Process for the alkylation of higher olefins

Abstract

The present application relates to the field of alkylation, and discloses a high-carbon olefin alkylation method. The high-carbon olefin alkylation method comprises the following steps: (1) high-carbon olefin is subjected to alkylation reaction with an alkylating agent in the presence of a solid acid catalyst to obtain an alkylation reaction product; (2) the alkylation reaction product obtained in step (1) is subjected to separation to obtain C5-C 11 alkylated gasoline and C 12 + isomerized alkanes solvent oil; the high-carbon olefin has 7-12 carbon atoms. The method can prepare isomerized alkanes solvent oil through high-carbon olefin alkylation reaction, realize high-value utilization of high-carbon olefin, and simultaneously produce alkylated gasoline as a by-product.

Description

Technical Field

[0001] This invention relates to the field of alkylation technology, and more specifically to a method for alkylating high-carbon olefins. Background Technology

[0002] With increasing emphasis on environmental protection and the ongoing pursuit of carbon neutrality, my country's demand for oil products is expected to decline. Refineries will increasingly focus on deep processing of feedstocks to produce high-value-added chemical products, making "oil conversion" a research hotspot for the present and foreseeable future. The high-value utilization of olefins is a particularly popular research direction within this field. Refinery catalytic cracking, pyrolysis, as well as alkylation and alkane dehydrogenation units, all generate significant amounts of olefins, particularly C7-C6 olefins. 12 High-carbon-number olefins are olefin components with higher utilization value.

[0003] High carbon olefins are currently mainly used in the fine chemical industry, such as alkylation with aromatics as a major raw material for detergents, oilfield displacement agents and lubricants, and can also be used to generate high carbon number alcohols through formylation reaction with syngas.

[0004] C 12 C 16 Isoalkanes are colorless, odorless, high-purity hydrocarbon solvents with a single composition, stable quality, and free of aromatics and sulfur. They are environmentally friendly, have a low pour point, low odor, low toxicity, good stability, consistent product quality, low surface tension, low density, and excellent low-temperature performance and solubility. In most cases, the applications of isoalkanes are no different from those of D-series dearomatic solvents. Due to their superior low odor, low aromaticity, and relatively high price, they are mainly used in high-end applications that replace D-series dearomatic solvents, such as: volatile stamping oils (air conditioner aluminum fins / food container aluminum foil) / aerosols / odor-neutralizing coatings / high-end mold release agents / high-end dry cleaning agents / metal cleaning / specialty fibers / plastic gloves. Furthermore, their safety indicators, exceeding those of D-series dearomatic solvents, make them unique and irreplaceable in applications such as LDPE polymerization initiator carriers and high-end skincare and cosmetic products. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide an alkylation method for high carbon olefins. This method can prepare isomeric alkane solvent oil through the alkylation reaction of high carbon olefins, realize the high-value utilization of high carbon olefins, and at the same time produce alkylated gasoline as a by-product.

[0006] To achieve the above objectives, the present invention provides a method for alkylating high-carbon olefins, wherein the method includes the following steps:

[0007] (1) In the presence of a solid acid catalyst, high carbon olefins undergo alkylation with alkylates to obtain alkylation reaction products;

[0008] (2) The alkylation reaction product obtained in step (1) is separated to obtain C5-C 11 Alkylated gasoline products and C 12 +Isoalkane solvent oil products;

[0009] The high-carbon olefin has 7-12 carbon atoms.

[0010] The method provided by this invention involves the alkylation reaction of high-carbon olefins with 7-12 carbon atoms in the presence of a solid acid catalyst to generate C642 olefins. 12 +Isoalkanes, used as high-end solvent oils, represent one of the directions for the high-value utilization of high-carbon olefins.

[0011] The method provided by this invention prepares isomeric alkane solvent oil through alkylation reaction of high carbon number olefins, which increases the technical route for high-value utilization of high carbon number olefins, and can also produce alkylated gasoline as a byproduct. In preferred cases, the solid acid catalytic method of this invention has the advantages of safety and environmental protection.

[0012] The isoalkane solvent oil synthesized by this invention has higher purity of isoalkane and increased product added value. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] This invention provides a method for alkylating high-carbon olefins, wherein the method includes the following steps:

[0015] (1) In the presence of a solid acid catalyst, high carbon olefins undergo alkylation with alkylates to obtain alkylation reaction products;

[0016] (2) The alkylation reaction product obtained in step (1) is separated to obtain C5-C 11 Alkylated gasoline and C 12 +Isoalkane solvent oil;

[0017] The high-carbon olefin has 7-12 carbon atoms.

[0018] The method provided by this invention involves reacting a high-carbon olefin with 7-12 carbon atoms with isobutane in the presence of a solid acid catalyst to generate C... 12+Isoalkanes, used as high-end solvent oils, represent one of the directions for high-value utilization of high-carbon olefins.

[0019] The method provided by this invention prepares isoalkane solvent oil from high-carbon-number olefins, which increases the technical route for the high-value utilization of high-carbon-number olefins. At the same time, it can also produce alkylated gasoline as a byproduct. In preferred cases, the solid acid catalytic method of this invention has the advantages of safety and environmental protection.

[0020] In this invention, a wide range of solid acid catalysts can be selected, and all solid acid catalysts conventionally defined in the art are applicable. Preferably, in step (1), the solid acid catalyst is selected from at least one of heteropoly acids, solid superacids, supported solid acids, and molecular sieves, and more preferably, molecular sieves. Using the above-mentioned solid acid catalysts in the alkylation to produce solvent oil is more environmentally friendly.

[0021] In a preferred embodiment, the molecular sieve is selected from at least one of X-type molecular sieves, Y-type molecular sieves, Beta-type molecular sieves, and MOR-type molecular sieves, more preferably X-type molecular sieves and / or Y-type molecular sieves. The advantages of this preferred embodiment are high catalytic activity, easy separation, high stability, and regenerability.

[0022] In a preferred embodiment, the mesopore volume of the molecular sieve is not less than 0.05 mL / g, preferably not less than 0.1 mL / g, and more preferably 0.1-0.3 mL / g. The advantage of this preferred embodiment is that the larger mesopores facilitate macromolecular diffusion, resulting in higher catalytic stability and a longer lifespan.

[0023] In this invention, the mesopore volume of the molecular sieve is obtained by BET pyridine adsorption test.

[0024] In a preferred embodiment, the ratio of the total acid content adsorbed by pyridine in the molecular sieve to the total acid content determined by NH3-TPD is not less than 0.14, preferably not less than 0.25, and more preferably 0.25-0.4. The advantages of this preferred embodiment are high accessibility of the acid centers, which is more conducive to macromolecular diffusion and reaction, and a longer catalytic cycle life.

[0025] In this invention, the pyridine acid content of the molecular sieve represents the amount of pyridine molecules adsorbed at the acidic sites of the molecular sieve, and is determined using pyridine adsorption infrared spectroscopy. The NH3 acid content of the molecular sieve represents the amount of NH3 molecules adsorbed at the acidic sites of the modified molecular sieve, and is determined using ammonia temperature-programmed desorption (NH3-TPD) method.

[0026] In this invention, the acidity of the molecular sieve is indirectly characterized by measuring the adsorption amounts of pyridine and NH3 molecules at the acidic sites of the sieve. The diameter of an NH3 molecule is 0.41 nm, and that of a pyridine molecule is 0.57 nm. The smaller the pore size of the molecular sieve, the more difficult it is for NH3 and pyridine molecules to enter the sieve, meaning the accessibility of the acid centers is poor. Therefore, the ratio of pyridine acidity to NH3 acidity in the molecular sieve indirectly reflects the accessibility of the acid centers. Better accessibility of the acid centers indicates higher reactivity for the alkylation of larger molecules.

[0027] In a preferred embodiment, the molecular sieve has an adsorption capacity of not less than 0.07 g / g for pentamethylheptane. cat Preferably not less than 0.1g / g cat More preferably, it is 0.1-0.3 g / g cat The molecular sieve provided by this invention has a large adsorption capacity for C12 isoalkanes, resulting in better selectivity and diffusion performance for target products, and a longer catalytic cycle life.

[0028] In this invention, pentamethylheptane is used as a probe molecule to characterize its adsorption selectivity for the main target products of high-carbon olefin alkylation reactions. Higher adsorption capacity indicates better catalytic selectivity. Furthermore, due to the relatively large molecular size of pentamethylheptane, a larger adsorption capacity also indicates better diffusion performance. The adsorption capacity of pentamethylheptane was determined using a dynamic chemisorption method. In this invention, data were obtained using a Chemstar TPx chemisorption analyzer from Quanta Computer Corporation (USA). Pentamethylheptane was subjected to pulsed bubbling adsorption, and its saturation adsorption capacity was determined using a quantitative ring assay. Adsorption was performed at 50°C.

[0029] In this invention, there is no particular limitation on the source of the molecular sieve. For example, it can be obtained commercially or prepared by conventional methods defined in the art. As long as it can meet the above-mentioned property parameters, it can be applied to this invention.

[0030] In this invention, there are no particular limitations on the position of the double bonds and the structure of the carbon chain in the high-carbon olefin. Preferably, in step (1), the high-carbon olefin is a monoolefin containing a straight chain and / or a branched chain, and more preferably an isomerized monoolefin. The advantage of using high-carbon olefins within the above preferred range is that the alkylation cycle life is longer and the degree of product isomerization is higher.

[0031] In this invention, straight-chain and branched-chain have the meanings conventionally defined in the art, namely, straight-chain olefins and branched-chain olefins.

[0032] In this invention, there is no particular limitation on the type of high-carbon olefin. Preferably, the high-carbon olefin is selected from at least one of isooctene, dimethylpentene, trimethylhexene, tetramethylhexene, tetramethylheptene, and pentamethylheptene, and more preferably from at least one of isooctene, trimethylhexene, and tetramethylheptene.

[0033] In this invention, there is no particular limitation on the type of alkylate. Preferably, in step (1), the alkylate is selected from at least one of isobutane, isopentane, and octopentane, and more preferably isobutane.

[0034] In this invention, the selection range of alkylation reaction conditions is relatively wide. Preferably, in step (1), the alkylation reaction conditions include: a temperature of 30-100℃, a pressure of 1-6MPa, a mass ratio of alkylate to higher olefin of 10-500:1, and a feed space velocity of 10-500mL / (g·h) for both alkylate and higher olefin; more preferably, in step (1), the alkylation reaction conditions include: a temperature of 30-60℃, a pressure of 2-4MPa, a mass ratio of alkylate to higher olefin of 20-200:1, and a feed space velocity of 20-100mL / (g·h) for both alkylate and higher olefin.

[0035] In this invention, preferably, the alkylation reaction is carried out in a fixed-bed reactor.

[0036] In this invention, the selection range for the separation conditions and methods in step (2) is relatively wide, as long as the target product C5-C can be obtained. 11 Alkylated gasoline and C 12 +Iso-alkane solvent oil is sufficient; the present invention does not impose any particular limitations on its specific operation methods and conditions.

[0037] The present invention will be described in detail below through embodiments. Unless otherwise specified, all embodiments in the following examples are derived from commercially available products.

[0038] Catalyst cycle life refers to the reaction time when the olefin conversion begins to fall below 95%.

[0039] Example 1

[0040] Isooctene was used as the high-carbon olefin. A mixture of isobutane and isooctene (mass ratio 200) was prepared by adding isobutane as the feed for the alkylation reaction. The alkylation reaction was carried out in a fixed-bed reactor at a temperature of 40℃ and a pressure of 2 MPa. The feed space velocity for isobutane and isooctene was 20 mL / (g·h). The composition of the alkylation products was analyzed by gas chromatography. HY molecular sieve was used as the alkylation catalyst (purchased from Sinopec Catalyst Co., Ltd., relative crystallinity 90%, w(Na₂O) = 0.0628%, mesopore volume 0.1 mL / g, total pyridine adsorption capacity for infrared spectroscopy 300 μmol / g, total NH₃-TPD capacity 1150 μmol / g, ratio of total pyridine adsorption capacity for infrared spectroscopy to total NH₃-TPD capacity 0.26, and adsorption capacity of pentamethylheptane 0.2 g / g). cat ).

[0041] Example 2

[0042] The method was the same as in Example 1, except that the reaction conditions were: temperature 30°C, pressure 4 MPa, mass ratio of isobutane to isooctene 100, and feed space velocity of isobutane and isooctene 100 mL / (g·h).

[0043] Example 3

[0044] The method was followed as in Example 1, except that the reaction conditions were: temperature 60°C, pressure 3 MPa, isobutane to isooctene mass ratio 20, feed space velocity of isobutane and isooctene 50 mL / (g·h), HY molecular sieve was used as the alkylation catalyst (purchased from Sinopec Catalyst Co., Ltd., relative crystallinity 88%, w(Na2O) = 0.12%, mesopore volume 0.3 mL / g, total pyridine adsorption infrared acidity 340 μmol / g, total NH3-TPD acidity 850 μmol / g, ratio of total pyridine adsorption infrared acidity to total NH3-TPD acidity 0.4, and adsorption capacity of pentamethylheptane 0.3 g / g). cat ).

[0045] Example 4

[0046] The method was followed as in Example 1, except that HY molecular sieve was used as the alkylation catalyst (relative crystallinity 95%, w(Na2O) = 0.1%, mesopore volume 0.12 mL / g, total pyridine adsorption capacity for infrared radiation 325 μmol / g, total NH3-TPD adsorption capacity 1300 μmol / g, ratio of total pyridine adsorption capacity for infrared radiation to total NH3-TPD adsorption capacity 0.25, and adsorption capacity of pentamethylheptane 0.11 g / g). cat .

[0047] Example 5

[0048] The method is the same as in Example 1, except that isopentane is used instead of isobutane for the alkylation reaction.

[0049] Example 6

[0050] The method was the same as in Example 1, except that isobutane was added to prepare a mixture of isobutane and isooctene in a mass ratio of 220 as the alkylation reaction feed. The alkylation reaction was carried out in a fixed-bed reactor at a reaction temperature of 80°C, a pressure of 5 MPa, and a feed space velocity of 120 mL / (g·h).

[0051] Example 7

[0052] The method was followed as in Example 1, except that HX molecular sieve was used as the alkylation catalyst (relative crystallinity 94%, w(Na2O) = 0.12%, mesopore volume 0.1 mL / g, total pyridine adsorption infrared acidity 340 μmol / g, total NH3-TPD acidity 1350 μmol / g, ratio of total pyridine adsorption infrared acidity to total NH3-TPD acidity 0.25, and adsorption capacity of pentamethylheptane 0.11 g / g). cat ).

[0053] Example 8

[0054] The method is the same as in Example 1, except that the high-carbon olefin is selected from 1,4-octadiene.

[0055] Example 9

[0056] The method was followed as in Example 1, except that the HY molecular sieve alkylation catalyst (relative crystallinity 85%, w(Na2O) = 0.1%, mesopore volume 0.06 mL / g, total pyridine adsorption capacity for infrared radiation 210 μmol / g, total NH3-TPD adsorption capacity 1450 μmol / g, ratio of total pyridine adsorption capacity for infrared radiation to total NH3-TPD adsorption capacity 0.14, and adsorption capacity of pentamethylheptane 0.08 g / g) was used. cat ).

[0057] Example 10

[0058] The method was followed as in Example 1, except that a MOR-type molecular sieve alkylation catalyst was used (relative crystallinity 85%, w(Na2O) = 0.2%, mesopore volume 0.1 mL / g, total pyridine adsorption infrared acidity 190 μmol / g, total NH3-TPD acidity 850 μmol / g, ratio of total pyridine adsorption infrared acidity to total NH3-TPD acidity 0.22, and adsorption capacity of pentamethylheptane 0.07 g / gcat).

[0059] Comparative Example 1

[0060] The method is the same as in Example 1, except that the reactant is n-hexadecene.

[0061] The distribution of alkylation reaction products and the alkylation reaction results of the above examples and comparative examples are shown in Table 1.

[0062] Table 1

[0063]

[0064]

[0065] As can be seen from the results in Table 1, the method provided by this invention can be used to prepare solvent oil by alkylation of high carbon olefins, and the solvent oil obtained has a high proportion of isoalkanes. At the same time, using the molecular sieve of this invention as a catalyst can promote the alkylation reaction, effectively control the reaction products, obtain solvent oil with a high content of isoalkanes, and improve the added value of the product.

[0066] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for alkylating high-carbon olefins, characterized in that, The method includes the following steps: (1) In the presence of a solid acid catalyst, high carbon olefins undergo alkylation with alkylates to obtain alkylation reaction products; (2) The alkylation reaction product obtained in step (1) is separated to obtain C5-C 11 Alkylated gasoline and C 12 +Isoalkane solvent oil; The high-carbon olefin has 7-12 carbon atoms; The solid acid catalyst is a molecular sieve, which is selected from X-type molecular sieves and / or Y-type molecular sieves. The ratio of the total acid content adsorbed by pyridine in the molecular sieve to the total acid content determined by NH3-TPD is not less than 0.

25.

2. The method according to claim 1, wherein, The mesopore volume of the molecular sieve is not less than 0.05 mL / g.

3. The method according to claim 2, wherein, The mesopore volume of the molecular sieve is not less than 0.1 mL / g.

4. The method according to claim 3, wherein, The molecular sieve has a mesopore volume of 0.1-0.3 mL / g.

5. The method according to any one of claims 1-4, wherein, The ratio of the total acid content of pyridine adsorption by the molecular sieve to the total acid content determined by NH3-TPD is 0.25-0.

4.

6. The method according to any one of claims 1-4, wherein, The molecular sieve has an adsorption capacity of not less than 0.07 g / g for pentamethylheptane. cat .

7. The method according to claim 6, wherein, The molecular sieve has an adsorption capacity of not less than 0.1 g / g for pentamethylheptane. cat .

8. The method according to claim 7, wherein, The molecular sieve has an adsorption capacity of 0.1-0.3 g / g for pentamethylheptane. cat .

9. The method according to any one of claims 1-4, wherein, In step (1), the high carbon olefin is a monoolefin containing a straight chain and / or a branched chain.

10. The method according to claim 9, wherein, In step (1), the high carbon olefin is an isomeric monoolefin.

11. The method according to claim 10, wherein, In step (1), the high carbon olefin is selected from at least one of isooctene, dimethylpentene, trimethylhexene, tetramethylhexene, tetramethylheptene and pentamethylheptene.

12. The method according to claim 11, wherein, In step (1), the high carbon olefin is at least one of isooctene, trimethylhexene and tetramethylheptene.

13. The method according to any one of claims 1-4, wherein, In step (1), the alkylate is selected from at least one of isobutane, isopentane and neopentane.

14. The method according to claim 13, wherein, In step (1), the alkylate is isobutane.

15. The method according to any one of claims 1-4, wherein, In step (1), the conditions for the alkylation reaction include: a temperature of 30-100℃, a pressure of 1-6MPa, a mass ratio of alkylate to high carbon olefin of 10-500:1, and a feed space velocity of 10-500mL / (g·h) for alkylate and high carbon olefin.

16. The method according to claim 15, wherein, In step (1), the conditions for the alkylation reaction include: a temperature of 30-60℃, a pressure of 2-4MPa, a mass ratio of alkylate to high carbon olefin of 20-200:1, and a feed space velocity of 20-100mL / (g·h) for alkylate and high carbon olefin.

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