1, 2-butadiene rectification preparation device and process

Abstract

The invention provides a 1, 2-butadiene rectification preparation device and process, and relates to the field of petrochemical industry. The device comprises a 1, 3-butadiene concentration unit and a 1, 2-butadiene product unit, the 1, 3-butadiene concentration unit comprises a 1, 3-butadiene concentration tower, a first tower kettle reboiler, a first tower top condenser and a first reflux tank; and the 1, 2-butadiene product unit comprises a 1, 2-butadiene product tower, a second tower kettle reboiler, a second tower top condenser and a second reflux tank. The process comprises the steps of light component removal rectification and heavy component removal rectification. According to the method, heavy components of a butadiene extraction unit of an ethylene device are used as raw materials, a continuous rectification mode of removing light components first and then removing heavy components is combined with a pasteurization treatment technology, a 1, 2-butadiene product with the purity being larger than or equal to 97.5 wt% can be obtained, 1, 3-butadiene is recycled, the overall utilization rate of resources is increased, and meanwhile energy conservation and emission reduction of enterprises are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical engineering, and in particular to a 1,2-butadiene distillation preparation device and process. Background Art

[0002] 1,2-Butadiene is a colorless gas with a special smell. It is slightly soluble in water, soluble in ethanol and methanol, and easily soluble in acetone, ether, chloroform, etc. It is a raw material for manufacturing synthetic rubber, synthetic resin, nylon, etc.

[0003] The main methods for producing 1,2-butadiene are the dehydrogenation of butane and butene, or separation from C4 fractions. Although both the butane dehydrogenation method and the butene dehydrogenation method have the characteristics of easy-to-obtain raw materials and relatively simple processes, the dehydrogenation reaction requires higher temperatures and pressures, consumes more energy, and has higher equipment investment and maintenance costs. The butane dehydrogenation method may produce by-products such as coke during the reaction, which affects the purity and yield of the product. Compared with the butane dehydrogenation method, the butene dehydrogenation method has a higher product yield and purity, but some dehydrogenation processes, such as the oxidative dehydrogenation method, are prone to form explosive mixtures if not properly controlled, which poses a safety risk. The selection and regeneration of catalysts are also technical difficulties that need to be paid attention to in the butene dehydrogenation method. The C4 fraction is a by-product of petroleum cracking or refining, and its source is abundant. High-purity 1,2-butadiene can be obtained through separation technologies such as distillation and extraction. Other valuable components, such as butane and butene, can be recovered during the separation process to improve resource utilization.

[0004] In the process of butadiene extraction in ethylene plants, the treatment of heavy components is an important step. Since the presence of these components may affect the purity of butadiene, they need to be separated through a series of operations. These heavy components include various C4 hydrocarbons (such as isobutane, butane, butene, 2-butene, etc.), high-boiling alkynes, and other by-products or impurities produced during the extraction process. In actual production, some companies have successfully achieved the reuse of heavy components in the butadiene extraction unit of ethylene plants.

[0005] By using the butadiene extraction unit of the ethylene plant as a raw material to extract 1,2-butadiene, the added value of the ethylene plant can be increased, the waste of raw materials can be significantly reduced, and the overall utilization rate of resources can be improved. Therefore, it is urgent to research and develop a distillation preparation device and process for 1,2-butadiene. Summary of the invention

[0006] The object of the present invention is to provide a 1,2-butadiene distillation preparation device and process, which reuses the heavy components of the butadiene extraction unit of an ethylene device as raw materials, produces 1,2-butadiene with a purity of ≥97.5wt%, and recovers 1,3-butadiene, thereby improving the overall resource utilization rate and being beneficial to energy conservation and emission reduction.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a 1,2-butadiene distillation preparation device, comprising a 1,3-butadiene concentration unit and a 1,2-butadiene product unit; the 1,3-butadiene concentration unit comprises a 1,3-butadiene concentration tower, a first tower bottom reboiler, a first tower top condenser, and a first reflux tank; the 1,2-butadiene product unit comprises a 1,2-butadiene product tower, a second tower bottom reboiler, a second tower top condenser, and a second reflux tank; The 1,3-butadiene concentration tower is a four-stage packed distillation tower, a heavy component input pipeline of the butadiene extraction unit of the ethylene device is arranged in the middle of the 1,3-butadiene concentration tower, a cold side medium inlet of the first tower bottom reboiler is connected to the first tower bottom pump, the first tower bottom pump is also connected to the bottom of the 1,3-butadiene concentration tower, the cold side medium outlet of the first tower bottom reboiler is divided into two paths, one of which is connected to the tower bottom of the 1,3-butadiene concentration tower, and the other is connected to the middle of the 1,2-butadiene product tower, the hot side medium inlet of the first tower top condenser is connected to the top of the 1,3-butadiene concentration tower, the hot side medium outlet of the first tower top condenser is connected to the first reflux tank, the first reflux tank is connected to the first reflux pump, and the outlet of the first reflux pump is divided into two paths, one of which is connected to the upper part of the 1,3-butadiene concentration tower, and the other is connected to the 1,3-butadiene concentration recovery tank for collecting 1,3-butadiene; Two distillation packing sections and one pasteurization section are arranged from bottom to top inside the 1,2-butadiene product tower. The cold side medium inlet of the second tower bottom reboiler is connected to the second tower bottom pump, and the second tower bottom pump is also connected to the bottom of the 1,2-butadiene product tower. The cold side medium outlet of the second tower bottom reboiler is divided into two paths, one of which is connected to the tower bottom of the 1,2-butadiene product tower, and the other is connected to a heavy component recovery tank for collecting heavy components. The hot side medium inlet of the second tower top condenser is connected to the top of the 1,2-butadiene product tower, and the hot side medium outlet of the second tower top condenser is connected to the second reflux tank. The second reflux tank is connected to the second reflux pump, and the outlet of the second reflux pump is divided into two paths, one of which is connected to the upper part of the 1,2-butadiene product tower, and the other is connected to the 1,2-butadiene product tank for collecting 1,2-butadiene.

[0008] Furthermore, the cold side medium inlet of the first tower top condenser and the second tower top condenser is connected to the external circulating cooling water supply pipeline, and the cold side medium outlet of the first tower top condenser and the second tower top condenser is connected to the external circulating cooling water return pipeline.

[0009] Furthermore, the hot side medium inlets of the first tower kettle reboiler and the second tower kettle reboiler are connected to the off-site condensate water supply pipeline, and the hot side medium outlets of the first tower kettle reboiler and the second tower kettle reboiler are connected to the off-site condensate water return pipeline.

[0010] Furthermore, a first stabilizer injection port is provided at the lower portion of the 1,3-butadiene concentration tower.

[0011] Furthermore, a second stabilizer injection port is provided at the lower portion of the 1,2-butadiene product tower.

[0012] Furthermore, a first nitrogen injection port is provided at the upper portion of the 1,3-butadiene concentration tower.

[0013] Furthermore, a second nitrogen injection port is provided at the upper portion of the 1,2-butadiene product tower.

[0014] Furthermore, the four sections of fillers of the 1,3-butadiene concentration tower are all supported by a corrugated first filler support plate, and a plurality of first air distribution holes are evenly arranged on the first filler support plate.

[0015] Preferably, the wave height on the first filler support plate is 100 mm, the aperture of the first air distribution holes is 3 mm, and the first air distribution holes are arranged in a regular triangle shape, with an opening rate between 35% and 42%.

[0016] Preferably, in the four sections of packing of the 1,3-butadiene concentration tower, each section of packing is 3 meters high, the number of theoretical plates per meter of packing is ≥ four, and high-efficiency wire mesh packing is used, with a wire diameter of not less than 0.6 mm, a minimum pore size of 0.6 mm, and an average pore size of ≥0.75 mm.

[0017] Furthermore, the two-stage packing of the 1,2-butadiene product tower both adopt a corrugated second packing support plate, and a plurality of second air distribution holes are evenly arranged on the second packing support plate.

[0018] Preferably, the wave height on the second filler support plate is 80 mm, the aperture of the second air distribution hole is 3.2 mm, and the second air distribution hole is arranged in a regular triangle shape, and the opening rate is between 40% and 50%. Preferably, each of the two sections of packing in the 1,2-butadiene product tower is 3 meters high, with a theoretical plate number of ≥ four per meter, and uses high-efficiency wire mesh packing with a wire diameter of not less than 0.6 mm, a minimum pore size of 0.5 mm, and an average pore size of ≥ 0.7 mm; the pasteurization section is 1.2 meters high, equivalent to four theoretical plates, and the pasteurization section uses regular plate corrugated packing.

[0019] In a second aspect, the present invention provides a 1,2-butadiene distillation preparation process, using the above-mentioned 1,2-butadiene distillation preparation device, comprising the following steps: (1) Light removal distillation: The heavy components of the butadiene extraction unit of the ethylene unit are used as raw materials and sent to the 1,3-butadiene concentration tower. After being heated in the first tower kettle pump, they are sent to the first tower kettle reboiler and refluxed into the 1,3-butadiene concentration tower kettle. The light components are extracted from the top of the 1,3-butadiene concentration tower, condensed in the first tower top condenser, and then sent to the first reflux tank. They are pumped by the first reflux pump, part of which is refluxed into the 1,3-butadiene concentration tower, and part of which is sent to the 1,3-butadiene concentration recovery tank for recovery of 1,3-butadiene concentrate. (2) Heavy removal distillation: The heavy components removed from the bottom of the 1,3-butadiene concentration tower are pumped into the first bottom reboiler for heating and then enter the 1,2-butadiene product tower. They are then heated in the second bottom reboiler and refluxed into the 1,2-butadiene product tower. After heavy removal distillation and pasteurization, the heavy components removed from the top of the 1,2-butadiene product tower are condensed in the second top condenser and enter the second reflux tank. They are pumped by the second reflux pump, with a portion of them refluxed into the 1,2-butadiene product tower and a portion of them sent to the 1,2-butadiene product tank. The heavy components removed from the bottom of the 1,2-butadiene product tower are pumped into the heavy component recovery tank via the second bottom reboiler. The recovered heavy components are used as fuel.

[0020] Furthermore, step (1) further includes the step of injecting a first stabilizer into the 1,3-butadiene concentration tower through a first stabilizer injection port.

[0021] Preferably, the first stabilizer is tributyl citrate (TBC) and 3,4-dimethylarylamine mixed in a mass ratio of 1:1.

[0022] Furthermore, step (1) further includes the step of controlling the top pressure of the 1,3-butadiene concentration tower by controlling the flow of supplementary nitrogen and circulating cooling water, wherein nitrogen is injected through a first nitrogen injection port, and circulating cooling water is circulated through an off-site circulating cooling water supply pipeline, a first tower top condenser and a return water pipeline.

[0023] Preferably, the top pressure of the 1,3-butadiene concentration tower is controlled in the range of 220 to 320 kPa.G.

[0024] Furthermore, in step (1), the bottom temperature of the 1,3-butadiene concentration tower is controlled at 60-65°C.

[0025] Furthermore, in step (1), the reflux ratio of the material pumped by the first reflux pump is controlled at 18-22.

[0026] Furthermore, step (2) further includes the step of injecting a second stabilizer into the 1,2-butadiene product tower through a second stabilizer injection port.

[0027] Preferably, the second stabilizer is tributyl citrate (TBC) and 3,4-dimethylarylamine mixed in a mass ratio of 1:1.

[0028] Furthermore, step (2) also includes the step of controlling the top pressure of the 1,2-butadiene product tower by controlling the flow of supplementary nitrogen and circulating cooling water, wherein nitrogen is injected through a second nitrogen injection port, and circulating cooling water is circulated through an off-site circulating cooling water supply pipeline, a second tower top condenser and a return water pipeline.

[0029] Preferably, the top pressure of the 1,2-butadiene product tower is controlled in the range of 200 to 300 kPa.G.

[0030] Furthermore, in step (2), the bottom temperature of the 1,2-butadiene product tower is controlled at 62-68°C.

[0031] Furthermore, in step (2), the reflux ratio of the material pumped by the second reflux pump is controlled at 25-30.

[0032] Compared with the prior art, the beneficial technical effects of the present invention are: 1. The present invention reuses the heavy components of the butadiene extraction unit of the ethylene device as raw materials to purify 1,2-butadiene products and recover 1,3-butadiene, which improves the overall resource utilization rate and is beneficial to enterprises in achieving energy conservation and emission reduction.

[0033] 2. The present invention adopts a continuous distillation method of first removing light components and then removing heavy components to purify 1,2-butadiene products, which can not only reduce the agglomeration of materials, but also improve the recovery rate of 1,3-butadiene and reduce the overall material consumption. After the heavy component removal distillation, pasteurization treatment is performed to obtain a 1,2-butadiene product with a purity of ≥97.5wt%. The yield of the 1,2-butadiene product is increased by 3.35%, and very few heavy components are finally discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a distillation preparation device for 1,2-butadiene of the present invention; Figure 2 for Figure 1 A three-dimensional view of the first filler support plate; Figure 3 for Figure 1 A front view of the first filler support plate; Figure 4 for Figure 1 A three-dimensional view of the second filler support plate; Figure numerals: 1, 1,3-butadiene concentration tower; 101, first packing support plate; 1011, first air distribution hole; 102, first stabilizer injection port; 103, first nitrogen injection port; 2, first tower bottom reboiler; 3, first tower bottom pump; 4, first tower top condenser; 5, first reflux tank; 6, first reflux pump; 7, 1,2-butadiene product tower; 701, second packing support plate; 7011, second air distribution hole; 702, pasteurization section; 703, second stabilizer injection port; 704, second nitrogen injection port; 8, second tower bottom reboiler; 9, second tower bottom pump; 10, second tower top condenser; 11, second reflux tank; 12, second reflux pump, 13, 1,3-butadiene concentration recovery tank; 14, heavy component recovery tank; 15, 1,2-butadiene product tank. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present patent. The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. It should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected, set, or detachably connected, set, or connected and set in one piece, it can be directly connected, it can also be indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0037] like Figure 1-4As shown, a 1,2-butadiene distillation preparation device provided in this embodiment includes a 1,3-butadiene concentration unit and a 1,2-butadiene product unit; the 1,3-butadiene concentration unit includes a 1,3-butadiene concentration tower 1, a first tower bottom reboiler 2, a first tower top condenser 4, and a first reflux tank 5; the 1,2-butadiene product unit includes a 1,2-butadiene product tower 7, a second tower bottom reboiler 8, a second tower top condenser 10, and a second reflux tank 11.

[0038] Specifically, the 1,3-butadiene concentration tower 1 is a four-stage packed distillation tower, a heavy component input pipeline of the butadiene extraction unit of the ethylene device is arranged in the middle of the 1,3-butadiene concentration tower 1, a first tower bottom pump 3 is connected to the cold side medium inlet of the first tower bottom reboiler 2, and the first tower bottom pump 3 is also connected to the bottom of the 1,3-butadiene concentration tower 1, and the cold side medium outlet of the first tower bottom reboiler 2 is divided into two paths, one of which is connected to the tower bottom of the 1,3-butadiene concentration tower 1, and the other is connected to the middle of the 1,2-butadiene product tower 7, the hot side medium inlet of the first tower top condenser 4 is connected to the top of the 1,3-butadiene concentration tower 1, and the hot side medium outlet of the first tower top condenser 4 is connected to the first reflux tank 5, and the first reflux tank 5 is connected to the first reflux pump 6, and the outlet of the first reflux pump 6 is divided into two paths, one of which is connected to the upper part of the 1,3-butadiene concentration tower 1, and the other is connected to the 1,3-butadiene concentration recovery tank 13 for collecting 1,3-butadiene; Specifically, two distillation packing sections and one pasteurization section 702 are arranged from bottom to top inside the 1,2-butadiene product tower 7, the cold side medium inlet of the second tower bottom reboiler 8 is connected to the second tower bottom pump 9, and the second tower bottom pump 9 is also connected to the bottom of the 1,2-butadiene product tower 7, the cold side medium outlet of the second tower bottom reboiler 8 is divided into two paths, one of which is connected to the tower bottom of the 1,2-butadiene product tower 7, and the other is connected to the heavy component recovery tank 14 for collecting heavy components, the hot side medium inlet of the second tower top condenser 10 is connected to the top of the 1,2-butadiene product tower 7, the hot side medium outlet of the second tower top condenser 10 is connected to the second reflux tank 11, the second reflux tank 11 is connected to the second reflux pump 12, and the outlet of the second reflux pump 12 is divided into two paths, one of which is connected to the upper part of the 1,2-butadiene product tower 7, and the other is connected to the 1,2-butadiene product tank 15 for collecting 1,2-butadiene.

[0039] Specifically, the cold side medium inlet of the first tower top condenser 4 and the second tower top condenser 10 is connected to the outside circulating cooling water supply pipeline, and the cold side medium outlet of the first tower top condenser 4 and the second tower top condenser 10 is connected to the outside circulating cooling water return pipeline; the hot side medium inlet of the first tower bottom reboiler 2 and the second tower bottom reboiler 8 is connected to the outside condensate water supply pipeline, and the hot side medium outlet of the first tower bottom reboiler 2 and the second tower bottom reboiler 8 is connected to the outside condensate water return pipeline.

[0040] Specifically, a first stabilizer injection port 102 is provided at the lower portion of the 1,3-butadiene concentration tower 1, a second stabilizer injection port 703 is provided at the lower portion of the 1,2-butadiene product tower 7, a first nitrogen injection port 103 is provided at the upper portion of the 1,3-butadiene concentration tower 1, and a second nitrogen injection port 704 is provided at the upper portion of the 1,2-butadiene product tower 7.

[0041] Specifically, the four-stage packing of the 1,3-butadiene concentration tower 1 is supported by a corrugated first packing support plate 101, and a plurality of first air distribution holes 1011 are evenly provided on the first packing support plate 101. The first packing support plate 101 has the functions of packing support and uniform air distribution.

[0042] In this embodiment, the wave height on the first filler support plate 101 is 100 mm, the aperture of the first air distribution hole 1011 is 3 mm, and the first air distribution hole 1011 is arranged in a regular triangle shape, with an opening rate between 35% and 42%; in the four sections of fillers of the 1,3-butadiene concentration tower 1, each section of fillers is 3 meters high, the number of theoretical plates per meter of fillers is ≥ four, and high-efficiency wire mesh fillers are used, with a wire diameter of not less than 0.6 mm, a minimum aperture of 0.6 mm, and an average aperture of ≥0.75 mm.

[0043] Specifically, the two-stage packing of the 1,2-butadiene product tower 7 both adopts a corrugated second packing support plate 701, and a plurality of second air distribution holes 7011 are evenly provided on the second packing support plate 701. The second packing support plate 701 has the functions of packing support and uniform air distribution.

[0044] In this embodiment, the wave height on the second filler support plate 701 is 80 mm, the aperture of the second air distribution hole 7011 is 3.2 mm, and the second air distribution holes 7011 are arranged in a regular triangle shape, with an opening rate between 40% and 50%; each of the two sections of fillers in the 1,2-butadiene product tower 7 is 3 meters high, and the theoretical plate number of each meter of filler is ≥ four. High-efficiency wire mesh fillers are used, with a wire diameter of not less than 0.6 mm, a minimum aperture of 0.5 mm, and an average aperture of ≥0.7 mm; the pasteurization section 702 is 1.2 meters high, equivalent to four theoretical plates, and the pasteurization section 702 uses regular plate corrugated fillers. Example 2

[0045] This embodiment provides a 1,2-butadiene distillation preparation process, using the 1,2-butadiene distillation preparation device of Example 1, comprising the following steps: (1) Light removal distillation: The heavy components of the butadiene extraction unit of the ethylene unit are used as raw materials and sent to the 1,3-butadiene concentration tower. After being heated in the first tower kettle pump, they are sent to the first tower kettle reboiler and refluxed into the 1,3-butadiene concentration tower kettle. The light components are extracted from the top of the 1,3-butadiene concentration tower, condensed in the first tower top condenser, and then sent to the first reflux tank. They are pumped by the first reflux pump, part of which is refluxed into the 1,3-butadiene concentration tower, and part of which is sent to the 1,3-butadiene concentration recovery tank for recovery of 1,3-butadiene concentrate. (2) Heavy removal distillation: The heavy components removed from the bottom of the 1,3-butadiene concentration tower are pumped into the first bottom reboiler for heating and then enter the 1,2-butadiene product tower. They are then heated in the second bottom reboiler and refluxed into the 1,2-butadiene product tower. After heavy removal distillation and pasteurization, the heavy components removed from the top of the 1,2-butadiene product tower are condensed in the second top condenser and enter the second reflux tank. They are pumped by the second reflux pump, with a portion of them refluxed into the 1,2-butadiene product tower and a portion of them sent to the 1,2-butadiene product tank. The heavy components removed from the bottom of the 1,2-butadiene product tower are pumped into the heavy component recovery tank via the second bottom reboiler. The recovered heavy components are used as fuel.

[0046] In this embodiment, during light removal distillation, a first stabilizer is injected into the 1,3-butadiene concentration tower through a first stabilizer injection port. The first stabilizer is a compound of tributyl citrate (TBC) and 3,4-dimethylaromatic amine in a mass ratio of 1:1.

[0047] In this embodiment, during the light removal distillation, the top pressure of the 1,3-butadiene concentration tower is also controlled by controlling the flow of supplementary nitrogen and circulating cooling water, nitrogen is injected through the first nitrogen injection port, and circulating cooling water is circulated through the outer circulating cooling water supply pipeline, the first top condenser and the return pipeline. The top pressure of the 1,3-butadiene concentration tower is controlled in the range of 220 to 320 kPa.G, the kettle temperature of the 1,3-butadiene concentration tower is controlled at 60 to 65°C, and the reflux ratio of the material pumped by the first reflux pump is controlled at 18 to 22.

[0048] In this embodiment, during the deheaving distillation, the second stabilizer is injected into the 1,2-butadiene product tower through the second stabilizer injection port, and the second stabilizer is a compound of tributyl citrate (TBC) and 3,4-dimethylaromatic amine in a mass ratio of 1:1.

[0049] In this embodiment, the top pressure of the 1,2-butadiene product tower is also controlled by controlling the flow of supplementary nitrogen and circulating cooling water during light distillation. Nitrogen is injected through the second nitrogen injection port, and circulating cooling water is circulated through the outer circulating cooling water supply pipeline, the second top condenser and the return pipeline. The top pressure of the 1,2-butadiene product tower is controlled in the range of 200 to 300 kPa.G. The reactor temperature of the 1,2-butadiene product tower is controlled at 62 to 68°C, and the reflux ratio of the material pumped by the second reflux pump is controlled at 25 to 30.

[0050] Comparative Example Different from Example 2, the 1,2-butadiene product tower is not provided with a pasteurization section and no pasteurization treatment is performed.

[0051] Application Examples The method of Example 2 was used to carry out an example operation. The results of the heavy component content and product component content of the butadiene extraction unit of the ethylene plant are shown in the table below.

[0052]

[0053] Test Example Effect of pasteurization on product purity and yield The example operation was carried out according to the method of Example 2 and the comparative example, and the purity and yield of the product before and after pasteurization were tested. The test results are shown in the following table.

[0054]

[0055] The above is a preferred embodiment of the present invention, which is used to explain the technical solution of the present invention in more detail, so that those skilled in the art can understand and use the present invention well. Those skilled in the art can also make routine modifications, equivalent substitutions and improvements within the spirit and principles of the present invention.

Claims

1. A 1,2-butadiene distillation preparation device, characterized in that: It includes a 1,3-butadiene concentration unit and a 1,2-butadiene product unit; the 1,3-butadiene concentration unit includes a 1,3-butadiene concentration tower, a first tower bottom reboiler, a first tower top condenser, and a first reflux tank; the 1,2-butadiene product unit includes a 1,2-butadiene product tower, a second tower bottom reboiler, a second tower top condenser, and a second reflux tank; The 1,3-butadiene concentration tower is a four-stage packed distillation tower, a heavy component input pipeline of the butadiene extraction unit of the ethylene device is arranged in the middle of the 1,3-butadiene concentration tower, a cold side medium inlet of the first tower bottom reboiler is connected to the first tower bottom pump, the first tower bottom pump is also connected to the bottom of the 1,3-butadiene concentration tower, the cold side medium outlet of the first tower bottom reboiler is divided into two paths, one of which is connected to the tower bottom of the 1,3-butadiene concentration tower, and the other is connected to the middle of the 1,2-butadiene product tower, the hot side medium inlet of the first tower top condenser is connected to the top of the 1,3-butadiene concentration tower, the hot side medium outlet of the first tower top condenser is connected to the first reflux tank, the first reflux tank is connected to the first reflux pump, and the outlet of the first reflux pump is divided into two paths, one of which is connected to the upper part of the 1,3-butadiene concentration tower, and the other is connected to the 1,3-butadiene concentration recovery tank for collecting 1,3-butadiene; Two distillation packing sections and one pasteurization section are arranged from bottom to top inside the 1,2-butadiene product tower. The cold side medium inlet of the second tower bottom reboiler is connected to the second tower bottom pump, and the second tower bottom pump is also connected to the bottom of the 1,2-butadiene product tower. The cold side medium outlet of the second tower bottom reboiler is divided into two paths, one of which is connected to the tower bottom of the 1,2-butadiene product tower, and the other is connected to a heavy component recovery tank for collecting heavy components. The hot side medium inlet of the second tower top condenser is connected to the top of the 1,2-butadiene product tower, and the hot side medium outlet of the second tower top condenser is connected to the second reflux tank. The second reflux tank is connected to the second reflux pump, and the outlet of the second reflux pump is divided into two paths, one of which is connected to the upper part of the 1,2-butadiene product tower, and the other is connected to the 1,2-butadiene product tank for collecting 1,2-butadiene.

2. A 1,2-butadiene distillation preparation device according to claim 1, characterized in that: The cold side medium inlet of the first tower top condenser and the second tower top condenser is connected to the outer circulating cooling water supply pipeline, and the cold side medium outlet of the first tower top condenser and the second tower top condenser is connected to the outer circulating cooling water return pipeline; The hot side medium inlets of the first tower kettle reboiler and the second tower kettle reboiler are connected to the out-of-boundary condensate water supply pipeline, and the hot side medium outlets of the first tower kettle reboiler and the second tower kettle reboiler are connected to the out-of-boundary condensate water return pipeline.

3. A 1,2-butadiene distillation preparation device according to claim 1, characterized in that: The lower part of the 1,3-butadiene concentration tower is provided with a first stabilizer injection port, the lower part of the 1,2-butadiene product tower is provided with a second stabilizer injection port, the upper part of the 1,3-butadiene concentration tower is provided with a first nitrogen injection port, and the upper part of the 1,2-butadiene product tower is provided with a second nitrogen injection port.

4. A 1,2-butadiene distillation preparation device according to claim 1, characterized in that: The four sections of packing of the 1,3-butadiene concentration tower are all supported by a corrugated first packing support plate, and a plurality of first air distribution holes are evenly arranged on the first packing support plate; the wave height on the first packing support plate is 100 mm, the aperture of the first air distribution hole is 3 mm, and the first air distribution holes are arranged in a regular triangle shape, and the opening rate is between 35% and 42%; among the four sections of packing of the 1,3-butadiene concentration tower, each section of packing is 3 meters high, the theoretical number of plates per meter of packing is ≥ four, and high-efficiency wire mesh packing is used, the wire diameter is not less than 0.6 mm, the minimum aperture is 0.6 mm, and the average aperture is ≥0.75 mm.

5. A 1,2-butadiene distillation preparation device according to claim 1, characterized in that: The two sections of packing of the 1,2-butadiene product tower both adopt a corrugated second packing support plate, and a plurality of second air distribution holes are evenly arranged on the second packing support plate; the wave height on the second packing support plate is 80 mm, the aperture of the second air distribution hole is 3.2 mm, and the second air distribution holes are arranged in a regular triangle shape, and the opening rate is between 40% and 50%; each section of the two sections of packing of the 1,2-butadiene product tower is 3 meters high, and the theoretical number of plates per meter of packing is ≥ four. High-efficiency wire mesh packing is adopted, and the wire diameter is not less than 0.6 mm, the minimum aperture is 0.5 mm, and the average aperture is ≥ 0.7 mm; the pasteurization section is 1.2 meters high, which is equivalent to four theoretical plates, and the pasteurization section adopts regular plate corrugated packing.

6. A 1,2-butadiene distillation preparation process, characterized in that: The 1,2-butadiene distillation preparation device according to any one of claims 1 to 5 comprises the following steps: (1) Light removal distillation: The heavy components of the butadiene extraction unit of the ethylene unit are used as raw materials and sent to the 1,3-butadiene concentration tower. After being heated in the first tower kettle pump, they are sent to the first tower kettle reboiler and refluxed into the 1,3-butadiene concentration tower kettle. The light components are extracted from the top of the 1,3-butadiene concentration tower, condensed in the first tower top condenser, and then sent to the first reflux tank. They are pumped by the first reflux pump, part of which is refluxed into the 1,3-butadiene concentration tower, and part of which is sent to the 1,3-butadiene concentration recovery tank for recovery of 1,3-butadiene concentrate. (2) Heavy removal distillation: The heavy components removed from the bottom of the 1,3-butadiene concentration tower are pumped into the first bottom reboiler for heating and then enter the 1,2-butadiene product tower. They are then heated in the second bottom reboiler and refluxed into the 1,2-butadiene product tower. After heavy removal distillation and pasteurization, the heavy components removed from the top of the 1,2-butadiene product tower are condensed in the second top condenser and enter the second reflux tank. They are pumped by the second reflux pump, with a portion of them refluxed into the 1,2-butadiene product tower and a portion of them sent to the 1,2-butadiene product tank. The heavy components removed from the bottom of the 1,2-butadiene product tower are pumped into the heavy component recovery tank via the second bottom reboiler. The recovered heavy components are used as fuel.

7. A 1,2-butadiene distillation preparation process according to claim 6, characterized in that: Step (1) further includes the step of injecting a first stabilizer into the 1,3-butadiene concentration tower through a first stabilizer injection port; the first stabilizer is a compound of tributyl citrate (TBC) and 3,4-dimethylarylamine in a mass ratio of 1:1; Step (2) further includes the step of injecting a second stabilizer into the 1,2-butadiene product tower through a second stabilizer injection port; the second stabilizer is a compound of tributyl citrate (TBC) and 3,4-dimethylaromatic amine in a mass ratio of 1:

1.

8. A 1,2-butadiene distillation preparation process according to claim 6, characterized in that: Step (1) further includes the step of controlling the top pressure of the 1,3-butadiene concentration tower by controlling the flow of supplementary nitrogen and circulating cooling water, wherein nitrogen is injected through a first nitrogen injection port, and circulating cooling water is circulated through an off-site circulating cooling water supply pipeline, a first tower top condenser, and a return water pipeline; Step (2) also includes the step of controlling the top pressure of the 1,2-butadiene product tower by controlling the flow of supplementary nitrogen and circulating cooling water, wherein nitrogen is injected through a second nitrogen injection port, and circulating cooling water is circulated through an off-site circulating cooling water supply pipeline, a second tower top condenser and a return water pipeline.

9. A 1,2-butadiene distillation preparation process according to claim 8, characterized in that: The top pressure of the 1,3-butadiene concentration tower is controlled in the range of 220-320 kPa.G, the kettle temperature of the 1,3-butadiene concentration tower is controlled in the range of 60-65°C, and the reflux ratio of the material pumped by the first reflux pump is controlled in the range of 18-22.

10. A 1,2-butadiene distillation preparation process according to claim 8, characterized in that: The top pressure of the 1,2-butadiene product tower is controlled in the range of 200-300 kPa.G, the kettle temperature of the 1,2-butadiene product tower is controlled in the range of 62-68°C, and the reflux ratio of the material pumped by the second reflux pump is controlled in the range of 25-30.

Images