Method for increasing naphthene content of special white oil raw material for thermoplastic elastomer

Abstract

The present invention relates to the field of petrochemical technology and is a method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomers. The method comprises mixing a paraffin-based distillate with hydrogen and introducing it into a hydrorefining reaction zone, causing it to contact and react with a hydrorefining catalyst, removing impurities, and performing aromatic saturation to obtain a hydrorefined product oil. The hydrorefined product oil is mixed with hydrogen and introduced into a hydromodification reaction zone, causing it to contact and react with a hydromodification catalyst to obtain a hydromodified product oil. The hydromodified product oil is subjected to regular vacuum distillation to obtain a distillate having a boiling point greater than 420°C. The preparation method of the present invention is simple, environmentally friendly, and has mild reaction conditions. It can effectively increase the cycloalkane content while improving the production efficiency of the product. The obtained high-cycloalkane-content white oil raw material for thermoplastic elastomers, when used to prepare elastomer white oil, ensures good compatibility with polymer materials and safety performance during processing, while also ensuring the performance of rubber and plastic products.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical industry, and is a method for increasing the cycloalkane content of a white oil raw material special for thermoplastic elastomer. Background Art

[0002] Lubricating oil base oil is a technical product with functions such as lubricity, auxiliary cooling, rust prevention and cleaning. It is usually obtained from crude oil fractions or waste lubricating oils after deep processing to remove impurities and improve performance. Its quality directly affects the final performance and use effect of the lubricant. The white oil specially used for thermoplastic elastomers is a colorless and transparent oily liquid with a suitable hydrocarbon structure and good compatibility with SEBS, which is prepared by a multi-stage hydrogenation process of a suitable distillate oil from petroleum fractionation. It has excellent physical properties such as high flash point and good ultraviolet light stability and thermal stability. Special white oil for thermoplastic elastomers is an important auxiliary agent in the processing of elastomers, which can improve the processing performance, flexibility and aging resistance of elastomers. The cycloalkane content is a key indicator affecting the performance of white oil. White oil with a high cycloalkane value has better compatibility with elastomers and can significantly improve the flexibility and low temperature performance of thermoplastic elastomers. However, in the traditional white oil production process, the cycloalkane content is low, which is difficult to meet the needs of high-end elastomer processing. In the existing technology, cycloalkane distillate oil is an important auxiliary agent for the preparation of high C N Paraffin-based distillates are the primary raw material for white oil, but their low flash point and high evaporation losses make them inadequate for safe operation during elastomer processing and for ensuring stable performance in rubber and plastic products. Paraffin-based distillates can address these issues, but existing processes produce products with low cycloalkane content. To ensure a product with a high flash point and low evaporation losses, developing a method to increase the cycloalkane content using paraffin-based distillates as a raw material is crucial.

[0003] Thermoplastic elastomer (TPE) is a polymer material with properties between rubber and thermoplastic plastics. It has the dual nature and broad properties of rubber and plastics. It has the high elasticity of rubber at room temperature and the high elasticity of vulcanized rubber at room temperature. At high temperatures, it is easy to process and shape like thermoplastic plastics. It is a polymer material with the properties of both vulcanized rubber and thermoplastic plastics.

[0004] A Chinese patent document with authorization announcement number CN102021032B discloses a cycloalkyl filler oil for soft rubber toys and a preparation method thereof. Cycloalkyl crude oil is subjected to regular vacuum distillation to cut out a distillate oil with an acid value of less than 0.5 mgKOH / g and a distillation range of 350°C to 500°C. The distillate oil is hydrogenated using a bifunctional catalyst containing a molecular sieve with an Al2O3 carrier and an active nickel-tungsten or cobalt-molybdenum component added to obtain a hydrogenated component with a distillation range of 300°C to 400°C; the hydrogenated component is solvent refined with a solvent ratio of 1:1 to 2:1 and an extraction temperature of 45°C to 70°C to obtain a raffinate oil; the raffinate oil is further hydrogenated and supplemented with a refined catalyst using a nickel-tungsten or nickel-molybdenum system as an active component and an Al2O3 carrier; and a cycloalkyl filler oil having a polycyclic aromatic hydrocarbon content of less than 0.5%, an appearance Saybolt color greater than +30, a thermally stable Saybolt color greater than +20, and an open flash point greater than 160°C is obtained. However, the furfural refining extraction tower has poor selectivity, the aromatic content of the refined oil after extraction is too high, and the medium-pressure hydrogenation pressure is too low, which cannot completely saturate the aromatics, nor can the cycloalkanes be cracked to the ideal content, so white oil cannot be produced. In addition, the aromatics and cycloalkanes in the oil affect the physical and chemical properties, mechanical properties and yellowing resistance of SEBS rubber products.

[0005] Chinese patent publication CN117304976A discloses a naphthenic white oil specifically for SEBS and its preparation method. The naphthenic white oil specifically for SEBS is obtained by the following method: using naphthenic distillate as a feedstock, centrifuging the feedstock with an extraction solvent, removing aromatics and polar compounds from the feedstock to obtain a low-aromatic oil; hydrotreating the low-aromatic oil to obtain a hydrotreated product oil; isomerizing and de-pour point-reducing the hydrotreated product oil to obtain an isomerized de-pour point product oil; hydrorefining the isomerized de-pour point product oil to obtain a hydrorefined product oil; and collecting the fraction at 300°C to 500°C to obtain the naphthenic white oil specifically for SEBS. The naphthenic white oil prepared in this manner has a high viscosity index and a certain naphthenic content, and can be used as a rubber softening filler oil for specialty SEBS products. However, this method uses naphthenic feedstock, which has a low flash point, resulting in high volatility of the white oil product, which is detrimental to the product's stability and service life. Moreover, this technology has not undergone a deep dearomatization process, and the storage stability of white oil is poor.

[0006] As can be seen, the above methods all use naphthenic distillate as raw material, and adopt a combination of solvent refining and hydrogenation processes, resulting in poor physical and chemical properties, mechanical properties, and stability of the white oil. Therefore, it is necessary to develop a new method to increase the naphthenic content of white oil raw materials for thermoplastic elastomers. Summary of the Invention

[0007] The present invention provides a method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomers, overcoming the deficiencies of the above-mentioned prior art. The method can effectively solve the problems of poor physical and chemical properties, mechanical properties and stability of the existing white oil obtained by using cycloalkane distillate oil as raw material, as well as high volatility of the white oil product, low product yield and complex production process.

[0008] The technical solution of the present invention is achieved by the following measures: A method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer is carried out according to the following steps:

[0009] S1, paraffin-based distillate oil is mixed with hydrogen and enters the hydrorefining reaction zone, where it contacts and reacts with a hydrorefining catalyst, removes impurities, and performs aromatic saturation to obtain hydrorefined product oil. The distillation range of the paraffin-based distillate oil is 360°C to 530°C, and the density is 860kg / m 3 Up to 875kg / m 3 , the total cycloalkanes content is 40% to 50%, C N The value is less than 25%;

[0010] S2, mixing the hydrorefined oil with hydrogen and entering the hydroreforming reaction zone to react with the hydroreforming catalyst to obtain the hydroreforming oil;

[0011] S3, subjecting the hydrogenated and reformed oil to regular vacuum distillation to obtain a distillate oil with a boiling point higher than 420°C, which is a special white oil raw material for thermoplastic elastomer with a high cycloparaffin content.

[0012] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions:

[0013] In the above step S1, the hydrorefining catalyst is loaded on the upper part of the reactor bed; in step S2, the hydroreforming catalyst is loaded on the lower part of the reactor bed.

[0014] In the above step S1, the hydrorefining catalyst uses an activated alumina and titanium oxide composition as a carrier, and the active metal components in the hydrorefining catalyst are at least one of W, Co, and Mo and Ni. The content of the active metal components, calculated as the mass of the oxide, accounts for 15% to 30% of the mass of the hydrorefining catalyst, wherein the mass of nickel oxide in the oxide is 8% to 12%.

[0015] In the above step S1, the process conditions of the hydrofining reaction zone include: hydrogen partial pressure of 14MPa to 20MPa, hydrogen to oil volume ratio of 800 to 1200:1, hydrofining reaction temperature of 342°C to 380°C, volume space velocity of 0.53h -1 to 0.67h -1 .

[0016] In the above step S2, the hydro-reforming catalyst is supported by amorphous silica-alumina and one of β molecular sieve or Y molecular sieve, and the active metal components in the hydro-reforming catalyst are at least two of W, Ni, Co, and Mo, and the content of the active metal components is 15% to 30% of the mass of the catalyst in terms of oxide mass.

[0017] In the above step S2, the process conditions of the hydro-reforming reaction zone include: hydrogen partial pressure of 14MPa to 20MPa, hydrogen-oil volume ratio of 800 to 1200:1, hydro-reforming reaction temperature of 340°C to 370°C, volume space velocity of 1.0h -1 to 1.6 hours -1 .

[0018] In the above steps S1 and S2, the loading mass ratio of the hydrotreating catalyst to the hydroupgrading catalyst is 75% to 60%: 25% to 40%, and the hydrotreating reaction temperature is 2°C to 10°C higher than the hydroupgrading reaction temperature.

[0019] In the above step S3, the obtained high cycloalkane content white oil raw material for thermoplastic elastomer has a cycloalkane content of 65% to 75%, an open flash point greater than 215°C, a sulfur content less than 2 μg / g, a nitrogen content less than 2 μg / g, and a yield of the prepared elastomer white oil greater than 80%.

[0020] The preparation method of the present invention has simple process, environmental protection and mild reaction conditions, and can effectively increase the cycloalkane content while improving the production efficiency of the product. In addition, when preparing the elastomer white oil, the obtained high-cycloalkane content special white oil raw material for thermoplastic elastomers ensures good compatibility with polymer materials and safety performance in the processing process, while also ensuring the performance of rubber and plastic products. DETAILED DESCRIPTION

[0021] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all chemical reagents and chemicals commonly known in the prior art; unless otherwise specified, the percentages in the present invention are all percentages by mass; unless otherwise specified, the solutions in the present invention are all aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous hydrochloric acid solution; normal temperature and room temperature in the present invention generally refer to temperatures between 15°C and 25°C, and are generally defined as 25°C.

[0022] The present invention will be further described below in conjunction with the embodiments:

[0023] Example 1: The method for increasing the cycloalkane content of the white oil raw material for thermoplastic elastomer is carried out according to the following steps:

[0024] S1, paraffin-based distillate oil is mixed with hydrogen and enters the hydrorefining reaction zone, where it contacts and reacts with a hydrorefining catalyst, removes impurities, and performs aromatic saturation to obtain hydrorefined product oil. The distillation range of the paraffin-based distillate oil is 360°C to 530°C, and the density is 860kg / m 3 Up to 875kg / m 3 , the total cycloalkanes content is 40% to 50%, C N The value is less than 25%;

[0025] S2, mixing the hydrorefined product oil with hydrogen and entering the hydroreforming reaction zone, where the mixture is contacted with the hydroreforming catalyst to react and obtain the hydroreforming product oil;

[0026] S3, subjecting the hydrogenated and reformed oil to regular vacuum distillation to obtain a distillate oil with a boiling point higher than 420°C, which is a special white oil raw material for thermoplastic elastomer with a high cycloparaffin content.

[0027] The invention uses paraffin-based distillate oil as raw material and prepares a special white oil raw material for thermoplastic elastomer with high cycloalkane content through hydrogenation refining reaction and hydrogenation modification reaction. The raw material has the significant advantages of high cycloalkane content, low volatility, high flash point and excellent compatibility.

[0028] Among them, high cycloalkane content: through hydrogenation refining reaction and hydrogenation modification reaction, the hydrogenation treatment process is optimized, which significantly increases the cycloalkane content in the raw material, thereby enhancing the compatibility of white oil with polymer materials, and helps to improve the physical properties of elastomer products, such as tensile strength, wear resistance and flexibility.

[0029] Low volatility: After the raw materials are hydrogenated, their volatility is significantly reduced, ensuring the stability of the white oil during high temperature or long-term use, reducing volatilization losses and extending the service life of the product.

[0030] High flash point: The flash point of paraffin-based distillate oil is significantly increased through hydrogenation treatment, which improves the safety of white oil and reduces the fire risk during storage and use.

[0031] Excellent compatibility: The white oil prepared using this raw material has good compatibility with a variety of polymer materials, and can effectively improve the processing performance of elastomer products and the physical properties of the final product.

[0032] In the present invention, the distillation range is 360℃ to 530℃ and the density is 860kg / m 3 Up to 875kg / m 3 The distillate oil has the characteristics of high flash point and low volatility, and is suitable as a raw material for white oil special for thermoplastic elastomers. As a raw material for white oil special for thermoplastic elastomers, it has better advantages in ensuring the flash point, low volatility, and light and heat stability of the product.

[0033] Example 2: As an optimization of the above example, in step S1, the hydrorefining catalyst is loaded on the upper part of the reactor bed; in step S2, the hydroreforming catalyst is loaded on the lower part of the reactor bed.

[0034] Example 3: As an optimization of the above example, in step S1, the hydrorefining catalyst uses an activated alumina and titanium oxide composition as a carrier, the active metal components in the hydrorefining catalyst are at least one of W, Co, Mo and Ni, and the content of the active metal components is 15% to 30% of the mass of the hydrorefining catalyst in terms of the mass of the oxide, wherein the mass of nickel oxide in the oxide is 8% to 12%. As needed, the hydrorefining catalyst needs to be pre-sulfurized in-situ before use.

[0035] Example 4: As an optimization of the above example, in step S1, the process conditions of the hydrofining reaction zone include: hydrogen partial pressure of 14 MPa to 20 MPa, hydrogen-to-oil volume ratio of 800 to 1200:1, hydrofining reaction temperature of 342°C to 380°C, volume space velocity of 0.53 h -1 to 0.67h -1 .

[0036] Example 5: As an optimization of the above example, in step S2, the hydro-reforming catalyst is supported by amorphous silica-alumina and one of β molecular sieve or Y molecular sieve, and the active metal components in the hydro-reforming catalyst are at least two of W, Ni, Co, and Mo. The content of the active metal components is 15% to 30% of the mass of the catalyst in terms of oxide mass. As needed, the hydro-refining catalyst needs to be pre-sulfurized in-situ before use.

[0037] Example 6: As an optimization of the above embodiment, in step S2, the process conditions of the hydro-reforming reaction zone include: hydrogen partial pressure of 14 MPa to 20 MPa, hydrogen-oil volume ratio of 800 to 1200:1, hydro-reforming reaction temperature of 340°C to 370°C, volume space velocity of 1.0 h -1 to 1.6 hours -1 .

[0038] Example 7: As an optimization of the above example, in steps S1 and S2, the loading mass ratio of the hydrotreating catalyst and the hydromodifying catalyst is 75% to 60%: 25% to 40%, and the hydrotreating reaction temperature is 2°C to 10°C higher than the hydromodifying reaction temperature.

[0039] Example 8: As an optimization of the above example, in step S3, the obtained white oil raw material for thermoplastic elastomer with a high cycloalkane content has a cycloalkane content of 65% to 75%, an open flash point greater than 215°C, a sulfur content less than 2μg / g, a nitrogen content less than 2μg / g, and the yield of the prepared elastomer white oil is greater than 80%.

[0040] Example 9: The method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer to obtain a white oil raw material for thermoplastic elastomer with a high cycloalkane content is as follows:

[0041] Paraffin-based distillate oil with a distillation range of 360°C to 460°C was used as raw material. The main properties of the raw material are shown in Table 1. The raw material was mixed with hydrogen and entered into a hydrorefining reaction zone, where it was contacted and reacted with a hydrorefining catalyst. The hydrorefining reaction conditions are shown in Table 2. The hydrorefining product oil entered into a hydroupgrading reaction zone, where it was contacted and reacted with a hydroupgrading catalyst. The hydroupgrading reaction conditions are shown in Table 3. The loading ratio (mass ratio) of the hydrorefining catalyst to the hydroupgrading catalyst was 75:25. The hydrorefining catalyst was supported on a combination of activated alumina and titanium oxide, and the active metal of the hydrorefining catalyst was Ni-Co-Mo, with the mass proportion of the oxides thereof being 18%. The hydroupgrading catalyst was supported on amorphous silica-alumina and β molecular sieve, and the active component of the hydroupgrading catalyst was Ni-W, with the mass proportion of the oxides thereof being 15%. The resulting hydro-modified oil is subjected to atmospheric and vacuum distillation, and the components with a temperature greater than 420°C are collected as white oil raw materials for thermoplastic elastomers with high cycloalkane content. The main properties are shown in Table 4.

[0042] Example 10: The method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer to obtain a white oil raw material for thermoplastic elastomer with a high cycloalkane content is as follows:

[0043] Paraffin-based distillate oil with a distillation range of 360°C to 460°C was used as raw material. The main properties of the raw material are shown in Table 1. The raw material was mixed with hydrogen and entered into a hydrorefining reaction zone, where it was contacted and reacted with a hydrorefining catalyst. The hydrorefining reaction conditions are shown in Table 2. The hydrorefining product oil entered into a hydroupgrading reaction zone, where it was contacted and reacted with a hydroupgrading catalyst. The hydroupgrading reaction conditions are shown in Table 3. The loading ratio (mass ratio) of the hydrorefining catalyst to the hydroupgrading catalyst was 73:27. The hydrorefining catalyst used an activated alumina and titanium oxide combination as a support, and the active metal of the hydrorefining catalyst was Ni-W-Mo, with the mass proportion of the oxides thereof being 15%. The hydroupgrading catalyst used an amorphous silica-alumina and β molecular sieve as a support, and the active component of the hydroupgrading catalyst was Ni-Mo, with the mass proportion of the oxides thereof being 15%. The resulting hydro-modified oil is subjected to atmospheric and vacuum distillation, and the components with a temperature greater than 420°C are collected as white oil raw materials for thermoplastic elastomers with high cycloalkane content. The main properties are shown in Table 4.

[0044] Example 11: The method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer to obtain a white oil raw material for thermoplastic elastomer with a high cycloalkane content is as follows:

[0045] Paraffin-based distillate oil with a distillation range of 360°C to 460°C was used as raw material. The main properties of the raw material are shown in Table 1. The raw material was mixed with hydrogen and entered into a hydrorefining reaction zone, where it was contacted and reacted with a hydrorefining catalyst. The hydrorefining reaction conditions are shown in Table 2. The hydrorefining product oil entered into a hydroupgrading reaction zone, where it was contacted and reacted with a hydroupgrading catalyst. The hydroupgrading reaction conditions are shown in Table 3. The loading ratio (mass ratio) of the hydrorefining catalyst to the hydroupgrading catalyst was 70:30. The hydrorefining catalyst was supported on a combination of activated alumina and titanium oxide, and the active metal of the hydrorefining catalyst was Ni-W-Co, with the mass proportion of the oxide thereof being 25%. The hydroupgrading catalyst was supported on amorphous silica-alumina and β molecular sieve, and the active component of the hydroupgrading catalyst was Ni-Co-W, with the mass proportion of the oxide thereof being 18%. The resulting hydro-modified oil is subjected to atmospheric and vacuum distillation, and the components with a temperature greater than 420°C are collected as white oil raw materials for thermoplastic elastomers with high cycloalkane content. The main properties are shown in Table 4.

[0046] Example 12: The method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer to obtain a white oil raw material for thermoplastic elastomer with a high cycloalkane content is as follows:

[0047] Paraffin-based distillate oil with a distillation range of 390°C to 530°C was used as raw material. The main properties of the raw material are shown in Table 1. The raw material was mixed with hydrogen and entered into a hydrorefining reaction zone for contact reaction with a hydrorefining catalyst. The hydrorefining reaction conditions are shown in Table 2. The hydrorefining product oil entered into a hydroupgrading reaction zone for contact reaction with a hydroupgrading catalyst. The hydroupgrading reaction conditions are shown in Table 3. The loading ratio (mass ratio) of the hydrorefining catalyst to the hydroupgrading catalyst was 65:35. The hydrorefining catalyst was supported on a combination of activated alumina and titanium oxide. The active metal of the hydrorefining catalyst was Ni-Mo-Co, and the weight proportion of the oxides thereof was 18%. The hydroupgrading catalyst was supported on amorphous silica-alumina and Y-type molecular sieve. The active component of the hydroupgrading catalyst was Ni-W, and the weight proportion of the oxides thereof was 17%. The resulting hydro-modified oil is subjected to atmospheric and vacuum distillation, and the components with a temperature greater than 420°C are collected as white oil raw materials for thermoplastic elastomers with high cycloalkane content. The main properties are shown in Table 4.

[0048] Example 13: The method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer to obtain a white oil raw material for thermoplastic elastomer with a high cycloalkane content is as follows:

[0049] Paraffin-based distillate oil with a distillation range of 390°C to 530°C was used as raw material. The main properties of the raw material are shown in Table 1. The raw material was mixed with hydrogen and entered into a hydrorefining reaction zone, where it was contacted and reacted with a hydrorefining catalyst. The hydrorefining reaction conditions are shown in Table 2. The hydrorefining product oil entered into a hydroupgrading reaction zone, where it was contacted and reacted with a hydroupgrading catalyst. The hydroupgrading reaction conditions are shown in Table 3. The loading ratio (mass ratio) of the hydrorefining catalyst to the hydroupgrading catalyst was 60:40. The hydrorefining catalyst was supported on a combination of activated alumina and titanium oxide, and the active metal of the hydrorefining catalyst was Ni-W-Co, with the mass proportion of the oxides being 30%. The hydroupgrading catalyst was supported on amorphous silica-alumina and Y-type molecular sieve, and the active component of the hydroupgrading catalyst was Ni-Co, with the mass proportion of the oxides being 20%. The resulting hydro-modified oil is subjected to atmospheric and vacuum distillation, and the components with a temperature greater than 420°C are collected as white oil raw materials for thermoplastic elastomers with high cycloalkane content. The main properties are shown in Table 4.

[0050] Comparative Example 1: Paraffin-based distillate oil with a distillation range of 360°C to 460°C was used as feedstock. The main properties of the feedstock are shown in Table 1. This feedstock was mixed with hydrogen and introduced into a hydroprocessing reaction zone, where it then reacted with a hydroprocessing catalyst. The hydroprocessing conditions are shown in Table 2. The active metals of the hydroprocessing catalyst were Ni-W-Mo, with the oxides comprising 23% by weight. The resulting oil was subjected to atmospheric and vacuum distillation, and the fraction with a temperature greater than 420°C was collected as the white oil feedstock. The main properties are shown in Table 4.

[0051] The data in Tables 2 to 4 indicate that, compared with Comparative Example 1 (using a single catalyst), the method of the present invention for increasing the cycloparaffin content of a white oil feedstock for thermoplastic elastomers (using a gradation of two catalysts) yields a high-cycloparaffin-content white oil feedstock for thermoplastic elastomers having the characteristics of a high cycloparaffin content, a high flash point, and low volatility, making it more suitable for preparing excellent white oil for elastomers.

[0052] In summary, the preparation method of the present invention is simple, environmentally friendly, and has mild reaction conditions. It can effectively increase the cycloalkane content while improving the production efficiency of the product. In addition, the obtained high-cycloalkane content white oil raw material for thermoplastic elastomers ensures good compatibility with polymer materials and safety performance in the processing process when preparing elastomer white oil, while also ensuring the performance of rubber and plastic products, and is suitable for large-scale industrial production.

[0053] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

[0054] Table 1

[0055] .

[0056] Table 2

[0057] .

[0058] Table 3

[0059] .

[0060] Table 4

[0061] .

Claims

1. A method for increasing the cycloalkane content of white oil raw material for thermoplastic elastomer, characterized in that Follow the steps below: S1, paraffin-based distillate oil is mixed with hydrogen and enters the hydrorefining reaction zone, where it contacts and reacts with a hydrorefining catalyst, removes impurities, and performs aromatic saturation to obtain hydrorefined product oil. The distillation range of the paraffin-based distillate oil is 360°C to 530°C, and the density is 860kg / m 3 Up to 875kg / m 3 , the total cycloalkanes content is 40% to 50%, C N The value is less than 25%, the hydrorefining catalyst uses an activated alumina and titanium oxide composition as a carrier, the active metal components in the hydrorefining catalyst are at least one of W, Co, Mo and Ni, the content of the active metal components is 15% to 30% of the mass of the hydrorefining catalyst based on the mass of the oxide, wherein the mass of nickel oxide in the oxide is 8% to 12%, and the hydrorefining catalyst is loaded on the upper part of the reactor bed; S2, mixing the hydrorefined product oil with hydrogen and entering the hydroreforming reaction zone, where the oil is contacted with a hydroreforming catalyst for reaction to obtain a hydroreforming product oil, wherein the hydroreforming catalyst is supported by amorphous silica-alumina and one of β molecular sieve or Y molecular sieve, and the active metal components in the hydroreforming catalyst are at least two of W, Ni, Co, and Mo, and the content of the active metal components is 15% to 30% of the mass of the catalyst in terms of oxide mass, and the hydroreforming catalyst is loaded in the lower part of the reactor bed; S3, subjecting the hydrogenated reformed oil to regular vacuum distillation to obtain a distillate oil with a boiling point higher than 420°C, which is a white oil raw material for thermoplastic elastomers with a high cycloalkane content. The obtained white oil raw material for thermoplastic elastomers with a high cycloalkane content has a cycloalkane content of 65% to 75%, an open flash point greater than 215°C, a sulfur content less than 2μg / g, a nitrogen content less than 2μg / g, and a yield of the prepared elastomer white oil greater than 80%.

2. The method for increasing the cycloalkane content of the white oil raw material for thermoplastic elastomer according to claim 1, characterized in that In step S1, the process conditions of the hydrofining reaction zone include: hydrogen partial pressure of 14 MPa to 20 MPa, hydrogen to oil volume ratio of 800 to 1200:1, hydrofining reaction temperature of 342°C to 380°C, volume space velocity of 0.53h -1 to 0.67h -1 .

3. The method for increasing the cycloalkane content of a white oil raw material for thermoplastic elastomer according to claim 1 or 2, characterized in that In step S2, the process conditions of the hydro-reforming reaction zone include: hydrogen partial pressure of 14 MPa to 20 MPa, hydrogen-to-oil volume ratio of 800 to 1200:1, hydro-reforming reaction temperature of 340°C to 370°C, volume space velocity of 1.0 h -1 to 1.6 hours -1 .

4. The method for increasing the cycloalkane content of the white oil raw material for thermoplastic elastomer according to claim 3, characterized in that In steps S1 and S2, the loading mass ratio of the hydrotreating catalyst to the hydroupgrading catalyst is 75% to 60%: 25% to 40%, and the hydrotreating reaction temperature is 2°C to 10°C higher than the hydroupgrading reaction temperature.