A method for alkylation

Abstract

The present invention discloses an alkylation method, which comprises contacting an alkylable substance, an alkylating agent and an alkylation catalyst under alkylation reaction conditions to carry out an alkylation reaction, wherein the alkylation catalyst contains a solid acid and a transition metal and the transition metal exists in an oxidized state. The method can reduce the processing steps of the alkylation catalyst, reduce the production cost of the catalyst and increase the single cycle life of the alkylation catalyst.

Description

Technical Field

[0001] The present invention relates to an alkylation method, and more particularly to an alkylation method catalyzed by a solid acid. Background Art

[0002] Isobutane and butene generate alkylated gasoline under the action of acid catalysis. Alkylated gasoline is an ideal gasoline blending component due to its good anti-knock performance, low sensitivity, low Reid vapor pressure, wide boiling point range, and no sulfur, nitrogen, olefins, aromatics and other components. At present, the industrial production technology of alkylation includes liquid acid alkylation technology and solid acid alkylation technology. The development of liquid acid alkylation technology has been restricted due to its corrosiveness, toxicity and waste acid discharge; while solid acid alkylation technology has the advantages of safety, easy separation, safety and environmental protection, and has made great progress in recent years. Since solid acid catalysts are easy to deactivate, it is necessary to load precious metals as regeneration active components to regenerate the deactivated catalysts in a hydrogen environment.

[0003] At present, the loading of the regenerated active components of solid acid catalysts mainly includes several steps such as impregnation, drying, calcination and reduction. The reduction step is carried out in a small fixed bed reactor, which has many shortcomings, such as (1) the catalyst single-time processing capacity of the small fixed bed reactor is low, so more batches of reduction processes are required for the catalyst produced in the same batch, which will require frequent heating and cooling operations, which is not only time-consuming but also energy-intensive; (2) the hydrogen used for reduction passes through the reactor bed at one time, which will lead to low hydrogen utilization and thus increase the cost. Therefore, it is particularly important to reduce the catalyst production cost by optimizing the loading step of the regenerated active components.

[0004] At present, most documents adopt the method of reducing first outside the reactor and then loading the agent, or loading the catalyst into the reactor for reduction, that is, reducing the regenerated active components from the oxidized state to the metallic state before carrying out the relevant reaction. For example, CN104557393B discloses an alkylation method for improving the stability and life of the catalyst, which is to contact the alkylable material with the alkylating agent in the presence of a solid acid catalyst and under alkylation reaction conditions to carry out an alkylation reaction, characterized in that the method also includes a step of pre-treating the solid acid catalyst with hydrogen before the alkylation reaction.

[0005] CN104588075B discloses a method for preparing an alkylation catalyst, which comprises the following steps: impregnating a solid acid with an impregnation solution containing noble metal ions of group VIII or noble metal ions of group VIII and transition metal ions, wherein the impregnation solution also contains Cl in an amount 3 to 4 times the weight of the noble metal ions of group VIII; the impregnation is performed at least twice according to the total load, and each impregnation needs to be dried and calcined before the next impregnation. The catalyst prepared by the method shows high stability in the isobutane / butene alkylation reaction. The method reduces the catalyst with hydrogen before the alkylation reaction, and the reduction conditions are 2.5MPa, 450℃ for 2h.

[0006] CN107382646A discloses a method for solid acid alkylation. The preparation method of the alkylation catalyst of the method comprises: impregnating a solid acid with an impregnation liquid containing a transition metal precursor, drying and calcining the impregnation liquid, wherein the mass ratio of the solid acid to the impregnation liquid is 1:(1-5), and the pH value of the impregnation liquid is adjusted to 3-13 before the impregnation; the method further comprises reducing the alkylation catalyst, and then contacting the alkylable substance and the alkylated substance with the alkylation catalyst for alkylation reaction.

[0007] CN107376983A discloses a method for preparing a solid acid alkylation catalyst and a solid acid alkylation catalyst prepared by the method, the method comprising impregnating a solid acid with an impregnation solution containing a transition metal precursor and then drying, wherein the mass ratio of the solid acid to the impregnation solution is 1:(1-5), and the pH value of the impregnation solution is adjusted to 3-13 before the impregnation. Summary of the invention

[0008] The inventors have discovered that in the process of loading the regenerated active components, the calcined solid acid catalyst is not reduced but directly loaded into the reactor bed, so that the regenerated active components can directly undergo alkylation reaction in the form of an oxidized state, which can achieve an activity that is better than that of a solid acid catalyst that is first reduced and then subjected to an alkylation reaction. This not only improves the single-cycle life of the solid acid catalyst, but also reduces the production cost of the catalyst. Based on this, the present invention is formed.

[0009] Therefore, an object of the present invention is to provide an alkylation method different from the prior art, which can reduce the processing steps of the alkylation catalyst, reduce the catalyst production cost and increase the single cycle life of the alkylation catalyst.

[0010] In order to achieve the above object, the present invention provides an alkylation method, which comprises contacting an alkylable substance, an alkylating agent and an alkylation catalyst under alkylation reaction conditions to carry out an alkylation reaction, characterized in that the alkylation catalyst contains a solid acid and a transition metal and the transition metal exists in an oxidized state.

[0011] The method comprises the following steps: contacting an alkylable substance, an alkylating agent and an alkylating catalyst under alkylating reaction conditions to carry out an alkylating reaction, wherein the alkylating catalyst is obtained by impregnating a solid acid with an impregnation solution containing a transition metal precursor, followed by drying and calcining; during the alkylating reaction, the transition metal in the solid acid catalyst maintains an oxidized state, and based on the solid acid catalyst, the transition metal accounts for 0.01 to 0.5 wt%, preferably 0.05 to 0.4 wt%, and more preferably 0.07 to 0.33 wt% in terms of a single substance.

[0012] Solid acid catalyst The solid acid comprises a molecular sieve and an inorganic oxide matrix, and the content of the molecular sieve in the solid acid is 60 to 90 wt%. Preferably, the solid acid component is a zeolite molecular sieve. The zeolite molecular sieve can be any zeolite in a solid acid catalyst for an alkylation process known to those skilled in the art, such as mordenite, β-zeolite, X-type zeolite, Y-type zeolite and a combination thereof. In a more preferred embodiment, a zeolite (X-type zeolite, Y-type zeolite) having a faujasite structure can be used as a solid acid component. When used to produce alkylation gasoline, a catalyst with Y-type zeolite as a solid acid component has better performance than a catalyst with X-type zeolite, mordenite and β-zeolite as a solid acid component, and therefore, most preferably, the zeolite molecular sieve is a Y-type zeolite.

[0013] The transition metal is selected from at least one of Group VIB metals, Group VIIB metals and Group VIII metals. Preferably, the transition metal is selected from Pt, Pd, Ni, Mn, Mo, Co and combinations thereof. More preferably, the transition metal is Pt.

[0014] Taking the transition metal Pt as an example, the transition metal precursor is selected from chloroplatinic acid, ammonium chloroplatinate, potassium chloroplatinate, platinum tetrachloride and tetraammine platinum nitrate and combinations thereof. Taking the transition metal as Pd as an example, the transition metal precursor is selected from palladium dichloride, sodium tetrachloropalladate and dichlorotetraammine palladium and combinations thereof. Taking the transition metal as Ni as an example, the transition metal precursor is selected from nickel nitrate hexahydrate, nickel acetate, nickel sulfate, nickel chloride and combinations thereof. Taking the transition metal as Mn as an example, the transition metal precursor is selected from manganese sulfate, manganese nitrate, manganese carbonate and combinations thereof. Taking the transition metal as Mo as an example, the transition metal precursor is selected from molybdenum pentachloride, ammonium paramolybdate and combinations thereof. Taking the transition metal as Co as an example, the transition metal precursor is selected from cobalt chloride, cobalt sulfate, cobalt oxalate, cobalt nitrate and combinations thereof.

[0015] The alkylation method provided by the present invention can delay the coking of the catalyst and extend the life of the catalyst because the precious metal component in the solid acid catalyst is in an oxidized state and does not have the dehydrogenation activity of the reduced precious metal. At the same time, the method of the present invention can omit the reduction process in the catalyst preparation process and can greatly reduce the production cost of the catalyst.

[0016] The alkylation method provided by the present invention can be implemented in a variety of reaction devices, such as a fluidized bed, a fixed bed and a slurry bed. In the present invention, the method is implemented using a fixed bed, but the application of the method of the present invention is not limited thereto. The performance of the alkylation reaction is evaluated using two indicators, cycle life and product distribution. Among them, the cycle life is based on the complete conversion of olefins, and the product distribution is based on C8 and TMP (trimethylpentane). The alkylation product is analyzed on a gas chromatograph. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below through examples. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, but are not intended to limit the content of the present invention.

[0018] Example 1

[0019] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0020] (1) Preparation of impregnation metal solution: Chloroplatinic acid (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0021] (2) Preparation of solid acid catalyst. Y-type zeolite (purchased from Sinopec Catalyst Branch, unit cell 2.456nm, crystallinity 90%) and alumina (purchased from Sinopec Catalyst Branch) were mixed in a weight ratio of 4:1 to form a solid acid. Chloroplatinic acid was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 1 hour, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours. Catalyst A1 was obtained.

[0022] The composition of catalyst A1 is shown in Table 1. In catalyst A1, the metal component Pt accounts for 0.05%.

[0023] The alkylation reaction was carried out in a fixed bed high pressure microreactor. The raw materials for the alkylation reaction were anhydrous isobutane and trans-butene. 5 g of alkylation catalyst A1 was loaded in a fixed bed reactor with an inner diameter of 10 mm and a length of 1 m. The reaction temperature was 75° C., the reaction pressure was 3 MPa, and the raw material flow rate was 200 mL / h (I / O=250, mass ratio).

[0024] The catalyst cycle life is determined by the olefin breakthrough time in the product. The catalyst cycle life refers to the time (h) when olefin breakthrough is detected in the product gasoline after chromatography.

[0025] The results of the alkylation reaction are shown in Table 4. In Table 4, TMP represents the selectivity of trimethylpentane in the product gasoline after the sixth regeneration.

[0026] The components in the alkylation product gasoline were analyzed by an online chromatograph (GC-7890B from Agilent).

[0027] Example 2

[0028] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0029] (1) Preparation of impregnation metal solution: Tetraammine platinum nitrate (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0030] (2) Preparation of solid acid catalyst. Y-type zeolite (purchased from Sinopec Catalyst Branch, unit cell 2.456nm, crystallinity 90%) and silicon oxide (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Tetraammine platinum nitrate was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 1.5 hours, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours. Catalyst A2 was obtained.

[0031] The catalyst composition is shown in Table 1. In catalyst A2, the metal component Pt accounts for 0.13%.

[0032] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0033] Example 3

[0034] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0035] (1) Preparation of impregnation metal solution: Potassium chloroplatinate (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0036] (2) Preparation of solid acid catalyst. Y-type zeolite (purchased from Sinopec Catalyst Branch, unit cell 2.456nm, crystallinity 90%) and titanium oxide (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Potassium chloroplatinate was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 1 hour, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours. Catalyst A3 was obtained.

[0037] The catalyst composition is shown in Table 1. In catalyst A3, the metal component Pt accounts for 0.34%.

[0038] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0039] Example 4

[0040] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0041] (1) Preparation of impregnation metal solution: Platinum tetrachloride (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0042] (2) Preparation of solid acid catalyst. Y-type zeolite (purchased from Sinopec Catalyst Branch, unit cell 2.456nm, crystallinity 90%) and zirconium oxide (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Platinum tetrachloride was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 2h, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5h, and calcined at 500°C for 2h. Catalyst A4 was obtained.

[0043] The catalyst composition is shown in Table 1. In catalyst A4, the metal component Pt accounts for 0.4%.

[0044] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0045] Example 5

[0046] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0047] (1) Preparation of impregnation metal solution: Palladium dichloride (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0048] (2) Preparation of solid acid catalyst. Beta zeolite (purchased from Sinopec Catalyst Branch) and silicon oxide (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Palladium dichloride was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 2 hours, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours. Catalyst A5 was obtained.

[0049] The catalyst composition is shown in Table 1. In catalyst A5, the metal component Pd accounts for 0.08%.

[0050] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0051] Example 6

[0052] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0053] (1) Preparation of impregnation metal solution: Nickel nitrate hexahydrate (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0054] (2) Preparation of solid acid catalyst. X-type zeolite (purchased from Sinopec Catalyst Branch) and titanium oxide (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Nickel nitrate hexahydrate was selected as the metal precursor. After vacuuming, the impregnation solution in step (1) was introduced and impregnated for 2 hours. Then, vacuuming and low-temperature evaporation were performed until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours. Catalyst A6 was obtained.

[0055] The catalyst composition is shown in Table 1. In catalyst A6, the metal component Ni accounts for 0.38%.

[0056] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0057] Example 7

[0058] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0059] (1) Preparation of impregnation metal solution: Cobalt nitrate (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal cobalt.

[0060] (2) Preparation of solid acid catalyst. Mordenite (purchased from Sinopec Catalyst Branch) and zirconium oxide (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Cobalt nitrate was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 2 hours, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours. Catalyst A7 was obtained.

[0061] The catalyst composition is shown in Table 1. In catalyst A7, the metal component Co accounts for 0.36%.

[0062] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0063] Table 1

[0064] Example Solid Acid Metal Type Metal state Metal component content, % A1 Y-type zeolite + alumina 4:1 Pt Oxidation state 0.05 A2 Y-type zeolite + silica 4:1 Pt Oxidation state 0.13 A3 Y-type zeolite + titanium oxide 4:1 Pt Oxidation state 0.34 A4 Y-type zeolite + zirconium oxide 4:1 Pt Oxidation state 0.4 A5 β zeolite + silicon oxide 4:1 Pd Oxidation state 0.08 A6 X-type zeolite + titanium oxide 4:1 Ni Oxidation state 0.38 A7 Mordenite + zirconium oxide 4:1 Co Oxidation state 0.36

[0065] Example 8

[0066] This example is used to illustrate the preparation method of the solid acid catalyst of the present invention.

[0067] (1) Preparation of impregnation metal solution: Chloroplatinic acid (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0068] (2) Preparation of solid acid catalyst. Y-type zeolite (purchased from Sinopec Catalyst Branch, unit cell 2.456nm, crystallinity 90%) and alumina (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Chloroplatinic acid was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 2h, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5h, and calcined at 500°C for 2h. Catalyst A8 was obtained.

[0069] The catalyst composition is shown in Table 2. In catalyst A8, the metal component Pt accounts for 0.06%.

[0070] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0071] Example 8-1 to Example 8-8

[0072] The eight embodiments 8-1 to 8-8 have the same proportion as that of embodiment 8, that is, the solid acid is a mixture of Y-type zeolite and alumina at a weight ratio of 4:1, and the difference is that the metal types in embodiments 8-1 to 8-8 are Pd, Ni, Mn, Co, Mo, Pt and the metal content are different. The catalyst composition is shown in Table 2.

[0073] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0074] Table 2

[0075] Example Solid Acid Metal Type Metal state Metal content, % A8 Y-type zeolite + alumina 4:1 Pt Oxidation state 0.06 A8-1 Y-type zeolite + alumina 4:1 Pd Oxidation state 0.10 A8-2 Y-type zeolite + alumina 4:1 Ni Oxidation state 0.36 A8-3 Y-type zeolite + alumina 4:1 Mn Oxidation state 0.40 A8-4 Y-type zeolite + alumina 4:1 Co Oxidation state 0.38 A8-5 Y-type zeolite + alumina 4:1 Mo Oxidation state 0.35 A8-6 Y-type zeolite + alumina 4:1 Pt Oxidation state 0.07 A8-7 Y-type zeolite + alumina 4:1 Pt Oxidation state 0.18 A8-8 Y-type zeolite + alumina 4:1 Pt Oxidation state 0.33

[0076] Comparative Example 1

[0077] This comparative example is used to illustrate the preparation method of the solid acid catalyst in the prior art.

[0078] (1) Preparation of impregnation metal solution: Chloroplatinic acid (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0079] (2) Preparation of solid acid catalyst precursor. Y-type zeolite (purchased from Sinopec Catalyst Branch, unit cell 2.456nm, crystallinity 90%) and alumina (Sinopharm Chemical Reagent Company, analytical grade) were mixed in a weight ratio of 4:1 to form a solid acid. Chloroplatinic acid was selected as the metal precursor, and after vacuuming, the impregnation solution in step (1) was introduced and impregnated for 2 hours, and then vacuumed and evaporated at low temperature until the solid acid content was 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours.

[0080] (3) Preparation of solid acid catalyst: The solid acid catalyst precursor obtained in step (2) was reduced in a hydrogen atmosphere under the following reduction conditions: heating to 330°C at 4°C / min, maintaining for 2 h, then heating to 590°C at 6°C / min, maintaining for 4.5 h, to obtain solid acid catalyst B1.

[0081] The catalyst composition is shown in Table 3. In catalyst B1, the metal component Pt accounts for 0.09%.

[0082] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0083] Comparative Example 2

[0084] This comparative example is used to illustrate the preparation method of the solid acid catalyst in the prior art.

[0085] (1) Preparation of impregnation metal solution: Tetraammine platinum nitrate (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0086] (2) Prepare a solid acid catalyst precursor. Y-type zeolite (purchased from Sinopec Catalyst Branch) and silicon oxide are mixed in a weight ratio of 4:1 to form a solid acid. Tetraammine platinum nitrate is selected as a metal precursor. After vacuuming, the impregnation solution in step (1) is introduced and impregnated for 2 hours. Then, vacuuming and low-temperature evaporation are performed until the solid acid content is 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours.

[0087] (3) Preparation of solid acid catalyst: The solid acid catalyst precursor obtained in step (2) was reduced in a hydrogen atmosphere under the following reduction conditions: heating to 330°C at 4°C / min, maintaining for 2 h, then heating to 590°C at 6°C / min, maintaining for 4.5 h, to obtain solid acid catalyst B2.

[0088] The catalyst composition is shown in Table 3. In catalyst B2, the metal component Pt accounts for 0.21%.

[0089] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0090] Comparative Example 3

[0091] This comparative example is used to illustrate the preparation method of the solid acid catalyst in the prior art.

[0092] (1) Preparation of impregnation metal solution: Ammonium chloroplatinate (Sinopharm Chemical Reagent Company, analytical grade) and deionized water were mixed and stirred for 15 minutes to obtain an aqueous solution of precious metal platinum.

[0093] (2) Prepare a solid acid catalyst precursor. Y-type zeolite (purchased from Sinopec Catalyst Branch) and titanium oxide are mixed in a weight ratio of 4:1 to form a solid acid. Ammonium chloroplatinate is selected as a metal precursor, and after vacuuming, the impregnation solution in step (1) is introduced and impregnated for 2 hours, and then vacuumed and evaporated at low temperature until the solid acid content is 80% by weight, dried at 110°C for 5 hours, and calcined at 500°C for 2 hours.

[0094] (3) Preparation of solid acid catalyst: The solid acid catalyst precursor obtained in step (2) was reduced in a hydrogen atmosphere under the following reduction conditions: heating to 330°C at 4°C / min, maintaining for 2 h, then heating to 590°C at 6°C / min, maintaining for 4.5 h, to obtain solid acid catalyst B3.

[0095] The catalyst composition is shown in Table 3. In catalyst B3, the metal component Pt accounts for 0.33%.

[0096] The alkylation reaction was the same as in Example 1. The results of the alkylation reaction are shown in Table 4.

[0097] Table 3

[0098] Comparative Example Solid Acid Metal Type Metal state Metal content, % B1 Y-type zeolite + alumina 4:1 Pt Reduced state 0.09 B2 Y-type zeolite + silica 4:1 Pt Reduced state 0.21 B3 Y-type zeolite + titanium oxide 4:1 Pt Reduced state 0.33

[0099] Table 4

[0100]

[0101] It can be seen from the results in Table 4 that the solid acid catalyst provided by the present invention in an oxidized state, when its metal content is the same as or lower than that of the reduced state catalyst, exhibits a longer alkylation cycle life, higher TMP selectivity and lower C9 + In addition, the alkylation performance of the catalyst with too much or too little metal content is not optimal, and the alkylation performance of the catalyst with a metal content of 0.07-0.33% is optimal.

[0102] The deactivation of the alkylation reaction is due to the generation of C8 + An addition reaction occurs to generate more macromolecular organic matter, but no hydrogen transfer reaction occurs to generate the ideal product C8 alkane. Catalysts in a reduced metal state, such as B1, B2 and B3, have significantly shorter alkylation reaction cycle life and lower TMP selectivity. In the method provided by the present invention, since the precious metal component in the solid acid catalyst is in an oxidized state and does not have the dehydrogenation activity of the reduced precious metal, the coking of the catalyst can be delayed and the life of the catalyst can be extended; at the same time, the method of the present invention can omit the reduction process in the catalyst preparation process, which can greatly reduce the catalyst production cost. In particular, when the precious metal content of catalyst A8-7 is 0.18%, not only can the cycle life reach 22h, but the C8 selectivity is as high as 79.2, and C9 + The component is also the lowest, only 3.4%.

Claims

1. An alkylation method, comprising contacting an alkylable substance, an alkylating agent and an alkylation catalyst under alkylation reaction conditions to carry out an alkylation reaction, characterized in that: The alkylation catalyst contains a solid acid and a transition metal, and the transition metal exists in an oxidized form; wherein the solid acid includes a molecular sieve and an inorganic oxide matrix, the molecular sieve is Y-type zeolite, the inorganic oxide is alumina, the transition metal is Pt, and based on the alkylation catalyst, Pt accounts for 0.07-0.33wt%.

2. The method according to claim 1, wherein Based on the solid acid catalyst, the content of the molecular sieve is 40-95wt%.

3. The method according to claim 1, wherein: The alkylation catalyst is obtained by the steps of impregnating a solid acid with an impregnation solution containing a transition metal precursor, drying and calcining.

4. A method according to claim 3, wherein The transition metal precursor is selected from chloroplatinic acid, ammonium chloroplatinate, potassium chloroplatinate, platinum tetrachloride, tetraammine platinum nitrate and combinations thereof.

5. The method according to claim 1, wherein The alkylate is an alkane, the alkylating agent is an olefin, and the alkylation reaction is to generate alkylated gasoline by contacting the alkane with the olefin.

6. A method according to claim 5, wherein The alkane includes isobutane and / or isopentane, and the olefin includes one or more of propylene, isobutylene, 1-butene, 2-butene and pentene.

7. A method according to claim 6, wherein The alkane is isobutane, and the olefin is a mixture of butenes.

8. The method according to claim 1, wherein The alkylation reaction conditions are as follows: temperature of 30-200° C., pressure of 0.5-6 MPa, and feed space velocity of 10-3000 mL / g·h.

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