Process for the production of polybutene and use of the product thereof

Abstract

The present application relates to a method for preparing olefin polymer by polymerizing C4 petroleum liquefied gas, which is used for preparing polybutene with different viscosity, such as lubricating oil base oil and metal processing oil. The method has less process, low requirement for raw material, low production cost and wide application field.

Description

Technical Field

[0001] This invention relates to a method for producing polybutene. Specifically, this invention relates to methods for producing and separating polybutene products of different viscosities, as well as the applications of these products. Background Technology

[0002] Polybutene is obtained by cationic catalytic polymerization of a mixture of C4 hydrocarbons, including isobutylene, butadiene, n-butene, and butane. These polybutenes are colorless, odorless, non-toxic, viscous, and adhesive substances, and are therefore widely used as adhesives, lubricating oil thickeners, insulating oils, sealants, crack sealants, plasticizers, asphalt modifiers, and dispersants, especially as lubricating oils and lubricating oil additives.

[0003] As is well known, polybutene can be prepared by polymerizing C4 hydrocarbons using a Friedel-Craft catalyst in a temperature range of -20°C to 50°C and then separating the residual catalyst from the product. The C4 hydrocarbons are produced from various feedstocks, such as feedstocks from heavy oil catalytic cracking in petroleum refining, or feedstocks obtained from a mixture of C4 hydrocarbons in naphtha cracking with or without 1,3-butadiene extraction.

[0004] US3121125 describes a method for producing polybutene using a catalyst ranging from 0.5% to 1.5% (by weight) relative to the weight of the olefin. However, this method has drawbacks. It uses the isobutylene polymerization product as the target product in the reaction system, while treating the polymerization of butene-1, butene-2, and butadiene as side reactions. This method not only reduces the viscosity index of the isobutylene polymerization product, limiting its application as a viscosity index enhancer in lubricating oils, but also requires additional processes such as raw material processing and catalyst recovery, increasing production costs and limiting product applications.

[0005] Similarly, in order to suppress this, Korean Patent Publication 93-6810 suggests adding a C4LPG as an additive component in the reaction system or partially hydrogenating the raw materials to eliminate butadiene, thereby reducing butadiene side reactions.

[0006] EP-A671419 discloses a method for preparing polybutene, in which the target polybutene is obtained by using boron trifluoride to catalyze the polymerization of C4 hydrocarbons. In order to reduce the polymerization reactions involving butene-1, butene-2, etc., a pretreatment step, such as selective hydroisomerization, is used to convert 1-butene into 2-butene to suppress so-called side reactions.

[0007] The patent method for polybutene disclosed in patent CN95104746 limits the butadiene content in the C4 hydrocarbon raw materials and requires methods to inhibit butadiene-involved polymerization. The polybutene method disclosed in patent CN104053685 requires the raw materials to maintain a high isobutylene content and a low butadiene content, and inhibits non-isobutylene-involved polymerization reactions by controlling the reaction process.

[0008] Conventional methods for removing catalyst remaining in the product after polymerization include physical methods (such as deposition, filtration, and adsorption) and chemical methods using water, ammonia, and alkaline solutions (such as ammonia / sodium hydroxide and potassium hydroxide). In this regard, US2677002 describes a method for removing residual catalyst by continuous deposition in a settling tank; however, this method has the disadvantage of losing unreacted gases and polymer contained in the removed catalyst.

[0009] Japanese Patent Publication No. 60-124603 describes a chemical method for removing catalyst remaining in a reaction system, which involves thoroughly washing the reaction products with water, an alkaline solution, and water, respectively. However, this method requires expensive equipment made of acid-resistant materials because HCl is generated during the washing process. US3121125 describes a method for removing catalyst using ammonia to form an ammonia-aluminum chloride complex, which is then separated from the reaction products by deposition, filtration, or centrifugation. However, ammonia may remain in the unreacted gas or products, and the amount of unreacted C4 mixture and polymer remaining in the separated complex is up to 10 times the amount of the ammonia-aluminum chloride complex.

[0010] Therefore, there is still a need for a polybutene production method that is simple in process, suitable for industrial production, and can overcome the problems existing in the production of polybutene using current technologies. Summary of the Invention

[0011] Based on the research results that solved these problems, the inventors of this invention discovered that polymerization products involving butene-1, butene-2, and butadiene can be separated from isobutene polymers through a simple separation method and further used as valuable products. This reduces reaction steps, lowers the requirements for raw materials in the polymerization reaction, and thus reduces production costs. Furthermore, the inventors also discovered that using powdered alkaline substances to remove residual catalysts simplifies the catalyst removal process and reduces the generation of wastewater, etc.

[0012] A first aspect of the present invention provides a method for preparing polybutene, the method comprising the steps of:

[0013] (a) Liquefied petroleum gas and a catalyst are added to a reactor, and polymerization is carried out in a temperature range of -10°C to 40°C, a pressure range of 1 to 10 bar, and a time range of 0.2 to 4 hours to obtain a polymerization reaction mixture; wherein the catalyst is a Lewis acid catalyst capable of initiating cationic polymerization of olefins.

[0014] (b) The polymerization reaction mixture in step (a) is contacted with a powdered alkaline substance to adsorb the catalyst and separate it from the reaction liquid to obtain a second polymerization reaction mixture;

[0015] (c) Under reduced pressure, unreacted liquefied petroleum gas is removed from the second polymerization reaction mixture to obtain a third polymerization reaction mixture;

[0016] (d) Catalytically hydrogenate the third polymerization reaction mixture obtained in step (c) to obtain the hydrogenated product.

[0017] In another preferred embodiment, the method further includes the step of:

[0018] (e) The hydrogenation product obtained in step (d) is fractionated to obtain the desired fraction of polybutene.

[0019] In another preferred embodiment, the method utilizes liquefied petroleum gas to polymerize and prepare the polybutene.

[0020] In another preferred embodiment, the polybutene is used as a base oil for lubricating oil or for metalworking.

[0021] In another preferred embodiment, the liquefied petroleum gas is a petroleum gas containing C4 olefins produced during the petroleum refining process, wherein the isobutene content is 5-50% (moles), the butene-1 content is 2-70% (moles), the butene-2 ​​(including cis-2-butene and trans-2-butene) content is 2-70% (moles), and the 1,3-butadiene content is 0-50% (moles).

[0022] In another preferred embodiment, the liquefied petroleum gas also includes small amounts of C3 and C5 hydrocarbons (including olefin and alkane components).

[0023] In another preferred embodiment, in step (a), the catalyst is selected from the group consisting of inorganic catalysts such as aluminum trichloride, ferric trichloride, boron trifluoride, tin tetrachloride, titanium tetrachloride, and zinc chloride, as well as alkyl aluminum halides and alkyl titanium halides.

[0024] In another preferred embodiment, in step (a), the reaction is further carried out in the presence of an auxiliary compound selected from the group consisting of alcohols, alkyl halides, or combinations thereof; preferably, the auxiliary compound is selected from the group consisting of methanol, ethanol, propanol, isopropanol, tert-butanol, chloroethane, chloropropane, tert-chlorobutane, or combinations thereof.

[0025] In another preferred embodiment, in step (a), the polymerization reaction is carried out in a solvent, and the solvent is an inert alkane organic solvent.

[0026] In another preferred embodiment, the inert alkane organic solvent refers to an alkane organic solvent that is inert to the reactants and catalyst.

[0027] In another preferred embodiment, the solvent can be removed from the reaction system and product during the flash evaporation and fractionation stages.

[0028] In another preferred embodiment, in step (b), the powdered alkaline substance used is an alkali metal or alkaline earth metal hydroxide powder, and the particle size of the powder is 5 to 100 micrometers.

[0029] In another preferred embodiment, the mass ratio of the powdered alkaline substance to the catalyst in step (a) is 0.02 to 20:1, preferably 0.2 to 10:1.

[0030] In another preferred embodiment, the catalytic hydrogenation is carried out in the presence of a solid supported hydrogenation catalyst.

[0031] In another preferred embodiment, the hydrogenation is carried out at a pressure of 0.5–10 MPa and a temperature of 50–200°C.

[0032] In another preferred embodiment, the volume ratio of hydrogen to feedstock oil solution is 100–400:1, and the space velocity is 0.5–3 h⁻¹. -1 .

[0033] In another preferred embodiment, in step (e), the fractionation is carried out using a rectification process, and the process parameters of the rectification process are as follows: rectification temperature: 150~280℃; rectification absolute pressure: 1~700Pa.

[0034] In another preferred embodiment, in step (e), the separated fraction is selected from the group consisting of: the fraction before 140°C, the fraction between 140°C and 200°C, the fraction above 200°C, or a combination thereof.

[0035] In another preferred embodiment, the fraction distilled at temperatures above 200°C is a high-viscosity fraction, which is used as the base oil for lubricating oil.

[0036] In another preferred embodiment, the kinematic viscosity of the fraction above 200°C at 100°C is >100 mmHg. 2 / s, acid value less than 0.01mg KOH / g, pour point below -15℃, viscosity index above 110.

[0037] In another preferred embodiment, the 140-200°C fraction is a medium viscosity fraction, used as a metalworking oil.

[0038] In another preferred embodiment, the 140-200℃ fraction has a kinematic viscosity of 10-100 mm² / s at 100℃, an acid value of less than 0.01 mg KOH / g, and a pour point below -15℃.

[0039] In another preferred embodiment, the 140°C pre-distillate is a low-viscosity fraction used as a metalworking oil.

[0040] In another preferred embodiment, the 140°C pre-distillate has a kinematic viscosity of 1–10 mm at 100°C. 2 / s, acid value less than 0.01mg KOH / g, pour point below -25℃.

[0041] In another preferred embodiment, the polybutene products of different viscosities further include a mixed fraction blended with high, medium and low viscosity fractions in a certain proportion.

[0042] In a second aspect, the present invention provides a polybutene product manufactured using the method described in the first aspect of the present invention.

[0043] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here. Detailed Implementation

[0044] This invention relates to a method for preparing polybutene, comprising the following steps: adding liquefied petroleum gas, solvent and catalyst to a reactor, and carrying out polymerization in a temperature range of -10℃ to 40℃, a pressure range of 1 to 10 bar and an hour of 0.2 to 4 hours;

[0045] The step of fully adsorbing the catalyst in the reaction solution of step (a) with a powdered alkaline substance;

[0046] The steps for removing unreacted liquefied petroleum gas under reduced pressure;

[0047] The remaining liquid is then hydrogenated using a hydrogenation catalyst.

[0048] The steps involve fractionating the polymer obtained above to obtain lubricating oil base oil and metalworking oil.

[0049] Liquefied petroleum gas

[0050] According to the present invention, the term "liquefied petroleum gas" uses the common concept in the art, namely, petroleum gas containing C4 olefins produced during petroleum refining. Besides isobutene, these C4 liquefied petroleum gases typically contain large amounts of 1-butene and 2-butene, and small amounts of 1,3-butadiene; furthermore, they usually contain a significant proportion of butane and isobutane. These isobutene-containing C4 liquefied petroleum gases are, for example, C4 raffinate, such as "raffinate 2," and especially "raffinate 1"; C4 fragments derived from isobutane dehydrogenation; C4 fragments derived from steam cracking and FCC cracking (fluid catalytic cracking), etc. The liquefied petroleum gas described in the present invention can also be the product of liquefied gas from the above-mentioned petroleum refining processes after certain component separation, enrichment, and isomerization, wherein the content of various C4 olefin components varies to some extent compared to industrially sourced liquefied petroleum gas.

[0051] In general, the content range of each C4 olefin component in the liquefied petroleum gas required by this invention is as follows: isobutene content of 5-50% (moles), butene-1 content of 2-70% (moles), butene-2 ​​content of 2-70% (moles), 1,3-butadiene content of 0-50% (moles), and the remainder being C3 and C5 hydrocarbons (including olefin and alkane components). Preferably, the composition consists of C4 hydrocarbons with isobutene content of 5-30% (moles), butene-1 content of 5-50% (moles), butene-2 ​​content of 5-30% (moles), and 1,3-butadiene content of 2-20% (moles).

[0052] Polymerization reaction

[0053] In this invention, a polymerization method is used to add liquefied petroleum gas to a reactor to prepare a polymer product, which is then further processed to obtain polybutene.

[0054] The reactor can be a stirred tank reactor or a tubular reactor, and can be a single reactor or a combination of multiple reactors; there are no particular limitations. The polymerization reaction is generally carried out in a temperature range of -10℃ to 40℃, and is generally conducted under isothermal conditions. Alternatively, the reaction can be carried out at one temperature for a period of time, followed by a change to another temperature for a period of time. The polymerization reaction is generally carried out in a pressure range of 1-10 bar, which can be the vapor pressure generated by the liquefied gas itself, or it can be provided by an inert gas such as nitrogen, depending on process requirements. The polymerization reaction time is generally 0.2-4 hours, preferably 0.3-1 hour. After the polymerization reaction is completed, the next process step is performed.

[0055] The catalyst described in this invention is a Lewis acid catalyst capable of initiating cationic polymerization of olefins. Among these catalysts, Friedel-Craft catalysts are preferred, such as inorganic catalysts like aluminum trichloride, ferric trichloride, boron trifluoride, tin tetrachloride, titanium tetrachloride, and zinc chloride, as well as alkyl metal compound catalysts like alkyl aluminum halides and alkyl titanium halides. Aluminum trichloride, boron trifluoride, titanium tetrachloride, and ethylaluminum dichloride are particularly preferred.

[0056] The catalyst system of this invention also includes auxiliary compounds, such as water, alcohols, and alkyl halides, which are used in conjunction with the aforementioned Friedel-Craft catalyst to generate carbocations to initiate polymerization reactions. These auxiliary compounds are preferably alcohols and alkyl halides, more preferably methanol, ethanol, propanol, isopropanol, tert-butanol, chloroethane, chloropropane, and tert-butane, with ethanol, isopropanol, tert-butanol, and tert-butane being the most preferred. The ratio of catalyst to auxiliary compound is selected from 1:10 to 2:1, preferably from 1:2 to 1:1.

[0057] The reaction components described in this invention can be fed simultaneously and separately, such as in a continuous reactor; or they can be fed separately as liquefied petroleum gas, catalyst, and auxiliary compounds and mixed in the reactor; or the catalyst and auxiliary compounds can be diluted separately with liquefied petroleum gas and then mixed in the reactor; or the required materials can be mixed with a solvent and then mixed in the reaction gas. There are no particular limitations on these methods.

[0058] The polymerization reaction described in this invention can be carried out in a solvent, which is an alkane-based organic solvent that is inert to the reactants and catalyst. The solvent can be removed from the reaction system and products during flash evaporation and fractionation. The solvent is preferably pentane, hexane, heptane, and cyclohexane. In this case, the volume ratio of C4 liquefied petroleum gas (LPG) to solvent is selected from 10:1 to 1:10, preferably from 5:1 to 1:5. The polymerization reaction can also be carried out under solvent-free conditions, in which case the LPG itself acts as the solvent.

[0059] The powdered alkaline substance described in this invention refers to an alkali metal or alkaline earth metal hydroxide powder, preferably sodium hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide, and more preferably magnesium hydroxide and calcium hydroxide. The powder particle size is 5–100 micrometers. The mass ratio of the powdered alkaline substance to the catalyst is 0.02–20:1, preferably 0.2–10:1. The process of the powdered alkaline substance adsorbing the catalyst includes the reaction of the alkaline substance with the catalyst to form metal halides and metal salts, and the adsorption of the reacted metal halides and metal salts on the surface of the powdered alkaline substance.

[0060] The process of separating the powdered alkaline substance from the polymerization reaction solution after adsorbing the catalyst, as described in this invention, can be carried out by means such as centrifugation or filtration, and there are no particular limitations.

[0061] The steps for removing unreacted liquefied petroleum gas described in this invention employ processes known to those skilled in the art, such as vacuum flash evaporation, and there are no particular limitations herein.

[0062] Hydrogenation

[0063] The hydrogenation step described in this invention refers to hydrogenating the pre-hydrogenated material obtained from the polymerization process in a fixed-bed or batch hydrogenation reactor to obtain hydrogenated base oil. The fixed-bed hydrogenation process can be described as follows: hydrogenation temperature: 150–280℃; hydrogenation pressure: 0.5–10.0 MPa; space velocity: 0.5–3.0 h⁻¹; hydrogen-to-oil ratio: 100–400:1. The batch hydrogenation process can be described as follows: hydrogenation temperature: 100–180℃; hydrogenation pressure: 2.0–6.0 MPa. In the hydrogenation step, the catalyst used is a commonly used hydrogenation catalyst, preferably a supported hydrogenation catalyst used in petrochemicals, such as DC series products, RIW series, supported Raney nickel catalysts, AlNi alloy hydrogenation catalysts, palladium-carbon catalysts, etc., but not limited to these listed hydrogenation catalysts. The hydrogenation step described in this invention can be carried out in the presence of a solvent, which is selected from alkane organic solvents that are inert to the hydrogenation reaction. Preferably, C5-C10 alkane solvents are used, with hexane, heptane, cyclohexane, and isooctane being more preferred. The solvent can be removed from the product during the fractionation stage. The volume ratio of the solvent to the C4 polymer at this stage is selected from 10:1 to 1:10, preferably from 5:1 to 1:5. The hydrogenation step can also be carried out under solvent-free conditions, in which case the C4 polymer itself acts as the solvent for the hydrogenation reaction.

[0064] Distillation

[0065] The distillation step described in this invention involves distilling the hydrogenated C4 polymer obtained from the hydrogenation process under negative pressure to obtain C4 polymer products of different viscosity grades. The distillation can be performed using a conventional distillation column, molecular distillation equipment, or any commercially available device capable of liquid fractionation. The process parameters for distillation are as follows: distillation temperature: 150–280°C; distillation absolute pressure: 1–700 Pa.

[0066] In addition, to ensure product quality, color consistency, and process stability, and to save costs, auxiliary processes can be added, such as solvent recovery, product decolorization, and filtration. All of these auxiliary processes can be used, or one or more can be used as needed; auxiliary processes can be used in different process stages as required.

[0067] According to the process steps described in this invention, the C4 polymer product obtained through the distillation step can be applied in different fields depending on its viscosity. The high-viscosity fraction can be used as a base oil for lubricating oils, with a kinematic viscosity >100 mmHg at 100°C. 2 The medium-viscosity fraction, used as a metalworking oil, has a kinematic viscosity of 10–100 mm² / s at 100°C, an acid value less than 0.01 mg KOH / g, a pour point below -15°C, and a viscosity index higher than 110. The low-viscosity fraction, used as a metalworking oil, has a kinematic viscosity of 1–10 mm² / s at 100°C. 2 The product has an acid value of less than 0.01 mg KOH / g and a pour point below -25°C. The above-mentioned products can be used alone as base oils for final products such as lubricating oils and quenching oils, or they can be blended with components of different viscosities in a certain proportion and used as blending components for the final product.

[0068] In one embodiment, the invention also relates to polybutene products produced from the aforementioned liquefied petroleum gas.

[0069] Compared with the prior art, the main advantages of the present invention include:

[0070] The production method of this invention can use low-viscosity materials, reduce reaction steps, lower the requirements of the polymerization reaction for raw materials, simplify the catalyst removal process, reduce production costs, expand the application fields of the product, and is more suitable for industrial production.

[0071] The lubricating oil base oil produced by the method provided by this invention has the characteristics of being clean, having good oxidation stability, and having a high viscosity index, making it suitable for blending finished lubricating oils.

[0072] The metalworking oil produced using the method provided by this invention has the characteristics of low halogen content and non-corrosiveness, making it suitable for blending such metalworking oils.

[0073] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. Percentages and parts are by weight unless otherwise stated.

[0074] The liquefied gas materials and their components used in the examples are shown in the table below:

[0075] Table 1 Material Composition of Liquefied Petroleum Gas

[0076] Serial Number Components Material 1 Material 2 Material 3 1 propylene 0.03 0.1 0.03 2 propane 0.06 0 0.04 3 butadiene 0.67 0 5.01 4 Isobutane 31.71 3.94 23.21 5 Isobutylene 22.64 48.13 25.44 6 Butene-1 9.72 27.61 10.89 7 trans-2-butene 14.30 8.86 14.35 8 n-Butane 9.86 6.13 10.03 9 cis-2-butene 10.52 5.23 10.46 10 n-Pentane 0.49 0 0.53 11 total 100 100 100

[0077] Example 1

[0078] In a continuous batch polymerization reactor, C4 liquefied petroleum gas (LPG) feedstock 1, BF3, and the auxiliary compound tert-butanol were separately injected. The molar ratio of tert-butanol to boron trifluoride (BF3) was 1.6:1. Boron trifluoride was injected at a concentration such that, relative to 100 parts by weight of feedstock 1 in the reactants, the content of boron trifluoride was 0.05 parts by weight. The reactor was maintained at -5°C and at a minimum pressure of 3 kg / cm³. 2 Under pressure, to maintain the reactants in a liquid state, the average residence time was 30 minutes. After 180 minutes, the collected polymerization product was added to another reactor, along with 5% (by mass) of potassium hydroxide powder with an average particle size of 150 μm. After stirring for 15 minutes, the solids were filtered off. The remaining reaction liquid was flash-evaporated to remove unreacted C4 liquefied gas and then pumped into a fixed-bed hydrogenation reactor. The reactor was packed with clover-shaped alumina supported on a 1 wt% palladium catalyst. The hydrogenation temperature was 180℃; the hydrogenation pressure was 3.0 MPa; the space velocity was 1.0 h⁻¹; and the hydrogen-to-oil ratio was 150:1. After hydrogenation, the product was subjected to negative pressure distillation at an absolute pressure of 30 Pa and a heating temperature of 200℃. The fractions before 140℃, the fractions between 140-200℃, and the remaining fraction were collected. The conversion rate of C4 liquefied gas to polymer product was calculated to be 29.7%. The mass percentage, viscosity, and viscosity index of each fraction in the polymer product are shown in Table 2.

[0079] Example 2

[0080] It is basically the same as Example 1, but with the following changes:

[0081] Liquefied petroleum gas (LPG) was used as material 2, aluminum trichloride was used as the catalyst, tert-butyl chloride was used as the auxiliary compound, and the reaction temperature was 5℃. The powdered alkaline substance was calcium hydroxide powder with an average particle size of 300 μm. The conversion rate of C4 LPG to polymer products was calculated to be 63.2%. The mass percentage, viscosity, and viscosity index of each fraction in the polymer products are shown in Table 2.

[0082] Example 3

[0083] It is basically the same as Example 1, but with the following changes:

[0084] A batch reactor was used. Liquefied petroleum gas (LPG) was used as material 3. The conversion rate of C4 LPG to polymer products was calculated to be 35.7%. The mass percentage, viscosity, and viscosity index of each fraction in the polymer products are shown in Table 2.

[0085] Example 4

[0086] It is basically the same as Example 1, but with the following changes:

[0087] The catalyst used was ethyl aluminum dichloride, and the auxiliary compound was benzyl chloride. The molar ratio of benzyl chloride to ethyl aluminum dichloride was 1.0:1. The content of ethyl aluminum dichloride was 0.15 parts by weight per 100 parts by weight of material 1 in the reactants. The reaction temperature was 10℃, and the powdered alkaline substance was magnesium hydroxide powder with an average particle size of 200 μm. The conversion rate of C4 liquefied petroleum gas to polymer products was calculated to be 30.1%. The mass percentage, viscosity, and viscosity index of each fraction in the polymer products are shown in Table 2.

[0088] The fractionation test results of the products prepared in Examples 1-4 above are shown in the table below.

[0089] Table 2. Product Fractionation Test Results

[0090]

[0091]

[0092] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A process for the preparation of polybutene, characterized in that, The method includes the following steps: (a) Liquefied petroleum gas and a catalyst are added to a reactor, and polymerization is carried out in a temperature range of -10°C to 40°C, a pressure range of 1 to 10 bar, and an hour of 0.2 to 4 hours to obtain a polymerization reaction mixture; wherein the catalyst is a Lewis acid catalyst capable of initiating cationic polymerization of olefins; and the Lewis acid catalyst is selected from the group consisting of: aluminum trichloride, ferric chloride, boron trifluoride, tin tetrachloride, titanium tetrachloride, zinc chloride, alkyl aluminum halide, and alkyl titanium halide; the reaction is also carried out in the presence of an auxiliary compound, and the auxiliary compound is selected from the group consisting of: alcohols, alkyl halides, or combinations thereof; (b) A powdered alkaline substance is brought into contact with the polymerization reaction mixture in step (a) to adsorb the catalyst and separate it from the reaction mixture to obtain a second polymerization reaction mixture; in step (b), the powdered alkaline substance used is an alkali metal or alkaline earth metal hydroxide powder, and the particle size of the powder is 5 to 100 micrometers. (c) Under reduced pressure, unreacted liquefied petroleum gas is removed from the second polymerization reaction mixture to obtain a third polymerization reaction mixture; (d) Catalytically hydrogenate the third polymerization reaction mixture obtained in step (c) to obtain the hydrogenated product.

2. The method of claim 1, wherein, The method further includes the steps of: (e) The hydrogenation product obtained in step (d) is fractionated to obtain the desired fraction of polybutene.

3. The method of claim 1, wherein, The liquefied petroleum gas is petroleum gas containing C4 olefins produced during the petroleum refining process, wherein the isobutene content is 5-50 mol%, the butene-1 content is 2-70 mol%, the butene-2 ​​includes cis-2-butene and trans-2-butene, with a content of 2-70 mol%, and the 1,3-butadiene content is 0-50 mol%.

4. The method of claim 1, wherein, In step (a), the auxiliary compound is selected from the group consisting of methanol, ethanol, propanol, isopropanol, tert-butanol, chloroethane, chloropropane, tert-chlorobutane, or combinations thereof.

5. The method of claim 1, wherein, In step (a), the polymerization reaction is carried out in a solvent, and the solvent is an inert alkane organic solvent.

6. The method as described in claim 1, characterized in that, The catalytic hydrogenation is carried out in the presence of a solid supported hydrogenation catalyst.

7. The method of claim 2, wherein, In step (e), the fractionation adopts a rectification process, and the process parameters of the rectification process are as follows: rectification temperature: 150~280 ℃; rectification absolute pressure: 1~700 Pa.

8. A polybutene product characterized in that, The polybutene product is manufactured using the method described in any one of claims 1 to 7.

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