A method and system for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene

Abstract

The invention discloses a method and system for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene: comprising the following steps: using crude diisobutylene as a raw material, firstly performing light-heavy-removal distillation separation to obtain diisobutylene, and then performing extractive distillation and solvent recovery to separate and obtain high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene products. The present application has the advantages of short process flow, high product purity, and wide solvent application range.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a method and a system for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene. Background Art

[0002] Diisobutylene is an important organic intermediate, widely used in synthetic rubber tackifiers, surfactants, octylphenol, isononyl alcohol and other fields.

[0003] In the industrial field, 2,4,4-trimethyl-2-pentene is usually mixed with 2,4,4-trimethyl-1-pentene and sold as a mixture of diisobutylene. However, in downstream applications, it is found that although both components can participate in the reaction, 2,4,4-trimethyl-2-pentene usually needs to be isomerized into 2,4,4-trimethyl-1-pentene before participating in the reaction, which directly affects the reaction rate and production efficiency. In order to improve the utilization rate and economy of the components, efficient separation of the two isomers is imperative.

[0004] CN109867583A discloses a process and system device for obtaining 2,4,4-trimethyl-1-pentene from C4 superimposed oil. However, this process separates the extractant from the heavy components after extraction and distillation, which results in high energy consumption and a small application range of the extractant.

[0005] CN108056576A discloses a method for preparing 2,4,4-trimethyl-1-pentene. Although the product does not require distillation and refining, it has problems such as long reaction time, high requirements on the material of reaction equipment, and high difficulty in industrialization. Summary of the invention

[0006] In view of this, the present invention aims to provide a method and system for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene to solve at least one technical problem in the background technology.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows: A method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene comprises the following steps: using crude diisobutylene as a raw material, firstly performing light-heavy-removal distillation separation to obtain diisobutylene, and then performing extractive distillation and solvent recovery to separate and obtain high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene products.

[0008] Furthermore, the crude diisobutylene includes, by mass, light components of 1%-15%, 2,4,4-trimethyl-1-pentene of 37%-58%, 2,4,4-trimethyl-2-pentene of 8%-20%, and C8+ components of 7%-40%.

[0009] Furthermore, the extractant in the extractive distillation includes one or more of N,N-dimethylformyl, N,N-diethylaniline, and triethanol.

[0010] Preferably, the extractant is N,N-dimethylformyl, N,N-diethylaniline and triethanol.

[0011] The light removal is carried out in a light removal tower, the top temperature of the tower is 80-90℃, the top pressure is 0.05-0.15MPaG, the bottom temperature is 140-160℃, and the bottom pressure is 0.10-0.14MpaG; The deweighting is carried out in a deweighting tower, the top temperature of the deweighting tower is 50-60℃, the top pressure is -0.6--0.8MpaG, the bottom temperature is 140-160℃, and the bottom pressure is -0.05--0.07MPaG; The extractive distillation is carried out in an extractive distillation tower, the top temperature of the extractive distillation tower is 55-60°C, the top pressure is -0.08--0.10MPaG, the bottom temperature is 110-120°C, and the bottom pressure is -0.06--0.12MPaG; The solvent recovery is carried out in a solvent recovery tower, the top temperature of the solvent recovery tower is 50-70°C, the top pressure is -0.06--0.08MPaG, the bottom temperature is 110-130°C, and the bottom pressure is -0.07--0.09MPaG.

[0012] The preparation system used in the above-mentioned method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene includes a light removal tower, a heavy removal tower reboiler, an extractive distillation tower, and a solvent recovery tower connected in sequence; The raw materials enter from one side of the light removal tower, the light components are discharged from the top of the light removal tower, and the C8+ components are discharged from the bottom of the reboiler of the heavy removal tower; The 2,4,4-trimethyl-1-pentene product is taken out from the top of the extractive distillation tower; The 2,4,4-trimethyl-2-pentene product is taken out from the top of the solvent recovery tower.

[0013] Furthermore, the bottom of the light removal tower is connected to the middle of the heavy removal tower, the top of the heavy removal tower is connected to the lower part of the extractive distillation tower, the bottom of the extractive distillation tower is connected to the middle part of the solvent recovery tower, and the bottom of the solvent recovery tower is connected to the upper part of the extractive distillation tower.

[0014] Furthermore, a first branch and a second branch are provided at the bottom of the light-removal tower, the first branch is connected to the middle of the heavy-removal tower, the second branch is connected to the bottom of the light-removal tower reboiler, and the light-removal tower reboiler is provided on the second branch; The top of the lightness removal tower is connected to a lightness removal tower cooler through a pipeline. The lightness removal tower cooler is provided with a third branch and a fourth branch. The third branch is used for extracting light components, and the fourth branch is connected to the upper part of the lightness removal tower.

[0015] Furthermore, the top of the deweighting tower is connected to a deweighting tower cooler through a pipeline, the deweighting tower cooler is connected to the fifth branch and the sixth branch, the fifth branch is connected to the middle of the extractive distillation tower, and the sixth branch is connected to the upper part of the deweighting tower; The bottom of the de-weighting tower is provided with a seventh branch and an eighth branch, the seventh branch is connected with the middle part of the de-weighting tower, a de-weighting tower reboiler is arranged on the seventh branch, and the eighth branch extracts C8+ components.

[0016] Furthermore, a ninth branch and a tenth branch are provided at the bottom of the extractive distillation tower, and the ninth branch is connected to the middle of the solvent recovery tower. The tenth branch is connected to the lower part of the extractive distillation tower; The tenth branch is provided with an extractive distillation tower reboiler; The top of the extractive distillation tower is connected to an extractive distillation tower cooler through a pipeline, and an eleventh branch and a twelfth branch are arranged behind the extractive distillation tower cooler. The eleventh branch is connected to the upper part of the extractive distillation tower, and the twelfth branch produces 2,4,4-trimethyl-1-pentene product.

[0017] Furthermore, the top of the solvent recovery tower is connected to a solvent recovery tower cooler through a pipeline, and the solvent recovery tower cooler is provided with a thirteenth branch and a fourteenth branch, the thirteenth branch is connected to the upper part of the solvent recovery tower, and the fourteenth branch produces a 2,4,4-trimethyl-2-pentene product; Furthermore, a fifteenth branch and a sixteenth branch are provided at the bottom of the solvent recovery tower, the fifteenth branch is connected to the lower part of the solvent recovery tower, a solvent recovery tower reboiler is provided on the fifteenth branch, and the sixteenth branch is connected to the upper part of the extraction distillation tower.

[0018] Compared with the prior art, the method and system for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene according to the present invention have the following advantages: The method has reasonable process settings and can separate the isomers of diisobutylene with low energy consumption to obtain high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene products. This method has strong universality and is friendly to composite extractants, providing a basis for the diversification of extraction and distillation extractants. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 This is a schematic diagram of a system for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene according to an embodiment of the present invention.

[0020] Description of reference numerals: 1. Light-removal tower; 2. Reboiler of light-removal tower; 3. Cooler of light-removal tower; 4. Cooler of heavy-removal tower; 5. Heavy-removal tower; 6. Reboiler of heavy-removal tower; 7. Cooler of extractive distillation tower; 8. Extractive distillation tower; 9. Reboiler of extractive distillation tower; 10. Cooler of solvent recovery tower; 11. Solvent recovery tower; 12. Reboiler of solvent recovery tower. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0024] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0025] like Figure 1 As shown, a method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene comprises the following steps: using crude diisobutylene as a raw material, firstly performing light and heavy fractionation separation to obtain diisobutylene, and then performing extractive distillation and solvent recovery to separate and obtain high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene products. Crude diisobutylene comprises, by mass, 1%-15% of light components, 37%-58% of 2,4,4-trimethyl-1-pentene, 8%-20% of 2,4,4-trimethyl-2-pentene, and 7%-40% of C8+ components.

[0026] The extractant in the extractive distillation includes one or more of N,N-dimethylformyl, N,N-diethylaniline, and triethanol; The light removal is carried out in the light removal tower 1, the tower top temperature of the light removal tower 1 is 80-90°C, the tower top pressure is 0.05-0.15MPaG, the tower bottom temperature is 140-160°C, and the tower bottom pressure is 0.10-0.14MpaG; The deweighting is carried out in the deweighting tower 5, the top temperature of the deweighting tower 5 is 50-60°C, the top pressure is -0.6--0.8MpaG, the bottom temperature is 140-160°C, and the bottom pressure is -0.05--0.07MPaG; The extractive distillation is carried out in an extractive distillation tower 8, the top temperature of the extractive distillation tower 8 is 55-60°C, the top pressure is -0.08--0.10MPaG, the bottom temperature is 110-120°C, and the bottom pressure is -0.06--0.12MPaG; The solvent recovery is carried out in the solvent recovery tower 11, the top temperature of the solvent recovery tower 11 is 50-70°C, the top pressure is -0.06--0.08MPaG, the bottom temperature is 110-130°C, and the bottom pressure is -0.07--0.09MPaG.

[0027] The preparation system used in the above-mentioned method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene includes a light removal tower 1, a heavy removal tower reboiler 6, an extractive distillation tower 8, and a solvent recovery tower 11 which are connected in sequence; the raw material enters from one side of the light removal tower 1, the light components are discharged from the top of the light removal tower 1, and the C8+ components are discharged from the bottom of the heavy removal tower reboiler 6; the 2,4,4-trimethyl-1-pentene product is extracted from the top of the extractive distillation tower 8; and the 2,4,4-trimethyl-2-pentene product is extracted from the top of the solvent recovery tower 11.

[0028] The bottom of the light-removing tower 1 is connected to the middle of the heavy-removing tower 5, the top of the heavy-removing tower 5 is connected to the lower part of the extractive distillation tower 8, the bottom of the extractive distillation tower 8 is connected to the middle of the solvent recovery tower 11, and the bottom of the solvent recovery tower 11 is connected to the upper part of the extractive distillation tower 8. The bottom of the light-removing tower 1 is provided with a first branch and a second branch, the first branch is connected to the middle of the heavy-removing tower 5, the second branch is connected to the bottom of the light-removing tower reboiler 2, and the second branch is provided with the light-removing tower reboiler 2; the top of the light-removing tower 1 is connected to the light-removing tower cooler 3 through a pipeline, and the light-removing tower cooler 3 is provided with a third branch and a fourth branch, the third branch is used to extract light components, and the fourth branch is connected to the upper part of the light-removing tower 1.

[0029] The top of the deweighting tower 5 is connected to the deweighting tower cooler 4 through a pipeline, the deweighting tower cooler 4 is connected to the fifth branch and the sixth branch, the fifth branch is connected to the middle part of the extractive distillation tower 8, and the sixth branch is connected to the upper part of the deweighting tower 5; the bottom of the deweighting tower 5 is provided with a seventh branch and an eighth branch, the seventh branch is connected to the middle part of the deweighting tower 5, the seventh branch is provided with a deweighting tower reboiler 6, and the eighth branch extracts C8+ components.

[0030] The bottom of the extractive distillation tower 8 is provided with a ninth branch and a tenth branch, the ninth branch is connected to the middle part of the solvent recovery tower 11, and the tenth branch is connected to the lower part of the extractive distillation tower 8; the tenth branch is provided with an extractive distillation tower reboiler 9; the top of the extractive distillation tower 8 is connected to the extractive distillation tower cooler 7 through a pipeline, and the eleventh branch and the twelfth branch are provided behind the extractive distillation tower cooler 7, the eleventh branch is connected to the upper part of the extractive distillation tower 8, and the twelfth branch produces 2,4,4-trimethyl-1-pentene product.

[0031] The top of the solvent recovery tower 11 is connected to the solvent recovery tower cooler 10 through a pipeline. The solvent recovery tower cooler 10 is provided with a thirteenth branch and a fourteenth branch. The thirteenth branch is connected to the upper part of the solvent recovery tower 11, and the fourteenth branch produces 2,4,4-trimethyl-2-pentene product; the bottom of the solvent recovery tower 11 is provided with a fifteenth branch and a sixteenth branch. The fifteenth branch is connected to the lower part of the solvent recovery tower 11, and a solvent recovery tower reboiler 12 is provided on the fifteenth branch. The sixteenth branch is connected to the upper part of the extractive distillation tower 8.

[0032] Example 1 In a specific implementation, the crude diisobutylene composition is 8.5% of light components, 45.2% of 2,4,4-trimethyl-1-pentene, 11.3% of 2,2,4-trimethyl-2-pentene, and 35% of isobutane as a C8+ component. The crude diisobutylene enters a light component removal tower 1, with a tower top temperature of 85°C, a tower top pressure of 0.1MPaG, a tower bottom temperature of 150°C, and a tower bottom pressure of 0.12MpaG. The light component is extracted from the tower top, and the components after light component removal are extracted through the tower bottom and enter a heavy component removal tower 5. The tower top temperature of the heavy component removal tower 5 is 55°C, the tower top pressure is -0.7MpaG, the tower bottom temperature is 150°C, the tower bottom pressure is -0.06MPaG, and the tower bottom extracts C8+ components; the C8+ components after heavy component removal are extracted through the tower top of the heavy component removal tower 5, and enter the extractive distillation tower 8 through the lower part of the extractive distillation tower 8; N,N-dimethylformamide is selected as the extractant, and the extractant is extracted through The upper part of the extractive distillation tower 8 enters the extractive distillation tower 8, the mass ratio of the solvent to the C8+ component is 3:1, the top temperature of the extractive distillation tower 8 is 55°C, the top pressure is -0.09MPaG, the bottom temperature is 115°C, the bottom pressure is -0.08MPaG, and after extractive distillation, 2,4,4-trimethyl-1-pentene product is produced from the top of the tower, and the product purity is 97.1%; the solvent rich in 2,4,4-trimethyl-2-pentene enters the solvent recovery tower 11 through the bottom of the extractive distillation tower 8, the top temperature of the solvent recovery tower 11 is 60°C, the top pressure is -0.07MPaG, the bottom temperature is 120°C, the bottom pressure is -0.08MPaG, and 2,4,4-trimethyl-2-pentene with a purity of 96.7% is produced from the top of the solvent recovery tower 11, and the recovered solvent is produced from the bottom of the tower and returned to the extractive distillation tower 8 for recycling.

[0033] Example 2 The difference from Example 1 is that the solvent composition is a mixture of 85wt% N,N-dimethylacetamide, 13w% N,N-diethylaniline, and 2wt% triethanolamine, and a 2,4,4-trimethyl-1-pentene product with a purity of 98.5% and a 2,4,4-trimethyl-2-pentene with a purity of 99.3% can be obtained.

[0034] Example 3 The difference from Example 1 is that the solvent composition is 85wt% N,N-dimethylacetamide and 15w% N,N-diethylaniline; The obtained products are 2,4,4-trimethyl-1-pentene with a purity of 97.5% and 2,4,4-trimethyl-2-pentene with a purity of 97.3%.

[0035] Example 4 The difference from Example 1 is that the solvent composition is 75wt% N,N-dimethylacetamide and 25w% triethanolamine; The obtained products are 2,4,4-trimethyl-1-pentene with a purity of 97.8% and 2,4,4-trimethyl-2-pentene with a purity of 97.9%.

[0036] Example 5 The difference from Example 1 is that the solvent composition is triethanolamine; a 2,4,4-trimethyl-1-pentene product with a purity of 90.5% and a 2,4,4-trimethyl-2-pentene with a purity of 85.3% can be obtained.

[0037] Example 6 In a specific implementation, the crude diisobutylene composition is 8.5% of light components, 45.2% of 2,4,4-trimethyl-1-pentene, 11.3% of 2,2,4-trimethyl-2-pentene, and 35% of C8+ component isobutane. The crude diisobutylene enters the light component removal tower 1, with a tower top temperature of 85°C, a tower top pressure of 0.1MPaG, a tower bottom temperature of 150°C, and a tower bottom pressure of 0.12MpaG. The light component is extracted from the tower top, and the components after light component removal are extracted through the tower bottom and enter the de-weighting tower 5. The tower top temperature of the de-weighting tower 5 is 55°C, the tower top pressure is -0.7MpaG, the tower bottom temperature is 150°C, the tower bottom pressure is -0.06MPaG, and the tower bottom extracts the C8+ component; the C8+ component after de-weighting is extracted through the tower top of the de-weighting tower 5, and enters the extractive distillation tower 8 through the lower part of the extractive distillation tower 8; N-formamide is selected as the extractant, and the extractant is extracted through the extraction The upper part of the distillation tower 8 enters the extractive distillation tower 8, the mass ratio of the solvent to the C8+ component is 4:1, the top temperature of the extractive distillation tower 8 is 57°C, the top pressure is -0.08MPaG, the bottom temperature is 118°C, the bottom pressure is -0.07MPaG, and after extractive distillation, 2,4,4-trimethyl-1-pentene product is extracted from the top of the tower, and the product purity is 96.1%; the solvent rich in 2,4,4-trimethyl-2-pentene enters the solvent recovery tower 11 through the bottom of the extractive distillation tower 8, the top temperature of the solvent recovery tower 11 is 60°C, the top pressure is -0.07MPaG, the bottom temperature is 120°C, the bottom pressure is -0.08MPaG, and the top of the solvent recovery tower 11 extracts 2,4,4-trimethyl-2-pentene with a purity of 95.7%, and the recovered solvent is extracted from the bottom of the tower and returned to the extractive distillation tower 8 for recycling. Example 7 In a specific implementation, the crude diisobutylene composition is 8.5% of light components, 45.2% of 2,4,4-trimethyl-1-pentene, 11.3% of 2,2,4-trimethyl-2-pentene, and 35% of isobutane, a C8+ component. The crude diisobutylene enters a light component removal tower 1, with a tower top temperature of 85°C, a tower top pressure of 0.1MPaG, a tower bottom temperature of 150°C, and a tower bottom pressure of 0.12MpaG. The light component is extracted from the tower top, and the components after light component removal are extracted through the tower bottom and enter a heavy component removal tower 5. The tower top temperature of the heavy component removal tower 5 is 55°C, the tower top pressure is -0.7MpaG, the tower bottom temperature is 150°C, the tower bottom pressure is -0.06MPaG, and the tower bottom extracts C8+ components; the C8+ components after heavy component removal are extracted through the tower top of the heavy component removal tower 5, and enter the extractive distillation tower 8 through the lower part of the extractive distillation tower 8; cyclopentane is selected as the extractant, and the extractant is extracted through the extractive distillation tower 8. The upper part of the distillation tower 8 enters the extractive distillation tower 8, the mass ratio of the solvent to the C8+ component is 6:1, the top temperature of the extractive distillation tower 8 is 55°C, the top pressure is -0.09MPaG, the bottom temperature is 115°C, the bottom pressure is -0.08MPaG, and after extractive distillation, 2,4,4-trimethyl-1-pentene product is extracted from the top of the tower, and the product purity is 92.7%; the solvent rich in 2,4,4-trimethyl-2-pentene enters the solvent recovery tower 11 through the bottom of the extractive distillation tower 8, the top temperature of the solvent recovery tower 11 is 60°C, the top pressure is -0.07MPaG, the bottom temperature is 120°C, the bottom pressure is -0.08MPaG, and the top of the solvent recovery tower 11 extracts 2,4,4-trimethyl-2-pentene with a purity of 91.7%, and the recovered solvent is extracted from the bottom of the tower and returned to the extractive distillation tower 8 for recycling. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene, characterized in that: The method comprises the following steps: taking crude diisobutylene as a raw material, firstly performing light-heavy-removal distillation separation to obtain diisobutylene, and then performing extractive distillation and solvent recovery to separate and obtain high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene products.

2. A method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene according to claim 1, characterized in that: Crude diisobutylene includes, by mass, light components of 1%-15%, 2,4,4-trimethyl-1-pentene of 37%-58%, 2,4,4-trimethyl-2-pentene of 8%-20%, and C8+ components of 7%-40%.

3. A method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene according to claim 1, characterized in that: The extractant in the extractive distillation comprises one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylaniline, triethanol, N-formylmorpholine, methylpyrrolidone, sulfolane, and dimethyl sulfoxide; Preferably, the light removal is carried out in a light removal tower, the tower top temperature of the light removal tower is 80-90°C, the tower top pressure is 0.05-0.15MPaG, the tower bottom temperature is 140-160°C, and the tower bottom pressure is 0.10-0.14MpaG; Preferably, the deweighting is carried out in a deweighting tower, the top temperature of the deweighting tower is 50-60°C, the top pressure is -0.6--0.8MpaG, the bottom temperature is 140-160°C, and the bottom pressure is -0.05--0.07MPaG; Preferably, the extractive distillation is carried out in an extractive distillation tower, the top temperature of the extractive distillation tower is 55-60°C, the top pressure is -0.08--0.10MPaG, the bottom temperature is 110-120°C, and the bottom pressure is -0.06--0.12MPaG; Preferably, the solvent recovery is carried out in a solvent recovery tower, the top temperature of the solvent recovery tower is 50-70°C, the top pressure is -0.06--0.08MPaG, the bottom temperature is 110-130°C, and the bottom pressure is -0.07--0.09MPaG.

4. A preparation system used in the method for preparing high-purity 2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene according to any one of claims 1 to 3, characterized in that: It includes a light removal tower, a heavy removal tower reboiler, an extractive distillation tower, and a solvent recovery tower connected in sequence; The raw materials enter from one side of the light removal tower, the light components are discharged from the top of the light removal tower, and the C8+ components are discharged from the bottom of the reboiler of the heavy removal tower; The 2,4,4-trimethyl-1-pentene product is taken out from the top of the extractive distillation tower; The 2,4,4-trimethyl-2-pentene product is taken out from the top of the solvent recovery tower.

5. The preparation system according to claim 4, characterized in that: The bottom of the light removal tower is connected to the middle of the heavy removal tower, the top of the heavy removal tower is connected to the lower part of the extractive distillation tower, the bottom of the extractive distillation tower is connected to the middle of the solvent recovery tower, and the bottom of the solvent recovery tower is connected to the upper part of the extractive distillation tower.

6. The preparation system according to claim 4, characterized in that: The bottom of the light-removing tower is provided with a first branch and a second branch, the first branch is connected to the middle of the heavy-removing tower, the second branch is connected to the bottom of the light-removing tower reboiler, and the light-removing tower reboiler is provided on the second branch; The top of the light-removing tower is connected to a light-removing tower cooler through a pipeline. The light-removing tower cooler is provided with a third branch and a fourth branch. The third branch is used for extracting light components, and the fourth branch is connected to the upper part of the light-removing tower.

7. The preparation system according to claim 4, characterized in that: The top of the deweighting tower 5 is connected to a deweighting tower cooler through a pipeline, the deweighting tower cooler is connected to the fifth branch and the sixth branch, the fifth branch is connected to the middle of the extractive distillation tower, and the sixth branch is connected to the upper part of the deweighting tower; The bottom of the de-weighting tower is provided with a seventh branch and an eighth branch, the seventh branch is connected with the middle part of the de-weighting tower, a de-weighting tower reboiler is arranged on the seventh branch, and the eighth branch extracts C8+ components.

8. The preparation system according to claim 4, characterized in that: The bottom of the extractive distillation tower is provided with a ninth branch and a tenth branch, and the ninth branch is connected to the middle of the solvent recovery tower. The tenth branch is connected to the lower part of the extractive distillation tower; The tenth branch is provided with an extractive distillation tower reboiler; The top of the extractive distillation tower is connected to an extractive distillation tower cooler through a pipeline, and an eleventh branch and a twelfth branch are arranged behind the extractive distillation tower cooler. The eleventh branch is connected to the upper part of the extractive distillation tower, and the twelfth branch produces 2,4,4-trimethyl-1-pentene product.

9. The preparation system according to claim 4, characterized in that: The top of the solvent recovery tower is connected to a solvent recovery tower cooler through a pipeline. The solvent recovery tower cooler is provided with a thirteenth branch and a fourteenth branch. The thirteenth branch is connected to the upper part of the solvent recovery tower, and the fourteenth branch produces a 2,4,4-trimethyl-2-pentene product.

10. The preparation system according to claim 9, characterized in that: The bottom of the solvent recovery tower is provided with a fifteenth branch and a sixteenth branch, the fifteenth branch is connected with the lower part of the solvent recovery tower, a solvent recovery tower reboiler is provided on the fifteenth branch, and the sixteenth branch is connected with the upper part of the extraction distillation tower.

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