyst by hydrogenation under different hydrogenated acid oil circulation rates; when the hydrogenated acid oil circulation rate is 10 wt%, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the obtained alkylated oil are the highest.

[0189] 2) As demonstrated in Examples 2-19 and Comparative Example 1, hydrogenation of deactivated composite ionic liquid catalysts using non-precious metal selective hydrogenation catalysts can effectively regenerate them. Compared to precious metal selective hydrogenation catalysts, non-precious metal selective hydrogenation catalysts can better restore the activity of composite ionic liquid catalysts, resulting in a higher activity index and a greater proportion of C8 components in the regenerated product. This is because, on the one hand, non-precious metal selective hydrogenation catalysts possess moderate hydrogen activation capacity and a high reduction temperature, enabling selective hydrogenation saturation of unsaturated C=C bonds in acid-soluble oils, thereby disrupting the complexation between the composite ionic liquid catalyst and the acid-soluble oil. On the other hand, non-precious metal selective hydrogenation catalysts do not cause co-reduction of transition metal ions in the composite ionic liquid catalyst, thus preventing the loss of transition metal ions from the catalyst.

[0190] 3) As can be seen from Examples 2-5 and Comparative Example 1, hydrogenation of deactivated composite ionic liquid catalysts using supported non-precious metal catalysts can effectively regenerate composite ionic liquid catalysts; when the catalyst support is Al2O3, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the obtained alkylated oil are the highest.

[0191] 4) As can be seen from Examples 2, 6-9 and Comparative Example 1, hydrogenation of deactivated composite ionic liquid catalysts using supported non-precious metal catalysts can effectively regenerate composite ionic liquid catalysts; when the active metal of the catalyst is the non-precious metal alloy NiMo, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0192] 5) As can be seen from Examples 10-12 and Comparative Example 2, hydrogenation of deactivated composite ionic liquid catalysts using non-precious metal sulfide catalysts can effectively regenerate composite ionic liquid catalysts; when the catalyst is a nickel-molybdenum bimetallic sulfide, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0193] 6) As can be seen from Examples 13-15 and Comparative Example 2, hydrogenation of deactivated composite ionic liquid catalysts using non-precious metal carbide catalysts can effectively regenerate composite ionic liquid catalysts; when the catalyst is a nickel-molybdenum bimetallic carbide, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0194] 7) As can be seen from Examples 16-18 and Comparative Example 2, hydrogenation of deactivated composite ionic liquid catalysts using non-precious metal oxide catalysts can effectively regenerate composite ionic liquid catalysts; when the catalyst is a nickel-molybdenum bimetallic oxide, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0195] 8) As can be seen from Examples 2, 20 and Comparative Example 2, both high-shear homogenizing pumps and high-pressure homogenizers can effectively mix selective hydrogenation catalysts and deactivated composite ionic liquid catalysts, thereby improving the hydrogenation regeneration effect. When a high-shear homogenizing pump is used, the raw material can be transported and mixed simultaneously, and the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0196] 9) As can be seen from Examples 2, 21, 22 and Comparative Example 2, hydrogenation of deactivated composite ionic liquid catalysts using a reaction vessel, fixed bed or slurry bed reactor can effectively regenerate composite ionic liquid catalysts; when the reactor is a slurry bed reactor, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0197] 10) As can be seen from Examples 2, 23, 24 and Comparative Example 2, hydrogenation of deactivated composite ionic liquid catalysts at different reaction temperatures can effectively regenerate composite ionic liquid catalysts; when the reaction temperature is 120°C, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0198] 11) As can be seen from Examples 2, 25, 26 and Comparative Example 2, hydrogenation of deactivated composite ionic liquid catalysts under different hydrogen pressures can effectively regenerate composite ionic liquid catalysts; when the hydrogen pressure is 6 MPa, the activity index of the regenerated composite ionic liquid catalyst and the octane number of the alkylated oil are the highest.

[0199] It can be seen that, compared with the comparative example, the regenerated composite ionic liquid catalyst in the examples has higher catalytic activity. When the regenerated composite ionic liquid catalyst in the examples is used to catalyze the C4 alkylation reaction, the C8 selectivity and the octane number (RON) of the alkylated oil in the product are higher than those in the comparative example. This is because the present invention uses a selective hydrogenation catalyst with a non-precious metal active component in the process of regenerating the composite ionic liquid catalyst. This selective hydrogenation catalyst can selectively hydrogenate the acid-soluble oil in the deactivated composite ionic liquid catalyst without reducing and precipitating the transition metal ions in the composite ionic liquid catalyst, thereby restoring the deactivated composite ionic liquid catalyst to a higher catalytic activity.

[0200] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for regenerating a composite ionic liquid catalyst, characterized by, The deactivated composite ionic liquid catalyst is selectively hydrogenated by using a selective hydrogenation catalyst to obtain hydrogenation tail oil; The hydrogenation tail oil is separated to obtain a regenerated composite ionic liquid catalyst, an intermediate selective hydrogenation catalyst and hydrogenated acid soluble oil; The active component in the selective hydrogenation catalyst comprises a non-noble metal element. The composite ionic liquid in the deactivated composite ionic liquid catalyst comprises at least two metal elements, one of which is a transition metal element.

2. The regeneration method according to claim 1, characterized by, Before the selective hydrogenation treatment, the selective hydrogenation catalyst is mixed with the deactivated composite ionic liquid catalyst for homogenization treatment.

3. The regeneration method according to claim 2, characterized by, In the homogenization treatment, the temperature is 10-250℃ and the time is 0.1-3600s.

4. The regeneration method according to any one of claims 2-3, characterized in that, The regenerated composite ionic liquid catalyst is used for catalyzing carbon four alkylation reaction; and / or, The intermediate selective hydrogenation catalyst participates in the homogenization treatment; and / or, The hydrogenated acid soluble oil participates in the homogenization treatment.

5. The regeneration method according to claim 4, characterized by, In the homogenization treatment, the mass of the hydrogenated acid soluble oil accounts for 0.5-30% of the mass of the deactivated composite ionic liquid catalyst.

6. The regeneration method according to any one of claims 1 to 5, characterized in that, The composite ionic liquid in the deactivated composite ionic liquid catalyst comprises an ammonium cation and an anion. The anion comprises a composite coordination anion of two or more metal salts, at least one of which is an aluminum salt, and the other metal salts are selected from at least one of the salts of the elements in group IB, the salts of the elements in group IIB and the salts of other transition metal elements in the periodic table.

7. The regeneration method according to any one of claims 1 to 6, characterized by, The selective hydrogenation catalyst comprises a carrier and an active component located on at least part of the surface and / or at least part of the pores of the carrier. The active component comprises at least one of Ni, Co, Mo and Mn.

8. The regeneration method according to any one of claims 1 to 6, characterized by, The selective hydrogenation catalyst comprises at least one of a non-noble metal sulfide, a non-noble metal carbide or a non-noble metal oxide.

9. The regeneration method according to any one of claims 1 to 8, characterized by, In the selective hydrogenation treatment, the temperature is 60-250℃, the time is 0.001-8h, and the hydrogen pressure is 0.2-8MPa.

10. A regeneration system for carrying out the method of regenerating the composite ionic liquid catalyst according to any one of claims 1 to 9, characterized in that It comprises: a selective hydrogenation unit and a separation unit; The selective hydrogenation unit has a raw material inlet and a hydrogenation tail oil outlet, and the separation unit has an intermediate selective hydrogenation catalyst outlet, a hydrogenated acid soluble oil outlet and a regenerated composite ionic liquid catalyst outlet; The hydrogenation tail oil outlet is in communication with the inlet of the separation unit; The active component in the selective hydrogenation catalyst comprises a non-noble metal element.

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