Method for determining process parameters of simulated moving bed separation process and method for separating long-chain α-olefins / alkanes

Abstract

The present invention discloses a method for determining process parameters of a simulated moving bed separation process and a method for separating long-chain α-olefins / alkanes. The method for determining process parameters of a simulated moving bed separation process includes: performing a first separation treatment on the material to be separated using a fixed bed to determine the adsorption temperature, adsorption pressure, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate; performing a second separation treatment on the material to be separated using a simulated moving bed, and determining the adsorption temperature, adsorption pressure, the second feed flow rate of the material to be separated, the second feed flow rate of the desorbent, the extract discharge flow rate, and the raffinate discharge flow rate according to the above results; performing a second component analysis on the material in the raffinate discharge unit to determine the residence time of the inlet and outlet units of the simulated moving bed. Thus, the process parameters for separating different material systems using a simulated moving bed can be determined, thereby effectively separating the materials and improving the purity and yield of the separated materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of separation, and specifically relates to a method for determining the process parameters of a simulated moving bed separation process and a method for separating long-chain α-olefins / alkanes. Background Art

[0002] Olefins contain carbon-carbon double bonds. Linear α-olefins (LAOs) are straight-chain olefins with double bonds at the terminal (α-position) of the molecule. Industrially, straight-chain olefins with a carbon chain length of 4 or more are usually called LAOs. LAOs are important raw materials for producing high-value-added products such as linear low-density polyethylene, high-density polyethylene, polyolefin elastomers, high-end automotive lubricants, surfactants, and plasticizer alcohols. The products have a wide range of applications, covering many fields such as petrochemicals, metallurgy, light industry, textiles, pesticides, and pharmaceuticals. In recent years, the global production capacity and market value of LAOs have been increasing year by year. However, the production of LAOs is mainly monopolized by foreign enterprises. The production capacity of LAOs in China is seriously insufficient. Only the production capacity of 1-hexene (C6) is relatively high, while the production of products with a carbon number of 1-octene (C8) and above is blank, and a large amount is relied on imports. The lack of LAOs production capacity has seriously affected the technological development and production application of downstream products, and has become a "bottleneck" problem restricting the high-quality development of high-end fine chemicals in China. Once the supply catches up, the domestic demand will quickly expand, and the market prospect is relatively broad.

[0003] At present, the production capacity of coal-to-oil by Fischer-Tropsch synthesis in China is increasing year by year. Developing new coal-based high-end chemicals and coal-based new materials based on coal-to-oil is an effective means to realize the transformation of the coal-to-oil industry towards high-end and differentiated directions and improve market competitiveness. The Fischer-Tropsch oil produced by the high-temperature Fischer-Tropsch synthesis method mainly consists of straight-chain alkanes and α-olefins. The content of α-olefins is usually between 40wt% and 70wt%. At present, it is often directly used as fuel through hydrogenation, resulting in a large amount of α-olefins not being effectively utilized. If the α-olefins therein can be separated and purified, the product added value can reach 3 to 4 times that of traditional coal-to-oil products. In the process of purification and separation, the separation of long-chain α-olefins / alkanes with the same carbon number is one of the most core and expensive separation processes. At present, a company uses the oil-washed naphtha of a coal-to-oil project as the raw material, and based on the self-developed laboratory technology for separating and deacidifying / deoxygenating Fischer-Tropsch oil, conducts pilot-scale verification, and finally separates α-olefins / alkanes by distillation to obtain C6 and C8 alkene products, but this method has high energy consumption; while the ionic liquid extraction method and the membrane separation method have little possibility of realizing production application due to various limitations such as raw material cost, equipment, and efficiency. Summary of the Invention

[0004] The present invention is mainly proposed based on the following problems and discoveries:

[0005] The adsorption separation method is currently the most promising method. The separation technology using simulated moving bed equipment is an efficient and advanced adsorption separation and purification technology, belonging to industrial high-tech. The operating unit of simulated moving bed chromatography is chromatographic separation, which utilizes the difference in the adsorption performance of the adsorbent for the matrix. Through the adsorption-elution process, several substances with very similar properties are separated. It mainly uses the different migration rates of various components in the adsorption column, that is, the different adsorption and distribution coefficients of each component in the stationary phase and the mobile phase, to achieve the separation purpose. In the chromatographic separation system of the countercurrent simulated moving bed, the stationary phase can be imagined to move in the direction opposite to the fluid flow direction. The material to be separated is continuously input at a certain point in the middle of the separation working area. By selecting the two-way flow rate ratio, the feed liquid is separated into two parts flowing in opposite directions at the inlet. Taking the feed inlet as the reference point, the adsorption medium seems to adsorb the product and move upward, so it is called "simulated moving bed". The simulated moving bed can continuously, efficiently and inexpensively separate substances that are difficult to separate by general methods, and shows unique separation characteristics in separating isomers with similar boiling points that are difficult to separate by precision distillation. Therefore, it is applicable to the separation of olefins / paraffins.

[0006] At present, many studies have been carried out on the method of separating alkanes and olefins using a simulated moving bed. For example, a desorbent and method for separating alkanes and olefins using a simulated moving bed have been proposed. This method uses a mixture of α-olefins and n-alkanes as the desorbent, and the desorption cost is relatively high. Moreover, only the concentration distribution map and process parameters of using the desorbent in a single-column pulse separation process are mentioned, and the process parameters for specifically implementing the separation of α-olefins / alkanes using a simulated moving bed are not involved. For another example, a method of using a high-carbon-number n-alkane as the desorbent to separate alkanes and olefins using a simulated moving bed has been proposed. Although this desorbent is beneficial to improving the desorption efficiency and reducing the cost, the subsequent rectification separation process with the olefin product is relatively difficult and the energy consumption is large. For another example, a method of using a mixture of hexene / hexane as the desorbent to separate alkanes and olefins using a simulated moving bed has been proposed, and there is also a proposal to use ethanol and methylcyclohexane as the desorbent to separate alkanes and olefins using a simulated moving bed. However, neither of the above two methods involves the setting of process parameters such as the discharge flow rate and the recycle flow rate during the separation process, and the above process parameters have a significant impact on the purity of the separated product.

[0007] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this reason, an object of the present invention is to propose a method for determining the process parameters of the simulated moving bed separation process and a method for separating long-chain α-olefins / alkanes, whereby the process parameters for separating different substance systems using a simulated moving bed can be determined or regulated, and thus the effective separation of long-chain α-olefins / alkanes can be achieved, which is not only beneficial to improving the yield and purity of long-chain α-olefins, but also has high economic benefits.

[0008] In one aspect of the present invention, there is provided a method for determining the separation process parameters of a simulated moving bed. According to an embodiment of the present invention, the method comprises:

[0009] (1) A fixed bed is used to perform a first separation treatment on the material to be separated. The material to be separated and the desorbent are input through the fixed bed feed unit, and the separated material is output through the fixed bed discharge unit. A first component analysis is performed on the separated material to determine the adsorption temperature, adsorption pressure of the fixed bed, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate;

[0010] (2) A simulated moving bed is used to perform a second separation treatment on the material to be separated. The simulated moving bed includes a separation unit, a material to be separated feed unit, a desorbent feed unit, an extract discharge unit, and a raffinate discharge unit. According to the analysis results of step (1), the adsorption temperature, adsorption pressure of the simulated moving bed, the second feed flow rate of the material to be separated, the second feed flow rate of the desorbent, the extract discharge flow rate, and the raffinate discharge flow rate are determined;

[0011] (3) A second component analysis is performed on the material in the raffinate discharge unit to determine the residence time of the inlet and outlet units of the simulated moving bed.

[0012] According to the method for determining the separation process parameters of a simulated moving bed in the above embodiment of the present invention, by sequentially using a fixed bed and a simulated moving bed to perform separation treatment on the material to be separated, the core process parameters during the separation operation using the simulated moving bed can be accurately set and regulated, including: adsorption temperature, adsorption pressure, etc., thereby facilitating the improvement of the purity and recovery rate of the separated product.

[0013] In addition, the method for determining the separation process parameters of a simulated moving bed in the above embodiment of the present invention may further have the following additional technical features:

[0014] In some embodiments of the present invention, a simulated moving bed separation system is used for the first separation process and the second separation process. The simulated moving bed separation system includes: the separation unit, which includes n adsorption columns arranged in sequence; m first multi-way solenoid valves, each of the first multi-way solenoid valves includes a first interface, a second interface and a third interface. The first interface of the first multi-way solenoid valve is connected to the lower part of one adsorption column, the second interface is connected to the inlet of the desorbent circulation unit, and the third interface is connected to the upper part of another adsorption column; k second multi-way solenoid valves, each of the second multi-way solenoid valves includes a first interface, a second interface, a third interface, a fourth interface and a fifth interface. The first interface of the second multi-way solenoid valve is connected to the desorbent feed unit, the second interface is connected to the extract discharge unit, the third interface is connected to the material to be separated feed unit, the fourth interface is connected to the raffinate discharge unit, and the fifth interface is connected to the lower part of the adsorption column. Wherein, the outlet of the desorbent circulation unit is connected to the desorbent feed unit, and n, m, and k are all positive integers, and n≥m, k and n≥2.

[0015] In some embodiments of the present invention, the simulated moving bed separation system further includes: an automatic control unit, which is connected to the first multi-way solenoid valve and the second multi-way solenoid valve, and controls the opening and closing of each interface of the first multi-way solenoid valve and the opening and closing of each interface of the second multi-way solenoid valve.

[0016] In some embodiments of the present invention, the first interface and the second interface of the first multi-way solenoid valve are not opened simultaneously.

[0017] In some embodiments of the present invention, among the first interface, the second interface, the third interface and the fourth interface of the second multi-way solenoid valve, only one interface is opened or all are kept closed at the same time.

[0018] In some embodiments of the present invention, step (1) includes: (1-1) adjusting the simulated moving bed separation system to a fixed bed mode by controlling the opening and closing of the interfaces of the first multi-way solenoid valve and the second multi-way solenoid valve; (1-2) injecting the desorbent into the separation unit through the third interface of the second multi-way solenoid valve to fill the adsorption column with the desorbent; (1-3) injecting the material to be separated into the separation unit through the third interface of the second multi-way solenoid valve; (1-4) continuously injecting the desorbent into the separation unit through the third interface of the second multi-way solenoid valve, outputting the separated material through the fourth interface of the second multi-way solenoid valve, and performing the first component analysis on the separated material to determine the adsorption temperature, adsorption pressure of the fixed bed, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate.

[0019] In some embodiments of the present invention, step (2) includes: adjusting the simulated moving bed separation system to a simulated moving bed mode by controlling the opening and closing of the first multi-way solenoid valve and the second multi-way solenoid valve.

[0020] In some embodiments of the present invention, step (3) includes: (3-1) keeping the state of the simulated moving bed feed and discharge unit unchanged and performing the second component analysis by sampling in the raffinate discharge unit; (3-2) in the raffinate discharge unit, selecting the separation time containing the raffinate component and not containing the extract component as the state holding time of the simulated moving bed feed and discharge unit.

[0021] In another aspect of the present invention, the present invention provides a method for separating long-chain α-olefins / alkanes using a simulated moving bed. According to the embodiments of the present invention, this method uses the above method for determining the process parameters of the simulated moving bed separation to determine the adsorption temperature, adsorption pressure of the simulated moving bed separation of long-chain α-olefins / alkanes, the feed flow rate of the material to be separated, the feed flow rate of the desorbent, the extract discharge flow rate, the raffinate discharge flow rate, and the state holding time of the feed and discharge unit of the simulated moving bed. Compared with the prior art, this method not only helps to reduce energy consumption and improve economic benefits, but also can obtain long-chain α-olefins with higher purity and higher yield.

[0022] In addition, the method for separating long-chain α-olefins / alkanes using a simulated moving bed according to the above embodiments of the present invention may further have the following additional technical features:

[0023] In some embodiments of the present invention, the method comprises: (1) feeding the long-chain α-olefin / alkane from the material to be separated feeding unit to the separation unit, and feeding the cyclohexane desorbent from the desorbent feeding unit to the separation unit; (2) controlling the adsorption temperature, adsorption pressure, extract discharge flow rate, raffinate discharge flow rate and the residence time of the feeding and discharging unit in the separation unit, and collecting the separated long-chain α-olefin in the extract discharge unit.

[0024] In some embodiments of the present invention, the separation unit comprises 8 to 32 adsorption columns, the inner diameter of the adsorption column is 10 to 50 mm, and the length of the adsorption column is 300 to 1500 mm.

[0025] In some embodiments of the present invention, the carbon number range of the long-chain α-olefin is C6 - C8.

[0026] In some embodiments of the present invention, the adsorption column is filled with an adsorbent, and the adsorbent comprises a Na-FAU type zeolite molecular sieve.

[0027] In some embodiments of the present invention, in the long-chain α-olefin / alkane, the content of the long-chain α-olefin is 10 - 90 wt%.

[0028] In some embodiments of the present invention, the adsorption temperature is 20 - 200 °C.

[0029] In some embodiments of the present invention, the adsorption pressure is 0.1 - 2.5 MPa.

[0030] In some embodiments of the present invention, the feeding flow rate of the long-chain α-olefin / alkane is 1 ml / min - 10 ml / min, and the feeding time is 1 min - 10 min.

[0031] In some embodiments of the present invention, the ratio of the feeding flow rate of the desorbent to the long-chain α-olefin / alkane is (3 - 8):1.

[0032] In some embodiments of the present invention, a simulated moving bed separation system is used to separate the long-chain α-olefin / alkane, and the circulation flow rate in the desorbent circulation unit of the simulated moving bed separation system is not more than 50 ml / min.

[0033] In some embodiments of the present invention, the residence time of the feeding and discharging unit is 600 - 1200 s.

[0034] In some embodiments of the present invention, the particle size range of the Na-FAU type zeolite molecular sieve is 0.5 mm - 2.5 mm.

[0035] In some embodiments of the present invention, the adsorption pressure is 0.5 to 1.5 MPa.

[0036] In some embodiments of the present invention, the circulation flow rate in the desorbent circulation unit is 5 to 20 ml / min.

[0037] In some embodiments of the present invention, in the extract discharge unit, the volume fraction of the long-chain α-olefin is not less than 95%, and the yield of the long-chain α-olefin is not less than 90%.

[0038] In some embodiments of the present invention, in the raffinate discharge unit, the volume fraction of the alkane is not less than 90%.

[0039] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0040] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0041] Figure 1 is a flowchart of a method for determining the process parameters of a simulated moving bed separation according to an embodiment of the present invention;

[0042] Figure 2 is a schematic diagram of a simulated moving bed separation system according to another embodiment of the present invention;

[0043] Figure 3 is a schematic diagram of a simulated moving bed separation system according to another embodiment of the present invention;

[0044] Figure 4 is a flowchart of a method for separating long-chain α-olefins / alkanes using a simulated moving bed according to an embodiment of the present invention;

[0045] Figure 5 is a curve of the concentration change of C8α-olefin and C8 alkane in the fixed bed separation treatment according to Embodiment 1 of the present invention;

[0046] Figure 6 is a curve of the concentration change of C8α-olefin and C8 alkane in the moving bed separation treatment according to Embodiment 1 of the present invention;

[0047] Figure 7 is a curve of the concentration change of C8α-olefin and C8 alkane in the extract discharge unit in the moving bed separation treatment according to Embodiment 1 of the present invention;

[0048] Figure 8It is the concentration change curve of C8α-olefins and C8 alkanes in the raffinate unit during the moving bed separation process according to Embodiment 1 of the present invention. Detailed implementation manners

[0049] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0050] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 thus should not be construed as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0051] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be the direct contact between the first and second features, or the indirect contact between the first and second features through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0052] In one aspect of the present invention, the present invention provides a method for determining the process parameters of a simulated moving bed separation process. According to an embodiment of the present invention, in combination with Figure 1 It is understood that the method includes:

[0053] S100: The first separation process is carried out on the material to be separated by using a fixed bed. The material to be separated and the desorbent are input through the fixed bed feeding unit, and the separated material is output through the fixed bed discharging unit. The first component analysis is carried out on the separated material to determine the adsorption temperature, adsorption pressure of the fixed bed, the first feeding flow rate of the material to be separated, the first feeding flow rate of the desorbent, and the first discharging flow rate.

[0054] According to the embodiments of the present invention, in combination with Figure 2 It is understood that the first separation process can be carried out on the material to be separated by using a traditional fixed bed, or the fixed bed mode obtained by transforming the simulated moving bed separation system 10 can be used to carry out the first separation process on the material to be separated. Among them, the simulated moving bed separation system 10 may include: a separation unit 300, m first multi-way solenoid valves 100, and k second multi-way solenoid valves 200. The separation unit includes n adsorption columns 310 arranged in sequence; the first multi-way solenoid valve 100 includes a first interface 110, a second interface 120, and a third interface 130. The first interface 110 of the first multi-way solenoid valve 100 is connected to the lower part of an adsorption column 310, the second interface 120 is connected to the inlet of the desorbent circulation unit 400, and the third interface 130 is connected to the upper part of another adsorption column 310; the second multi-way solenoid valve 200 includes a first interface 210, a second interface 220, a third interface 230, a fourth interface 240, and a fifth interface 250. The first interface 210 of the second multi-way solenoid valve 200 is connected to the desorbent feeding unit 500, the second interface 220 is connected to the extract discharging unit 600, the third interface 230 is connected to the material to be separated feeding unit 700, the fourth interface 240 is connected to the raffinate discharging unit 800, and the fifth interface 250 is connected to the lower part of the adsorption column 310. Among them, the outlet of the desorbent circulation unit 400 is connected to the desorbent feeding unit. n, m, and k are all positive integers, and n≥m, k and n≥2. By setting m first multi-way solenoid valves each having at least three interfaces and controlling their connection modes, the series connection of multiple adsorption columns and the state switching of the connection between the adsorption column and the circulation unit can be realized according to actual needs; by setting k second multi-way solenoid valves each having at least five interfaces and controlling their connection modes, the connection between the adsorption column and the desorbent feeding unit, the extract discharging unit, the material to be separated feeding unit, and the raffinate discharging unit can be connected or disconnected according to actual needs. Thus, by controlling the opening and closing states of the interfaces of the first multi-way solenoid valve and the second multi-way solenoid valve and making them cooperate with each other, the flexible transformation between the fixed bed mode and the simulated moving bed mode can be realized according to needs. The specific transformation method can be understood in combination with the following text.

[0055] According to the embodiments of the present invention, in combination with Figures 1 - 2It is understood that the specific process of transforming the simulated moving bed separation system 10 into a fixed bed mode and using the obtained fixed bed mode to perform the first separation process on the material to be separated may include:

[0056] (i) By controlling the opening and closing of the interfaces of the first multi-way solenoid valve 100 and the second multi-way solenoid valve 200, the simulated moving bed separation system 10 is adjusted to the fixed bed mode. For example, according to some specific examples of the present invention, combined with Figure 2 It is understood that taking 8 adsorption columns, 8 first multi-way solenoid valves and 8 second multi-way solenoid valves as an example, the first multi-way solenoid valve connected to the upper end of the nth (n≤8) adsorption column is called 1-n, and the second multi-way solenoid valve connected to the lower end of the nth adsorption column is called 2-n. The states of the first multi-way solenoid valve can be respectively: 1: The first interface and the third interface are opened simultaneously; 2: The second interface and the third interface are opened simultaneously; The states of the second multi-way solenoid valve can be respectively: 1: The first interface and the fifth interface are opened simultaneously; 2: The second interface and the fifth interface are opened simultaneously; 3: The third interface and the fifth interface are opened simultaneously; 4: The fourth interface and the fifth interface are opened; 5: The first, second, third, fourth, and fifth interfaces are closed simultaneously;

[0057] Set according to the opening and closing states of the first solenoid valve and the second solenoid valve shown in Table 1. By controlling the first interfaces and the third interfaces of 1-5 and 1-6 in the first multi-way solenoid valve to be opened, and the first interfaces and the second interfaces of 1-1, 1-2, 1-3, 1-4, 1-7, 1-8 to be opened, so that the fifth adsorption column and the sixth adsorption column are connected in series, and the first, second, third, fourth, seventh, and eighth adsorption columns are connected to the desorbent circulation unit. At the same time, control the 2-1, 2-2, 2-3, 2-4, 2-6, 2-8 of the second multi-way solenoid valve to be closed, 2-5 to be connected to the material to be separated feeding unit and the fifth adsorption column, and 2-7 to be connected to the raffinate discharging unit, so as to obtain a fixed bed mode formed by the series connection of the fifth adsorption column and the sixth adsorption column to form a double adsorption column, and other adsorption columns are not connected into this fixed bed mode;

[0058] Table 1 Combined states of the first multi-way solenoid valve and the second multi-way solenoid valve

[0059]

[0060] (ii) Based on the fixed bed mode obtained by transforming the simulated moving bed separation system 10, desorbent can be injected into the separation unit 300 through the third interface 230 of the second multi-way solenoid valve 200 to fill the adsorption column 310 with desorbent, which not only helps to ensure the uniformity of the overall adsorption column, but also can effectively avoid introducing air bubbles into the adsorption column and affecting the separation effect;

[0061] (iii) Inject the material to be separated into the separation unit 300 (including the adsorption column in the fixed bed mode of the simulated moving bed separation system) through the third interface 230 of the second multi-way solenoid valve 200. There is no special limitation on the first feed flow rate of the material to be separated here, and those skilled in the art can flexibly adjust it according to different separation systems;

[0062] (iv) Continuously inject the desorbent into the separation unit 300 through the third interface 230 of the second multi-way solenoid valve 200, so that the separated material is output through the fourth interface 240 of the second multi-way solenoid valve 200. Continuous sampling is carried out at this fourth interface 240, and the first component analysis of the separated material is performed to determine the adsorption temperature, adsorption pressure of the fixed bed, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate. Specifically, according to some specific examples of the present invention, by performing component analysis on the separated material, a change curve of the volume fraction of different substances with the outflow volume can be obtained, and thus the adsorption temperature, adsorption pressure, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate with the best separation effect can be obtained.

[0063] According to the embodiments of the present invention, in combination with Figure 2 Understand that the simulated moving bed separation system 10 may further include: an automatic control unit (not shown in the figure). The automatic control unit can be connected to the first multi-way solenoid valve 100 and the second multi-way solenoid valve 200, and control the opening and closing of each interface of the first multi-way solenoid valve 100 and the opening and closing of each interface of the second multi-way solenoid valve 200. Thus, the inlets and outlets of the adsorption column can be automatically switched in different ways, so that the transformation between the fixed bed and the simulated moving bed modes, the adjustment of the number of adsorption columns in the fixed bed mode, and the flexible change of the number of adsorption columns in different functional areas in the simulated moving bed mode can be realized more flexibly. At the same time, it is also beneficial to control the operation accuracy and improve the switching efficiency.

[0064] S200: Perform a second separation treatment on the material to be separated using a simulated moving bed. The simulated moving bed includes a separation unit, a material to be separated feed unit, a desorbent feed unit, an extract discharge unit, and a raffinate discharge unit. Determine the adsorption temperature, adsorption pressure of the simulated moving bed, the second feed flow rate of the material to be separated, the second feed flow rate of the desorbent, the extract discharge flow rate, and the raffinate discharge flow rate according to the analysis results of S100

[0065] According to the embodiments of the present invention, the simulated moving bed separation system 10 can be used to perform a second separation treatment on the material to be separated. In combination with Figures 1 - 2 Understand that the specific process of performing the second separation treatment using the simulated moving bed separation system 10 may include: adjusting the simulated moving bed separation system 10 to the simulated moving bed mode by controlling the opening and closing of the first multi-way solenoid valve 100 and the second multi-way solenoid valve 200. In combination withFigure 2 It is understood that in the simulated moving bed mode, the feed unit 700 for the material to be separated, the desorbent feed unit 500, the extract product discharge unit 600, and the raffinate product discharge unit 800 can divide the simulated moving bed separation system into four regions, namely the adsorption region, the rectification region, the desorption region, and the buffer region. Specifically, between the feed unit 700 for the material to be separated and the raffinate product discharge unit 800 is the adsorption region, where strongly retained products are adsorbed and discharged from the raffinate product discharge unit; between the extract product discharge unit 600 and the feed unit 700 for the material to be separated is the rectification region, where weakly retained products are eluted and discharged from the extract product discharge unit; between the desorbent feed unit 500 and the extract product discharge unit 600 is the desorption region, also known as the "stationary phase regeneration region", in which the material to be separated is desorbed and the purification of the stationary phase can be achieved; between the raffinate product discharge unit 800 and the desorbent feed unit 500 is the buffer region, through which the desorbent can be recycled to the desorption region for reuse. According to some specific examples of the present invention, taking the simulated moving bed separation system 10 with 8 adsorption columns 310, 8 first multi-way solenoid valves 100, and 8 second multi-way solenoid valves 200 in step (i) above as an example, combined with Figures 2 - 3 It is understood that according to the opening and closing states of the first solenoid valve and the second solenoid valve shown in Table 2, the simulated moving bed is set to be in a state where the number distribution of adsorption columns in the "adsorption region - rectification region - desorption region - buffer region" is "2 - 2 - 2 - 2", as Figure 3 shown.

[0066] Table 2 Combined states of the first multi-way solenoid valve and the second multi-way solenoid valve

[0067]

[0068] According to the embodiments of the present invention, combined with Figure 2It is understood that the first interface 110 and the second interface 120 of the first multi-way solenoid valve 100 may not be opened simultaneously, whereby multiple adsorption columns can be connected in series or the adsorption column can be connected to the desorbent circulation unit; further, only one of the first interface 210, the second interface 220, the third interface 230, and the fourth interface 240 of the second multi-way solenoid valve 200 is opened or all are kept closed at the same time, whereby any one or a group of adsorption columns 310 can be controlled to be located in any functional area of the adsorption area, the rectification area, the desorption area, or the buffer area. According to an embodiment of the present invention, the adsorption temperature, the adsorption pressure of the simulated moving bed, and the second feed flow rate of the material to be separated, the second feed flow rate of the desorbent, the extract discharge flow rate, and the raffinate discharge flow rate can be determined according to the analysis result of step S100. Among them, the adsorption temperature and the adsorption pressure of the simulated moving bed can be the same as the adsorption temperature and the adsorption pressure of the fixed bed; the second feed flow rate of the material to be separated can be the same as the first feed flow rate of the material to be separated in the fixed bed mode; the difference between the second feed flow rate of the desorbent and the extract discharge flow rate is equal to the first feed flow rate of the desorbent; when the second feed flow rate of the material to be separated, the second feed flow rate of the desorbent, and the extract discharge flow rate are determined, the raffinate discharge flow rate can be determined.

[0069] S300: Perform a second component analysis on the material in the raffinate discharge unit to determine the state holding time of the inlet and outlet units of the simulated moving bed

[0070] According to an embodiment of the present invention, after the second separation process is completed, by performing a second component analysis on the composition of the substance obtained in the raffinate discharge unit, the outflow time with the best separation effect can be determined, that is, the state holding time of the inlet and outlet units of the simulated moving bed, which is also the valve switching time of the simulated moving bed.

[0071] According to an embodiment of the present invention, in combination with Figures 1 - 3 It is understood that the second component analysis of the material in the raffinate discharge unit specifically may include:

[0072] (a) Set the state of the inlet and outlet units of the simulated moving bed to remain unchanged, and perform a second component analysis by sampling in the raffinate discharge unit 800. That is, the valve switching time of the simulated moving bed can be set to be infinitely long. Respectively, input the material to be separated through the material to be separated feed unit 700 and input the desorbent through the desorbent feed unit 500. After performing the second separation process according to the various parameters determined in step (II), perform a second component analysis by sampling in the raffinate discharge unit, and the change curve of the volume fraction of different substances with the outflow time can be obtained;

[0073] (b) In the raffinate discharge unit 800, the separation time when the raffinate component is contained and the extract component is not contained is selected as the state retention time of the inlet and outlet units of the simulated moving bed. For example, according to some specific examples of the present invention, when the simulated moving bed separation system is used to separate long-chain α-olefins / alkanes, the time when alkanes flow out from the raffinate and long-chain α-olefins do not flow out from the raffinate can be selected as the state retention time of the inlet and outlet units of the simulated moving bed, that is, the valve switching time.

[0074] In summary, according to the method for determining the simulated moving bed separation process parameters in the above embodiments of the present invention, by sequentially separating the material to be separated by a fixed bed and a simulated moving bed, the core process parameters when using the simulated moving bed for separation operation can be accurately set and regulated, including: adsorption temperature, adsorption pressure, etc., which is beneficial to improving the purity and recovery rate of the separated products.

[0075] In another aspect of the present invention, the present invention proposes a method for separating long-chain α-olefins / alkanes by a simulated moving bed. According to the embodiments of the present invention, this method uses the above method for determining the simulated moving bed separation process parameters to determine the adsorption temperature, adsorption pressure, feed flow rate of the material to be separated, feed flow rate of the desorbent, extract discharge flow rate, raffinate discharge flow rate, and state retention time of the inlet and outlet units of the simulated moving bed for separating long-chain α-olefins / alkanes. Compared with the prior art, this method is not only beneficial to reducing energy consumption and improving economic benefits, but also can improve the purity and yield of the separated long-chain α-olefins.

[0076] According to the embodiments of the present invention, in combination with Figure 1 、 4 it is understood that the method for separating long-chain α-olefins / alkanes by a simulated moving bed may include:

[0077] S410: Supply the long-chain α-olefins / alkanes from the material to be separated feed unit to the separation unit, and supply the cyclohexane desorbent from the desorbent feed unit to the separation unit

[0078] According to the embodiments of the present invention, after determining the core parameters of the simulated moving bed separation process by the above method, the simulated moving bed separation system 10 can be used to separate long-chain α-olefins / alkanes. In combination with Figure 2Understand that, first, by controlling the opening and closing of the first multi-way solenoid valve and the second multi-way solenoid valve, the simulated moving bed separation system 10 can be adjusted to the simulated moving bed mode. The long-chain α-olefin / alkane is supplied from the material to be separated feeding unit 700 to the separation unit 300, and the cyclohexane desorbent is supplied from the desorbent feeding unit 500 to the separation unit 300. In the separation unit 300, through the adsorption-elution process, the long-chain α-olefin and alkane are separated. In an ideal state, all the long-chain α-olefins are output through the extract product unit 600, and all the alkanes are output through the raffinate product unit 800. However, in actual situations, process parameters during the separation process and conditions such as the selection of the adsorbent will all affect the separation effect. Therefore, only by controlling the separation conditions can the separation effect of the long-chain α-olefin and alkane be improved. Among them, by using cyclohexane as the desorbent in the present invention, not only is the price low, but it is also beneficial to realize the subsequent separation of cyclohexane and long-chain α-olefins, thereby further improving the purity and yield of long-chain α-olefins and reducing production costs at the same time. It should be noted that there is no special limitation on the carbon number of the long-chain α-olefins in the present invention, and those skilled in the art can flexibly select according to the actual situation. For example, according to some specific examples of the present invention, the carbon number range of the long-chain α-olefins can be C6~C 18 , within this carbon number range, there is a relatively large market demand for long-chain α-olefins, which has high practical application value. In addition, in the long-chain α-olefin / alkane, the content of the long-chain α-olefin can be 10~90wt%, for example, it can be 15wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt% etc.

[0079] According to the embodiments of the present invention, combined with Figures 2 - 3 Understand that there is no special limitation on the number of adsorption columns 310 included in the separation unit 300 of the simulated moving bed separation system 10 in the present invention, and those skilled in the art can flexibly select according to the actual situation. For example, according to some specific examples of the present invention, the separation unit 300 may include 8~32 adsorption columns 310, the inner diameter of the adsorption column 310 can be 10~50mm, and the length of the adsorption column 310 can be 300~1500mm. In addition, the adsorption column 310 is filled with an adsorbent, and there is no special limitation on the type of the adsorbent in the present invention. For example, it may include Na-FAU type zeolite molecular sieve, and the particle size of the zeolite molecular sieve can be 0.5mm~2.5mm, for example, it can be 0.6mm, 0.8mm, 1.5mm or 2mm etc.

[0080] According to an embodiment of the present invention, the feed flow rate of the long-chain α-olefin / alkane can be 1 ml / min to 10 ml / min, for example, it can be 2 ml / min, 3 ml / min, 4 ml / min, 6 ml / min or 8 ml / min, etc., and the feed time can be 1 min to 10 min, for example, it can be 2 min, 4 min, 6 min or 8 min, etc. The inventors have found that if the feed flow rate of the material to be separated is too small and the feed time is too short, the separation efficiency will decrease; if the feed flow rate of the material to be separated is too large and the feed time is too long, the separation effect will be affected. Further, the ratio of the feed flow rate of the desorbent to the feed flow rate of the long-chain α-olefin / alkane can be (3-8):1, for example, it can be 4:1, 5:1, 6:1 or 7:1, etc. The inventors have found that if the ratio of the feed flow rate of the desorbent to the material to be separated is too small, that is, the feed flow rate of the desorbent is too small, it is easy to increase the backmixing phenomenon and affect the separation effect; if the ratio of the feed flow rate of the desorbent to the material to be separated is too large, that is, the feed flow rate of the desorbent is too large, the residence time of the desorbent in the adsorption column is too short, and it is difficult to effectively separate the material to be separated. By controlling the ratio of the feed flow rate of the desorbent to the material to be separated within the above range, the present invention is beneficial to taking into account the separation efficiency and separation effect of the long-chain α-olefin / alkane.

[0081] S420: Control the adsorption temperature, adsorption pressure, extract discharge flow rate, raffinate discharge flow rate and the state holding time of the feed and discharge unit in the separation unit, and collect the separated long-chain α-olefin in the extract discharge unit

[0082] According to an embodiment of the present invention, after the long-chain α-olefin / alkane and the cyclohexane desorbent are introduced into the separation unit, the adsorption temperature of the separation unit can be controlled to be 20-200 °C, for example, it can be 50 °C, 80 °C, 120 °C, 160 °C or 180 °C, etc. The inventors have found that if the adsorption temperature is too low, the adsorption effect will become poor and the adsorption efficiency will also be reduced; if the adsorption temperature is too high, it is easy to cause the material to be separated to gasify and reduce the yield of the separation product. By controlling the adsorption temperature within the above range, the present invention is beneficial to improving the yield and purity of the separated long-chain α-olefin. In addition, it should be noted that the higher the carbon number of the α-olefin, the higher the required adsorption temperature, and those skilled in the art can flexibly select according to actual needs. In addition, according to some other embodiments of the present invention, the adsorption pressure can be 0.1-2.5 MPa, for example, it can be 0.6 MPa, 1 MPa, 1.2 MPa or 2 MPa, etc. The inventors have found that if the adsorption pressure is too low, the separation effect will be reduced; if the adsorption pressure is too high, the equipment cost will increase and unnecessary resource waste will be generated. By controlling the adsorption pressure within the above range, the present invention is beneficial to taking into account the production cost and the separation effect.

[0083] According to an embodiment of the present invention, the simulated moving bed separation system 10 may further include a desorbent recycling unit 400 for recycling the desorbent to the desorbent feeding unit 500 for recovery and reuse. Therefore, the recycling flow rate affects the flow rate of the desorbent in the separation unit. During the process of separating long-chain α-olefins / alkanes using the simulated moving bed separation system, the recycling flow rate in the desorbent recycling unit 400 may not be greater than 50 ml / min, and for example, it may be 3 ml / min, 10 ml / min, 15 ml / min, 30 ml / min, or 40 ml / min, etc. The inventors found that if the recycling flow rate is too large, it is easy to carry the incompletely separated materials into the desorbent feeding unit 500 in a cycle, increasing the load of the system and affecting the separation efficiency and separation effect. By controlling the recycling flow rate within the above range, the present invention is beneficial to improving the yield and purity of the separated long-chain α-olefins. Further, according to some specific examples of the present invention, the recycling flow rate in the desorbent recycling unit 400 may preferably be 5 - 20 ml / min, whereby the amount of desorbent used can be further reduced, and thus the production cost can be reduced.

[0084] According to an embodiment of the present invention, the residence time (i.e., the valve switching time) of the feed and discharge unit is closely related to the column length of the above-mentioned adsorption column, the feed and discharge flow rate, the recycling flow rate, etc., and those skilled in the art can flexibly adjust according to the actual situation. According to some specific examples of the present invention, the valve switching time may be 600 - 1200 s, and for example, it may be 800 s, 900 s, 1000 s, or 1100 s, etc.

[0085] According to an embodiment of the present invention, by using the above method for separating long-chain α-olefins / alkanes, the purity and yield of the separated materials can be significantly improved. Specifically, the volume fraction of the long-chain α-olefins obtained in the extract discharge unit can be as high as 95% or more, and the yield can be as high as 90% or more; in the raffinate discharge unit, the volume fraction of the alkane by-product obtained can be as high as 90% or more.

[0086] The embodiments of the present invention will be described in detail below. The following described embodiments are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention. For those not specified in the embodiments regarding specific technologies or conditions, they shall be carried out according to the technologies or conditions described in the literature in the art or according to the product specifications. For the reagents or instruments not specified in terms of the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0087] Example 1

[0088] (1) By controlling the opening and closing of the interfaces of the first multi-way solenoid valve 100 and the second multi-way solenoid valve 200, the simulated moving bed separation system 10 is adjusted to a fixed bed mode composed of two adsorption columns. The combined states of the first multi-way solenoid valve and the second multi-way solenoid valve are shown in Table 1; cyclohexane is injected into the separation unit through the third interface of the second multi-way solenoid valve to fill the adsorption column with cyclohexane; C8α-olefin (50 wt%) / alkane (50 wt%) is injected into the separation unit through the third interface of the second multi-way solenoid valve; cyclohexane is continuously injected into the separation unit through the third interface of the second multi-way solenoid valve so that C8α-olefin (50% wt) / alkane (50% wt) is output through the fourth interface of the second multi-way solenoid valve, and the obtained material is continuously sampled for the first component analysis to obtain the change curve of the volume fraction of different substances with the effluent volume. The change curves of the volume fractions of C8α-olefin and C8 alkane corresponding to the best separation effect with the effluent volume are as Figure 5 shown. From this, it can be obtained that the adsorption temperature for the fixed bed to have the best separation effect is 40 °C, the adsorption pressure is 1.5 MPa, the first feed flow rate of the material to be separated is 5 ml / min, the feed time is 2 min, and the first feed flow rate of the desorbent is 8 ml / min;

[0089] (2) By controlling the opening and closing of the interfaces of the first multi-way solenoid valve 100 and the second multi-way solenoid valve 200, the distribution of the adsorption columns in the "adsorption zone - rectification zone - desorption zone - buffer zone" of the simulated moving bed separation system 10 is adjusted to the state of "2 - 2 - 2 - 2". The combined states of the first multi-way solenoid valve and the second multi-way solenoid valve are shown in Table 2; according to the analysis results of step (1), the adsorption temperature of the simulated moving bed is determined to be 40 °C, the adsorption pressure is 1.5 MPa, the second feed flow rate of the material to be separated is 4 ml / min, the second feed flow rate of the desorbent is 8 ml / min, the extract discharge flow rate is 6 ml / min, the raffinate discharge flow rate is 6 ml / min, and the circulation flow rate is 6 ml / min;

[0090] (3) The valve switching time of the first multi-way solenoid valve and the second multi-way solenoid valve is set to be infinitely long (i.e., controlling the opening and closing states of the first multi-way solenoid valve and the second multi-way solenoid valve not to change). The second component analysis is continuously sampled in the raffinate discharge unit, and the change curve of the volume fraction of different substances with the effluent time can be obtained, as Figure 6 shown. The time when the alkane flows out from the raffinate and the α-olefin does not flow out from the raffinate is selected as the valve switching time, which is 750 s.

[0091] (4) According to the process parameters obtained in step (2) and step (3), the C8α-olefin (50 wt%) / alkane (50 wt%) is separated by using the simulated moving bed separation system in step (2). The concentration distributions of C8α-olefin and C8 alkane in the extract discharge unit are asFigure 7 As shown, the concentration distributions of C8 α-olefins and C8 alkanes in the raffinate discharge unit are as follows Figure 8 As shown, through integral calculation, in the extract discharge unit, the purity of the separated C8 α-olefins is 95.0% and the yield is 93.5%. In the raffinate discharge unit, the purity of the alkane by-product is 97.2%.

[0092] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0093] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for determining the process parameters of a simulated moving bed separation process, characterized in that, Comprising: (1) A fixed bed is used to perform a first separation process on the material to be separated. The material to be separated and the desorbent are input through the fixed bed feed unit, and the separated material is output through the fixed bed discharge unit. A first component analysis is performed on the separated material to determine the adsorption temperature, adsorption pressure of the fixed bed, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate; (2) A simulated moving bed is used to perform a second separation process on the material to be separated. The simulated moving bed includes a separation unit, a material to be separated feed unit, a desorbent feed unit, an extract discharge unit, and a raffinate discharge unit. According to the analysis results of step (1), the adsorption temperature, adsorption pressure of the simulated moving bed, the second feed flow rate of the material to be separated, the second feed flow rate of the desorbent, the extract discharge flow rate, and the raffinate discharge flow rate are determined; (3) A second component analysis is performed on the material in the raffinate discharge unit to determine the residence time of the inlet and outlet units of the simulated moving bed; The first separation process and the second separation process are performed using a simulated moving bed separation system. The simulated moving bed separation system includes: The separation unit, which includes n adsorption columns arranged in sequence; m first multi-way solenoid valves. The first multi-way solenoid valve includes a first interface, a second interface, and a third interface. The first interface of the first multi-way solenoid valve is connected to the lower part of one adsorption column, the second interface is connected to the inlet of the desorbent circulation unit, and the third interface is connected to the upper part of another adsorption column; k second multi-way solenoid valves. The second multi-way solenoid valve includes a first interface, a second interface, a third interface, a fourth interface, and a fifth interface. The first interface of the second multi-way solenoid valve is connected to the desorbent feed unit, the second interface is connected to the extract discharge unit, the third interface is connected to the material to be separated feed unit, the fourth interface is connected to the raffinate discharge unit, and the fifth interface is connected to the lower part of the adsorption column, wherein, the outlet of the desorbent circulation unit is connected to the desorbent feed unit, and n, m, and k are all positive integers, and n ≥ m, k and n ≥ 2; The simulated moving bed separation system further includes: an automatic control unit, which is connected to the first multi-way solenoid valve and the second multi-way solenoid valve, and controls the opening and closing of each interface of the first multi-way solenoid valve and the opening and closing of each interface of the second multi-way solenoid valve.

2. The method according to claim 1, wherein The first interface and the second interface of the first multi-way solenoid valve are not opened simultaneously.

3. The method according to claim 1, wherein Among the first interface, the second interface, the third interface, and the fourth interface of the second multi-way solenoid valve, only one interface is opened or all are kept closed at the same time.

4. The method for determining the process parameters of a simulated moving bed separation process according to claim 1, wherein Step (1) includes: (1-1) By controlling the opening and closing of the interfaces of the first multi-way solenoid valve and the second multi-way solenoid valve, the simulated moving bed separation system is adjusted to the fixed bed mode; (1-2) The desorbent is injected into the separation unit through the third interface of the second multi-way solenoid valve to fill the adsorption column with the desorbent; (1-3) Inject the material to be separated into the separation unit through the third interface of the second multi-way solenoid valve; (1-4) Continuously inject the desorbent into the separation unit through the third interface of the second multi-way solenoid valve, so that the separated material is output through the fourth interface of the second multi-way solenoid valve, and perform the first component analysis on the separated material to determine the adsorption temperature, adsorption pressure of the fixed bed, the first feed flow rate of the material to be separated, the first feed flow rate of the desorbent, and the first discharge flow rate.

5. The method for determining the process parameters of a simulated moving bed separation process according to claim 1, characterized in that, Step (2) includes: adjusting the simulated moving bed separation system to the simulated moving bed mode by controlling the opening and closing of the first multi-way solenoid valve and the second multi-way solenoid valve.

6. The method for determining the process parameters of the simulated moving bed separation process according to claim 5, wherein Step (3) includes: (3-1) Keep the state of the simulated moving bed feeding and discharging unit unchanged, and sample in the raffinate discharging unit for the second component analysis; (3-2) In the raffinate discharging unit, select the separation time containing the raffinate component and not containing the extract component as the state holding time of the simulated moving bed feeding and discharging unit.

7. A method for separating long-chain α-olefins / alkanes by simulated moving bed, characterized in that, Use the method according to any one of claims 1 to 6 to determine the adsorption temperature, adsorption pressure of the simulated moving bed for separating long-chain α-olefins / alkanes, the feed flow rate of the material to be separated, the feed flow rate of the desorbent, the extract discharge flow rate, the raffinate discharge flow rate, and the state holding time of the feeding and discharging unit of the simulated moving bed.

8. The method for separating long-chain α-olefins / alkanes according to claim 7, characterized in that, It includes: (1) Supply the long-chain α-olefins / alkanes from the material to be separated feeding unit to the separation unit, and supply the cyclohexane desorbent from the desorbent feeding unit to the separation unit; (2) Control the adsorption temperature, adsorption pressure, the extract discharge flow rate, the raffinate discharge flow rate, and the state holding time of the feeding and discharging unit in the separation unit, and collect the separated long-chain α-olefins in the extract discharge unit.

9. The method for separating long-chain α-olefins / alkanes according to claim 8, characterized in that, The separation unit includes 8 to 32 adsorption columns, the inner diameter of the adsorption column is 10 to 50 mm, and the length of the adsorption column is 300 to 1500 mm.

10. The method for separating long-chain α-olefins / alkanes according to claim 7, characterized in that, The carbon number range of the long-chain α-olefins is C6 to C8.

11. The method for separating long-chain α-olefins / alkanes according to claim 9, wherein The adsorption column is filled with an adsorbent, and the adsorbent includes Na-FAU type zeolite molecular sieve.

12. The method for separating long-chain α-olefins / alkanes according to claim 7, wherein In the long-chain α-olefins / alkanes, the content of long-chain α-olefins is 10 to 90 wt%.

13. The method for separating long-chain α-olefins / alkanes according to claim 7, characterized in that, The adsorption temperature is 20 to 200 °C.

14. The method for separating long-chain α-olefins / alkanes according to claim 7, characterized in that, The adsorption pressure is 0.1 to 2.5 MPa.

15. The method for separating long-chain α-olefins / alkanes according to claim 7, wherein The feed flow rate of the long-chain α-olefins / alkanes is 1 ml / min to 10 ml / min, and the feed time is 1 min to 10 min.

16. The method for separating long-chain α-olefins / alkanes according to claim 8, wherein The ratio of the feed flow rate of the desorbent to the long-chain α-olefins / alkanes is (3 to 8):

1.

17. The method for separating long-chain α-olefins / alkanes according to claim 7, characterized in that, Use a simulated moving bed separation system to separate the long-chain α-olefins / alkanes, and the circulation flow rate in the desorbent circulation unit of the simulated moving bed separation system is not greater than 50 ml / min.

18. The method for separating long-chain α-olefins / alkanes according to claim 8, characterized in that, The state holding time of the feeding and discharging unit is 600 to 1200 s.

19. The method for separating long-chain α-olefins / alkanes according to claim 11, wherein The particle size of the Na-FAU type zeolite molecular sieve is 0.5 mm to 2.5 mm.

20. The method for separating long-chain α-olefins / alkanes according to claim 17, characterized in that, The circulation flow rate in the desorbent circulation unit is 5 to 20 ml / min.

21. The method for separating long-chain α-olefins / alkanes according to claim 8, wherein In the extract discharge unit, the volume fraction of the long-chain α-olefin is not less than 95%, and the yield of the long-chain α-olefin is not less than 90%.

22. The method for separating long-chain α-olefins / alkanes according to claim 7, characterized in that, In the raffinate discharge unit, the volume fraction of the alkane is not less than 90%.

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