Method for separating 2, 2-dimethylbutane and cyclopentane

Abstract

The invention provides a method for separating 2, 2-dimethylbutane and cyclopentane, and relates to the technical field of cyclopentane separation, raw material pre-fractionation, cyclopentane light component removal and cyclopentane distillation heavy component separation are respectively carried out, raw material mixed aromatic hydrocarbon enters a pre-rectification tower for pre-rectification so as to remove part of aromatic hydrocarbon substances, the pre-rectified mixture is pumped into an extraction tower, and the extraction tower is used for extracting 2, 2-dimethylbutane and cyclopentane. Through complexation reaction with an extraction agent, benzene ring aromatic hydrocarbon substances are removed; the extracted material enters a cyclopentane light component removal tower, the temperature and pressure in the tower are controlled, and the tower bottom material enters a cyclopentane heavy component distillation tower; the temperature and the pressure in the cyclopentane heavy distillation tower are controlled, tower top cyclopentane steam enters a reflux tank of the cyclopentane heavy distillation tower after being subjected to cooling and secondary copious cooling through a tower top air cooler of the cyclopentane heavy distillation tower, one part of the tower top cyclopentane steam is subjected to tower top reflux through a reflux pump of the cyclopentane heavy distillation tower, the other part of the tower top cyclopentane steam is conveyed to a cyclopentane product tank, and 2, 4-dichloro-2, 4-dichloroethane is separated and recycled through a side line of the cyclopentane heavy distillation tower. The purity of the cyclopentane produced by the process disclosed by the invention is as high as 99.96%, and the yield of the cyclopentane is 99.5%.

Description

Technical Field

[0001] The invention relates to the technical field of cyclopentane separation, and in particular to a method for separating 2,2-dimethylbutane and cyclopentane. Background Art

[0002] Cyclopentane (C5H 12 ) is an organic compound commonly used in the petrochemical industry, and is widely used in the fields of solvents, lubricants, fuel additives, refrigerator and freezer insulation materials, and rigid PU foam blowing agents. There are many methods for the preparation of cyclopentane, and the most common method is to separate cyclopentane from mixed hydrocarbons such as mixed C5.

[0003] Mixed C5 mainly comes from the residual oil component of the reforming unit of the oil refinery, and its main components are isopentane, n-pentane, cyclopentane and 2,2-dimethylbutane (neohexane) and a small amount of C6 component. Among them, the boiling point of cyclopentane is 49.25℃, and the boiling point of 2,2-dimethylbutane is 49.74℃, with a difference of 0.49℃. The two are not only near-boiling systems, but also azeotropic systems, with a relative volatility close to 1. High-purity cyclopentane monomer cannot be obtained through ordinary distillation. The method used in industry is to add another solvent to the system to be separated. Due to the difference in the effect of the solvent on each component in the system to be separated, a non-ideal solution is formed, the activity coefficient of each component is changed, and the relative volatility between key components is increased to achieve the purpose of effective separation. Currently, the effective methods for separating near-boiling systems and azeotropic systems include: azeotropic distillation, reactive distillation, extractive distillation and membrane separation. Among them, the extractive distillation, reactive distillation and membrane separation processes have low energy consumption. The extractive distillation process is the easiest to industrialize, but it needs to be matched with a solvent with a small solvent ratio and low loss.

[0004] In the prior art, it is a common technical route to find a new extractant to separate high-purity cyclopentane. For example, Chinese patent CN201510029414.1 discloses a method for separating cyclopentane and neohexane by extractive distillation. A new composite extractant has been developed, which has excellent separation effect on cyclopentane and neohexane and low energy consumption. The purity of the cyclopentane obtained reaches 99.5%, but there are problems such as large solvent ratio and solvent loss. To this end, Chinese patent CN202211152303.6 discloses a method for separating cyclopentane and 2,2-dimethylbutane by a low eutectic solvent, which uses a low eutectic solvent formed by a mixture of choline chloride and propylene glycol as a solvent, and separates cyclopentane and 2,2-dimethylbutane by an extractive distillation process. The low eutectic solvent has good selectivity for cyclopentane, increases the relative volatility between cyclopentane and 2,2-dimethylbutane, greatly reduces the circulation amount of the solvent, and reduces the solvent loss. The purity of the obtained cyclopentane reaches 99.6%.

[0005] The cyclopentane produced by the above-mentioned prior art processes generally has the problem of low purity and cannot meet the demand for high-purity cyclopentane. Summary of the invention

[0006] The present invention provides a method for separating 2,2-dimethylbutane and cyclopentane in view of the above problems existing in the prior art. 2,2-dimethylbutane is removed by pressurizing to remove light components and distilling to separate heavy components to produce high-purity cyclopentane. The purity of the produced cyclopentane is as high as 99.96%, the yield is above 99.5%, and the process operation is simple, the pollution is small, and the energy consumption is low.

[0007] The technical solution of the present invention to solve the above technical problem is as follows: A method for separating 2,2-dimethylbutane and cyclopentane, characterized in that it comprises the following steps:

[0008] S1. Raw material pre-fractionation: The raw material mixed aromatic hydrocarbons enter the pre-distillation tower for pre-distillation to remove some aromatic substances, and then the pre-distilled mixture is sent to the extraction tower to remove benzene ring aromatic substances through complex reaction with the extraction agent;

[0009] S2, cyclopentane light removal: the material extracted in step S1 enters the cyclopentane light removal tower, the temperature and pressure in the tower are controlled, and the bottom material enters the cyclopentane heavy distillation tower;

[0010] S3, cyclopentane heavy distillation separation: in step S2, the material extracted from the bottom of the cyclopentane light removal tower enters the cyclopentane heavy distillation tower, and the temperature and pressure in the cyclopentane heavy distillation tower are controlled. The cyclopentane vapor at the top of the tower is cooled by the top air cooler of the cyclopentane heavy distillation tower, and after secondary deep cooling, it enters the reflux tank of the cyclopentane heavy distillation tower, a part of which is refluxed at the top of the tower through the cyclopentane heavy distillation tower reflux pump, and the other part is transported to the cyclopentane product tank, and 2,2-dimethylbutane is separated and recovered through the side line of the cyclopentane heavy distillation tower.

[0011] Furthermore, in the above scheme, the main components of the raw mixed aromatic hydrocarbons are n-pentane, isopentane, cyclopentane, 2,2-dimethylbutane, 2-methylpentane, n-hexane, methylcyclopentane, benzene, cyclohexane, 2-methylpentane, cis-1,3-dimethylcyclopentane, trans-1,3-dimethylcyclopentane, trans-1,2-dimethylcyclopentane, and n-heptane, and the extractant is sulfolane.

[0012] Furthermore, in step S2, the material obtained in step S1 enters the cyclopentane light removal tower, and when the liquid level at the bottom of the tower reaches 30%, the bottom reboiler is turned on to increase the temperature.

[0013] Furthermore, in step S2, the temperature of the cyclopentane light removal tower is raised to a temperature at the bottom of the tower controlled at 80-93° C., a pressure controlled at ≤155 KPa, and a temperature at the top of the tower controlled at 38-47° C., a pressure controlled at ≤105 KPa.

[0014] Further, in step S2, the non-aromatic vapor extracted from the top of the light removal tower is cooled by a cooler and then enters the cyclopentane light removal tower reflux tank, a portion of which is refluxed from the top of the tower by a cyclopentane light removal tower reflux pump, and the reflux rate is controlled at 5-20m 3 / h, and the other part is transported to non-aromatic storage tanks.

[0015] Furthermore, in step S3, when the liquid level in the bottom of the cyclopentane distillation heavy tower reaches 30%, the bottom reboiler is turned on to increase the temperature.

[0016] Furthermore, in step S3, the temperature of the cyclopentane distillation heavy tower is raised to 115-120°C, the pressure is 170-195KPa, the tower top temperature is <50°C, and the pressure is ≤20KPa.

[0017] Furthermore, in step S3, the reflux rate of the cyclopentane distillation tower is controlled at 10-30m 3 / h.

[0018] Furthermore, in step S3, the theoretical number of trays of the cyclopentane distillation weight tower is 80-120, the tray spacing is 350 mm, and the opening rate of the rising pores of the tray is 14%±0.2%.

[0019] The beneficial effects of the present invention are as follows: the present invention realizes the separation of cyclopentane and 2,2-dimethylbutane through the overall process through raw material pre-fractionation, cyclopentane light removal, and cyclopentane heavy separation, especially strict process control in the two process links of cyclopentane light removal and cyclopentane heavy separation, including the control of liquid level and temperature rise, the control of temperature and pressure at the top and bottom of the tower, the regulation of tower reflux volume, and the regulation of the opening rate of specific tower plate rising pores, and the coordination of multiple factors; more importantly, the invention creatively obtains a high-purity cyclopentane product with a yield of more than 99.5% and a purity of 99.96%, which has a significant purity advantage compared to the cyclopentane product with a purity of about 99.5% in the prior art. Moreover, the process method has the advantages of high efficiency, high yield, low energy consumption, and low pollution, and effectively improves the production efficiency of cyclopentane. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 It is a production device diagram of the present invention;

[0021] Attached Figure 2 This is a diagram of the equipment for the cyclopentane light removal process of the present invention;

[0022] Attached Figure 3 This is an equipment diagram of the cyclopentane distillation and re-separation process of the present invention;

[0023] Attached Figure 4 and 5 is a test report of cyclopentane obtained in Example 1 of the present invention;

[0024] Attached Figure 6 is the gas chromatographic analysis of cyclopentane obtained in Example 2 of the present invention;

[0025] Attached Figure 7 It is a process flow chart of the present invention;

[0026] in:

[0027] Attached Figure 1 Middle: 100, pre-distillation tower, 200, extraction distillation tower, 300, light removal tower, 400, heavy distillation tower; 101, raw material tank, 102, pre-distillation feed intermediate tank, 103, crude non-aromatic hydrocarbon storage tank, 201, extraction tower feed tank, 301, cyclopentane feed tank, 302, non-aromatic hydrocarbon product tank, 401, cyclopentane product tank, 402, 2,2-dimethylbutane recovery tank, 403, non-aromatic hydrocarbon storage tank;

[0028] Attached Figure 2 In: 11, cyclopentane light removal tower, 12, tower bottom reboiler, 13, feed pressurized heat exchanger, 14, evaporative cooler, 15, cooler, 16, reflux tank, 7A, tower bottom extraction pump A pump (cyclopentane refining feed pump), 7B, tower bottom extraction pump B pump (cyclopentane refining feed pump), 8A, cyclopentane light removal tower reflux pump A pump, 8B, cyclopentane light removal tower reflux pump B pump;

[0029] Attached Figure 3 In: 21, cyclopentane distillation weight tower, 22, tower bottom reboiler, 23, evaporative cooler, 24, cooler, 25, reflux tank, 26, production cooler, 7A, tower bottom production pump A pump, 7B, tower bottom production pump B pump, 8A, cyclopentane distillation weight tower reflux pump A pump, 8B, cyclopentane distillation weight tower reflux pump B pump, 29, feed pressure regulating heat exchanger. DETAILED DESCRIPTION

[0030] The principles and features of the present invention are described below. The examples given are only used to explain the present invention but not to limit the scope of the present invention.

[0031] Example 1

[0032] The method for separating 2,2-dimethylbutane and cyclopentane in this embodiment is carried out according to the following steps:

[0033] S1. Raw material pre-fractionation: The raw material mixed aromatic hydrocarbons enter the pre-distillation tower for pre-distillation to remove some heavy aromatic hydrocarbons, and then the pre-distilled mixture is sent to the extraction tower, where the extractant is sulfolane, and the benzene ring aromatic hydrocarbons are removed through complex reaction with the extractant;

[0034] Specifically, when the liquid level at the bottom of the pre-distillation tower reaches 30%, the steam regulating valve of the reboiler at the bottom of the tower is slowly opened to increase the temperature. The bottom temperature of the pre-distillation tower is controlled at 110°C and the pressure is controlled at 40KPa. The top temperature is controlled at 65°C and the pressure is controlled at <20KPa. The non-aromatic vapor extracted from the top of the tower is cooled by the cooler and enters the reflux tank of the pre-distillation tower. A part of it is refluxed to the top of the tower through the reflux pump of the pre-distillation tower. The reflux volume is controlled at 5m 3 / h, and the other part is sent to the extraction tower for extraction.

[0035] S2, cyclopentane light removal: the material extracted in step S1 enters the cyclopentane light removal tower, and when the liquid level at the bottom of the tower reaches 30%, the steam regulating valve of the reboiler at the bottom of the tower is slowly opened to increase the temperature, and the bottom temperature of the cyclopentane light removal tower is controlled at 80°C, the pressure is controlled at ≤155KPa, and the top temperature is controlled at 38°C, and the pressure is controlled at ≤105KPa; the non-aromatic vapor produced from the top of the tower is cooled by the cooler and enters the reflux tank of the cyclopentane light removal tower, a part of which is refluxed to the top of the tower through the cyclopentane light removal tower reflux pump, and the reflux amount is controlled at 5m 3 / h, and the other part is transported to the non-aromatic storage tank; the bottom material enters the cyclopentane distillation heavy tower through the cyclopentane light tower bottom material pump and regulating valve.

[0036] S3, cyclopentane heavy distillation separation: Step S2: the material extracted from the bottom of the cyclopentane light removal tower enters the cyclopentane heavy distillation tower. When the liquid level of the cyclopentane heavy distillation tower reaches 30%, slowly open the steam cut-off valve and regulating valve of the tower bottom reboiler to increase the temperature. The bottom temperature of the cyclopentane heavy distillation tower is controlled at 115°C and the pressure is controlled at 170KPa. The top temperature is controlled at <50°C and the pressure is controlled at ≤20KPa. The cyclopentane vapor at the top of the tower is cooled by the top air cooler of the cyclopentane heavy distillation tower and then enters the reflux tank of the cyclopentane heavy distillation tower. A part of it is refluxed at the top of the tower through the cyclopentane heavy distillation tower reflux pump. The reflux rate is controlled at 10m 3 / h, and the other part is transported to the cyclopentane product tank, where 2,2-dimethylbutane is separated and recovered through the side line of the cyclopentane distillation heavy tower.

[0037] The process of the present invention uses three major systems: DCS system (distributed control system), SIS system (safety instrument system), GDS system (combustible gas and toxic gas alarm system) to adjust the core parameters of the production device, such as the temperature, pressure, liquid level, medium flow rate, etc. The cyclopentane distillation weight tower adopts the existing technology three-dimensional mass transfer tray tower (CTST), and is specially designed with a theoretical number of trays of 80-120, a tray spacing of 350mm, and a porosity of 14% ± 0.2% of the tray rising pores. Specifically, the theoretical number of trays of the distillation weight tower of the present embodiment is 120, the tray spacing is 350mm, and the porosity of 13.89% of the tray rising pores.

[0038] The yield of the cyclopentane product obtained in this example is 99.5% and the purity is 99.96%. Figure 4 and 5 shown.

[0039] Example 2

[0040] The method for separating 2,2-dimethylbutane and cyclopentane in this embodiment is carried out according to the following steps:

[0041] S1. Raw material pre-fractionation: The raw material mixed aromatic hydrocarbons enter the pre-distillation tower for pre-distillation to remove some aromatic substances, and then the pre-distilled mixture is sent to the extraction tower, where the extractant is sulfolane, and the benzene ring aromatic substances are removed through complex reaction with the extractant;

[0042] Specifically, when the liquid level at the bottom of the pre-distillation tower reaches 30%, the steam regulating valve of the reboiler at the bottom of the tower is slowly opened to increase the temperature. The bottom temperature of the pre-distillation tower is controlled at 110°C and the pressure is controlled at 40KPa. The top temperature is controlled at 65°C and the pressure is controlled at <20KPa. The non-aromatic vapor extracted from the top of the tower is cooled by the cooler and enters the reflux tank of the pre-distillation tower. A part of it is refluxed to the top of the tower through the reflux pump of the pre-distillation tower. The reflux volume is controlled at 5m 3 / h, and the other part is sent to the extraction tower for extraction.

[0043] S2, cyclopentane light removal: the material extracted in step S1 enters the cyclopentane light removal tower, and when the liquid level at the bottom of the tower reaches 30%, the steam regulating valve of the tower bottom reboiler is slowly opened to increase the temperature, and the bottom temperature of the cyclopentane light removal tower is controlled at 93°C, the pressure is controlled at ≤155KPa, and the top temperature is controlled at 47°C, and the pressure is controlled at ≤105KPa; the non-aromatic vapor produced from the top of the tower is cooled by the cooler and enters the reflux tank of the cyclopentane light removal tower, a part of which is refluxed to the top of the tower through the cyclopentane light removal tower reflux pump, and the reflux amount is controlled at 20m 3 / h, and the other part is transported to the non-aromatic storage tank; the bottom material enters the cyclopentane distillation heavy tower through the cyclopentane light tower bottom material pump and regulating valve.

[0044] S3, cyclopentane distillation and heavy separation: Step S2 The material extracted from the bottom of the cyclopentane light removal tower enters the cyclopentane distillation heavy tower (i.e. Figure 1 The cyclopentane refinement tower shown in the figure), when the cyclopentane distillation tower kettle liquid level reaches 30%, slowly open the tower bottom reboiler steam cut-off valve and regulating valve to increase the temperature, the cyclopentane distillation tower bottom temperature is controlled at 120℃, and the pressure is controlled at 195KPa. The top cyclopentane vapor is cooled by the cyclopentane distillation tower top air cooler and enters the cyclopentane distillation tower reflux tank, a part of which is refluxed by the cyclopentane distillation tower reflux pump for the top of the tower, and the reflux rate is controlled at 30m 3 / h, and the other part is transported to the cyclopentane product tank, and 2,2-dimethylbutane is separated and recovered by the cyclopentane distillation weight tower side line. Among them, the theoretical number of trays of the cyclopentane distillation weight tower is 100, the tray spacing is 350mm, and the opening rate of the tray rising pores is 14%±0.2%. Specifically, the theoretical number of trays of the distillation weight tower of this embodiment is 120, the tray spacing is 350mm, and the opening rate of the tray rising pores is 13.89%.

[0045] The yield of the cyclopentane product obtained in this example is 99.48% and the purity is 99.96%. Figure 6 shown.

[0046] The production device used in the above embodiment is shown in Figure 1-Figure 3 As shown, it includes a pre-distillation tower 100, an extractive distillation tower 200, a light removal tower 300 and a heavy removal tower 400 which are sequentially connected along the production line direction, wherein the pre-distillation tower 100 and the extractive distillation tower 200 respectively adopt the distillation tower and the extraction tower of the prior art.

[0047] The raw materials enter the pre-distillation tower 100 through a pump. The raw materials come from the raw material tank 101 and the pre-distillation feed intermediate tank 102 arranged on the feed side of the pre-distillation tower 100; the bottom of the pre-distillation tower 100 is connected to the crude non-aromatic hydrocarbon storage tank 103, and the top of the pre-distillation tower 100 is connected to the cooler and the reflux tank, and two paths are separated from the reflux tank, one of which refluxes to the top of the pre-distillation tower, and the other is connected to the extraction tower feed tank 201, and the extraction tower feed tank 201 is connected to the extraction distillation tower 200;

[0048] The top of the extractive distillation tower 200 is connected to a cyclopentane feed tank 301 , and the cyclopentane feed tank 301 is connected to a lightness removal tower 300 .

[0049] See Figure 2 As shown, the light-removing tower 300 is a cyclopentane light-removing tower 11, and a bottom reboiler 12 is connected to the bottom of the tower; the input side of the light-removing tower 300 is connected to the cyclopentane feed tank 301 through a feed pressurized heat exchanger 13 (specifically, a floating head heat exchanger can be used); the top of the light-removing tower 300 is connected to an evaporative cooler 14, and the evaporative cooler 14 is connected to a cooler 15 for double deep cooling, and the cooler 15 is connected to a reflux tank 16, and the reflux tank 16 is connected to a light-removing tower reflux pump ( Figure 2 8A, 8B) are connected to two routes, one of which is refluxed to the top of the light removal tower 300, and the other is connected to the non-aromatic product tank 302; the bottom of the light removal tower 300 is pumped through the bottom extraction pump ( Figure 2 7A, 7B) are extracted and sent to the distillation tower 400.

[0050] See Figure 3As shown, the retort 400 is a cyclopentane retort 21, and the bottom of the retort is connected to a bottom reboiler 22; the input side of the retort 400 is connected to the bottom of the lightness removal tower through a feed pressure regulating heat exchanger 29 (specifically, a tube-sheet heat exchanger can be used, and the pressure of the material entering the retort 400 is regulated by water flow control); the top of the retort 400 is connected to an evaporative cooler 23, and the evaporative cooler 23 is connected to a cooler 24 for double deep cooling, and the cooler 24 is connected to a reflux tank 25, and the reflux tank 25 is connected to a retort pump ( Figure 3 8A, 8B) in the figure are connected to two routes, one of which is refluxed to the top of the re-distillation tower 400, and the other is connected to the cyclopentane product tank 401; the side line of the re-distillation tower 400 is connected to the 2,2-dimethylbutane recovery tank 402; the bottom of the re-distillation tower 400 is connected to the bottom extraction pump ( Figure 3 7A, 7B) are divided into two routes, one of which is connected to the non-aromatic storage tank 403, and the other is connected to the pre-distillation feed intermediate tank 102 as one of the raw materials for pre-distillation. The distillation weight tower of this embodiment has a built-in three-dimensional mass transfer tray, the theoretical number of trays is 80-120, and the opening rate of the rising pores of the tray is 14%±0.2%.

[0051] In this embodiment, the bottom of the light-removal tower 300 is extracted through a bottom extraction pump and connected to the feed pressurization heat exchanger 13 of the light-removal tower 300 to provide heat exchange for it, and then connected to the heavy distillation tower 400 through the feed pressure regulating heat exchanger 29 to deliver heavy distillation raw materials of suitable pressure to the heavy distillation tower 400.

[0052] In working state, see Figure 7 As shown, the raw material mixed aromatic hydrocarbons enter the pre-distillation tower 100 from the raw material tank 101 for pre-distillation to remove some heavy aromatic hydrocarbons, and then the pre-distilled mixture is pumped into the extractive distillation tower 200 to remove the benzene ring aromatic substances through complex reaction with the extractant; the extracted material is transported to the cyclopentane feed tank 301, and then enters the light removal tower 300 through the pressurized heat exchanger 13, and the non-aromatic vapor extracted from the top of the light removal tower 300 is cooled by the cooler and enters the cyclopentane light removal tower reflux tank, a part of which is refluxed from the top of the tower by the cyclopentane light removal tower reflux pump, and the other part is transported to the non-aromatic storage tank 302, and the material extracted from the bottom of the light removal tower 300 is first The feed pressurizing heat exchanger 13 provides a heat source for heat exchange, and then enters the cyclopentane distillation weight tower 400 after pressure regulation by the feed pressure regulating heat exchanger 29; the cyclopentane vapor at the top of the distillation weight tower 400 is cooled by the top air cooler of the distillation weight tower 400 and enters the cyclopentane distillation weight tower reflux tank, one part of which is refluxed to the top of the tower through the cyclopentane distillation weight tower reflux pump, and the other part is transported to the cyclopentane product tank 401, and 2,2-dimethylbutane is separated and recovered by the cyclopentane distillation weight tower side line. After being extracted from the bottom of the distillation weight tower 400, it is divided into two paths, one of which is transported to the non-aromatic hydrocarbon storage tank 403, and the other is transported to the pre-distillation feed intermediate tank 102, as one of the raw materials for pre-distillation, and recycled.

[0053] In the above embodiments, the raw material mixed aromatics are mainly purchased from the market, specifically, byproducts obtained from oil and coke refining in petrochemical enterprises, and then a mixed substance obtained by hydrogenation. The main components of the raw material mixed aromatics are as follows:

[0054]

[0055]

[0056] The above is only a detailed description of the preferred embodiment of the present invention, but is not intended to limit the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope described in the claims.

Claims

1. A method for separating 2,2-dimethylbutane and cyclopentane, characterized in that: The steps include: S1. Raw material pre-fractionation: The raw material mixed aromatic hydrocarbons enter the pre-distillation tower for pre-distillation to remove some aromatic substances, and then the pre-distilled mixture is sent to the extraction tower to remove benzene ring aromatic substances through complex reaction with the extraction agent; S2, cyclopentane light removal: the material extracted in step S1 enters the cyclopentane light removal tower, the temperature and pressure in the tower are controlled, and the material extracted from the bottom of the tower enters the cyclopentane heavy distillation tower; S3, cyclopentane heavy distillation separation: in step S2, the material extracted from the bottom of the cyclopentane light removal tower enters the cyclopentane heavy distillation tower, and the temperature and pressure in the cyclopentane heavy distillation tower are controlled. The cyclopentane vapor at the top of the tower is cooled by the top air cooler of the cyclopentane heavy distillation tower and then enters the reflux tank of the cyclopentane heavy distillation tower, a part of which is refluxed at the top of the tower through the cyclopentane heavy distillation tower reflux pump, and the other part is transported to the cyclopentane product tank, and 2,2-dimethylbutane is separated and recovered through the side line of the cyclopentane heavy distillation tower.

2. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 1, characterized in that: In step S2, the material obtained in step S1 enters the cyclopentane light removal tower, and when the liquid level at the bottom of the tower reaches 30%, the bottom reboiler is turned on to increase the temperature.

3. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 2, characterized in that: In step S2, the temperature of the cyclopentane light removal tower is raised to a temperature at the bottom of the tower controlled at 80-93° C. and a pressure controlled at ≤155 KPa, and a temperature at the top of the tower is controlled at 38-47° C. and a pressure controlled at ≤105 KPa.

4. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 1, characterized in that: In step S2, the non-aromatic vapor extracted from the top of the light removal tower is cooled by a cooler and then enters the cyclopentane light removal tower reflux tank, a part of which is refluxed to the top of the tower through a cyclopentane light removal tower reflux pump, and the other part is transported to the non-aromatic storage tank.

5. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 4, characterized in that: The return flow is controlled at 5-20m 3 / h.

6. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 1, characterized in that: In step S3, when the liquid level in the bottom of the cyclopentane distillation heavy tower reaches 30%, the tower bottom reboiler is turned on to increase the temperature.

7. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 6, characterized in that: Step S3 is to heat up the cyclopentane distillation tower so that the bottom temperature is controlled at 115-120°C and the pressure is controlled at 170-195KPa, and the top temperature is controlled at <50°C and the pressure is controlled at ≤20KPa.

8. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 1, characterized in that: In step S3, the reflux rate of the cyclopentane distillation tower is controlled at 10-30m 3 / h.

9. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 1, characterized in that: In step S3, the theoretical number of trays of the cyclopentane distillation weight tower is 80-120, the tray spacing is 350 mm, and the opening rate of the rising pores of the tray is 14%±0.2%.

10. The method for separating 2,2-dimethylbutane and cyclopentane according to claim 1, characterized in that: The main components of the raw material mixed aromatic hydrocarbons are n-pentane, isopentane, cyclopentane, 2,2-dimethylbutane, 2-methylpentane, n-hexane, methylcyclopentane, benzene, cyclohexane, 2-methylpentane, cis-1,3-dimethylcyclopentane, trans-1,3-dimethylcyclopentane, trans-1,2-dimethylcyclopentane and n-heptane, and the extractant is sulfolane.

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