Rectification equipment for removing light components from MIBK (methyl isobutyl ketone)

Abstract

The utility model discloses rectification equipment for removing light components from MIBK (methyl isobutyl ketone), and belongs to the technical field of chemical rectification. A rectifying tower of the rectifying equipment comprises a tower body with a cylindrical barrel structure, and a vertical partition plate is arranged in the tower body and divides the rectifying tower into a first pre-fractionation section, an azeotrope rectifying section, a stripping section, a second pre-fractionation section and an acetone rectifying section. By adopting the rectification equipment, an organic matter mixed solution containing light components such as 2-MPA and acetone from an MIBK synthesis system can be rectified, extracted and separated. A target product 2-MPA debounded region is obtained in the extraction section; a target product diacetone obtained in an acetone rectifying section of the rectifying tower is directly returned to an MIBK synthesis system as a raw material for use; a target product tri-MIBK solution obtained in the stripping section of the rectifying tower is subjected to boundary region rectification, and MIBK is separated. By utilizing the rectification equipment, the quantity of equipment can be reduced, the process flow is simplified, the device investment is reduced, the consumption of raw materials and energy in production is reduced, the production cost is reduced, and the carbon emission of a production device is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical distillation, in particular to distillation equipment for removing light components from MIBK. Background Art

[0002] MIBK chemical name methyl isobutyl ketone, also known as 4-methyl-2-pentanone, is an organic compound with the chemical formula C6H 12 O, mainly used as a solvent for spray paint, nitrocellulose, certain cellulose ethers, camphor, oils and fats, natural and synthetic rubber.

[0003] In the MIBK synthesis system, every ton of MIBK produced produces approximately 2,824 kg of light fractions, including the raw material acetone and the byproduct 2-MPA. Of these, approximately 2,802 kg contain acetone and 22 kg contain 2-MPA. These organic light fractions require distillation, extraction, and subsequent recovery of useful components. In existing production, a two-step distillation process is typically employed. Step 1: The azeotrope is purified and recovered in an azeotrope fractionation and separation recovery system. The azeotrope is then sent to an extraction system to recover the target product (2-MPA). The acetone-water solution produced in the extraction system is then mixed with the bottoms liquid from the azeotrope fractionation and separation recovery system. Step 2: The bottoms liquid from step 1 is fed into an acetone fractionation and separation recovery system to recover the target product (2) (acetone). The bottoms liquid is then used as the target product (3) (MIBK solution, depleted of light components). The above light components such as 2-MPA and acetone are separated and recovered through two sets of distillation separation and recovery systems. Distillation separation is the most mature and widely used separation technology in chemical production, but the distillation process consumes huge energy. More than 50% of the energy consumption in chemical production is used for separation, and distillation separation energy consumption accounts for 95% of this.

[0004] Therefore, it is necessary to improve the existing distillation equipment for the separation and recovery of light components such as 2-MPA and acetone, and it is urgent to provide a distillation equipment for removing light components from MIBK with a short process, small footprint, low investment and low energy consumption. Utility Model Content

[0005] The purpose of the utility model is to provide a distillation device for removing light components from MIBK, which has a short process, small footprint, low investment and low energy consumption, and is used for distilling, extracting and separating a mixed organic liquid containing light components such as 2-MPA and acetone from a MIBK synthesis system.

[0006] The utility model discloses a distillation device for removing light components from MIBK, which adopts the following technical solution: a distillation device for removing light components from MIBK, comprising a distillation tower, wherein the distillation tower comprises a tower body with a cylindrical barrel structure, a vertical partition plate is provided in the tower body, the upper end of the partition plate is vertically arranged and fixedly connected to the top of the tower body, an azeotrope outlet A and an acetone outlet B are provided at the top of the tower body, an azeotrope reflux port C and an acetone reflux port D are provided on the side of the upper part of the tower body, a raw material inlet E and an acetone aqueous solution inlet F are provided on the side of the middle part of the tower body, a reflux port G and a bottom liquid sidewall outlet H are provided at the lower part of the tower body, and a bottom liquid outlet J is provided at the bottom of the tower body, the azeotrope outlet A, the azeotrope reflux port C, and the raw material inlet E are located on the same side of the partition plate, the acetone outlet B, the acetone reflux port D, and the acetone aqueous solution inlet F are located on the other side of the same part of the partition plate, and the reflux port G, the bottom liquid outlet H, and the bottom liquid outlet J are located below the partition plate;

[0007] The tower body comprises an azeotrope rectifying section on one side of the partition plate, and a first pre-fractionation section on the lower part; an acetone rectifying section on the other side of the partition plate, and a second pre-fractionation section on the lower part; and a stripping section located below the partition plate in the tower body; the first pre-fractionation section rectifying layer is located on the upper part of the first pre-fractionation section, and the first pre-fractionation section stripping layer is located on the lower part of the first pre-fractionation section, and the bottom end of the first pre-fractionation section stripping layer is not lower than the bottom end of the partition plate; the raw material inlet E is located between the first pre-fractionation section rectifying layer and the first pre-fractionation section stripping layer, and a raw material feed pipe connected to the raw material inlet E is provided in the tower body, and the raw material feed pipe is located in the gap between the first pre-fractionation section rectifying layer and the first pre-fractionation section stripping layer;

[0008] The azeotrope distillation section is located between the azeotrope outlet A at the top of the tower body and the first pre-fractionation section distillation layer. The azeotrope distillation section is provided with an azeotrope distillation section distillation layer, and the azeotrope distillation section distillation layer is spaced apart from the first pre-fractionation section distillation layer.

[0009] The stripping section is provided with a stripping layer, a gap is provided between the stripping layer and the partition plate, and a stripping section liquid distributor is horizontally installed in the gap;

[0010] The upper portion of the second pre-fractionation section is a second pre-fractionation section rectifying layer, and the lower portion is a second pre-fractionation section stripping layer, and the bottom end of the second pre-fractionation section stripping layer is not lower than the bottom end of the partition plate; the acetone aqueous solution inlet F is located between the second pre-fractionation section rectifying layer and the second pre-fractionation section stripping layer, and an acetone aqueous solution feed pipe connected to the acetone aqueous solution inlet F is provided in the tower body, and the acetone aqueous solution feed pipe is located in the gap between the second pre-fractionation section rectifying layer and the second pre-fractionation section stripping layer;

[0011] The acetone distillation section is located between the distillation layer above the second pre-fractionation section and the acetone outlet B at the top of the distillation tower. An acetone distillation section distillation layer is provided in the acetone distillation section, and a gap is provided between the acetone distillation section distillation layer and the second pre-fractionation section distillation layer.

[0012] A raw material inlet liquid distributor is horizontally installed below the raw material feed pipe; a gap is provided between the rectifying layer of the azeotrope rectifying section and the rectifying layer of the first pre-fractionation section, in which a first liquid distributor is horizontally installed; a second liquid distributor is horizontally installed below the acetone aqueous solution feed pipe; a gap is provided between the rectifying layer of the acetone rectifying section and the rectifying layer of the second pre-fractionation section, in which a third liquid distributor is horizontally installed.

[0013] There is a gap between the distillation layer of the azeotrope distillation section and the azeotrope outlet A, and an azeotrope reflux port C is provided on the side wall of the gap. A first row of tubular liquid distributors is horizontally installed at the azeotrope reflux port C, and the azeotrope is refluxed through the azeotrope outlet A and the azeotrope reflux port C in sequence.

[0014] An azeotrope condenser, an azeotrope reflux tank, and an azeotrope reflux pump are sequentially connected between the azeotrope outlet A and the azeotrope reflux port C through pipelines.

[0015] There is a gap between the distillation layer of the acetone distillation section and the acetone outlet B. An acetone reflux port D is provided on the side wall of the gap. A second row of tubular liquid distributors is horizontally installed at the acetone reflux port D. Acetone refluxes in sequence through the acetone outlet B and the acetone reflux port D.

[0016] An acetone condenser, an acetone reflux tank, and an acetone reflux pump are sequentially connected between the acetone outlet B and the acetone reflux port D through pipelines.

[0017] There is a gap between the stripping layer of the stripping section and the side wall outlet H of the tower bottom liquid. A reflux port G is provided on the side wall of the gap. An air inlet distributor is horizontally installed at the reflux port G. The tower bottom steam refluxes through the side wall outlet H and the reflux port G in turn.

[0018] A reboiler is connected between the tower bottom liquid side wall outlet H and the reflux port G via a pipeline.

[0019] The ratio of the horizontal cross-sectional area of ​​the distillation layer of the azeotrope distillation section to the distillation layer of the acetone distillation section, the distillation layer of the first pre-fractionation section to the distillation layer of the second pre-fractionation section, and the distillation layer of the first pre-fractionation section to the distillation layer of the second pre-fractionation section is 1:10~10:1.

[0020] The distillation layer of the azeotrope distillation section, the distillation layer of the acetone distillation section, the distillation layer of the first pre-fractionation section, the distillation layer of the second pre-fractionation section, the distillation layer of the first pre-fractionation section, and the distillation layer of the second pre-fractionation section are all packing layers with a height of 2 to 12 meters; the distillation layer of the stripping section is a packing layer with a height of 2 to 12 meters.

[0021] The beneficial effects of the present invention are as follows: In a MIBK synthesis system, every ton of MIBK synthesized produces approximately 2,824 kilograms of light fractions, including the raw material acetone and the byproduct 2-MPA, of which approximately 2,802 kilograms are acetone and approximately 22 kilograms are 2-MPA. The present invention provides a distillation device for removing light fractions from MIBK. This distillation device can effectively recover acetone and 2-MPA, with approximately 992.2 kilograms of acetone and approximately 7.8 kilograms of 2-MPA recovered per ton of light fractions removed.

[0022] The present invention utilizes a partitioned distillation tower to replace the azeotrope distillation tower and the acetone distillation tower, combining the two distillation towers into one while eliminating a reboiler and saving approximately 25% in equipment investment. The boiling points of the azeotrope and acetone are similar, so dividing the distillation tower's distillation section into an azeotrope distillation section and an acetone distillation section facilitates the distillation of the two light components. Acetone appears simultaneously in both the azeotrope distillation section and the acetone distillation section. The composition of the raw materials entering the partitioned distillation tower's raw material inlet and the composition of the acetone aqueous solution entering the acetone aqueous solution inlet are well matched to the compositions of the liquid distributors in the first and second pre-fractionation sections, reducing the mixing effect at the liquid distributors. This reduces the mixing effect caused by the different compositions of the feed and liquid distributors, meets the requirements of an optimal liquid distributor, and improves thermodynamic efficiency. Because the heat of the partitioned distillation tower is recycled within the same tower, energy consumption is also saved, with the energy savings being approximately 25%.

[0023] The above distillation equipment is used to obtain target product one - 2-MPA, target product two - acetone, and target product three - MIBK solution. It is a safe, environmentally friendly, high-yield, low-energy-consuming distillation equipment for removing light components from MIBK. The utility model aims to save energy and reduce consumption, reduce carbon emissions from production equipment, and protect the environment.

[0024] The utility model can realize the distillation, extraction and separation of an organic mixed liquid containing light components such as 2-MPA and acetone from a MIBK synthesis system, wherein the first target product recovered by a phase separator is the 2-MPA delimited zone, the second target product recovered by an acetone reflux tank is the acetone to be reused in the MIBK synthesis system, and the third target product recovered by a distillation tower is the MIBK product of the MIBK distillation system delimited zone of the MIBK solution (with the light components removed).

[0025] Unlike existing distillation towers, the present invention incorporates a vertical partition plate within the distillation tower, with two feed inlets on either side. The tower also features two gas outlets at the top and two liquid reflux ports at the upper portion, resulting in two distillation sections. The azeotrope recovered in the distillation tower's azeotrope distillation section is used to recover target product one—2-MPA—in the extraction section. Target product two—acetone—is recovered in the acetone distillation section and is directly recycled into the MIBK synthesis system as a raw material. Target product three—the MIBK solution (with light components removed) is recovered in the stripping section and then distilled into the MIBK distillation system in the boundary zone.

[0026] By adopting the technical solution of the utility model, only one set of distillation equipment is needed to recover the target product. The utility model is a distillation equipment for removing light components from MIBK with a short process, small footprint, low investment and low energy consumption. The utility model has the advantages of energy saving and consumption reduction, reduced investment in production equipment, reduced carbon emissions and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a diagram showing the working section division of a distillation device for removing light components from MIBK according to an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of a distillation device for removing light components from MIBK according to an embodiment of the present invention;

[0029] Figure 3 To utilize Figure 1 System flow chart of the distillation equipment for removing light components from MIBK;

[0030] Figure 4 This is the performance evaluation result table of the 10,000 tons / year MIBK light component removal device.

[0031] Among them, 1, raw material preheater, 2, distillation tower, 2-1, raw material feed pipe, 2-2, raw material inlet liquid distributor, 2-3, first pre-fractionation section distillation layer, 2-4, first pre-fractionation section stripping layer, 2-5, azeotrope distillation section distillation layer, 2-6, first liquid distributor, 2-7, first row of tube liquid distributor, 2-8, stripping section stripping layer, 2-9, stripping section liquid distributor, 2-10, air inlet distributor, 2-11, acetone aqueous solution feed pipe, 2-12, second liquid distributor, 2-13, second pre-fractionation section distillation layer, 2-14, second pre Distillation section stripping layer, 2-15, acetone distillation section distillation layer, 2-16, third liquid distributor, 2-17, second row of tubular liquid distributor, 3, partition plate, 4, azeotrope condenser, 5, azeotrope reflux tank, 6, azeotrope reflux pump, 7, azeotrope extraction cooler, 8, azeotrope extraction tank, 9, extraction tower feed pump, 10, extraction tower, 11, phase separator, 12, acetone aqueous solution extraction tank, 13, acetone aqueous solution feed pump, 14, acetone aqueous solution heater, 15, acetone condenser, 16, acetone reflux tank, 17, acetone reflux pump, 18, reboiler. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention generally described and illustrated in the drawings herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments derived by ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0034] The distillation equipment for removing light components from MIBK according to an embodiment of the present invention is as follows Figure 1 、 2As shown, this distillation equipment can distill, extract, and separate a mixed organic liquid containing light components such as 2-MPA and acetone from a MIBK synthesis system. The distillation equipment includes a distillation tower 2, which comprises a cylindrical tower body with a vertical partition plate 3 disposed therein, extending directly to the top of the distillation tower 2. The distillation tower 2 is provided with an azeotrope outlet A and an acetone outlet B at the top, an azeotrope reflux port C and an acetone reflux port D on the upper side of the distillation tower 2, a raw material inlet E and an acetone aqueous solution inlet F on the side of the middle of the distillation tower 2, a reflux port G and a bottom liquid outlet H at the bottom of the distillation tower 2, and a bottom liquid outlet J at the bottom of the distillation tower 2. The azeotrope outlet A, azeotrope reflux port C, and raw material inlet E are located on the same side of the partition plate 3. The acetone outlet B, acetone reflux port D, and acetone aqueous solution inlet F are located on the other side of the partition plate 3. The reflux port G, bottom liquid outlet H, and bottom liquid outlet J are located below the partition plate 3.

[0035] like Figure 1-2 As shown, the upper portion of the distillation tower 2, which has the azeotrope outlet A, azeotrope reflux port C, and raw material inlet E on the side of the partition plate 3, is the azeotrope rectifying section, and the lower portion is the first pre-fractionation section. The upper portion of the first pre-fractionation section is the first pre-fractionation section rectifying layer 2-3, and the lower portion is the first pre-fractionation section stripping layer 2-4. The bottom end of the first pre-fractionation section stripping layer 2-4 is no lower than the bottom end of the partition plate 3. A gap is defined between the first pre-fractionation section rectifying layer 2-3 and the first pre-fractionation section stripping layer 2-4. A raw material feed pipe 2-1 is horizontally mounted on the side wall of the gap at the raw material inlet E. A raw material inlet liquid distributor 2-2 is horizontally mounted below the raw material feed pipe 2-1. The azeotrope distillation section is formed from the first pre-fractionation section distillation layer 2-3 to the azeotrope outlet A at the top of the distillation tower 2. The middle of the azeotrope distillation section is the azeotrope distillation section distillation layer 2-5. A gap exists between the azeotrope distillation section distillation layer 2-5 and the first pre-fractionation section distillation layer 2-3, in which a first liquid distributor 2-6 is horizontally installed. A gap exists between the azeotrope distillation section distillation layer 2-5 and the azeotrope outlet A. An azeotrope reflux port C is provided on the sidewall of the gap. A first row of tubular liquid distributors 2-7 is horizontally installed at the azeotrope reflux port C, allowing the azeotrope to reflux sequentially through the azeotrope outlet A and the azeotrope reflux port C.

[0036] like Figure 1-2 As shown, the middle part of the stripping section is the stripping layer 2-8 of the stripping section, and there is a gap between the stripping layer 2-8 of the stripping section and the partition plate 3, in which a stripping section liquid distributor 2-9 is horizontally installed; there is a gap between the stripping layer 2-8 of the stripping section and the bottom liquid outlet H, and a reflux port G is provided on the side wall of the gap, and an air inlet distributor 2-10 is horizontally installed at the reflux port G, and the bottom steam is refluxed through the bottom liquid outlet H and the reflux port G in turn.

[0037] like Figure 1-2As shown, the upper portion of the distillation tower 2, which has the acetone outlet B, acetone reflux port D, and acetone aqueous solution inlet F on the side of the partition plate 3, is the acetone rectifying section, while the lower portion is the second pre-fractionation section. The upper portion of the second pre-fractionation section is the second pre-fractionation section rectifying layer 2-13, while the lower portion is the second pre-fractionation section stripping layer 2-14. The bottom of the second pre-fractionation section stripping layer 2-14 is no lower than the bottom of the partition plate 3. A gap is defined between the second pre-fractionation section rectifying layer 2-13 and the second pre-fractionation section stripping layer 2-14. An acetone aqueous solution feed pipe 2-11 is horizontally mounted on the side wall of the gap at the acetone aqueous solution inlet F. A second liquid distributor 2-12 is horizontally mounted below the acetone aqueous solution feed pipe 2-11. The acetone rectifying section extends from the second pre-fractionation section's rectifying layer 2-13 to the acetone outlet B at the top of the rectifying column 2. The acetone rectifying section comprises the acetone rectifying section's rectifying layer 2-15, with a gap between the rectifying layer 2-15 and the second pre-fractionation section's rectifying layer 2-13. A third liquid distributor 2-16 is horizontally mounted in the gap. A gap exists between the rectifying layer 2-15 and the acetone outlet B, with an acetone reflux port D provided on the sidewall of the gap. A second row of tubular liquid distributors 2-17 is horizontally mounted at the acetone reflux port D. Acetone refluxes sequentially through the acetone outlet B and the acetone reflux port D.

[0038] like Figure 2 As shown, the ratio of the horizontal cross-sectional area of ​​the azeotrope distillation section distillation layer 2-5 and the acetone distillation section distillation layer 2-15, the first pre-fractionation section distillation layer 2-3 and the second pre-fractionation section distillation layer 2-13, and the first pre-fractionation section stripping layer 2-4 and the second pre-fractionation section stripping layer 2-14 is 64:100; the azeotrope distillation section distillation layer 2-5, the first pre-fractionation section distillation layer 2-3, the first pre-fractionation section stripping layer 2-4, and the acetone distillation section distillation layer 2-15 are all packing layers with a height of 3 meters, and the second pre-fractionation section distillation layer 2-13 and the second pre-fractionation section stripping layer 2-14 are all packing layers with a height of 4 meters.

[0039] like Figure 2 As shown, the stripping layers 2-8 of the stripping section are packing layers and are 3 meters high.

[0040] Utilize the MIBK of above-described embodiment to remove the system of the distillation equipment of light component as Figure 3 As shown, the outside of the distillation tower 2 is provided with a raw material preheater 1, an azeotrope condenser 4, an azeotrope reflux tank 5, an azeotrope reflux pump 6, an azeotrope extraction cooler 7, an azeotrope extraction tank 8, an extraction tower feed pump 9, an extraction tower 10, a phase separator 11, an acetone aqueous solution extraction tank 12, an acetone aqueous solution feed pump 13, an acetone aqueous solution heater 14, an acetone condenser 15, an acetone reflux tank 16, an acetone reflux pump 17, and a reboiler 18.

[0041] The organic mixed liquid feedstock pipeline from the MIBK synthesis system is connected to the feedstock inlet E on the middle side of distillation tower 2 via a feedstock preheater 1. The azeotrope outlet A at the top of distillation tower 2 is sequentially connected to the azeotrope condenser 4, the azeotrope reflux tank 5, the azeotrope extraction cooler 7, the azeotrope extraction tank 8, the extraction tower feed pump 9, and the upper inlet B of extraction tower 10. The lower outlet C of extraction tower 10 is connected to the middle inlet A of phase separator 11, and the upper outlet B of phase separator 11 is connected to the pipeline for the target product, 2-MPA, in the delimited zone.

[0042] The bottom outlet C of the phase separator 11 is connected in sequence to the acetone aqueous solution extraction tank 12, the acetone aqueous solution feed pump 13, the acetone aqueous solution heater 14, and the acetone aqueous solution inlet F on the side of the middle portion of the distillation column 2. The acetone outlet B at the top of the distillation column 2 is connected to the top inlet A of the acetone reflux tank 16 through the acetone condenser 15. The lower outlet C of the acetone reflux tank 16 is connected to a pipeline for the second target product, acetone, to be recycled.

[0043] The bottom liquid outlet J of the distillation tower 2 is connected to the target product three of the de-boundary area - MIBK solution pipeline.

[0044] The lower outlet B of the azeotrope reflux tank 5 is connected to the azeotrope reflux port C at the top of the distillation tower 2 through the azeotrope reflux pump 6; the lower outlet B of the acetone reflux tank 16 is connected to the acetone reflux port D at the top of the distillation tower 2 through the acetone reflux pump 17; the lower bottom liquid outlet H of the distillation tower 2 is connected to the bottom inlet A of the reboiler 18, and the top outlet B of the reboiler 18 is connected to the lower reflux port G of the distillation tower 2.

[0045] The water pipe from the boundary area is connected to the upper inlet A of the extraction tower 2.

[0046] Figure 3 The operating sections of the distillation system include:

[0047] (1) First pre-fractionation section: The raw material from the MIBK synthesis system - the organic mixed liquid (temperature 45°C, containing 0.55% 2-MPA by mass concentration, 69.06% acetone by mass concentration, 24.65% MIBK by mass concentration, and the rest being heavy components and water) is preheated in the raw material preheater 1 (temperature 64°C) and then enters the first pre-fractionation section of the distillation tower 2 from the raw material inlet E of the first pre-fractionation section for pre-fractionation. After pre-fractionation, the organic mixed liquid is preliminarily fractionated. The mixed liquid of MIBK, heavy components and water flows downward and is first distilled in the first pre-fractionation section stripping layer 2-4, and then goes to the stripping section; the azeotropic gas of 2-MPA and acetone flows upward and is first distilled in the first pre-fractionation section stripping layer 2-3, and then goes to the azeotropic fractionation section;

[0048] (2) Azeotropic distillation section: The azeotropic gas of 2-MPA and acetone from the distillation layer 2-3 of the first pre-fractionation section is distilled in the distillation layer 2-5 of the azeotropic distillation section, and heat and mass transfer is carried out with the azeotropic solution refluxed from the azeotropic reflux port C on the upper side of the distillation tower 2. The azeotropic solution flows downward into the first pre-fractionation section, and the azeotropic gas after distillation (temperature 55°C, 25% 2-MPA mass concentration, 75% acetone mass concentration) exits the distillation tower 2 from the azeotropic outlet A at the top of the distillation tower 2 and passes through the azeotropic distillation tower 2. The azeotropic condenser 4 condenses the azeotropic solution into liquid (temperature 55°C) and then enters the azeotropic reflux tank 5. A portion of the azeotropic solution in the azeotropic reflux tank 5 is discharged from the reflux liquid outlet B of the azeotropic reflux tank 5 as reflux liquid and enters the azeotropic distillation section of the distillation tower 2 from the azeotropic reflux port C on the upper side of the distillation tower 2 through the azeotropic reflux pump 6. The other portion of the azeotropic solution in the azeotropic reflux tank 5 is discharged from the azeotropic reflux port C of the azeotropic reflux tank 5 as the produced product to the azeotropic extraction section. The ratio of the two portions of the azeotropic solution is 378:1.

[0049] (3) Azeotrope extraction section: The azeotrope solution of 2-MPA and acetone from the azeotrope distillation section is first cooled by the azeotrope extraction cooler 7 (temperature 45°C), and then enters the azeotrope extraction tank 8. The azeotrope solution in the azeotrope extraction tank 8 is fed into the extraction tower 10 from the upper inlet B of the extraction tower 10 by the extraction tower feed pump 9. Water from the boundary zone enters the extraction tower 10 from the upper inlet A of the extraction tower 10. In the extraction tower 10, the acetone in the azeotrope solution enters the water and forms an acetone aqueous solution with the water. 2-MPA is insoluble in water. After extraction, a mixture of the acetone aqueous solution and the 2-MPA solution exits the extraction tower 10 from the lower outlet C of the extraction tower 10 and enters the phase separator 11 through the middle inlet A of the phase separator 11. In the phase separator 11, the acetone aqueous solution and the 2-MPA solution are phase-separated. The acetone aqueous solution (containing an acetone concentration of 19.95% by mass and the remainder being water) enters the lower layer of the phase separator 11 and proceeds to the second pre-fractionation section from the bottom outlet C of the phase separator 11. The 2-MPA solution (containing a 2-MPA concentration of 99% by mass) enters the upper layer of the phase separator 11 and proceeds to the de-boundary zone from the upper outlet B of the phase separator 11 as the target product.

[0050] (4) Second pre-fractionation section: The acetone aqueous solution from the azeotrope extraction section enters the acetone aqueous solution extraction tank 12, and is sent to the acetone aqueous solution heater 14 by the acetone aqueous solution feed pump 13 for heating (temperature 70°C). After that, the acetone aqueous solution enters the second pre-fractionation section of the distillation tower 2 from the acetone aqueous solution inlet F for pre-fractionation. After pre-fractionation, the acetone aqueous solution is preliminarily fractionated. The aqueous solution flows downward and is first distilled in the second pre-fractionation section stripping layer 2-14, and then goes to the stripping section; the acetone gas flows upward and is first distilled in the second pre-fractionation section stripping layer 2-13, and then goes to the acetone rectification section;

[0051] (5) Acetone distillation section: The acetone gas from the second pre-fractionation section distillation layer 2-13 is distilled in the acetone distillation section distillation layer 2-15, and heat and mass transfer is carried out with the acetone solution refluxed from the acetone reflux port D on the upper side of the distillation tower 2. The acetone solution flows downward into the second pre-fractionation section. The acetone gas after distillation (temperature 56.5°C, acetone mass concentration 99.5%) leaves the distillation tower 2 from the acetone outlet B at the top of the distillation tower 2 and is condensed into liquid (temperature 56.5°C) through the acetone condenser 15. ℃) and then enters the acetone reflux tank 16. A portion of the acetone solution in the acetone reflux tank 16 is discharged as reflux liquid from the acetone reflux liquid outlet B of the acetone reflux tank 16 through the acetone reflux port D on the upper side of the distillation tower 2 and enters the acetone rectification section of the distillation tower 2. Another portion of the acetone solution in the acetone reflux tank 16 (containing acetone at a mass concentration of 99.5%) is discharged as the target product 2 from the acetone outlet C of the acetone reflux tank 16 to the MIBK synthesis system for reuse. The ratio of the two portions of acetone solution is 6.3:1.

[0052] (6) Distillation Section: The mixed liquid of MIBK, heavy components, and water from the first pre-fractionation section and the aqueous solution from the second pre-fractionation section are stripped in the stripping section, and heat and mass transfer is carried out with the gas phase refluxed from the reflux port G at the bottom of the distillation tower 2. The stripped acetone gas flows upward into the second pre-fractionation section, and the mixed liquid of MIBK, heavy components, and water flows downward. A portion of the mixed liquid is sent to the reboiler 18 from the bottom liquid outlet H at the bottom of the distillation tower 2. In the reboiler 18, the mixed liquid is heated, and the acetone in the mixed liquid is heated and evaporated into gas as the gas phase and enters the stripping section from the reflux port G at the bottom of the distillation tower 2. The other portion of the mixed liquid (temperature 98°C, MIBK mass concentration 67.27%, the rest being heavy components and water) is distilled from the bottom liquid outlet J at the bottom of the distillation tower 2 as the target product three - the MIBK solution (light components removed) to the MIBK distillation system in the boundary zone.

[0053] The operating results of the above system are as follows: Figure 4 As shown in the table, Figure 4 Shown are the performance assessment results of a 10,000 t / a MIBK light component removal unit.

Claims

1. A distillation device for removing light components from MIBK, comprising a distillation tower, characterized in that: The distillation tower comprises a tower body with a cylindrical barrel structure, a vertical partition plate (3) is provided in the tower body, the upper end of the partition plate (3) is vertically arranged and fixedly connected to the top of the tower body, the top of the tower body is provided with an azeotrope outlet A and an acetone outlet B, the upper side of the tower body is provided with an azeotrope reflux port C and an acetone reflux port D, the side of the middle of the tower body is provided with a raw material inlet E and an acetone aqueous solution inlet F, the lower part of the tower body is provided with a reflux port G and a bottom liquid side wall outlet H, the bottom of the tower body is provided with a bottom liquid outlet J, the azeotrope outlet A, the azeotrope reflux port C and the raw material inlet E are located on the same side of the partition plate (3), the acetone outlet B, the acetone reflux port D and the acetone aqueous solution inlet F are located on the other side of the partition plate (3), and the reflux port G, the bottom liquid outlet H and the bottom liquid outlet J are located below the partition plate (3); In the tower body, the upper part of one side of the partition plate is the azeotrope distillation section, and the lower part is the first pre-fractionation section; the upper part of the other side of the partition plate is the acetone distillation section, and the lower part is the second pre-fractionation section; the position below the partition plate in the tower body is the stripping section; the upper part of the first pre-fractionation section is the first pre-fractionation section distillation layer (2-3), and the lower part is the first pre-fractionation section stripping layer (2-4); the bottom end height of the first pre-fractionation section stripping layer (2-4) is not lower than the bottom end of the partition plate (3); the raw material inlet E is located between the first pre-fractionation section distillation layer (2-3) and the first pre-fractionation section stripping layer (2-4); a raw material feed pipe (2-1) connected to the raw material inlet E is provided in the tower body, and the raw material feed pipe (2-1) is located in the gap between the first pre-fractionation section distillation layer (2-3) and the first pre-fractionation section stripping layer (2-4); The azeotrope distillation section is located between the first pre-fractionation section distillation layer (2-3) and the azeotrope outlet A at the top of the tower body. The azeotrope distillation section is provided with an azeotrope distillation section distillation layer (2-5), and the azeotrope distillation section distillation layer (2-5) is spaced apart from the first pre-fractionation section distillation layer (2-3). A stripping section stripping layer (2-8) is provided in the stripping section, a gap is provided between the stripping section stripping layer (2-8) and the partition plate (3), and a stripping section liquid distributor (2-9) is horizontally installed in the gap; The upper portion of the second pre-fractionation section is a second pre-fractionation section rectifying layer (2-13), and the lower portion is a second pre-fractionation section stripping layer (2-14), and the bottom end of the second pre-fractionation section stripping layer (2-14) is not lower than the bottom end of the partition plate (3); the acetone aqueous solution inlet F is located between the second pre-fractionation section rectifying layer (2-13) and the second pre-fractionation section stripping layer (2-14), and an acetone aqueous solution feed pipe (2-11) connected to the acetone aqueous solution inlet F is provided in the tower body, and the acetone aqueous solution feed pipe (2-11) is located in the gap between the second pre-fractionation section rectifying layer (2-13) and the second pre-fractionation section stripping layer (2-14); The acetone distillation section is located between the second pre-fractionation section distillation layer (2-13) and the acetone outlet B at the top of the distillation tower (2). An acetone distillation section distillation layer (2-15) is provided in the acetone distillation section, and a gap is provided between the acetone distillation section distillation layer (2-15) and the second pre-fractionation section distillation layer (2-13).

2. The distillation equipment for removing light components from MIBK according to claim 1, wherein: A raw material inlet liquid distributor (2-2) is horizontally installed below the raw material feed pipe (2-1); a gap is provided between the azeotropic distillation section distillation layer (2-5) and the first pre-fractionation section distillation layer (2-3), and a first liquid distributor (2-6) is horizontally installed in the gap; a second liquid distributor (2-12) is horizontally installed below the acetone aqueous solution feed pipe (2-11); a gap is provided between the acetone distillation section distillation layer (2-15) and the second pre-fractionation section distillation layer (2-13), and a third liquid distributor (2-16) is horizontally installed in the gap.

3. The distillation equipment for removing light components from MIBK according to claim 1, wherein: There is a gap between the distillation layer (2-5) of the azeotrope distillation section and the azeotrope outlet A, and an azeotrope reflux port C is provided on the side wall of the gap. A first row of tubular liquid distributors (2-7) is horizontally installed at the azeotrope reflux port C, and the azeotrope is refluxed in sequence through the azeotrope outlet A and the azeotrope reflux port C.

4. The distillation equipment for removing light components from MIBK according to claim 3, wherein: The azeotrope outlet A and the azeotrope reflux port C are sequentially connected via pipelines to an azeotrope condenser (4), an azeotrope reflux tank (5), and an azeotrope reflux pump (6).

5. The distillation equipment for removing light components from MIBK according to claim 1, wherein: There is a gap between the distillation layer (2-15) of the acetone distillation section and the acetone outlet B, and an acetone reflux port D is provided on the side wall of the gap. A second row of tubular liquid distributors (2-17) is horizontally installed at the acetone reflux port D, and the acetone is refluxed through the acetone outlet B and the acetone reflux port D in sequence.

6. The distillation equipment for removing light components from MIBK according to claim 5, characterized in that: An acetone condenser (15), an acetone reflux tank (16), and an acetone reflux pump (17) are sequentially connected between the acetone outlet B and the acetone reflux port D via pipelines.

7. The distillation equipment for removing light components from MIBK according to claim 1, wherein: There is a gap between the stripping layer (2-8) of the stripping section and the bottom liquid side wall outlet H, a reflux port G is provided on the side wall of the gap, an air inlet distributor (2-10) is horizontally installed at the reflux port G, and the bottom steam is refluxed in sequence through the bottom liquid side wall outlet H and the reflux port G; a reboiler (18) is connected between the bottom liquid side wall outlet H and the reflux port G via a pipeline.

8. The distillation equipment for removing light components from MIBK according to any one of claims 1 to 7, characterized in that: The ratio of the horizontal cross-sectional areas of the azeotrope distillation section distillation layer (2-5) to the acetone distillation section distillation layer (2-15), the first pre-fractionation section distillation layer (2-3) to the second pre-fractionation section distillation layer (2-13), and the first pre-fractionation section stripping layer (2-4) to the second pre-fractionation section stripping layer (2-14) is 1:10 to 10:

1.

9. The distillation equipment for removing light components from MIBK according to any one of claims 1 to 7, characterized in that: The azeotropic distillation section distillation layer (2-5), the acetone distillation section distillation layer (2-15), the first pre-fractionation section distillation layer (2-3), the second pre-fractionation section distillation layer (2-13), the first pre-fractionation section stripping layer (2-4), and the second pre-fractionation section stripping layer (2-14) are all packing layers with a height of 2 to 12 meters; the stripping section stripping layer (2-8) is a packing layer with a height of 2 to 12 meters.

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