A process and apparatus for the production of polyalkylarene components, and the products obtained

Abstract

The application discloses a method and device for preparing a polyalkyl aromatic component and a product obtained by the method, and relates to the technical field of oil refining, in particular to a method for preparing a polyalkyl aromatic component, which comprises the following steps: fractionating an aromatic-rich oil to obtain an aromatic-rich oil fraction with a distillation range of 180-320 DEG C; and performing two-stage alkylation reactions in the presence of an alkylation catalyst to obtain an alkylation product; the temperature of the second-stage alkylation reaction is 30-70 DEG C higher than that of the first-stage alkylation reaction; and the alkylation product is fractionated to obtain a light component and a heavy component with a cut point of 450-540 DEG C, wherein the heavy component is the polyalkyl aromatic component product. The method provided by the application can be used for preparing a polyalkyl aromatic component with high selectivity, and the polyalkyl aromatic component can be used as a high-quality bright oil product and has a high aromatic carbon ratio and can be used as an environmental-friendly aromatic rubber plasticizer product.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and specifically to a method and apparatus for preparing polyalkyl aromatic hydrocarbon components. Background Technology

[0002] Bright oil is a high-viscosity lubricating oil base oil used to adjust the high-temperature viscosity of lubricating oil products. It is widely used in industrial oils and heavy internal combustion engine oils. As a heavy base oil, bright oil not only requires high viscosity but also a high viscosity index, good oxidation stability, and low-temperature fluidity. Bright oil is mainly produced from crude oil vacuum residue through physical separation and hydrotreating processes. However, due to the diversification of crude oil sources and the decreasing availability of high-quality resources, bright oil products exhibit variations in viscosity, viscosity index, and oxidation stability, leading to fluctuations in product quality and making it difficult to produce high-quality bright oil products that combine both high viscosity and a high viscosity index. Environmentally friendly aromatic rubber plasticizers are another type of high-viscosity specialty oil, mainly used as tire rubber fillers. They improve the elasticity, toughness, and processability of rubber and are characterized by high aromatic carbon content, low polycyclic aromatic hydrocarbon content (PCA < 3%), high density, high viscosity, and good compatibility with polar rubbers. Current processes primarily use extracted oil, a byproduct of the solvent refining process for lubricating oil base oils, as raw material. Through physical separation or hydrogenation, they produce rubber plasticizers that meet environmental standards. However, this process faces challenges such as limited raw material sources, low product yield, and low aromatic carbon content. Due to raw material and process limitations, high-viscosity index bright oils and high-aromatic-carbon environmentally friendly aromatic rubber plasticizers are scarce in the market.

[0003] Alkylation of aromatics with alkenes is an important method for synthesizing alkyl aromatics, commonly used in the petrochemical industry for the production of ethylbenzene, styrene, dodecylbenzene, alkyl biphenyls, alkylnaphthalenes, and other chemicals. Existing alkylation processes involve preparing aromatic components containing an alkyl side chain under acidic catalyst and excess aromatics conditions. CN101130477A describes the preparation of branched long-chain alkylbenzene products from short-chain alkylbenzenes and long-chain olefins under supported aluminum chloride molecular sieve catalysis, with mild reaction conditions and 100% olefin conversion. CN1225617A describes the preparation of straight-chain alkylbenzenes from haloalkanes and alkenes using a low-temperature molten ionic liquid catalyst of metal halides. CN101205161A describes the preparation of long-chain alkylnaphthalene products from naphthalene and long-chain olefins under silica-supported heteropolyacid catalysis.

[0004] Long-chain polyalkyl aromatic hydrocarbons are aromatic hydrocarbon components containing two or more alkyl side chains. These components have high molecular weight, high viscosity, and high flash point, but often act as byproducts during alkylation reactions. These polyalkyl aromatic hydrocarbons not only possess an aromatic ring structure, exhibiting good compatibility with polar rubbers, but also have long alkyl side chains, resulting in high viscosity index and high oxidation stability. Therefore, this component structure can be applied in the fields of bright oils and environmentally friendly aromatic plasticizers. Unlike existing processes for preparing monoalkyl side chains of alkylbenzenes or alkylnaphthalenes, the synthesis of polyalkyl aromatic hydrocarbons requires an excess of olefin feedstock, and the aromatic hydrocarbons and olefins must undergo multiple alkylation reactions. To achieve polyalkyl aromatic hydrocarbons, the steric hindrance of the alkyl side chains must be overcome under high reaction temperatures and strong acidic catalysts. However, alkylation is an exothermic reaction; increasing the reaction temperature reduces the yield of alkylation products and increases side reactions, making olefins prone to polymerization. CN109824467A discloses a method for preparing alkylnaphthalene components containing 3-4 alkyl side chains, using a metal halide ionic liquid to catalyze the polyalkylation reaction of naphthalene with hexene and octene. However, this catalytic system easily introduces halogens, affecting the use of subsequent products. CN102660322A discloses a method for preparing heavy alkylbenzenes, using an aluminum trichloride and organoammonium salt-based catalytic system, employing alkylbenzenes and C20-C24 olefins to prepare high-carbon-number alkylbenzenes, but mainly producing monoalkyl products. Therefore, for polyalkyl aromatic hydrocarbon components, there is a lack not only of acidic catalytic systems with good catalytic effect and easy separation, but also of process routes for the preparation of polyalkyl aromatic hydrocarbon components with high selectivity. Summary of the Invention

[0005] One of the technical problems to be solved by the present invention is that it is difficult to achieve highly selective preparation of polyalkyl aromatic components in the prior art, and provides a method for producing polyalkyl aromatic components.

[0006] The second technical problem to be solved by the present invention is to provide a polyalkyl aromatic hydrocarbon product obtained by the above method.

[0007] The third technical problem to be solved by the present invention is to provide an apparatus for producing polyaromatic components.

[0008] In a first aspect, the present invention provides a method for preparing polyalkyl aromatic hydrocarbon components, comprising:

[0009] (1) Fractional distillation of aromatic oil yields aromatic oil fractions with a distillation range of 180–320℃.

[0010] (2) The first alkylation reaction is carried out in the presence of an alkylation catalyst, using the aromatic oil fraction or a mixture of it and aromatic compounds as aromatic feedstock, and alkylating it with olefin feedstock to obtain intermediate alkylation products.

[0011] (3) Second stage alkylation reaction: In the presence of an alkylation catalyst, the intermediate alkylation product and the olefin feedstock undergo alkylation reaction at a higher temperature to obtain the alkylated product; the temperature of the second stage alkylation reaction is 30-70°C higher than that of the first stage alkylation reaction.

[0012] (4) The alkylation product is fractionated to obtain light and heavy components with a cutting point of 450-540°C. The heavy component is a polyalkyl aromatic hydrocarbon component product.

[0013] Secondly, the polyalkyl aromatic hydrocarbon component prepared by the above method has a distillation range of not less than 450°C.

[0014] Thirdly, the present invention provides an apparatus for preparing polyalkyl aromatic hydrocarbon components, for use in any of the methods for preparing polyalkyl aromatic hydrocarbon components described above, comprising a first fractionating tower, an alkylation reactor, and a second fractionating tower connected in sequence, wherein the first fractionating tower is provided with a feed inlet, a top outlet, a side outlet, and a bottom outlet; the alkylation reactor is provided with an aromatic feed inlet, an olefin feed inlet, a catalyst inlet, a product outlet, and a catalyst outlet; the alkylation product outlet is connected to the feed inlet of the second fractionating tower; and the second fractionating tower is further provided with a top outlet and a bottom outlet.

[0015] Compared with the prior art, the beneficial effects of the method and apparatus for preparing polyalkyl aromatic hydrocarbon components provided by the present invention are as follows:

[0016] (1) The method provided by this invention uses suitable aromatic hydrocarbons and long-chain olefins as raw materials, and prepares aromatic hydrocarbon components with multiple alkyl groups through a two-stage alkylation reaction under the action of a strongly acidic catalytic system. At low alkylation temperatures, products containing 1 to 2 alkyl side chains are generated, while avoiding side reactions such as olefin polymerization; at high alkylation temperatures, the steric hindrance can be overcome to generate polyalkyl aromatic hydrocarbon components with 2 to 3 alkyl side chains, thus achieving highly selective preparation of polyalkyl aromatic hydrocarbon components.

[0017] (2) The polyalkyl aromatic components provided by the present invention have high viscosity and high viscosity index, and can be used as high-quality bright oil products. At the same time, they have a high aromatic carbon ratio and do not contain more than three-ring aromatics, and can be used as environmentally friendly aromatic rubber plasticizer products. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of one embodiment of the method for preparing polyalkyl aromatic hydrocarbon components provided by the present invention.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. First fractionation tower; 2. Alkylation reactor

[0021] 3. Second fractionation tower 4. Raw material inlet

[0022] 5. Bottom discharge from the first fractionation tower; 6. Side discharge from the first fractionation tower.

[0023] 7. Top discharge of the first fractionation column; 8. Inlet of the alkylation catalyst.

[0024] 9. Olefin feedstock inlet; 10. Waste catalyst outlet

[0025] 11. Product outlet 12. Bottom discharge of the second fractionation tower

[0026] 13. Top discharge of the second fractionation tower Detailed Implementation

[0027] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0028] In a first aspect, the present invention provides a method for preparing polyalkyl aromatic hydrocarbon components, comprising:

[0029] (1) Fractional distillation of aromatic oil yields aromatic oil fractions with a distillation range of 180–320℃.

[0030] (2) The first alkylation reaction is carried out in the presence of an alkylation catalyst, using the aromatic oil fraction or a mixture of it and aromatic compounds as aromatic feedstock, and alkylating it with olefin feedstock to obtain intermediate alkylation products.

[0031] (3) Second stage alkylation reaction: In the presence of an alkylation catalyst, the intermediate alkylation product and the olefin feedstock undergo alkylation reaction at a higher temperature to obtain the alkylated product; the temperature of the second stage alkylation reaction is 30-70°C higher than that of the first stage alkylation reaction.

[0032] (4) The alkylation product is fractionated to obtain light and heavy components with a cutting point of 450-540°C. The heavy component is a polyalkyl aromatic hydrocarbon component product.

[0033] In this invention, the aromatic oil contains more than 70 wt% aromatics; preferably, the aromatic oil is selected from one or more of catalytic cracking diesel, catalytic cracking recycle oil, catalytic cracking slurry, reformed heavy aromatic oil, and ethylene tar; the aromatic compounds are monocyclic or bicyclic aromatic compounds with a boiling point of 180-320℃; preferably, catalytic cracking diesel.

[0034] To enrich monocyclic and dicyclic aromatic components, the aromatic-rich oil is distilled to obtain a suitable fraction at 180–320°C. Preferably, the aromatic feedstock has a distillation range of 200–300°C, and the aromatic content in the feedstock is greater than 70 wt%, more preferably greater than 80 wt%.

[0035] In this invention, the aromatic compound is selected from one or more of methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, biphenyl, acenaphthenes, fluorenes and hexylbenzene; preferably, the aromatic compound is methylnaphthalene and / or dimethylnaphthalene.

[0036] In this invention, the olefin-rich oil has an olefin content greater than 50 wt%, preferably greater than 70 wt%. Preferably, the olefin-rich oil is selected from at least one pure olefin compound, wherein the olefin is at least one of a C8-C20 straight-chain α-olefin or an internal olefin. By using preferred conditions, it can be ensured that the aromatic feedstock and the high-concentration olefin oil can undergo an alkylation reaction, and that the oil has a suitable carbon chain length, thus meeting the requirements for high viscosity.

[0037] In this invention, the alkylation catalyst is an acidic catalyst, including strongly acidic Bronsted acids and composite acids of Bronsted and Lewis acids. A wide range of types of strongly acidic Bronsted acid catalysts are available. The strongly acidic Bronsted acid catalyst refers to a strong acid with an acidity coefficient (pKa) less than 0.

[0038] To achieve the alkylation reaction of aromatic oils with olefins, the catalyst needs to meet the requirement of strong acidity. Simultaneously, to ensure easy separation of the synthesis product from the catalyst, a liquid acid catalytic system that is immiscible with the reaction product is selected. The strong liquid acid is selected from ultra-strong liquid acids with an acidity coefficient less than -5; preferably, it is selected from at least one of concentrated sulfuric acid (98 wt%), trifluoromethanesulfonic acid, fluorosulfonic acid, perchloric acid, and hydrobromic acid; most preferably, concentrated sulfuric acid and / or trifluoromethanesulfonic acid.

[0039] For the composite acid of Bronsted acid and Lewis acid, the Bronsted acid catalyst is selected from strong acids with an acidity coefficient (pKa) less than 0, preferably including at least one of methanesulfonic acid, benzenesulfonic acid, trifluoromethanesulfonic acid, fluorosulfonic acid, perchloric acid, and hydrobromic acid; the Lewis acid includes metal halides, preferably including at least one of boron tribromide, boron trichloride, aluminum trichloride, boron trifluoride, ferric chloride, and zinc trichloride.

[0040] In this invention, to achieve multiple alkylation reactions, when only Bronsted acid is used, a strong acid catalyst with an acidity coefficient (pKa) of less than -5 is preferred. When a complex acid of Lewis acid and Bronsted acid is used, the presence of Lewis acid can promote multiple alkylation reactions. In this case, a strong acid Bronsted acid catalyst with an acidity coefficient (pKa) of less than 0 is preferred. The mass ratio of the Bronsted acid to Lewis acid complex acid is 1 to 10:1, preferably 2 to 5:1.

[0041] In this invention, the reaction temperature in the first alkylation reaction is 20-60℃, preferably 30-50℃. The pressure is atmospheric pressure. The alkylation reaction is a strongly exothermic reaction and has a fast reaction rate. Preparing alkyl aromatic components containing 1-2 alkyl side chains at a lower reaction temperature, under the action of a strong acid catalyst, can reduce side reactions and slow down the reaction rate.

[0042] In the second-stage alkylation reaction, the reaction temperature is 60-120℃, preferably 80-100℃. The pressure is atmospheric pressure. Due to the steric hindrance of the long side chains, further alkylation is more difficult, requiring an increase in the reaction temperature to achieve a multi-alkylation reaction.

[0043] In this invention, the alkylation catalysts used in the first alkylation reaction and the second alkylation reaction can be the same or different, but preferably the alkylation catalysts used in the two alkylation reactions are the same.

[0044] The olefin feedstock used in the first and second alkylation reactions can be the same or different, but it is preferred that the olefin feedstock used in the two alkylation reactions be the same.

[0045] In a preferred embodiment of the present invention, the alkylation catalyst is a strong liquid acid. In the first stage of the alkylation reaction, the alkylation reactor is a stirred tank reactor. The aromatic feedstock and the strong liquid acid are added to the alkylation reactor. Preferably, the olefin feedstock is continuously added to the alkylation reactor over a period of 10-100 minutes, more preferably 15-60 minutes. Since the alkylation reaction is strongly exothermic, to reduce the temperature rise and maintain a constant reaction temperature, the olefin feedstock is added continuously and at a uniform rate.

[0046] In this invention, during the first alkylation reaction, the mass ratio of the aromatic oil to the olefin is 1:0.3-3, preferably 1:0.5-2; the mass ratio of the alkylation catalyst to the aromatic feedstock is 0.01-0.3:1, preferably 0.05-0.2:1; and the alkylation reaction time is 5-90 min, preferably 20-60 min. Under these preferred conditions, an intermediate alkylated product containing 1-2 side chains can be obtained.

[0047] In the second-stage alkylation reaction, the mass ratio of the aromatic feedstock to the olefin is 1:0.3-3, preferably 1:0.5-2; the mass ratio of the alkylation catalyst to the aromatic feedstock is 0.01-0.3:1, preferably 0.05-0.2:1. The reaction time is 5-90 min, preferably 20-60 min.

[0048] In a preferred embodiment of the method provided by the present invention, the alkylation catalyst is a strongly acidic liquid-phase catalyst. In the first stage of the alkylation reaction, the olefin feedstock is continuously added to the strongly acidic liquid-phase catalyst for 10-100 min, preferably 15-60 min. In the second stage of the alkylation reaction, the olefin feedstock is continuously added to the strongly acidic liquid-phase catalyst for 10-100 min, preferably 15-60 min. After the reaction is completed, the sedimentation and separation time of the reaction product and the catalyst is 5-240 min, preferably 15-60 min.

[0049] Adding olefins in two stages can avoid side reactions of excessive olefin polymerization and improve the effective utilization rate of olefins. By using alkylation reactions at different temperatures, the reaction rate can be reduced and side reactions can be minimized at low temperatures, while the steric hindrance can be overcome at high temperatures to achieve polyalkylation reactions.

[0050] In a preferred embodiment of the present invention, the alkylation reaction product and the catalyst are separated by sedimentation. The upper layer of reaction product is introduced into a distillation column for fractionation to obtain a light component stream and a heavy component stream, wherein the heavy component stream is a polyalkyl aromatic hydrocarbon product. The cut-off point between the light component stream and the heavy component is 450–540°C. The lower layer of catalyst is recycled back to the reactor for the catalytic alkylation reaction. In the present invention, the sedimentation time between the reaction product and the catalyst is 5–240 min, preferably 15–60 min. The catalyst system and the reaction product in the present invention are immiscible and have a density difference, which can be separated by static sedimentation.

[0051] In this invention, the fractionation tower is selected from plate towers and packed towers; preferably, the distillation tower is selected from packed towers.

[0052] In a second aspect, the present invention provides a polyalkyl aromatic hydrocarbon component prepared by the method provided in the first aspect, wherein the distillation range of the polyalkyl aromatic hydrocarbon component is not less than 450°C.

[0053] The fraction of the polyalkyl aromatic hydrocarbon component with a cutting temperature of not less than 500°C is used as a high-viscosity and high-viscosity index bright oil product; or the fraction of the polyalkyl aromatic hydrocarbon component with a cutting temperature of not less than 450°C is used as a high-aromatic-carbon environmentally friendly aromatic rubber plasticizer product.

[0054] Thirdly, the present invention provides an apparatus for preparing polyalkyl aromatic hydrocarbon components, for use in any of the methods for preparing polyalkyl aromatic hydrocarbon components described above, comprising a first fractionating tower, an alkylation reactor, and a second fractionating tower connected in sequence, wherein the first fractionating tower is provided with a feed inlet, a top outlet, a side outlet, and a bottom outlet; the alkylation reactor is provided with an aromatic feed inlet, an olefin feed inlet, a catalyst inlet, a product outlet, and a catalyst outlet; the alkylation product outlet is connected to the feed inlet of the second fractionating tower; and the second fractionating tower is further provided with a top outlet and a bottom outlet.

[0055] Preferably, the alkylation reactor consists of a first alkylation reactor and a second alkylation reactor, wherein the first and second alkylation reactors are provided with an aromatic feedstock inlet, an olefin feedstock inlet, a catalyst inlet, a product outlet, and a catalyst outlet, and the product outlet of the first alkylation reactor is connected to the feedstock inlet of the second alkylation reactor.

[0056] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention, but the drawings and embodiments do not constitute a limitation of the present invention.

[0057] Appendix Figure 1 A schematic flow chart of one embodiment of a method for preparing polyalkyl aromatic hydrocarbon components. (See attached diagram.) Figure 1 As shown, the apparatus for producing polyalkyl aromatic hydrocarbon components provided by the present invention includes a first fractionating tower 1, an alkylation reactor 2, and a second fractionating tower 3 connected in sequence. The first fractionating tower is provided with a feed inlet 4, a top outlet 7, a side outlet 6, and a bottom outlet 5. The side outlet is connected to the aromatic feed inlet of the alkylation reactor 2. The alkylation reactor 2 is also provided with an olefin feed inlet 9, a catalyst inlet 8, a product outlet 11, and a waste catalyst outlet 10. The product outlet 11 is connected to the feed inlet of the second fractionating tower 3. The second fractionating tower is also provided with a top outlet 13 and a bottom outlet 12.

[0058] Aromatic oil enters the first fractionation tower 1 through feed inlet 4. After fractionation, the middle fraction of aromatic oil with a distillation range of 180-300℃ is obtained through side stream outlet 6. Alkylation catalyst enters the alkylation reactor 2 through catalyst inlet 8. The middle fraction of aromatic oil is used as aromatic feedstock in the alkylation reactor 2. Olefin feedstock is continuously added to the alkylation reactor 2 through olefin feedstock inlet 9. The first stage alkylation reaction is carried out with the aromatic feedstock at a lower temperature to obtain intermediate alkylation product. Then, the reaction temperature is increased by 30-70℃, and olefin feedstock is added again. The intermediate alkylation product and the olefin feedstock are carried out in the second stage alkylation reaction at a higher temperature to obtain alkylation product. Waste catalyst is discharged through waste catalyst outlet 10. Alkyation product enters the second fractionation tower 3 through product outlet 11 for fractionation. Light component is obtained from the top outlet 13, and polyalkyl aromatic component is obtained from the bottom outlet 12.

[0059] The present invention will be described in detail below through embodiments.

[0060] The catalytic cracked diesel fuel is sourced from the catalytic cracking unit of China Petroleum & Chemical Corporation's Jinan branch.

[0061] The olefins are derived from the ethylene oligomerization unit of China Petroleum & Chemical Corporation's Maoming branch, including dodecene and tetradecene.

[0062] The alkylation catalysts were trifluoromethanesulfonic acid, concentrated sulfuric acid, methanesulfonic acid, and boron tribromide, purchased from Aladdin Reagent Company.

[0063] Density parameters were measured according to GB / T 13377;

[0064] The kinematic viscosity parameters were measured according to GB / T 265;

[0065] The hydrocarbon composition was determined using SH / T 0606;

[0066] Pour point parameters were measured according to GB / T 3535-2008;

[0067] The total acid value was measured according to GB / T 7304;

[0068] Viscosity index was calculated according to GB / T 1995;

[0069] Oxidation stability (rotating oxygen and nitrogen) was measured using SH / T 0193;

[0070] The aromatic carbon content was measured using SH / T 0725;

[0071] Polycyclic aromatic hydrocarbons (PACs) were determined using NB / SH / T 0838;

[0072] Eight polycyclic aromatic hydrocarbons (PAHs) were determined using SN / T 1877.3-2007.

[0073] Example 1

[0074] (1) Catalytic cracked diesel is introduced into the distillation tower to obtain a 200-300℃ fraction. The properties of the feedstock and the middle fraction are shown in Table 1.

[0075] (2) In the first stage of alkylation reaction, the middle distillate of catalytic cracked diesel at 200-300℃ and trifluoromethanesulfonic acid are added to the reactor. At the reaction temperature of 40℃, dodecene is continuously added for 20 min. After the olefin feedstock is added, the intermediate alkylation product is obtained at the set reaction temperature and time (reaction temperature is 40℃, reaction time is 30 min, the weight ratio of aromatic feedstock to dodecene is 1.5:1, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock is 0.1:1).

[0076] (3) In the second stage of alkylation reaction, trifluoromethanesulfonic acid is added to the reactor at a reaction temperature of 90°C. Dodecene is added continuously over a period of 20 min. After the olefin feedstock is added, the alkylation product is obtained at the set reaction temperature and time (reaction temperature is 90°C, reaction time is 30 min, the weight ratio of aromatic feedstock to dodecene is 1.5:1, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock is 0.1:1).

[0077] (4) The above alkylation product was subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon component with a distillation range of >520℃. The main physical properties are listed in Table 2.

[0078] Table 1

[0079]

[0080]

[0081] Example 2

[0082] (1) Catalytic cracked diesel is introduced into a distillation tower to obtain a middle distillate section at 250-320℃. The properties of the catalytic cracked diesel feedstock and the middle distillate section are shown in Table 1.

[0083] (2) In the first stage of alkylation reaction, the above-mentioned 250-320℃ middle distillate and trifluoromethanesulfonic acid are added to the reactor. The reaction temperature is 30℃, and dodecene is continuously added for 60 min. After the olefin feedstock is added, the intermediate alkylation product is obtained under the set reaction temperature and time (reaction temperature is 30℃, reaction time is 20 min, the weight ratio of aromatic feedstock to dodecene is 1:1, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock is 0.2:1).

[0084] (3) In the second stage of alkylation reaction, trifluoromethanesulfonic acid is added to the reactor at a reaction temperature of 80°C. Dodecene is added continuously over a period of 60 min. After the olefin feedstock is added, the alkylation product is obtained at the set reaction temperature and time (reaction temperature is 80°C, reaction time is 20 min, the weight ratio of aromatic feedstock to dodecene is 1:1.5, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock is 0.2:1).

[0085] (4) The above alkylated products were subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon fraction with a distillation range of >500℃. The main physical properties are listed in Table 2.

[0086] Example 3

[0087] (1) In the first stage of alkylation reaction, methylnaphthalene is added to the reactor, and a composite catalyst of methanesulfonic acid and boron tribromide (mass ratio of methanesulfonic acid to boron tribromide is 1:0.3) is added to the reactor. The reaction temperature is 50°C, and tetradecene is added continuously for 30 min. After the olefin feedstock is added, the intermediate alkylation product is obtained under the set reaction temperature and time (reaction temperature is 50°C, reaction time is 40 min, weight ratio of aromatic feedstock to tetradecene is 1:2, and weight ratio of composite catalyst to aromatic feedstock is 0.2:1).

[0088] (2) In the second stage of alkylation reaction, a composite catalyst of methanesulfonic acid and boron tribromide (methanesulfonic acid to boron tribromide mass ratio 1:0.3) is added to the reactor. The reaction temperature is 100℃, and dodecene is added continuously over a period of 30 min. After the olefin feedstock is added, the alkylation product is obtained under the set reaction temperature and time (reaction temperature 100℃, reaction time 60 min, aromatic feedstock to dodecene weight ratio 1:1, trifluoromethanesulfonic acid catalyst to aromatic feedstock weight ratio 0.2:1).

[0089] (3) The above alkylation product was subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon component with a distillation range of >500℃. The main physical properties are listed in Table 2.

[0090] Example 4

[0091] (1) Catalytic cracked diesel is introduced into a distillation tower to obtain a middle distillate section at 200-300℃. The properties of the catalytic cracked diesel feedstock and the middle distillate section are shown in Table 1.

[0092] (2) In the first stage of alkylation reaction, the above-mentioned 200-300℃ middle distillate segment is mixed with methylnaphthalene at a mass ratio of 1:1, and then added to the reactor with trifluoromethanesulfonic acid. At the reaction temperature of 50℃, dodecene is continuously added for 15 min. After the olefin raw material is added, the intermediate alkylation product is obtained at the set reaction temperature and time (reaction temperature of 50℃, reaction time of 30 min, weight ratio of aromatic raw material to dodecene of 1:1, weight ratio of trifluoromethanesulfonic acid catalyst to aromatic raw material of 0.05:1).

[0093] (3) In the second stage of alkylation reaction, trifluoromethanesulfonic acid is added to the reactor at a reaction temperature of 100°C. Dodecene is added continuously over a period of 15 min. After the olefin feedstock is added, the alkylation product is obtained at the set reaction temperature and time (reaction temperature is 80°C, reaction time is 30 min, the weight ratio of aromatic feedstock to dodecene is 1:1, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock is 0.05:1).

[0094] (4) The above alkylated products were subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon fraction with a distillation range of >450℃. The main physical properties are listed in Table 3.

[0095] Example 5

[0096] (1) Catalytic cracked diesel is introduced into a distillation tower to obtain an intermediate fraction at 180-290℃.

[0097] (2) In the first stage of alkylation reaction, the above-mentioned 180-290℃ middle distillate segment and concentrated sulfuric acid are added to the reactor. At the reaction temperature of 30℃, dodecene is continuously added for 30 min. After the olefin feedstock is added, the intermediate alkylation product is obtained at the set reaction temperature and time (reaction temperature is 30℃, reaction time is 30 min, the weight ratio of aromatic feedstock to dodecene is 1:1, and the weight ratio of concentrated sulfuric acid catalyst to aromatic feedstock is 0.2:1).

[0098] (3) In the second stage of alkylation reaction, concentrated sulfuric acid is added to the reactor at a reaction temperature of 90°C. Dodecene is added continuously over a period of 30 minutes. After the olefin feedstock is added, the alkylation product is obtained at the set reaction temperature and time (reaction temperature is 80°C, reaction time is 30 minutes, the weight ratio of aromatic feedstock to dodecene is 1:0.5, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock is 0.2:1).

[0099] (4) The above alkylated products were subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon fraction with a distillation range of >450℃. The main physical properties are listed in Table 3.

[0100] Comparative Example 1

[0101] (1) Catalytic cracked diesel is introduced into a distillation tower to obtain a middle distillate section at 200-300℃. The properties of the feedstock and the middle distillate section are shown in Table 1.

[0102] (2) Alkylation reaction: The above-mentioned 200-300℃ middle distillate and trifluoromethanesulfonic acid were added to the reactor. The reaction temperature was 40℃, and dodecene was continuously added for 30 min. After the olefin feedstock was added, the intermediate alkylation product was obtained under the set reaction temperature and time (reaction temperature 40℃, reaction time 60 min, the weight ratio of aromatic feedstock to dodecene was 1:3, and the weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock was 0.3:1).

[0103] (3) The above alkylation product was subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon component with a distillation range of >450℃. The main physical properties are listed in Table 4.

[0104] Comparative Example 2

[0105] (1) Catalytic cracked diesel is introduced into a distillation tower to obtain a middle distillate section at 200-300℃. The properties of the feedstock and the middle distillate section are shown in Table 1.

[0106] (2) Alkylation reaction: The above-mentioned 200-300℃ middle distillate segment and trifluoromethanesulfonic acid were added to the reactor. The reaction temperature was 100℃, and dodecene was continuously added for 30 min. After the olefin feedstock was added, the alkylation product was obtained under the set reaction temperature and time (reaction temperature 100℃, reaction time 60 min, weight ratio of aromatic feedstock to dodecene 1:3, weight ratio of trifluoromethanesulfonic acid catalyst to aromatic feedstock 0.3:1).

[0107] (3) The above alkylation product was subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon component with a distillation range of >450℃. The main physical properties are listed in Table 4.

[0108] Comparative Example 3

[0109] (1) Catalytic cracked diesel is introduced into a distillation tower to obtain a middle distillate section at 200-300℃. The properties of the feedstock and the middle distillate section are shown in Table 1.

[0110] (2) First stage alkylation reaction: The above-mentioned 200-300℃ middle distillate and methanesulfonic acid are added to the reactor. The reaction temperature is 50℃, and dodecene is continuously added for 30 min. After the olefin feedstock is added, the intermediate alkylation product is obtained under the set reaction temperature and time (reaction temperature is 50℃, reaction time is 30 min, the weight ratio of aromatic feedstock to dodecene is 1:1, and the weight ratio of methanesulfonic acid catalyst to aromatic feedstock is 0.2:1).

[0111] (3) In the second stage of alkylation reaction, acetic acid is added to the reactor at a reaction temperature of 90°C, and dodecene is added continuously over a period of 30 min. After the olefin feedstock is added, the alkylation product is obtained at the set reaction temperature and time (reaction temperature is 100°C, reaction time is 30 min, the weight ratio of aromatic feedstock to dodecene is 1:0.5, and the weight ratio of methanesulfonic acid catalyst to aromatic feedstock is 0.2:1).

[0112] (4) The above alkylation product was subjected to a second distillation to obtain a polyalkyl aromatic hydrocarbon component with a distillation range of >500℃. The main physical properties are listed in Table 4.

[0113] Table 2

[0114]

[0115] Table 3

[0116] project Example 4 Example 5 Olefin conversion rate / % 100 99 Distillation range / (polyalkyl aromatic hydrocarbon components, °C) >450 >450 Yield / % 81 74 <![CDATA[Density (20 °C) / (kg / m 3 )]]> 891.6 875.2 <![CDATA[Kinematic viscosity (100 °C) / (mm 2 / s)]]> 18.96 16.23 <![CDATA[Aromatic carbon ratio / (C A , %)]]> 28.3 29.1 Polycyclic aromatic hydrocarbons (IP346) / % 0.27 0.19 w(B(a)P) / (mg / kg) 0.01 0.02 w(PAHs) / (mg / kg) 0.29 0.31

[0117] Table 4

[0118]

[0119]

[0120] As shown in Table 2-3, using the method provided by this invention, with aromatic oil and long-chain olefins as raw materials, a kinematic viscosity >22 mm can be obtained under suitable conditions. 2 It can produce bright oil products with a viscosity index >95 and high aromatic carbon content >28% and eight polycyclic aromatic hydrocarbon content less than 10mg / kg, and can also produce high aromatic environmentally friendly aromatic rubber plasticizer products.

[0121] Compared to Example 2, Comparative Example 1 involved alkylation only at low temperature, with all olefins continuously added to the alkylation reactor. At the same distillation cutting temperature, the yield of the resulting polyalkyl aromatic hydrocarbon components was lower, and both the product viscosity and viscosity index were also lower.

[0122] Compared to Example 2, Comparative Example 2 involved alkylation only at high temperature, with all olefins continuously added to the alkylation reactor. At the same distillation cut temperature, olefin conversion reached 100%, but the generated polyalkyl aromatic hydrocarbon components were less abundant, resulting in a lower product viscosity.

[0123] Compared to Examples 1-7, Comparative Example 3 used methanesulfonic acid as a catalyst. Due to its weaker acidity, the olefin conversion rate was lower, and only a small amount of polyalkyl aromatic hydrocarbon components were generated.

[0124] Therefore, this method, through a strongly acidic catalytic system and a two-stage alkylation reaction process, can achieve highly selective preparation of long-chain polyalkyl aromatic components. These components possess both high viscosity and viscosity index, making them suitable as high-quality bright oil products, and also exhibit a high aromatic carbon content and low polycyclic aromatic hydrocarbon content, making them suitable as environmentally friendly aromatic rubber plasticizer products.

[0125] 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.

Claims

1. A method for preparing polyalkyl aromatic hydrocarbon components, characterized in that, The method includes: (1) Fractional distillation of aromatic oil yields aromatic oil fractions with a distillation range of 180~320℃; (2) The first alkylation reaction is carried out in the presence of an alkylation catalyst, using the aromatic oil fraction or a mixture thereof with aromatic compounds as aromatic feedstock, and alkylating it with olefin feedstock to obtain intermediate alkylation product; the reaction temperature is 30-50℃, the reaction time is 5-90min; the mass ratio of aromatic oil to olefin is 1:0.3-3. (3) Second stage alkylation reaction: In the presence of an alkylation catalyst, the intermediate alkylation product and the olefin feedstock are alkylated at a higher temperature to obtain the alkylated product; the temperature of the second stage alkylation reaction is 30-70℃ higher than that of the first stage alkylation reaction; the reaction temperature is 60-120℃ and the reaction time is 5-90min. (4) The alkylation product is fractionated to obtain light and heavy components with a cutting point of 500~540℃, wherein the heavy component is a polyalkyl aromatic component product; The aromatic oil is selected from one or more of catalytic cracking diesel, catalytic cracking recycle oil, catalytic cracking slurry oil, reformed heavy aromatic oil, and ethylene tar; the aromatic compounds are monocyclic or bicyclic aromatic compounds with a boiling point of 180-320℃.

2. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 1, characterized in that, The aromatic feedstock contains more than 70 wt% aromatics; the olefin feedstock contains more than 50 wt% C8-C20 olefins, wherein the C8-C20 olefins are straight-chain α-olefins and / or internal olefins.

3. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 1 or 2, characterized in that, The aromatic compounds are selected from one or more of methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, biphenyl, acenaphthenes, fluorenes, and hexylbenzene.

4. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 1 or 2, characterized in that, The alkylation catalyst is selected from strongly acidic Bronsted acids with an acidity coefficient less than 0, or a composite acid of strongly acidic Bronsted acids and Lewis acids.

5. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 4, characterized in that, The strongly acidic Bronsted acid is selected from at least one of concentrated sulfuric acid, trifluoromethanesulfonic acid, fluorosulfonic acid, perchloric acid, and hydrobromic acid; the Lewis acid is selected from one or more of boron tribromide, boron trichloride, aluminum trichloride, boron trifluoride, ferric chloride, and zinc trichloride.

6. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 5, characterized in that, The alkylation catalyst is a composite acid with a strong acid Bronsted acid and Lewis acid in a mass ratio of 1 to 10:

1.

7. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 6, characterized in that, The mass ratio of the strongly acidic Bronsted acid to Lewis acid is 2~5:

1.

8. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 1 or 2, characterized in that, In the first stage of alkylation reaction, the mass ratio of the aromatic feedstock to the olefin is 1:0.5-2, and the mass ratio of the alkylation catalyst to the aromatic feedstock is 0.01-0.3:

1.

9. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 1 or 2, characterized in that, The operating conditions for the first stage alkylation reaction are: atmospheric pressure and reaction time of 20-60 min.

10. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 1 or 2, characterized in that, The operating conditions for the second-stage alkylation reaction are: atmospheric pressure; reaction temperature of 80-100℃; and reaction time of 20-60 min.

11. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 4, characterized in that, The first and second alkylation reactions use the same alkylation catalyst and the same olefin feedstock.

12. The method for preparing polyalkyl aromatic hydrocarbon components according to claim 4, characterized in that, The alkylation catalyst is a strongly acidic liquid-phase catalyst. In the first stage of the alkylation reaction, the olefin feedstock is continuously added to the strongly acidic liquid-phase catalyst for 10-100 min. In the second stage of the alkylation reaction, the olefin feedstock is continuously added to the strongly acidic liquid-phase catalyst for 10-100 min. After the reaction is completed, the reaction product and the catalyst settle and separate into layers in 5-240 min.

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