Rectification equipment for rectifying heavy components in MIBK tower bottoms

Abstract

The utility model provides rectification equipment for rectifying heavy components in MIBK (methyl isobutyl ketone) tower bottoms and belongs to the technical field of chemical rectification. The rectifying equipment comprises a rectifying tower with a cylindrical barrel structure, and a vertical partition plate is arranged in the rectifying tower and divides the rectifying tower into a pre-fractionating section, a rectifying section, a stripping section and a middle discharging section. By adopting the rectification equipment, tower bottoms from an MIBK rectification system can be rectified and separated, and a target product 1-MIBK is recovered at the rectification section of the rectification tower; a target product 2-DIBK (the chemical name is diisobutyl ketone, hereinafter referred to as DIBK) is recycled at a middle discharging section of the rectifying tower; and recovering the target product 3-C9 saturated alkane by a reboiler. The rectification equipment disclosed by the utility model can be used for improving the product quality, simplifying the process flow, reducing the device investment, reducing the consumption of raw materials and energy in production, reducing the production cost and reducing the carbon emission of a production device.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical distillation, in particular to a distillation device for distilling heavy components of a MIBK tower bottom liquid. 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] DIBK, chemical name diisobutyl ketone, is an organic compound with the chemical formula C9H 18 O is used to make solvent resin, has good solvent properties, does not corrode the substrate, has good performance in plastic paint, and is mainly used in vacuum electroplating coatings, plastic paints and leather finishing industries.

[0004] C9 saturated alkanes have stable chemical properties and are widely used in practical applications, including chemical raw materials, fuels, lubricant additives, and biomedical materials.

[0005] The heavy component of the bottoms liquid from the MIBK distillation system contains MIBK, DIBK, and C9 saturated alkanes, with the mass concentration of MIBK being approximately 14% and DIBK being approximately 62%, with the remainder being C9 saturated alkanes. These organic compounds require distillation, separation, and recovery. Existing MIBK bottoms liquid heavy component distillation production typically utilizes a two-step distillation process: Step 1: The heavy component of the bottoms liquid from the MIBK distillation system is distilled through a de-MIBK tower to recover MIBK; Step 2: The bottoms liquid from Step 1 is distilled through a DIBK product tower to separate the DIBK product. The bottoms liquid is the C9 saturated alkanes. The de-MIBK and distillation separation of DIBK and C9 saturated alkanes are separated and recovered through two distillation separation and recovery systems. Distillation separation is the most mature and widely used separation technology in chemical production, but the distillation process consumes significant energy. Over 50% of the energy consumed in chemical production is used for separation, and distillation separation accounts for 95% of this energy consumption.

[0006] Therefore, it is necessary to improve the existing equipment for distilling the heavy fraction of the MIBK tower bottom liquid, and it is urgent to provide a distillation equipment for distilling the heavy fraction of the MIBK tower bottom liquid with a short process, small footprint, low investment and low energy consumption. Utility Model Content

[0007] The utility model aims to provide a distillation device for distilling heavy components of MIBK tower bottom liquid, wherein the heavy components of the tower bottom liquid from the MIBK distillation system are distilled and separated in a partition plate distillation tower. Unlike conventional distillation towers, the partition plate distillation tower has not only a distillation section and a stripping section, but also a pre-fractionation section and an intermediate discharge section. The distillation section of the distillation tower recovers target product 1, namely, MIBK; the intermediate discharge section of the distillation tower recovers target product 2, namely, DIBK; and the reboiler recovers target product 3, namely, C9 saturated alkanes.

[0008] By adopting the above distillation equipment, only one set of distillation equipment is needed to recover the target product. It is a distillation equipment for distilling the heavy components of the MIBK tower bottom liquid with a short process, small footprint, low investment and low energy consumption. The utility model aims to save energy and reduce consumption, reduce investment in production equipment, reduce carbon emissions and protect the environment.

[0009] The purpose of the utility model can be achieved through the following technical solutions:

[0010] A distillation device for distilling a heavy component of a MIBK tower bottom liquid comprises a distillation tower and a reboiler. The distillation tower is provided with a vertical partition plate located in the middle of the distillation tower, and a plurality of liquid distributors are installed in the distillation tower. The upper portion of the distillation tower is provided with a distillation section, the top of which is provided with an MIBK gas outlet A, and the side of the distillation section is provided with an MIBK solution reflux port B. The middle portion of the distillation tower is provided with a pre-fractionation section and an intermediate discharge section on both sides of the vertical partition plate. The pre-fractionation section is provided with an MIBK tower bottom liquid heavy component feed port C, and the intermediate discharge section is provided with a MIBK solution outlet D. The lower portion of the distillation tower is provided with a stripping section, and the bottom of the stripping section is provided with a discharge reflux port E. Both the pre-fractionation section and the intermediate discharge section are provided with a stripping layer and a distillation layer.

[0011] As a preferred embodiment of the present invention, a heating coil is provided inside the reboiler; a steam inlet F is provided on the side of the reboiler, a condensate outlet G is provided at the lower end of the steam inlet F, and both ends of the heating coil are connected to the steam inlet F and the condensate outlet G respectively; a C9 saturated alkane solution outlet H is provided at the bottom of the reboiler.

[0012] As a preferred embodiment of the present invention, a second distillation layer is provided in the middle of the distillation section, a tube-type liquid distributor is horizontally installed at the MIBK solution reflux port B above the second distillation layer, and a second liquid distributor is horizontally installed below the second distillation layer.

[0013] As a preferred embodiment of the present invention, a first distillation layer is provided at the upper part of the pre-fractionation section, a first liquid distributor is horizontally installed below the first distillation layer, a first stripping layer is provided below the first liquid distributor, and a raw material feed pipe is horizontally installed at the feed port C of the heavy component of the MIBK tower bottom liquid between the first distillation layer and the first liquid distributor.

[0014] As a preferred embodiment of the present invention, a third distillation layer is provided on the upper part of the intermediate discharging section, a fourth liquid distributor is horizontally installed below the third distillation layer, a third stripping layer is provided below the fourth liquid distributor, and the DIBK solution outlet D is located between the third distillation layer and the fourth liquid distributor.

[0015] As a preferred embodiment of the present invention, a third liquid distributor is provided on the upper portion of the stripping section, and a second stripping layer is provided below the third liquid distributor.

[0016] As a preferred embodiment of the present invention, the top of the vertical partition plate is at the same height as or higher than the top of the distillation layer of the pre-fractionation section and the intermediate discharging section, and the bottom end is at the same height as or lower than the bottom end of the distillation layer of the pre-fractionation section and the intermediate discharging section.

[0017] As a preference of the present invention, the ratio of the horizontal cross-sectional area of ​​the pre-fractionation section to the rectifying layer of the intermediate discharge section and / or the ratio of the horizontal cross-sectional area of ​​the pre-fractionation section to the stripping layer of the intermediate discharge section is 1:10 to 10:1.

[0018] As a preferred embodiment of the present invention, the rectification layer and / or stripping layer is a packing layer and has a height of 2 to 12 meters.

[0019] As a preferred embodiment of the present invention, the distillation tower and / or reboiler is a vertical cylindrical shell.

[0020] Some specific technical solutions include the following:

[0021] The heavy component pipeline for the bottoms liquid, the raw material from the MIBK distillation system, is connected sequentially to the MIBK bottoms liquid heavy component tank, the distillation column feed pump, the preheater, and the MIBK bottoms liquid heavy component feed port C on the side of the middle distillation column. The MIBK gas outlet A at the top of the distillation column is connected to the top inlet A of the reflux drum via a condenser. The outlet B on the lower side of the reflux drum is connected to the MIBK solution reflux port B on the upper side of the distillation column via a reflux pump. The lower outlet C of the reflux drum is connected to the MIBK pipeline for the target product 1 in the delimited zone.

[0022] In the above-mentioned distillation equipment: the DIBK solution outlet D on the side of the middle part of the distillation tower is connected to the target product 2 in the deboundary area - DIBK pipeline.

[0023] In the above distillation equipment: the C9 saturated alkane solution outlet H at the bottom of the reboiler is connected to the target product 3 in the deboundary zone - C9 saturated alkane pipeline.

[0024] In the above-mentioned distillation equipment: the distillation layer of the pre-fractionation section, the distillation layer of the intermediate discharging section, the retention layer of the pre-fractionation section, and the retention layer of the intermediate discharging section are all packing layers with a height of 2 to 12 meters; the distillation layer of the distillation section is a packing layer with a height of 2 to 12 meters, and the stripping layer of the stripping section is a packing layer with a height of 2 to 12 meters.

[0025] The method for achieving the distillation of the heavy components of the MIBK tower bottom liquid using the above-mentioned distillation equipment includes the following steps:

[0026] (1) Pretreatment section: The raw material from the MIBK distillation system, the bottom liquid heavy component, enters the MIBK bottom liquid heavy component tank from the top inlet A of the MIBK bottom liquid heavy component tank. The bottom liquid heavy component in the MIBK bottom liquid heavy component tank enters the preheater from the lower outlet B of the MIBK bottom liquid heavy component tank through the distillation tower feed pump. After being heated in the preheater, the bottom liquid heavy component exits the preheater and goes to the pre-fractionation section.

[0027] (2) Pre-fractionation section: The heavy components of the MIBK bottom liquid from the pre-treatment section enter the distillation tower through the MIBK bottom liquid heavy component feed port C on the side of the middle of the distillation tower for pre-fractionation. After pre-fractionation, the heavy components of the MIBK bottom liquid are initially fractionated. The mixed gas of MIBK and DIBK flows upward and is first distilled in the distillation layer of the pre-fractionation section before going to the distillation section; the mixed liquid of DIBK and C9 saturated alkanes flows downward and is first retained in the stripping layer of the pre-fractionation section before going to the stripping section.

[0028] (3) Distillation section: The mixed gas of MIBK and DIBK from the pre-fractionation section of the distillation tower is distilled in the distillation layer of the distillation section, and heat and mass transfer is carried out with the MIBK solution refluxed from the MIBK solution reflux port B on the upper side of the distillation tower. The DIBK solution flows downward into the middle discharge section, and the distilled MIBK gas flows upward, exits the distillation section of the distillation tower from the MIBK gas outlet A at the top of the distillation tower, is condensed into liquid through the condenser, and then enters the reflux tank. A portion of the MIBK in the reflux tank is used as reflux liquid and enters the distillation section of the distillation tower from the lower side outlet B of the reflux tank through the reflux pump and the MIBK solution reflux port B on the upper side of the distillation tower; the other portion of the MIBK in the reflux tank is used as the target product 1 and is discharged from the lower side outlet C of the reflux tank to the boundary area.

[0029] (4) Distillation section: The mixed liquid of DIBK and C9 saturated alkanes from the pre-fractionation section of the distillation tower is distilled in the stripping layer of the stripping section, and heat and mass transfer is carried out with the gas phase refluxed from the bottom discharge reflux port E of the distillation tower. The DIBK gas after distillation flows upward and enters the middle discharge section, and the C9 saturated alkane solution flows downward and exits the distillation section of the distillation tower from the bottom discharge reflux port E of the distillation tower and enters the reboiler. In the reboiler, the C9 saturated alkane solution is heated by the heating coil, and the DIBK in the C9 saturated alkane solution is heated and evaporated into gas. As the gas phase, it exits the reboiler from the bottom discharge reflux port E of the distillation tower and enters the stripping section of the distillation tower; the C9 saturated alkane solution at the bottom of the reboiler exits the reboiler from the C9 saturated alkane solution outlet H at the bottom of the reboiler as the target product 3 de-boundary area.

[0030] (5) Intermediate discharging section: The DIBK solution flowing downward from the rectifying section of the distillation tower into the intermediate discharging section of the distillation tower is distilled in the rectifying layer of the intermediate discharging section, and the DIBK gas flowing upward from the stripping section of the distillation tower into the intermediate discharging section of the distillation tower is retained in the retention layer of the intermediate discharging section. The DIBK is purified in the intermediate discharging section, and the purified DIBK is taken as the target product 2 from the DIBK solution outlet D of the intermediate discharging section of the distillation tower to the boundary area.

[0031] In the above method, the raw material from the MIBK distillation system contains MIBK at a mass concentration of ≤20%, DIBK at a mass concentration of ≥55%, and the remainder is C9 saturated alkanes.

[0032] Beneficial effects of the utility model:

[0033] The heavy components of the bottoms liquid from a MIBK distillation system contain MIBK, DIBK, and C9 saturated alkanes. These components need to be separated to maximize their utilization. The utility model provides a distillation device for the distillation of the heavy components of the MIBK bottoms liquid. This distillation device can effectively separate the heavy components of the MIBK bottoms liquid. For every ton of heavy components distilled from the MIBK bottoms liquid, approximately 140 kg of MIBK, approximately 620 kg of DIBK, and approximately 240 kg of C9 saturated alkanes can be obtained.

[0034] This distillation tower utilizes a partition plate distillation tower to replace the MIBK removal tower and DIBK product tower, combining the two distillation towers into one. This eliminates a condenser and a reboiler, saving approximately 30% of distillation equipment investment. DIBK appears simultaneously at the top and bottom of the tower, allowing the composition of the feed entering the partition plate distillation tower to better match that of the pre-fractionation section liquid distributor. This reduces mixing effects at the liquid distributor, specifically the effects of different feed and liquid distributor compositions. This reduces the need for an optimal feed liquid distributor and improves thermodynamic efficiency. Because heat from the partition plate distillation tower is recycled within the same tower, distillation energy consumption is also reduced, by approximately 30%.

[0035] The reboiler is vertical and has heating coils along the inner wall, so that the entire reboiler is heated evenly, the tower bottom liquid can easily reach a higher temperature, and there is no dead angle in the flow of fluid in the bottom.

[0036] The above distillation equipment is used to obtain target product 1 - MIBK, target product 2 - DIBK and target product 3 - C9 saturated alkanes. It is a safe, environmentally friendly, high-yield, low-energy distillation equipment for the distillation of heavy components of MIBK tower bottom liquid. The utility model aims to save energy and reduce consumption, reduce carbon emissions of production equipment and protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the division diagram of the working section of the distillation equipment in this utility model

[0038] Figure 2 This is the distillation equipment diagram of this utility model

[0039] Figure 3 This is the process flow diagram of this utility model

[0040] Among them, the MIBK tower bottom liquid re-constituent tank 1, the distillation tower feed pump 2, the preheater 3, the distillation tower 4, the partition plate 5, the condenser 6, the reflux tank 7, the reflux pump 8, the reboiler 9, and the heating coil 10; the raw material feed pipe 4-1, the first liquid distributor 4-2, the first distillation layer 4-3, the first retention layer 4-4, the second distillation layer 4-5, the second liquid distributor 4-6, the calandria liquid distributor 4-7, the second distillation layer 4-8, the third liquid distributor 4-9, the third distillation layer 4-10, the third retention layer 4-11, and the fourth liquid distributor 4-12. DETAILED DESCRIPTION

[0041] 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.

[0042] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0043] like Figure 1 、 2 The distillation equipment shown is for distilling the heavy components of the MIBK tower bottom liquid. The distillation equipment can distill and separate the tower bottom liquid from the MIBK distillation system. The distillation section of the distillation tower recovers the target product 1 - MIBK, the middle discharge section of the distillation tower recovers the target product 2 - DIBK, and the reboiler recovers the target product 3 - C9 saturated alkanes. The distillation equipment includes a distillation tower 4 and a reboiler 9; a vertical partition plate 5 is provided in the distillation tower 4, and the vertical partition plate 5 is located in the middle of the distillation tower 4. A plurality of liquid distributors are installed in the distillation tower 4; a distillation section is provided at the top of the distillation section, a MIBK gas outlet A is provided at the top of the distillation section, and a MIBK solution reflux port B is provided on the side of the distillation section; a pre-fractionation section and an intermediate discharge section are provided on both sides of the vertical partition plate 5 in the middle of the distillation tower 4, the pre-fractionation section is provided with a feed port C for the heavy component of the MIBK bottom liquid, and the intermediate discharge section is provided with a DIBK solution outlet D; a stripping section is provided in the lower part of the distillation tower 4, and a discharge reflux port E is provided at the bottom of the stripping section; the pre-fractionation section and the intermediate discharge section are both provided with a stripping layer and a distillation layer.

[0044] In the above-mentioned distillation equipment: the distillation tower 4 and the reboiler 9 are both vertical cylindrical barrels.

[0045] In the above-mentioned distillation equipment: a heating coil 10 is provided inside the reboiler 9; a steam inlet F is provided on the side of the reboiler 9, and a condensate outlet G is provided at the lower end of the steam inlet F. The two ends of the heating coil 10 are respectively connected to the steam inlet F and the condensate outlet G; and a C9 saturated alkane solution outlet H is provided at the bottom of the reboiler 9.

[0046] In the above distillation equipment: a second distillation layer 4-5 is provided in the middle of the distillation section, a calandria liquid distributor 4-7 is horizontally installed at the MIBK solution reflux port B above the second distillation layer 4-5, and a second liquid distributor 4-6 is horizontally installed below the second distillation layer 4-5.

[0047] In the above-mentioned distillation equipment: a first distillation layer 4-3 is provided at the upper part of the pre-fractionation section, a first liquid distributor 4-2 is horizontally installed below the first distillation layer 4-3, a first stripping layer 4-4 is provided below the first liquid distributor 4-2, and a raw material feed pipe 4-1 is horizontally installed at the feed port C of the heavy component of the MIBK tower bottom liquid between the first distillation layer 4-3 and the first liquid distributor 4-2.

[0048] In the above-mentioned distillation equipment: a third distillation layer 4-10 is provided at the upper part of the intermediate discharge section, a fourth liquid distributor 4-12 is horizontally installed below the third distillation layer 4-10, a third stripping layer 4-11 is provided below the fourth liquid distributor 4-12, and the DIBK solution outlet D is located between the third distillation layer 4-10 and the fourth liquid distributor 4-12.

[0049] In the above distillation equipment: a third liquid distributor 4-9 is provided on the upper part of the stripping section, and a second stripping layer 4-8 is provided below the third liquid distributor 4-9.

[0050] In the above distillation equipment: the top of the vertical partition plate 5 is not lower than the top of the first distillation layer 4-3 and the top of the third distillation layer 4-10, and the bottom is not higher than the bottom of the first distillation layer 4-4 and the bottom of the third distillation layer 4-11.

[0051] In the above distillation equipment: the ratio of the horizontal cross-sectional areas of the first distillation layer 4-3 and the third distillation layer 4-10 is 1:1; the ratio of the horizontal cross-sectional areas of the first stripping layer 4-4 and the third stripping layer 4-11 is 1:1.

[0052] In the above distillation equipment: the first distillation layer 4-3, the third distillation layer 4-10, the first retention layer 4-4, and the third retention layer 4-11 are all packing layers and have a height of 2.5 meters.

[0053] The second rectifying layer 4-5 is a packing layer with a height of 2.5 meters, and the second stripping layer 4-8 is a packing layer with a height of 2.5 meters.

[0054] like Figure 3The distillation equipment further comprises a MIBK tower bottom liquid heavy component tank 1 arranged outside the distillation tower 4 and the reboiler 9, a distillation tower feed pump 2, a preheater 3, a condenser 6, a reflux tank 7, and a reflux pump 8.

[0055] In some more specific embodiments, the content is as follows:

[0056] The pipeline for the heavy component of the bottom liquid, the raw material from the MIBK distillation system, is connected in sequence to MIBK bottom liquid heavy component tank 1, distillation column feed pump 2, preheater 3, and MIBK bottom liquid heavy component feed port C on the middle side of distillation column 4. MIBK gas outlet A at the top of distillation column 4 is connected to inlet A at the top of reflux drum 7 via condenser 6. Outlet B at the lower side of reflux drum 7 is connected to MIBK solution reflux port B on the upper side of distillation column 4 via reflux pump 8. The lower outlet C of reflux drum 7 is connected to the pipeline for the target product 1 in the delimited zone—MIBK.

[0057] The DIBK solution outlet D on the side of the middle part of the distillation tower 4 is connected to the target product 2 - DIBK pipeline of the de-boundary area.

[0058] The C9 saturated alkane solution outlet H at the bottom of the reboiler 9 is connected to the target product 3 of the deboundary zone - C9 saturated alkane pipeline.

[0059] The method for achieving the distillation of the heavy components of the MIBK tower bottom liquid using the above-mentioned distillation equipment includes the following steps:

[0060] (1) Pretreatment section: The raw material from the MIBK distillation system, namely the bottom liquid heavy component (temperature 45°C, MIBK content 14%, DIBK content 62%, C9 saturated alkane content 24%), enters the MIBK bottom liquid heavy component tank 1 from the top inlet A of the MIBK bottom liquid heavy component tank 1. The bottom liquid heavy component in the MIBK bottom liquid heavy component tank 1 enters the preheater 3 from the lower outlet B of the MIBK bottom liquid heavy component tank 1 through the distillation tower feed pump 2. In the preheater 3, the bottom liquid heavy component is heated (temperature 165°C) and then exits the preheater 3 to the pre-fractionation section.

[0061] (2) Pre-fractionation Section: The heavy components of the MIBK bottom liquid from the pre-treatment section enter the distillation tower 4 through the feed port C on the middle side of the distillation tower 4 through the raw material feed pipe 4-1 for pre-fractionation. After pre-fractionation, the heavy components of the MIBK bottom liquid are initially fractionated. The mixed gas of MIBK and DIBK flows upward and is first distilled in the first distillation layer 4-3 before being distilled in the distillation section. The mixed liquid of DIBK and C9 saturated alkanes flows downward and is first distilled in the first stripping layer 4-4 before being distilled in the stripping section.

[0062] (3) Distillation section: The mixed gas of MIBK and DIBK from the pre-fractionation section of the distillation tower 4 is distilled in the distillation layer 4-5 of the distillation section, and heat and mass transfer is carried out with the MIBK solution (temperature 116.5°C, MIBK concentration 99% by mass) refluxed from the MIBK solution reflux port B on the upper side of the distillation tower 4. The DIBK solution flows downward into the middle discharge section, and the distilled MIBK gas (temperature 116.5°C, MIBK concentration 99% by mass) flows upward, exits the distillation section of the distillation tower from the MIBK gas outlet A at the top of the distillation tower 4, is condensed into liquid (temperature 116.5°C) by the condenser 6, and then enters the reflux tank 7. A portion of the MIBK in the reflux tank 7 is discharged as reflux liquid from the lower side outlet B of the reflux tank 7 through the reflux pump 8, via the MIBK solution reflux port B on the upper side of the distillation tower 4, and into the rectifying section of the distillation tower 4 through the calandria liquid distributor 4-7. Another portion of the MIBK in the reflux tank 7 (temperature 116.5° C., MIBK concentration 99% by mass) is discharged as the target product 1 from the lower side outlet C of the reflux tank 7 to the boundary zone.

[0063] (4) Distillation section: The mixed liquid of DIBK and C9 saturated alkanes from the pre-fractionation section of the distillation tower 4 is distilled in the second distillation layer 4-8, and heat and mass transfer is carried out with the gas phase (temperature 198°C) refluxed from the bottom discharge reflux port E of the distillation tower 4. The distilled DIBK gas flows upward into the middle discharge section, and the C9 saturated alkanes solution flows downward, exits the distillation section of the distillation tower 4 from the bottom discharge reflux port E of the distillation tower 4 and enters the reboiler 9. In the reboiler 9, the C9 saturated alkanes are heated and cooled. The alkane solution is heated by the heating coil, and the DIBK in the C9 saturated alkane solution (temperature 198° C.) is heated and evaporated into gas (temperature 198° C.), which is discharged from the reboiler 9 through the reflux outlet E at the bottom of the distillation tower 4 as the gas phase and enters the stripping section of the distillation tower 4; the C9 saturated alkane solution at the bottom of the reboiler 4 (temperature 198° C., containing 99% C9 saturated alkane by mass) is discharged from the reboiler 9 through the C9 saturated alkane solution outlet H at the bottom of the reboiler 9 as the target product 3 to the de-boundary zone.

[0064] (5) Intermediate discharging section: The DIBK solution flowing downward from the rectifying section of the rectifying tower 4 into the intermediate discharging section of the rectifying tower is rectified in the third rectifying layer 4-10, and the DIBK gas flowing upward from the stripping section of the rectifying tower into the intermediate discharging section of the rectifying tower is retained in the third stripping layer 4-11. The DIBK is purified in the intermediate discharging section, and the purified DIBK (containing a DIBK mass concentration of 99%) is discharged as the target product 2 from the DIBK solution outlet D of the intermediate discharging section of the rectifying tower 4 to the boundary area.

[0065] The results of the operation of the utility model are shown in Table 1.

[0066] Table 1 Performance evaluation results of 1000 tons / year MIBK tower bottom liquid heavy component distillation unit

[0067] Table 1 Performance evaluation results of 1000 tons / year MIBK bottom liquid heavy component distillation unit

[0068]

Claims

1. A distillation device for distilling heavy components of MIBK tower bottom liquid, characterized in that: The distillation equipment comprises a distillation tower (4) and a reboiler (9); a vertical partition plate (5) is provided in the distillation tower (4), the vertical partition plate (5) is located in the middle of the distillation tower (4), and a plurality of liquid distributors are installed in the distillation tower (4); a distillation section is provided at the upper part of the distillation tower (4), a MIBK gas outlet A is provided at the top of the distillation section, and a MIBK solution reflux port B is provided on the side of the distillation section; a pre-fractionation section and an intermediate discharge section are provided on both sides of the vertical partition plate (5) in the middle of the distillation tower (4), the pre-fractionation section is provided with a MIBK tower bottom liquid heavy component feed port C, and the intermediate discharge section is provided with a DIBK solution outlet D; a stripping section is provided at the lower part of the distillation tower (4), and a discharge reflux port E is provided at the bottom of the stripping section; the pre-fractionation section and the intermediate discharge section are both provided with a stripping layer and a distillation layer.

2. The distillation equipment according to claim 1, characterized in that A heating coil (10) is provided inside the reboiler (9); a steam inlet F is provided on the side of the reboiler (9), a condensate outlet G is provided at the lower end of the steam inlet F, and both ends of the heating coil (10) are connected to the steam inlet F and the condensate outlet G respectively; a C9 saturated alkane solution outlet H is provided at the bottom of the reboiler (9).

3. The distillation equipment according to claim 1, characterized in that A second rectifying layer (4-5) is provided in the middle of the rectifying section, a tube-type liquid distributor (4-7) is horizontally installed at the MIBK solution reflux port B above the second rectifying layer (4-5), and a second liquid distributor (4-6) is horizontally installed below the second rectifying layer (4-5).

4. The distillation equipment according to claim 1, characterized in that A first distillation layer (4-3) is provided at the upper part of the pre-fractionation section, a first liquid distributor (4-2) is horizontally installed below the first distillation layer (4-3), a first stripping layer (4-4) is provided below the first liquid distributor (4-2), and a raw material feed pipe (4-1) is horizontally installed at a feed port C of the heavy component of the MIBK tower bottom liquid between the first distillation layer (4-3) and the first liquid distributor (4-2).

5. The distillation equipment according to claim 1, characterized in that A third distillation layer (4-10) is provided at the upper portion of the intermediate discharging section, a fourth liquid distributor (4-12) is horizontally installed below the third distillation layer (4-10), a third stripping layer (4-11) is provided below the fourth liquid distributor (4-12), and a DIBK solution outlet D is located between the third distillation layer (4-10) and the fourth liquid distributor (4-12).

6. The distillation equipment according to claim 1, characterized in that A third liquid distributor (4-9) is provided on the upper portion of the stripping section, and a second stripping layer (4-8) is provided below the third liquid distributor (4-9).

7. The distillation equipment according to claim 1, characterized in that The top of the vertical partition plate (5) is at the same height as or higher than the top of the rectifying layer of the pre-fractionation section and the intermediate discharging section, and the bottom is at the same height as or lower than the bottom of the stripping layer of the pre-fractionation section and the intermediate discharging section.

8. The distillation equipment according to claim 7, characterized in that The ratio of the horizontal cross-sectional area between the pre-fractionation section and the rectifying layer of the middle discharging section and / or between the pre-fractionation section and the stripping layer of the middle discharging section is 1:10 to 10:

1.

9. The distillation equipment according to claim 1, characterized in that: The rectification layer and / or stripping layer is a packing layer and has a height of 2 to 12 meters.

10. The distillation equipment according to claim 1, characterized in that The distillation tower (4) and / or the reboiler (9) are vertical cylindrical barrels.

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