Alkylation method of high-carbon olefin

Abstract

The invention relates to the field of alkylation, and discloses a high-carbon olefin alkylation method. The invention relates to a high-carbon olefin alkylation method, which comprises: (1) carrying out an alkylation reaction on high-carbon olefin and an alkylate in the presence of a solid acid catalyst to obtain an alkylation reaction product, (2) separating the alkylation reaction product obtained in the step (1) to obtain C5-C11 alkylated gasoline and C12 < + > isoparaffin solvent oil; the number of carbon atoms in the high-carbon olefin is 7-12. According to the method, the isoparaffin solvent oil can be prepared through high-carbon olefin alkylation reaction, high-valued utilization of high-carbon olefin is realized, and meanwhile, a byproduct of alkylated gasoline can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of alkylation, and in particular to a method for alkylating high-carbon olefins. Background Art

[0002] As people pay more attention to environmental protection and the dual carbon goals are continuously promoted, my country's demand for oil products will show a downward trend. Refinery raw materials will be more inclined to be processed into high-value-added chemical products. "Oil conversion" will be a research hotspot at present and in the future. The high-value utilization of olefins is a popular research direction. Refinery catalytic cracking, cracking, superposition, alkane dehydrogenation and other units will produce a large amount of olefins, among which C7-C 12 The high carbon number olefins are the olefin components with higher utilization value.

[0003] High carbon olefins are currently mainly used in the field of fine chemicals. For example, they can be alkylated with aromatics as the main raw materials for detergents, oilfield flooding agents, and lubricants. They can also be formylated with synthesis gas to produce high carbon alcohols.

[0004] C 12 , C 16 Isoparaffins are colorless, odorless, high-purity hydrocarbon solvent oils with a single component, stable quality, no aromatics and sulfur, green and environmentally friendly, low freezing point, low odor, low toxicity and good stability, consistent product quality, low surface tension, low density, good low-temperature performance and solvency, etc. In most cases, the application of isoparaffins is no different from that of D series dearomatized solvent oils. Due to their excellent low odor, low aromatic performance and relatively high price, they are mainly used in high-end applications to replace D series dearomatized solvent oils, such as: volatile stamping oil (aluminum fins of air conditioners / aluminum foil for dining boxes) / aerosols / odorless coatings / high-end mold release agents / high-end clothing dry cleaning agents / metal cleaning / special fibers / plastic gloves. At the same time, because it exceeds the safety indicators of D series dearomatized solvent oils, it is unique and irreplaceable in the use of LDPE polymerization initiator carriers / high-end skin care cosmetics and other fields. Summary of the invention

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

[0006] In order to achieve the above object, the present invention provides a method for alkylating higher olefins, wherein the method comprises the following steps:

[0007] (1) In the presence of a solid acid catalyst, a high carbon olefin and an alkylate undergo an alkylation reaction to obtain an alkylation reaction product;

[0008] (2) Separating the alkylation reaction product obtained in step (1) to obtain C5-C 11 Alkylation gasoline products and C 12 +Isoparaffin solvent oil products;

[0009] The carbon number of the higher olefin is 7-12.

[0010] The method provided by the present invention comprises the following steps: alkylating a high carbon olefin having 7 to 12 carbon atoms in the presence of a solid acid catalyst to generate C 12 + Isoalkanes, which are used as high-end solvent oils, are one of the directions for high-value utilization of high-carbon olefins.

[0011] The method provided by the present invention prepares isoparaffin solvent oil by alkylating high-carbon olefins, thereby increasing the technical route for high-value utilization of high-carbon olefins and producing alkylated gasoline as a by-product. Preferably, the solid acid catalysis method of the present invention has the advantages of being safer and more environmentally friendly.

[0012] The isoparaffins in the isoparaffin solvent oil synthesized by the invention have higher purity and improved product added value. DETAILED DESCRIPTION

[0013] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0014] The present invention provides a method for alkylating higher carbon olefins, wherein the method comprises the following steps:

[0015] (1) In the presence of a solid acid catalyst, a high carbon olefin and an alkylate undergo an alkylation reaction to obtain an alkylation reaction product;

[0016] (2) Separating the alkylation reaction product obtained in step (1) to obtain C5-C 11 Alkylate gasoline and C 12 + isoparaffin solvent oil;

[0017] The carbon number of the higher olefin is 7-12.

[0018] The method provided by the present invention comprises the following steps: a high carbon olefin having 7 to 12 carbon atoms is subjected to an alkylation reaction with isobutane in the presence of a solid acid catalyst to generate C 12+ isoalkanes, used as high-end solvent oil, are one of the directions for high-value utilization of high-carbon olefins.

[0019] The method provided by the present invention prepares isoparaffin solvent oil from high-carbon number olefins, thereby increasing the technical route for high-value utilization of high-carbon number olefins and also producing alkylated gasoline as a by-product. Preferably, the solid acid catalysis method of the present invention has the advantages of greater safety and environmental protection.

[0020] In the present invention, the solid acid catalyst has a wide range of types, and all solid acid catalysts conventionally defined in the art are applicable to the present invention. Preferably, in step (1), the solid acid catalyst is selected from at least one of a heteropoly acid, a solid superacid, a supported solid acid and a molecular sieve, and is more preferably a molecular sieve. By selecting the above solid acid catalyst for alkylation to generate solvent oil, it is more environmentally friendly.

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

[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 advantages of adopting this preferred embodiment are that larger mesopores are conducive to the diffusion of macromolecules, higher catalytic stability and longer life.

[0023] In the present 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 amount of pyridine adsorption infrared to the total acid amount measured by NH3-TPD of the molecular sieve is not less than 0.14, preferably not less than 0.25, and more preferably 0.25-0.4. The advantage of adopting this preferred embodiment is that the high accessibility of the acid center is more conducive to the diffusion and reaction of macromolecules, and the catalytic cycle life is longer.

[0025] In the present invention, the pyridine acid amount of the molecular sieve represents the adsorption amount of pyridine molecules at the acidic site of the molecular sieve, which is measured by pyridine adsorption infrared method. The NH3 acid amount of the molecular sieve represents the adsorption amount of NH3 molecules at the acidic site of the modified molecular sieve, which is measured by ammonia temperature programmed desorption (NH3-TPD) method.

[0026] In the present invention, the acid amount of the molecular sieve is indirectly characterized by measuring the adsorption amount of pyridine molecules and NH3 molecules at the acidic position of the molecular sieve. Among them, the diameter of NH3 molecules is 0.41nm, and that of pyridine molecules is 0.57nm. The smaller the pore size of the molecular sieve, the more difficult it is for NH3 molecules and pyridine molecules to enter the molecular sieve, that is, the accessibility of the acid center of the molecular sieve is poor. Therefore, the ratio of the amount of pyridine acid to the amount of NH3 acid in the molecular sieve reflects the size of the accessibility of the acid center of the molecular sieve. The better the accessibility of the acid center, the higher its alkylation reaction activity to larger molecules.

[0027] In a preferred embodiment, the adsorption capacity of the molecular sieve for pentamethylheptane is not less than 0.07 g / g cat , preferably not less than 0.1g / g cat , more preferably 0.1-0.3g / g cat The molecular sieve provided by the present invention has a larger adsorption capacity for carbon dodecanane, better target product selectivity and diffusion performance, and a longer catalytic cycle life.

[0028] In the present invention, pentamethylheptane is used as a probe molecule to characterize its adsorption selectivity for the main target product of the high-carbon olefin alkylation reaction. The higher the adsorption capacity, the better the catalytic selectivity. At the same time, due to the larger molecular size of pentamethylheptane, the larger the adsorption capacity, the better its diffusion performance. The adsorption capacity of pentamethylheptane is determined by dynamic chemical adsorption. The data in the present invention is determined by Chemstar TPx chemical adsorption instrument of Quantachrome Corporation of the United States. Pentamethylheptane is pulsed adsorbed by bubbling method, and its saturated adsorption capacity is determined by quantitative loop. The adsorption is measured at 50°C.

[0029] In the present invention, there is no particular limitation on the source of the molecular sieve, for example, it can be obtained commercially, or it can be prepared by a preparation method conventionally defined in the art, and as long as it can meet the above-mentioned property parameters, it can be applied to the present invention.

[0030] In the present invention, there is no particular limitation on the position of the double bond and the structure of the carbon chain in the higher olefin. Preferably, in step (1), the higher olefin is a linear monoolefin and / or a branched monoolefin, and more preferably an isomerized monoolefin. The advantages of selecting the higher olefin within the above preferred range are longer alkylation cycle life and higher product isomerization degree.

[0031] In the present invention, straight chain and branched chain have the meanings commonly defined in the art, namely, straight chain olefins and branched chain olefins.

[0032] In the present invention, there is no particular limitation on the type of higher carbon olefins. In the present invention, preferably, the higher carbon olefins are selected from at least one of isooctene, dimethylpentene, trimethylhexene, tetramethylhexene, tetramethylheptene and pentamethylheptene, and more preferably at least one of isooctene, trimethylhexene and tetramethylheptene.

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

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

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

[0036] In the present invention, the conditions and methods for separation in step (2) can be selected in a wide range, as long as the target product C5-C 11 Alkylate gasoline and C 12 + isoparaffin solvent oil, and the present invention does not specifically limit its specific operation mode and conditions.

[0037] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all products are from commercially available products.

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

[0039] Example 1

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

[0041] Example 2

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

[0043] Example 3

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

[0045] Example 4

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

[0047] Example 5

[0048] The method of Example 1 is followed, except that isopentane is used instead of isobutane to carry out the alkylation reaction.

[0049] Example 6

[0050] The method of Example 1 is followed, except that a mixture of isobutane and isooctene in a mass ratio of 2:20 is added as a feed for the alkylation reaction. The alkylation reaction is 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 of Example 1 was followed, except that HX molecular sieve was used as the alkylation catalyst (relative crystallinity 94%, w(Na2O)=0.12%, mesopore volume 0.1 mL / g, pyridine adsorption infrared total acidity 340 μmol / g, NH3-TPD total acidity 1350 μmol / g, pyridine adsorption total infrared acidity to NH3-TPD total acidity ratio of 0.25, pentamethylheptane adsorption capacity of 0.11 g / g cat ).

[0053] Example 8

[0054] The method of Example 1 is followed, except that the higher carbon olefin is selected from 1,4-octadiene.

[0055] Example 9

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

[0057] Example 10

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

[0059] Comparative Example 1

[0060] The method of Example 1 is followed, except that the reaction raw material 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] It can be seen from the results in Table 1 that the method provided by the present invention can be used to alkylate high-carbon olefins to prepare solvent oil, and the proportion of isoparaffins in the prepared solvent oil is relatively high; at the same time, the use of the molecular sieve of the present invention as a catalyst can promote the alkylation reaction, effectively control the reaction products, obtain solvent oil with a high isoparaffin content, and improve the added value of the product.

[0066] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for alkylating higher olefins, characterized in that: The method comprises the following steps: (1) In the presence of a solid acid catalyst, a high carbon olefin and an alkylate undergo an alkylation reaction to obtain an alkylation reaction product; (2) Separating the alkylation reaction product obtained in step (1) to obtain C5-C 11 Alkylate gasoline and C 12 + isoparaffin solvent oil; The carbon number of the higher olefin is 7-12.

2. The method according to claim 1, wherein: In step (1), the solid acid catalyst is selected from at least one of heteropolyacids, solid superacids, supported solid acids and molecular sieves, and is preferably a molecular sieve.

3. The method according to claim 2, wherein: The molecular sieve is at least one selected from X-type molecular sieve, Y-type molecular sieve, Beta-type molecular sieve and MOR-type molecular sieve, preferably X-type molecular sieve and / or Y-type molecular sieve.

4. The method according to claim 2 or 3, wherein: 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.

5. The method according to claim 2 or 3, wherein: The ratio of the total acid amount of pyridine adsorbed by infrared to the total acid amount measured by NH3-TPD of the molecular sieve is not less than 0.14, preferably not less than 0.25, and more preferably 0.25-0.

4.

6. The method according to claim 2 or 3, wherein: 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 0.1-0.3g / g cat .

7. The method according to any one of claims 1 to 6, wherein: In step (1), the higher carbon olefin is a linear monoolefin and / or a branched monoolefin, preferably an isomeric monoolefin; Preferably, the high carbon olefin is selected from at least one of isooctene, dimethylpentene, trimethylhexene, tetramethylhexene, tetramethylheptene and pentamethylheptene, and more preferably is selected from at least one of isooctene, trimethylhexene and tetramethylheptene.

8. The method according to any one of claims 1 to 7, wherein: In step (1), the alkylate is selected from at least one of isobutane, isopentane and oct-pentane, preferably isobutane.

9. The method according to any one of claims 1 to 8, wherein: In step (1), the conditions of the alkylation reaction include: temperature of 30-100°C, pressure of 1-6MPa, mass ratio of alkylate to higher olefins of 10-500:1, and feed space velocity of alkylate and higher olefins of 10-500mL / (g·h).

10. The method according to claim 9, wherein: In step (1), the conditions of the alkylation reaction include: temperature of 30-60°C, pressure of 2-4 MPa, mass ratio of alkylate to higher olefins of 20-200:1, and feed space velocity of alkylate and higher olefins of 20-100 mL / (g·h).

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