Separation system and separation method

Abstract

The application discloses a separation system and a separation method. The separation system comprises a bias partition column, a partition column tower bottom production pump, an ionic liquid recovery tower and a recovery tower condenser. The bias partition column comprises a common rectification section at the top of the column, a feed production section in the column and a common stripping section at the bottom of the column. The common rectification section comprises a plurality of rectification section trays. The feed production section is provided with a partition extending along the axial direction of the bias partition column. The partition forms a feed area and a production area on both sides of the partition. The partition deviates from the central axis of the bias partition column. The width of the production area and the width of the feed area are different along the radial direction of the bias partition column. The ionic liquid recovery tower is connected with the common rectification section to recover light component ionic liquid. The recovery tower condenser is connected with the ionic liquid recovery tower. The recovery tower condenser is also connected with the ionic liquid recovery tower and / or the common rectification section. The application can remove light components and heavy components, and improve the purity of products.

Description

Technical Field

[0001] This application relates to the field of chemical technology, and in particular to separation systems and separation methods. Background Technology

[0002] n-Butanol, as an important basic chemical raw material, plays a crucial role in multiple industrial sectors. In the solvent industry, n-Butanol is widely used in the production of coatings, inks, resins, and adhesives due to its good solubility and moderate volatility. In the plasticizer field, n-Butanol, as a key precursor to dibutyl phthalate (DBP), can significantly improve the flexibility and processing performance of plastic products. As a biofuel additive, n-Butanol, due to its high energy density and low hydrophilicity, is gradually replacing ethanol as a more advantageous gasoline additive, effectively improving fuel octane number and combustion efficiency.

[0003] Crude n-butanol produced in traditional industries typically contains multiple impurity components, primarily toluene, methanol, water, isobutanol, and small amounts of heavy components such as butyl butyrate and butyraldehyde condensate. These impurity components easily form complex multi-component azeotropic systems: n-butanol and water form a minimum azeotrope at atmospheric pressure, with a boiling point of approximately 92.6°C and containing about 57 wt% n-butanol; n-butanol and isobutanol form a near-boiling-point mixture with a boiling point difference of only about 10°C; and toluene and methanol form a binary azeotrope with a boiling point of approximately 110°C. This multi-component azeotropic system leads to a significant reduction in the relative volatility of each impurity component. For example, in the n-butanol / water system, the relative volatility at atmospheric pressure is only about 1.2–1.5, making it difficult to efficiently separate light components such as methanol and water due to their boiling points being close to that of n-butanol. Simultaneously, heavy components such as butyl butyrate tend to accumulate at the bottom of the column, resulting in a final product n-butanol with a purity of less than 99.5%, which is insufficient for high-end applications. Multi-component azeotropic systems not only increase the complexity of separation processes, but also significantly increase energy consumption and operating costs.

[0004] To address the separation problem, traditional technologies commonly employ a two-column series distillation method. First, a pre-distillation column removes light components such as toluene, methanol, and water, followed by a distillation column to remove heavy components such as isobutanol and butyl butyrate. However, this two-column series distillation method suffers from backmixing of light and heavy components within the columns. Specifically, in the pre-distillation column, light components remix with rising vapor as they descend, while heavy components move upwards due to reflux. This disrupts the concentration gradient, significantly reducing separation efficiency and resulting in low-purity n-butanol, often requiring additional distillation steps for purification, leading to high overall energy consumption. To overcome the shortcomings of traditional two-column series distillation methods, the Dividing Wall Column (DWC) technology has been introduced as a solution. This technology divides the column into multiple functional zones, such as the feed zone, side stream collection zone, top zone, and bottom zone, by setting vertical partition walls inside a single column. This enables the simultaneous removal of both light and heavy components. Although DWC technology improves separation efficiency, the azeotrope formed by light components, especially toluene, methanol, and n-butanol, remains a bottleneck restricting separation efficiency, product purity, and energy consumption. Summary of the Invention

[0005] Therefore, it is necessary to provide a separation system and method that can remove light and heavy components, improve product purity, and reduce energy consumption.

[0006] One embodiment of this application provides a separation system.

[0007] A separation system includes an offset baffle column, a baffle column bottom pump, an ionic liquid recovery column, and a recovery column condenser; wherein the offset baffle column includes a common rectification section at the top, a feed and discharge section in the middle, and a common stripping section at the bottom; the common rectification section includes multiple rectification trays, and an oil collection tank is provided at the bottom of the common rectification section; the feed and discharge section is provided with a baffle extending along the axial direction of the offset baffle column, with a feed zone and a discharge zone formed on both sides of the baffle, the baffle being offset from the central axis of the offset baffle column; the width of the discharge zone is different from the width of the feed zone along the radial direction of the offset baffle column; the feed zone is provided with multiple feed trays; the discharge zone is provided with multiple discharge trays; and the common stripping section includes multiple stripping trays.

[0008] The ionic liquid recovery tower is connected to the oil collection tank to recover the light component ionic liquid in the oil collection tank. The recovery tower condenser is connected to the ionic liquid recovery tower to condense the gas phase from the top of the ionic liquid recovery tower into liquid. The recovery tower condenser can also return the liquid to the ionic liquid recovery tower and / or the common rectification section.

[0009] In some embodiments, the separation system further includes a baffle column condenser connected to the common rectification section of the offset baffle column to condense the gaseous material from the common rectification section into a liquid, and the liquid outlet of the baffle column condenser is also circulated to the common rectification section, the feed zone, and the collection zone to reflux the condensing medium.

[0010] In some embodiments, the separation system further includes a diaphragm column reflux tank connected to the diaphragm column condenser to collect condensed liquid, and the diaphragm column reflux tank is connected to the common rectification section, the feed zone, and the collection zone via the first reflux pipe to reflux the liquid in the diaphragm column reflux tank.

[0011] In some embodiments, the separation system further includes a baffle reflux pump, which is located in the first reflux pipeline to reflux a portion of the liquid in the baffle reflux tank back to the common rectification section, a portion back to the feed zone, and a portion back to the extraction zone.

[0012] In some embodiments, the separation system further includes a baffle reboiler connected to the common stripping section to vaporize a portion of the material from the common stripping section and reflux it back to the common stripping section, and a baffle bottom pump connected to the common stripping section's outlet line to extract a portion of the material from the common stripping section.

[0013] In some embodiments, the separation system further includes a recovery tower reflux tank connected to the recovery tower condenser to collect the liquid condensed by the recovery tower condenser, the recovery tower condenser being connected to the ionic liquid recovery tower via a second reflux pipe.

[0014] In some embodiments, the separation system further includes a recovery tower reflux pump, which is disposed in the second reflux pipeline to reflux a portion of the liquid in the recovery tower reflux tank back to the ionic liquid recovery tower, a portion back to the feed zone, a portion back to the extraction zone, and a portion extracted.

[0015] In some embodiments, the separation system further includes a recovery tower reboiler connected to the bottom of the ionic liquid recovery tower to vaporize a portion of the material from the ionic liquid recovery tower and return it to the ionic liquid recovery tower.

[0016] In some embodiments, the separation system further includes a recovery tower bottom pump. The recovery tower bottom pump is connected to the bottom outlet line of the ionic liquid recovery tower to return a portion of the material from the bottom of the ionic liquid recovery tower to the common rectification section and to extract a portion.

[0017] In some embodiments, the ionic liquid recovery tower includes a plate recovery tower, and the plate type of the ionic liquid recovery tower includes a sieve plate.

[0018] In some embodiments, the sieve plate type includes one or both of the following: a floating valve tray and a cross-flow tray.

[0019] In some embodiments, the offset partition tower has a cylindrical structure, and the distance between the partition and the central axis of the offset partition tower is 5% to 45% of the radius of the offset partition tower.

[0020] Optionally, the distance between the partition and the central axis of the offset partition tower is 15% to 25% of the radius of the offset partition tower.

[0021] In some embodiments, the multiple distillation section trays are staggered to form a meandering first flow channel.

[0022] In some embodiments, the plurality of feed trays are staggered to form a meandering second flow path.

[0023] In some embodiments, the plurality of extraction trays are staggered to form a meandering third flow channel.

[0024] In some embodiments, multiple stripping trays are staggered to form a meandering fourth flow channel.

[0025] In some embodiments, the number of rectification section trays is 5 to 15, and the multiple rectification section trays are distributed at equal intervals.

[0026] In some embodiments, the number of feed trays is 25 to 35, and the multiple feed trays are distributed at equal intervals.

[0027] In some embodiments, the number of extraction trays is 25 to 35, and the multiple extraction trays are distributed at equal intervals.

[0028] In some embodiments, the number of stripping trays is 5 to 15, and the multiple stripping trays are distributed at equal intervals.

[0029] In some embodiments, the operating pressure inside the offset diaphragm tower can be controlled to be 0.1 MPaA to 0.2 MPaA.

[0030] In some embodiments, the top temperature of the offset partition tower can be controlled at 114°C to 130°C, and the bottom temperature can be controlled at 120°C to 160°C.

[0031] In some embodiments, the ionic liquid recovery tower has multiple recovery trays distributed in a staggered manner, forming a meandering fifth flow channel.

[0032] In some embodiments, the number of recovery trays is 5 to 10, and the multiple recovery trays are distributed at equal intervals.

[0033] In some embodiments, the operating pressure inside the ionic liquid recovery tower can be controlled to be 0.1 MPaA to 0.2 MPaA.

[0034] In some embodiments, the temperature at the top of the ionic liquid recovery tower can be controlled at 100°C to 120°C, and the temperature at the bottom of the tower can be controlled at 130°C to 150°C.

[0035] One embodiment of this application provides a separation method.

[0036] A separation method includes the following steps:

[0037] The crude raw material to be separated and the ionic liquid are controlled to enter the common rectification section of the biased plate column for rectification.

[0038] The vapor phase obtained from the controlled distillation process is condensed into a liquid, and the condensed liquid is controlled to flow back to the common distillation section, the feed zone, and the extraction zone.

[0039] The light component ionic liquid in the common distillation section is controlled to enter the ionic liquid recovery tower from the oil collection tank for recovery treatment to obtain the target product;

[0040] In addition, the gas phase obtained from the recovery process is controlled to enter the condenser of the recovery tower for condensation into liquid, and the condensed liquid is controlled to flow back to the ionic liquid recovery tower and / or the common rectification section;

[0041] In some embodiments, the operating pressure inside the offset diaphragm tower is controlled to be 0.1 MPaA to 0.2 MPaA.

[0042] In some embodiments, the top temperature of the offset partition tower is controlled at 114°C to 130°C, and the bottom temperature is controlled at 120°C to 160°C.

[0043] In some embodiments, the operating pressure inside the ionic liquid recovery tower is controlled at 0.1 MPaA to 0.2 MPaA.

[0044] In some embodiments, the temperature at the top of the ionic liquid recovery tower is controlled at 100°C to 120°C, and the temperature at the bottom of the tower is controlled at 130°C to 150°C.

[0045] In some embodiments, the flow rate of the ionic liquid is controlled to be 0.5% to 5% of the flow rate of the crude raw material to be separated.

[0046] In some embodiments, the temperature of the ionic liquid is controlled at 42°C to 125°C, and the pressure is controlled at 0.2 MPaG to 0.5 MPaG.

[0047] In some embodiments, the ionic liquid includes one or more of [C4mim][Ac] (1-butyl-3-methylimidazolium acetate), [C4mim][DCA] (1-butyl-3-methylimidazolium dicyandiamide), [C4mim][OTf] (1-butyl-3-methylimidazolium trifluoromethanesulfonate), [C4mim][MS] (1-butyl-3-methylimidazolium methanesulfonate), and [C6mim][Cl] (1-hexyl-3-methylimidazolium chloride).

[0048] In some embodiments, the operational performance of the offset baffle tower is evaluated; the evaluation factor HEF for the operational performance of the offset baffle tower is as follows:

[0049]

[0050] In the formula, This indicates the volumetric flow rate of the gaseous material in the first feed tray of the feed zone, in m³. 3 / h;

[0051] This indicates the volumetric flow rate of the gaseous material in the last feed tray of the feed zone, in m³. 3 / h;

[0052] This represents the volumetric flow rate of gaseous material in the first producing tray of the producing area, in m³. 3 / h;

[0053] This represents the volumetric flow rate of gaseous material in the last producing tray of the producing area, in m³. 3 / h;

[0054] This indicates the volumetric flow rate of the liquid phase material in the first feed tray of the feed zone, in m³. 3 / h;

[0055] This indicates the volumetric flow rate of the liquid phase material in the last feed tray of the feed zone, in m³. 3 / h;

[0056] This represents the volumetric flow rate of liquid material in the first producing tray of the producing area, in m³. 3 / h;

[0057] This represents the volumetric flow rate of liquid material in the last producing tray of the producing area, in m³. 3 / h;

[0058] Indicates the cross-sectional area of ​​the feed zone; Indicates the cross-sectional area of ​​the extraction zone;

[0059] This indicates the mass flow rate of gaseous material in the first feed tray of the feed zone, in kg / h;

[0060] This indicates the gaseous material mass flow rate of the last feed tray in the feed zone, in kg / h;

[0061] This indicates the mass flow rate of gaseous material in the first producing tray of the producing area, in kg / h;

[0062] This indicates the mass flow rate of gaseous material in the last extraction tray of the extraction zone, in kg / h.

[0063] The aforementioned separation system can be applied to the separation of crude butanol containing both light and heavy components, as well as other similar near-boiling point mixtures. When used to separate the light components of crude butanol from ionic liquids, it can yield high-purity n-butanol products with lower energy consumption than traditional distillation processes. The separation system and method of this application can obtain high-purity target products while simultaneously saving on equipment investment and energy consumption. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0065] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0066] Figure 1 This is a schematic diagram of a separation system according to an embodiment of this application;

[0067] Figure 2 This is a schematic diagram of an offset baffle tower of a separation system according to an embodiment of this application;

[0068] Figure 3This is a schematic diagram of the offset baffle tower of the separation system described in one embodiment of this application from another angle; Figure 2 , Figure 3 N1 to N11 in the diagram represent interfaces;

[0069] Figure 4 This is a schematic diagram of the separation method described in one embodiment of this application;

[0070] Figure 5 This is a schematic diagram of a two-tower series distillation system for Comparative Example 2.

[0071] Explanation of reference numerals in the attached figures

[0072] 10. Separation system; 100. Offset baffle column; 101. Common rectification section; 102. Feed zone; 103. Production zone; 104. Common stripping section; 105. Oil collection tank; 106. Baffle; 200. Baffle column condenser; 300. Baffle column bottom pump; 400. Ion liquid recovery column; 500. Recovery column condenser; 600. Baffle column reflux tank; 700. Baffle column reflux pump; 800. Baffle column Reboiler; 900, Reflux tank of recovery tower; 1000, Reflux pump of recovery tower; 1100, Reboiler of recovery tower; 1110, Distillation section tray; 1120, Feed tray; 1130, Outlet tray; 1140, Stripping section tray; 1150, Recovery tray; 20, Two-tower series distillation system; 21, Distillation tower; 22, Distillation condenser; 23, Distillation buffer tank; 24, Distillation reflux pump; 25, Distillation reboiler. Detailed Implementation

[0073] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0074] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0075] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0076] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0077] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0078] In this document, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain."

[0079] In this document, unless otherwise stated, the reaction steps may be performed in the order described herein or not. For example, other steps may be included between reaction steps, and the order of reaction steps may be appropriately interchanged. This is something that those skilled in the art can determine based on conventional knowledge and experience. Preferably, the reaction methods described herein are performed sequentially.

[0080] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0081] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0082] This application provides a separation system to address at least one of the following technical problems in the production of crude n-butanol using conventional techniques: (1) The crude n-butanol produced typically contains multiple impurity components, which easily form complex multi-component azeotropic systems. These multi-component azeotropic systems increase the complexity of the separation process and significantly increase energy consumption and operating costs. (2) When using a two-tower series distillation method, there is a backmixing phenomenon between light and heavy components in the tower, which significantly reduces the separation efficiency and results in low purity of the n-butanol product. Additional distillation steps are often required for purification, leading to high overall energy consumption. (3) When using a partitioned wall distillation (DWC) column to remove light and heavy components, the azeotrope formed by the light components, especially toluene, methanol, and n-butanol, still restricts further reduction in energy consumption. The separation system will be described below with reference to the accompanying drawings.

[0083] The separation system 10 provided in one embodiment of this application is exemplary; please refer to [link to relevant documentation]. Figure 1 As shown, Figure 1 This is a schematic diagram of the separation system 10 provided in one embodiment of this application. The separation system 10 of this application can be used for the low-cost and high-efficiency processing and purification of crude raw materials such as isobutanol and n-butanol. For example, crude n-butanol raw material can be separated to prepare the target product, and the prepared n-butanol has high purity.

[0084] To illustrate the structure of the separation system 10 more clearly, the separation system 10 will be described below in conjunction with the accompanying drawings.

[0085] For example, please refer to Figure 1 As shown, a separation system 10 includes an offset baffle column 100, a baffle column condenser 200, a baffle column bottom pump 300, an ionic liquid recovery column 400, and a recovery column condenser 500. See also... Figure 2 , Figure 3 As shown, Figure 2 This is a schematic diagram of an offset baffle tower 100 of a separation system 10 according to an embodiment of this application. Figure 3 This is a schematic diagram from another angle of an offset baffle column 100 of a separation system 10 according to an embodiment of this application. The offset baffle column 100 includes a common rectification section 101 at the top, a feed and collection section in the middle of the column, and a common stripping section 104 at the bottom. The common rectification section 101 includes multiple rectification trays 1110, and an oil collection tank 105 is provided at the bottom of the common rectification section 101. The feed and collection section is provided with a baffle 106 extending along the axial direction of the offset baffle column 100. A feed zone 102 and a collection zone 103 are formed on both sides of the baffle 106, respectively. The baffle 106 is offset from the central axis of the offset baffle column 100, and the width of the collection zone 103 is different from the width of the feed zone 102 along the radial direction of the offset baffle column 100. The feed zone 102 is provided with multiple feed trays 1120. The production zone 103 is equipped with multiple production trays 1130. The common stripping section 104 includes multiple stripping trays 1140.

[0086] The ionic liquid recovery tower 400 is connected to the oil collection tank 105 to collect the light component ionic liquid within the oil collection tank 105. The recovery tower condenser 500 is connected to the ionic liquid recovery tower 400 to condense the vapor phase from the top of the ionic liquid recovery tower 400 into liquid. The liquid outlet of the recovery tower condenser 500 is also recirculated to the ionic liquid recovery tower 400 and / or the common rectification section 101 to return the liquid to the ionic liquid recovery tower 400 and / or the common rectification section 101.

[0087] The separation system 10 described above is equipped with an offset baffle tower 100, which divides the feed and collection section inside the tower into a left rectification zone (feed zone 102) and a right rectification zone (collection zone 103) with different areas. An ionic liquid (such as [C4mim][Ac]) is injected into the top of the common rectification section 101 to significantly increase the relative volatility of light components such as toluene / water / methanol and products to be separated, such as isobutanol and n-butanol. The mixture containing the ionic liquid is collected from the oil collection tank 105, separated by the ionic liquid recovery tower 400, and then the ionic liquid is recycled back to the main tower to obtain the target product. By matching the gas-liquid load difference between the feed zone 102 and the output zone 103 on both sides of the asymmetric partition 106 through the asymmetric layout of the partition 106, excessive opening of the small flow side plate is avoided, reducing equipment manufacturing costs and avoiding energy waste caused by large-scale backmixing of light and heavy components. The offset partition tower 100 can realize the function of single-tower integrated removal of light and heavy components. The matching small ionic liquid recovery tower 400 can replace the large tower system of the two-tower series distillation method in traditional technology, reducing investment costs by at least 35% and energy consumption by at least 28%.

[0088] In some of these implementations, please refer to Figure 1 As shown, the separation system 10 also includes a diaphragm column condenser 200. The diaphragm column condenser 200 is connected to the common rectification section 101 of the offset diaphragm column 100 to condense the gaseous material from the common rectification section 101 into a liquid. The liquid outlet of the diaphragm column condenser 200 is also recirculated to the common rectification section 101, the feed zone 102, and the collection zone 103 to reflux the condensate.

[0089] In some of these implementations, please refer to Figure 1 As shown, the separation system 10 also includes a diaphragm column reflux tank 600. The diaphragm column reflux tank 600 is connected to the diaphragm column condenser 200 to collect the condensed liquid. The diaphragm column reflux tank 600 is connected to the common rectification section 101, the feed zone 102, and the collection zone 103 via a first reflux pipe to reflux the liquid in the diaphragm column reflux tank 600.

[0090] In some of these implementations, please refer to Figure 1 As shown, the separation system 10 also includes a diaphragm column reflux pump 700. The diaphragm column reflux pump is installed in the first reflux pipeline to reflux a portion of the liquid in the diaphragm column reflux tank 600 back to the common rectification section 101, a portion back to the feed zone 102, and a portion back to the extraction zone 103.

[0091] In some of these implementations, please refer to Figure 1As shown, the separation system 10 also includes a baffled reboiler 800. The baffled reboiler 800 is connected to the common stripping section 104 to vaporize a portion of the material from the common stripping section 104 and reflux it back to the common stripping section 104. The baffled reboiler pump 300 is connected to the discharge line of the common stripping section 104 to discharge a portion of the material from the common stripping section 104, for example, to discharge it as waste liquid downstream.

[0092] In some of these implementations, please refer to Figure 1 As shown, the separation system 10 also includes a recovery tower reflux tank 900. The recovery tower reflux tank 900 is connected to the recovery tower condenser 500 to collect the liquid condensed by the recovery tower condenser 500. The recovery tower condenser 500 is also connected to the ionic liquid recovery tower 400 via a second reflux pipe.

[0093] In some of these implementations, please refer to Figure 1 As shown, the separation system 10 also includes a recovery tower reflux pump 1000. The recovery tower reflux pump 1000 is installed in the second reflux pipeline to reflux a portion of the liquid in the recovery tower reflux tank 900 back to the ionic liquid recovery tower 400, a portion back to the feed zone 102, a portion back to the collection zone 103, and a portion collected as waste liquid.

[0094] In some of these implementations, please refer to Figure 1 As shown, the separation system 10 also includes a recovery tower reboiler 1100. The recovery tower reboiler 1100 is connected to the bottom of the ionic liquid recovery tower 400 to vaporize a portion of the material from the ionic liquid recovery tower 400 and return it to the ionic liquid recovery tower 400.

[0095] In some embodiments, the separation system further includes a recovery tower bottom pump. The recovery tower bottom pump is connected to the bottom outlet line of the ionic liquid recovery tower 400 to return a portion of the material from the bottom of the ionic liquid recovery tower 400 to the common rectification section 101 and to discharge a portion as waste liquid.

[0096] In some embodiments, the ionic liquid recovery tower 400 includes a plate recovery tower. The plate type of the ionic liquid recovery tower 400 includes sieve plates.

[0097] In some embodiments, the tray type of the ion liquid recovery tower 400 includes one or both of the following: a floating valve tray and a cross-flow tray.

[0098] In some embodiments, the offset partition tower 100 has a cylindrical structure. The distance between the partition 106 and the central axis of the offset partition tower 100 is 5% to 45% of the radius of the offset partition tower 100.

[0099] Optionally, the distance between the partition 106 and the central axis of the offset partition tower 100 is 15% to 25% of the radius of the offset partition tower 100.

[0100] In some implementations, see Figure 2 As shown, multiple distillation trays 1110 are staggered to form a meandering first flow channel.

[0101] In some implementations, see Figure 2 As shown, multiple feed trays 1120 are staggered to form a meandering second flow channel.

[0102] In some implementations, see Figure 2 As shown, multiple extraction trays 1130 are staggered to form a meandering third flow channel.

[0103] In some implementations, see Figure 2 As shown, multiple stripping section trays 1140 are staggered to form a meandering fourth flow channel.

[0104] In some embodiments, the number of rectification section trays 1110 is 5 to 15. Multiple rectification section trays 1110 are distributed at equal intervals.

[0105] In some embodiments, the number of feed trays 1120 is 25 to 35. Multiple feed trays 1120 are distributed at equal intervals.

[0106] In some embodiments, the number of extraction trays 1130 is 25 to 35. Multiple extraction trays 1130 are distributed at equal intervals.

[0107] In some embodiments, the number of stripping section trays 1140 is 5 to 15. Multiple stripping section trays 1140 are distributed at equal intervals.

[0108] In some embodiments, the operating pressure inside the offset diaphragm tower 100 can be controlled to be 0.1 MPaA to 0.2 MPaA.

[0109] In some embodiments, the top temperature of the offset partition tower 100 can be controlled at 114°C to 130°C, and the bottom temperature can be controlled at 120°C to 160°C.

[0110] In some embodiments, multiple recovery trays 1150 are staggered within the ionic liquid recovery tower 400, forming a meandering fifth flow channel.

[0111] In some embodiments, the number of recovery trays 1150 is 5 to 10, and the multiple recovery trays 1150 are distributed at equal intervals.

[0112] In some embodiments, the operating pressure inside the ionic liquid recovery tower 400 can be controlled to be 0.1 MPaA to 0.2 MPaA.

[0113] In some embodiments, the top temperature of the ionic liquid recovery tower 400 can be controlled at 100°C to 120°C, and the bottom temperature can be controlled at 130°C to 150°C.

[0114] One embodiment of this application provides a separation method.

[0115] One separation method, see Figure 4 As shown, Figure 4 This is a schematic flowchart of a separation method according to an embodiment of the present application, including the following steps:

[0116] S10. Control the crude raw material to be separated and the ionic liquid to enter the common rectification section 101 of the biased plate column 100 for rectification.

[0117] S20. Control the vapor phase obtained from the distillation process to condense into liquid, and control the condensed liquid to flow back to the common distillation section 101, the feed zone 102 and the extraction zone 103.

[0118] S30. The light component ionic liquid in the common distillation section 101 is controlled to enter the ionic liquid recovery tower 400 through the oil collection tank 105 for recovery treatment to obtain the target product.

[0119] S40. Control the gas phase obtained from the recovery process to enter the recovery tower condenser 500 for condensation into liquid, and control the condensed liquid to flow back to the ion liquid recovery tower 400 and / or the common rectification section 101.

[0120] In some embodiments, the operating pressure inside the offset diaphragm tower 100 is controlled to be 0.1 MPaA to 0.2 MPaA.

[0121] In some embodiments, the top temperature of the offset partition tower 100 is controlled at 114°C to 130°C, and the bottom temperature is controlled at 120°C to 160°C.

[0122] In some embodiments, the operating pressure inside the ionic liquid recovery tower 400 is controlled at 0.1 MPaA to 0.2 MPaA.

[0123] In some embodiments, the top temperature of the ion liquid recovery tower 400 is controlled at 100°C to 120°C, and the bottom temperature is controlled at 130°C to 150°C.

[0124] In some embodiments, the flow rate of the ionic liquid is controlled to be 0.5% to 5% of the flow rate of the crude feedstock to be separated.

[0125] In some embodiments, the temperature of the ionic liquid is controlled at 42°C to 125°C, and the pressure is controlled at 0.2 MPaG to 0.5 MPaG.

[0126] In some embodiments, the ionic liquid includes one or more of [C4mim][Ac] (1-butyl-3-methylimidazolium acetate), [C4mim][DCA] (1-butyl-3-methylimidazolium dicyandiamide), [C4mim][OTf] (1-butyl-3-methylimidazolium trifluoromethanesulfonate), [C4mim][MS] (1-butyl-3-methylimidazolium methanesulfonate), and [C6mim][Cl] (1-hexyl-3-methylimidazolium chloride).

[0127] In some embodiments, the operational performance of the offset baffle tower 100 is evaluated; the evaluation factor HEF for the operational performance of the offset baffle tower 100 is as follows:

[0128]

[0129] In the formula, This indicates the gaseous material volumetric flow rate (m³) of the first feed tray 1120 in feed zone 102. 3 / h;

[0130] This indicates the gaseous material volumetric flow rate (m³) of the last feed tray 1120 in feed zone 102. 3 / h;

[0131] This represents the gaseous material volumetric flow rate (m³) of the first production tray 1130 in production zone 103. 3 / h;

[0132] This represents the gaseous material volumetric flow rate (m³) of the last extraction tray 1130 in extraction zone 103. 3 / h;

[0133] This indicates the volumetric flow rate of liquid material in the first feed tray 1120 of feed zone 102, in m³. 3 / h;

[0134] This indicates the volumetric flow rate of liquid material in the last feed tray 1120 of feed zone 102, in m³. 3 / h;

[0135] This represents the volumetric flow rate of liquid material in the first production tray 1130 of production zone 103, in m³. 3 / h;

[0136] This indicates the volumetric flow rate of liquid material in the last producing tray 1130 of producing zone 103, in m³. 3 / h;

[0137] This indicates the cross-sectional area of ​​the feed area, 102. This represents the cross-sectional area of ​​the extraction zone 103; it should be noted that the cross-sectional area refers to the cross-sectional area along the radial direction of the offset diaphragm tower 100.

[0138] This indicates the gaseous material mass flow rate of the first feed tray 1120 in feed zone 102, in kg / h;

[0139] This indicates the gaseous material mass flow rate of the last feed tray 1120 in feed zone 102, in kg / h;

[0140] This represents the gaseous material mass flow rate of the first production tray 1130 in production zone 103, in kg / h.

[0141] This indicates the gaseous material mass flow rate (kg / h) of the last extraction tray 1130 in extraction zone 103.

[0142] A smaller HEF evaluation factor indicates a more balanced and reasonable hydraulic system in the feed zone 102 and the production zone 103; a larger HEF indicates a higher risk of flooding and uneven distribution within the offset baffle tower 100.

[0143] Example 1

[0144] This embodiment provides a separation system 10.

[0145] See Figure 1 As shown, the separation system 10 of this embodiment includes an offset baffle column 100, a baffle column condenser 200, a baffle column reflux tank 600, a baffle column reflux pump 700, a baffle column reboiler 800, a baffle column bottom pump 300, an ionic liquid recovery column 400, a recovery column condenser 500, a recovery column reflux tank 900, a recovery column reflux pump 1000, a recovery column reboiler 1100, and a recovery column bottom pump.

[0146] The offset baffle column 100 includes a common rectification section 101 at the top, a feed and collection section in the middle, and a common stripping section 104 at the bottom. The common rectification section 101 includes multiple rectification trays 1110, which are staggered to form a meandering first flow channel. An oil collection tank 105 is provided at the bottom of the common rectification section 101. The feed and collection section includes a baffle 106 extending vertically. A feed zone 102 and a collection zone 103 are formed on both sides of the baffle 106, and the baffle 106 is offset. The central axis of the partition column 100 is such that the width of the extraction zone 103 is greater than the width of the feed zone 102. The feed zone 102 is provided with multiple feed trays 1120, which are staggered to form a meandering second flow channel. The extraction zone 103 is provided with multiple extraction trays 1130, which are staggered to form a meandering third flow channel. The common stripping section 104 includes multiple stripping section trays 1140, which are staggered to form a meandering fourth flow channel.

[0147] The diaphragm column condenser 200 is connected to the common rectification section 101 of the offset diaphragm column 100 to condense the gaseous material from the common rectification section 101 into liquid. The diaphragm column reflux tank 600 is connected to the diaphragm column condenser 200 to collect the condensed liquid. The diaphragm column reflux tank 600 is also connected to the common rectification section 101, the feed zone 102, and the product zone 103 through a first reflux pipe. The first reflux pipe is connected to the feed zone 102 through the left reflux pipe of the diaphragm 106, and to the product zone 103 through the right reflux pipe of the diaphragm 106. The plate column reflux pump is installed in the first reflux pipe to reflux a portion of the liquid in the diaphragm column reflux tank 600 back to the common rectification section 101, a portion back to the feed zone 102, and a portion back to the product zone 103.

[0148] The reboiler 800 of the diaphragm tower is connected to the common stripping section 104 so that a portion of the material in the common stripping section 104 is vaporized and refluxed back to the common stripping section 104. The bottom pump 300 of the diaphragm tower is connected to the outlet pipeline of the common stripping section 104 so that a portion of the material in the common stripping section 104 is sent downstream as waste liquid.

[0149] The ionic liquid recovery tower 400 is connected to the oil collection tank 105 to collect the light component ionic liquid in the oil collection tank 105. The recovery tower condenser 500 is connected to the ionic liquid recovery tower 400 to condense the gas phase from the top of the ionic liquid recovery tower 400 into liquid. The recovery tower reflux tank 900 is connected to the recovery tower condenser 500 to collect the liquid condensed by the recovery tower condenser 500. The recovery tower condenser 500 is also connected to the ionic liquid recovery tower 400 through a second reflux pipe. The recovery tower reflux pump 1000 is installed in the second reflux pipe to return a portion of the liquid in the recovery tower reflux tank 900 back to the ionic liquid recovery tower 400, a portion back to the feed area 102, a portion back to the extraction area 103, and a portion as waste liquid.

[0150] The reboiler 1100 of the recovery tower is connected to the bottom of the ionic liquid recovery tower 400 to vaporize a portion of the material in the ionic liquid recovery tower 400 and return it to the ionic liquid recovery tower 400. The bottom pump of the recovery tower is connected to the bottom pumping line of the ionic liquid recovery tower 400 to return a portion of the material in the bottom of the ionic liquid recovery tower 400 to the common rectification section 101 and to collect a portion as waste liquid.

[0151] Example 2

[0152] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3 The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 7.62:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0153] The separation method includes the following steps:

[0154] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid is [C4mim][Ac] (1-butyl-3-methylimidazolium acetate) with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0155] The operating pressure inside the offset baffle column 100 is controlled at 0.1 MPaA. The top temperature inside the offset baffle column 100 is controlled at 114℃, and the bottom temperature is controlled at 120℃.

[0156] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0157] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower to the ionic liquid recovery tower 400 is 10 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 100℃, and the bottom temperature is controlled at 130℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.1 MPaA.

[0158] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0159] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0160] The hydraulic data for this embodiment are shown in Table 1. After testing, the purity of the n-butanol prepared in this embodiment was 99.91%, and the energy consumption was 7.98 MW.

[0161] Table 1

[0162]

[0163] Example 3

[0164] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 5.23:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0165] The separation method includes the following steps:

[0166] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid is [C4mim][Ac] (1-butyl-3-methylimidazolium acetate) with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0167] The operating pressure inside the offset baffle column 100 is controlled at 0.2 MPaA. The top temperature inside the offset baffle column 100 is controlled at 130℃, and the bottom temperature is controlled at 160℃.

[0168] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0169] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower entering the ionic liquid recovery tower 400 is 9 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 120℃, and the bottom temperature is controlled at 150℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.2 MPaA.

[0170] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0171] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0172] The hydraulic data for this embodiment are shown in Table 2. After testing, the purity of the n-butanol prepared in this embodiment was 99.917%, and the energy consumption was 7.977 MW.

[0173] Table 2

[0174]

[0175] Example 4

[0176] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3 The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 3.85:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0177] The separation method includes the following steps:

[0178] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid is [C4mim][Ac] (1-butyl-3-methylimidazolium acetate) with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0179] The operating pressure inside the offset baffle column 100 is controlled at 0.2 MPaA. The top temperature inside the offset baffle column 100 is controlled at 130℃, and the bottom temperature is controlled at 160℃.

[0180] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0181] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower entering the ionic liquid recovery tower 400 is 10 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 120℃, and the bottom temperature is controlled at 150℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.2 MPaA.

[0182] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0183] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0184] The hydraulic data for this embodiment are shown in Table 3. After testing, the purity of the n-butanol prepared in this embodiment was 99.92%, and the energy consumption was 7.97 MW.

[0185] Table 3

[0186]

[0187] Example 5

[0188] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 1.91:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0189] The separation method includes the following steps:

[0190] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid is [C4mim][Ac] (1-butyl-3-methylimidazolium acetate) with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0191] The operating pressure inside the offset baffle column 100 is controlled at 0.1 MPaA. The top temperature inside the offset baffle column 100 is controlled at 114℃, and the bottom temperature is controlled at 120℃.

[0192] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0193] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower entering the ionic liquid recovery tower 400 is 10 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 100℃, and the bottom temperature is controlled at 130℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.1 MPa.

[0194] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0195] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0196] The hydraulic data for this embodiment are shown in Table 4. After testing, the purity of the n-butanol prepared in this embodiment was 99.927%, and the energy consumption was 7.94 MW.

[0197] Table 4

[0198]

[0199] Example 6

[0200] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3 The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 0.85:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0201] The separation method includes the following steps:

[0202] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid is [C4mim][Ac] (1-butyl-3-methylimidazolium acetate) with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0203] The operating pressure inside the offset baffle column 100 is controlled at 0.15 MPaA. The top temperature inside the offset baffle column 100 is controlled at 120℃, and the bottom temperature is controlled at 140℃.

[0204] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0205] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower to the ionic liquid recovery tower 400 is 10 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 110℃, and the bottom temperature is controlled at 140℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.15 MPaA.

[0206] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0207] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0208] The hydraulic data for this embodiment are shown in Table 5. After testing, the purity of the n-butanol prepared in this embodiment was 99.927%, and the energy consumption was 7.93 MW.

[0209] Table 5

[0210]

[0211] Example 7

[0212] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 0.45:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0213] The separation method includes the following steps:

[0214] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid is [C4mim][Ac] (1-butyl-3-methylimidazolium acetate) with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0215] The operating pressure inside the offset baffle column 100 is controlled at 0.15 MPaA. The top temperature inside the offset baffle column 100 is controlled at 120℃, and the bottom temperature is controlled at 150℃.

[0216] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0217] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower to the ionic liquid recovery tower 400 is 10 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 115℃, and the bottom temperature is controlled at 140℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.15 MPaA.

[0218] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0219] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0220] The hydraulic data for this embodiment are shown in Table 6. After testing, the purity of the n-butanol prepared in this embodiment was 99.926%, and the energy consumption was 7.9 MW.

[0221] Table 6

[0222]

[0223] Example 8

[0224] This embodiment provides a separation method. The separation method adopts the method described in Embodiment 1. Figure 3 The separation system 10 shown has different internal hydraulic loads in the feed zone 102 and the production zone 103. The area ratio of the feed zone 102 to the production zone 103 is 7.62:1. The common rectification section 101 of the offset plate tower 100 has 7 rectification trays 1110, the feed zone 102 has 20 feed trays 1120, the production zone 103 has 25 production trays 1130, the common stripping section 104 has 10 stripping trays 1140, and the ion liquid recovery tower 400 has 11 recovery trays 1150. The total investment in the separation system 10 is approximately 2.25 million yuan.

[0225] The separation method includes the following steps:

[0226] S100, crude n-butanol feedstock and ionic liquid are fed into the common rectification section 101 of the biased plate column 100 for rectification. The flow rate of crude n-butanol feedstock is 10 t / h, and the ionic liquid selected is [C4mim][DCA] (1-butyl-3-methylimidazolium dicyandiamide salt), with a flow rate of 500 kg / h. The external flow rate of the withdrawal zone 103 of the biased plate column 106 is 9.8 t / h.

[0227] The operating pressure inside the offset baffle column 100 is controlled at 0.1 MPaA. The top temperature inside the offset baffle column 100 is controlled at 114℃, and the bottom temperature is controlled at 120℃.

[0228] S200, the vapor phase obtained from the controlled distillation process enters the condenser 200 of the partition tower and is condensed into liquid. The condensed liquid enters the reflux tank 600 of the partition tower for storage. The liquid in the reflux tank 600 is split into streams by the drive of the plate tower reflux pump on the first reflux pipeline. Part of the liquid is refluxed back to the common distillation section 101, part of the liquid is refluxed back to the feed area 102, and part of the liquid is refluxed back to the extraction area 103.

[0229] S300, the light component ionic liquid from the common rectification section 101 is collected in the oil collecting tank 105, and then enters the ionic liquid recovery tower 400 for recovery treatment to obtain n-butanol. The ionic liquid outflow rate from the baffle 106 tower to the ionic liquid recovery tower 400 is 10 t / h. The top temperature of the ionic liquid recovery tower 400 is controlled at 100℃, and the bottom temperature is controlled at 130℃. The operating pressure of the ionic liquid recovery tower 400 is controlled at 0.1 MPaA.

[0230] S400: The gas phase obtained from the controlled recovery process enters the recovery tower condenser 500 for condensation into liquid. The condensed liquid enters the recovery tower reflux tank 900 for buffering. Driven by the recovery tower reflux pump 1000, the liquid in the recovery tower reflux tank 900 is divided into streams through the second reflux pipeline. Part of the liquid flows back to the ionic liquid recovery tower 400, part flows back to the common rectification section 101, part flows back to the feed area 102, part flows back to the collection area 103, and part is collected as waste liquid.

[0231] The reflux flow rate of the common rectification section 101 at the top of the offset partition column 100 is 11.5 t / h.

[0232] The hydraulic data for this embodiment are shown in Table 7. After testing, the purity of the n-butanol prepared in this embodiment was 99.90%, and the energy consumption was 7.99 MW.

[0233] Table 7

[0234]

[0235] Comparative Example 1

[0236] This comparative example provides a separation method. The separation method is based on the same method as in Example 1, except that in Comparative Example 1, the area ratio of the feed zone 102 to the area of ​​the discharge zone 103 is 1:1.

[0237] The hydraulic data for this embodiment are shown in Table 8. After testing, the purity of the n-butanol prepared in this embodiment was 99.927%, and the energy consumption was 7.94 MW.

[0238] Table 8

[0239]

[0240] Comparative Example 2

[0241] This comparative example provides a method for the separation of n-butanol.

[0242] The n-butanol separation method employs a traditional two-tower series distillation method. Comparative Example 1 uses a two-tower series distillation system 20... Figure 5 As shown, Figure 5 The schematic diagram of the two-column series distillation system 20 in Comparative Example 2 shows two distillation columns 21 connected in series. Each column 21 has a distillation condenser 22, a distillation buffer tank 23, and a distillation reflux pump 24 connected in a circulating manner at its top. Each column 21 also has a distillation reboiler 25 connected in a circulating manner at its bottom. The first column 21 has 50 trays, and the second column 21 has 40 trays. The total investment for the two-column series distillation system 20 is approximately 3.57 million yuan.

[0243] The separation method includes the following steps:

[0244] The crude n-butanol feedstock is controlled to enter two distillation columns 21 connected in series for distillation. The flow rate of the crude n-butanol feedstock in the first distillation column 21 is 10 t / h. The feed flow rate of the second distillation column 21 is 9.9 t / h. The reflux flow rate at the top of the first distillation column 21 is 3.3 t / h, and the reflux flow rate at the top of the second distillation column 21 is 15 t / h. The side-collected product flow rate of the second distillation column 21 is 9.8 t / h.

[0245] The operating pressure inside the offset baffle tower 100 is controlled at 0.1 MPaA. The top temperature inside the offset baffle tower 100 is controlled at 114℃, and the bottom temperature is controlled at 120℃.

[0246] The data for the distillation condenser 22 and the distillation reboiler 25 in this comparative example are shown in Table 9. After testing, the purity of the n-butanol prepared in this example was 99.86%, and the energy consumption was 12.9 MW.

[0247] Table 9

[0248]

[0249] In Examples 2-8 and Comparative Example 1, the position of the partition 106 was adjusted, and the areas of the feed zone 102 and the discharge zone 103 on the left and right sides of the partition 106 were adjusted to achieve the purpose of adjusting the HEF factor of the partition 106 tower. The calculation results of each example are summarized in Table 10.

[0250] Table 10

[0251]

[0252] As shown in Table 10, this application can effectively separate crude butanol to obtain butanol products with purity meeting the standard requirements. The optimal offset position is when the area ratio between the feed zone 102 and the collection zone 103 on both sides of the partition 106 is (1.9~1):1, or when the area ratio between the feed zone 102 and the collection zone 103 is 1:(1.9~1). At this position, the HEF factor of the system is 1.2, the gas-liquid phase load distribution in the offset partition tower 100 is most reasonable, and the risk of abnormal operation such as flooding is lower. From the above embodiments and comparative examples, it can be seen that the equipment investment of the offset partition tower 100 connected in series with the ionic liquid recovery tower 400 n-butanol separation system 10 of this invention is significantly lower than that of the traditional n-butanol separation system 10. The product purity reaches over 99.9%, and it is energy-efficient compared to the traditional process, saving approximately 30% in energy consumption to achieve the same product purity.

[0253] In summary, the separation system 10 of this application can be applied to the separation of crude butanol containing light and heavy components, as well as to the separation of other similar near-boiling point mixtures. When used to separate the light components of crude butanol from ionic liquids, it can obtain n-butanol products with high purity (greater than 99.8%), and its energy consumption is lower than that of traditional distillation processes, saving approximately 30%. The separation system 10 and method of this application can obtain high-purity target products while achieving the goals of saving equipment investment and energy consumption.

[0254] Ionic liquids are molten salts composed of organic cations and inorganic / organic anions, possessing unique advantages such as near-zero vapor pressure, high thermal stability (>300℃), strong designability, and recyclability. Ionic liquids with specific structures can specifically disrupt azeotropic systems. For example, 1-butyl-2,3-dimethylimidazolium acetate, when used in toluene / methanol separation, selectively binds to methanol through hydrogen bonding, increasing its relative volatility by three times. Ethyltrimethylammonium acetate, in the toluene / methanol system, achieves a 40% energy saving in extractive distillation by altering the component activity coefficient. In the purification of n-butanol, similarly designed ILs (such as 1-butyl-3-methylimidazolium acetate) preferentially form stronger interactions with water or methanol, disrupting their azeotropic behavior with n-butanol and making it easier to remove lighter components at the top of the distillation flow condenser (DWC). After injection of ionic liquids at the top of the column, a recovery rate of over 98% can be achieved through simple flash evaporation, significantly reducing operating costs. This synergistic innovation of DWC and ionic liquids not only simplifies the separation process to a single-tower operation, but also further reduces overall energy consumption by 30% to 60%, providing a brand-new solution for the green and efficient production of high-purity n-butanol.

[0255] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this patent application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A separation system, characterized by This includes biased baffle towers, ionic liquid recovery towers, recovery tower condensers, and baffle tower condensers. The offset plate column includes a common rectification section at the top, a feed and collection section in the middle, and a common stripping section at the bottom. The common rectification section includes multiple rectification trays, and an oil collection tank is provided at the bottom of the common rectification section. The feed and collection section is provided with a baffle extending along the axial direction of the offset plate column. A feed zone and a collection zone are formed on both sides of the baffle, respectively. The baffle is offset from the central axis of the offset plate column. The width of the collection zone is different from the width of the feed zone along the radial direction of the offset plate column. The feed zone is provided with multiple feed trays, and the collection zone is provided with multiple collection trays. The common stripping section includes multiple stripping trays. The ionic liquid recovery tower is connected to the oil collection tank to recover the light component ionic liquid in the oil collection tank. The recovery tower condenser is connected to the ionic liquid recovery tower to condense the gas phase from the top of the ionic liquid recovery tower into liquid. The recovery tower condenser can also reflux the liquid back to the ionic liquid recovery tower and / or the common rectification section. The diaphragm tower condenser is connected to the common rectification section of the offset diaphragm tower to condense the gaseous material from the common rectification section into liquid. The liquid outlet of the diaphragm tower condenser is also circulated to the common rectification section, the feed zone, and the collection zone to reflux the condensed liquid.

2. The separation system of claim 1, wherein, It also includes a diaphragm column reflux tank, which is connected to the diaphragm column condenser to collect the condensed liquid. The diaphragm column reflux tank is connected to the common rectification section, the feed zone, and the collection zone through a first reflux pipe to reflux the liquid in the diaphragm column reflux tank.

3. The separation system according to claim 2, characterized in that, It also includes a diaphragm tower reflux pump, which is installed in the first reflux pipeline to reflux a portion of the liquid in the diaphragm tower reflux tank back to the common rectification section, a portion back to the feed area, and a portion back to the extraction area.

4. The separation system according to claim 1, characterized in that, It also satisfies at least one of the following conditions: (1) It also includes a partition tower reboiler, which is connected to the common stripping section to vaporize a portion of the material in the common stripping section and then reflux it back to the common stripping section; (2) It also includes a diaphragm tower bottom pump, which is connected to the bottom pumping line of the common stripping section to extract a portion of the material from the common stripping section.

5. The separation system according to claim 1, characterized in that, It also includes a recovery tower reflux tank, which is connected to the recovery tower condenser to collect the liquid condensed by the recovery tower condenser, and the recovery tower condenser is also connected to the ionic liquid recovery tower through a second reflux pipe.

6. The separation system according to claim 5, characterized in that, It also includes a recovery tower reflux pump, which is installed in the second reflux pipeline to reflux a portion of the liquid in the recovery tower reflux tank back to the ionic liquid recovery tower, a portion back to the feed area, a portion back to the extraction area, and a portion extracted.

7. The separation system according to claim 1, characterized in that, It also includes a recovery tower reboiler, which is connected to the bottom of the ionic liquid recovery tower to vaporize a portion of the material from the ionic liquid recovery tower and return it to the ionic liquid recovery tower.

8. The separation system according to claim 7, characterized in that, It also includes a recovery tower bottom pump, which is connected to the bottom pumping line of the ionic liquid recovery tower to return a portion of the material in the bottom of the ionic liquid recovery tower to the common distillation section and to extract a portion.

9. The separation system according to any one of claims 1 to 8, characterized in that, The ionic liquid recovery tower includes a plate recovery tower, and the plate type of the ionic liquid recovery tower includes a sieve plate. The tray types of the ionic liquid recovery tower include one or both of the following: floating valve trays and cross-flow trays.

10. The separation system according to any one of claims 1 to 8, characterized in that, The offset baffle tower has a cylindrical structure, and the distance between the baffle and the central axis of the offset baffle tower is 5% to 45% of the radius of the offset baffle tower.

11. The separation system according to claim 10, characterized in that, The distance between the partition and the central axis of the offset partition tower is 15% to 25% of the radius of the offset partition tower.

12. The separation system according to any one of claims 1 to 8, 11, characterized in that, It also satisfies at least one of the following conditions: (1) Multiple distillation section trays are staggered to form a meandering first flow channel; (2) The multiple feed trays are staggered to form a meandering second flow channel; (3) Multiple extraction trays are staggered to form a meandering third flow channel; (4) Multiple stripping section trays are staggered to form a meandering fourth flow channel; (5) The number of the rectification section trays is 5 to 15, and the multiple rectification section trays are distributed at equal intervals; (6) The number of the feed trays is 25 to 35, and the multiple feed trays are distributed at equal intervals; (7) The number of the extraction trays is 25 to 35, and the multiple extraction trays are distributed at equal intervals; (8) The number of stripping section trays is 5 to 15, and the multiple stripping section trays are distributed at equal intervals; (9) The operating pressure inside the offset diaphragm tower can be controlled to be 0.1 MPaA~0.2 MPaA; (10) The temperature at the top of the offset partition tower can be controlled at 114℃~130℃, and the temperature at the bottom of the tower can be controlled at 120℃~160℃. (11) The ionic liquid recovery tower has multiple recovery trays distributed in a staggered manner, and the multiple recovery trays form a meandering fifth flow channel; (12) The operating pressure inside the ionic liquid recovery tower can be controlled to be 0.1 MPaA~0.2 MPaA; (13) The temperature at the top of the ionic liquid recovery tower can be controlled at 100℃~120℃, and the temperature at the bottom of the tower can be controlled at 130℃~150℃.

13. A separation method, characterized in that, The separation system according to any one of claims 1 to 12 includes the following steps: The crude raw material to be separated and the ionic liquid are controlled to enter the common rectification section of the biased plate column for rectification. The vapor phase obtained from the controlled distillation process is condensed into a liquid, and the condensed liquid is controlled to flow back to the common distillation section, the feed zone, and the extraction zone. Furthermore, the light component ionic liquid in the common distillation section is controlled to enter the ionic liquid recovery tower from the oil collection tank for recovery treatment to obtain the target product.

14. The separation method according to claim 13, characterized in that, It also satisfies at least one of the following conditions: (1) The operating pressure inside the offset diaphragm tower is controlled at 0.1 MPaA~0.2 MPaA; (2) The temperature at the top of the offset partition tower is controlled at 114℃~130℃, and the temperature at the bottom of the tower is controlled at 120℃~160℃. (3) The operating pressure inside the ionic liquid recovery tower is controlled at 0.1 MPaA~0.2 MPaA; (4) The temperature at the top of the ionic liquid recovery tower is controlled at 100℃~120℃, and the temperature at the bottom of the tower is controlled at 130℃~150℃; (5) Control the flow rate of the ionic liquid to be 0.5%~5% of the flow rate of the crude raw material to be separated; (6) The temperature of the ionic liquid is controlled at 42℃~125℃ and the pressure is controlled at 0.2MPaG~0.5MPaG; (7) The ionic liquid comprises one or more of 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium dicyandiamide, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium methanesulfonate, and 1-hexyl-3-methylimidazolium chloride; (8) It also includes the following steps: controlling the gas phase obtained from the recovery process to enter the condenser of the recovery tower for condensation into liquid, and controlling the condensed liquid to flow back to the ionic liquid recovery tower and / or the common distillation section.

Images