Industrial chain production system and method of 2, 2 '-dipyridyl
The hydrogen is purified through a multi-stage hollow fiber degassing film and a pressure-switching adsorption purification device, and recycled hydrogen for catalyst reduction, which solves the problem of short catalyst activity, improves the production efficiency and cost-effectiveness of 2,2'-bipyridine, and forms a A complete industrial chain.
Patent Information
- Application Number
- CN202411414235.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-01-10
AI Technical Summary
During the existing 2,2’-bipyridine production process, the activity of the catalyst is maintained for a short time and needs to be replaced frequently, resulting in low production efficiency of the industrial chain and high cost of reducing high-purity hydrogen.
The multi-stage hollow fiber degassing film and pressure swing adsorption purification device are used to purify hydrogen through partial pressure difference and multi-layer structure of the composite adsorption bed, and recycle hydrogen for catalyst reduction, extending the active life of the catalyst.
High purification of hydrogen and long-term maintenance of catalyst activity have been achieved, production costs and equipment investment have been reduced, and a complete industrial chain has been formed.
Smart Images
Figure CN119285534A_ABST
Abstract
Description
Technical Field
[0001] The invention discloses an industrial chain production system and method for 2,2'-bipyridine, and relates to the technical field of chemical synthesis. Background Art
[0002] 2,2'-Bipyridine is one of the isomers of bipyridine and an important organic synthesis intermediate. It is mainly used in pharmaceutical intermediates and organic synthesis. It is also a widely used chelating agent and coating additive in dye production, pesticide production and fragrances.
[0003] At present, 2,2'-bipyridine is usually produced by hydrogen reduction of nickel-based catalysts and then pyridine coupling to prepare 2,2'-bipyridine. However, the reduction of the catalyst requires a large amount of high-purity hydrogen for a long time to reduce and activate the activity of the catalyst. At the same time, the activity of the catalyst is short-lived and needs to be replaced frequently. This process is not conducive to industrial chain production. Summary of the invention
[0004] In view of the problems of the prior art, the present invention provides an industrial chain production system and method for 2,2'-bipyridine. The specific solution proposed by the present invention is:
[0005] A method for producing 2,2'-bipyridine in an industrial chain, comprising:
[0006] Step 1: Formaldehyde preparation: Methanol is oxidized in a formaldehyde production system to prepare a formaldehyde mixed gas, the formaldehyde mixed gas is treated and then sent to a hydrogen treatment system, and hydrogen is purified through a multi-stage hollow fiber degassing membrane in the hydrogen treatment system, wherein the formaldehyde mixed gas first passes through a hollow fiber degassing membrane with a membrane pore size between 0.25-0.35nm, and hydrogen and nitrogen are permeated out by using the partial pressure difference on both sides of the hollow fiber degassing membrane, and a residual gas containing formaldehyde gas is obtained, and then hydrogen and nitrogen are permeated through a hollow fiber degassing membrane with a membrane pore size of less than 0.25nm to complete hydrogen purification.
[0007] The purified hydrogen is sent to a hydrogen buffer tank, and the residual gas containing formaldehyde gas is sent to a pressure swing adsorption purification device to remove impurities to obtain formaldehyde gas, and the formaldehyde gas is sent to a pyridine production system, wherein the pressure swing adsorption purification device is layered with a composite adsorption bed, a zeolite molecular sieve adsorbent containing crystalline metasilicate containing alkaline earth elements is filled at the bottom of the composite adsorption bed, a silica gel adsorbent is filled in the middle of the composite adsorption bed, and activated alumina is filled in the upper part of the composite adsorption bed, and the residual gas passes through the bottom, middle and upper parts of the composite adsorption bed in turn to remove impurities from the formaldehyde gas.
[0008] Step 2: Preparation of pyridine: In the pyridine production system, acetaldehyde gas and formaldehyde gas are preheated and reacted with ammonia gas to obtain pyridine, which is then fed into the 2,2'-bipyridine production system.
[0009] Step 3: Preparation of 2,2'-bipyridine: In the 2,2'-bipyridine production system, 2,2'-bipyridine is prepared by pyridine reaction under the action of a catalyst to obtain a crude product and hydrogen. The hydrogen is purified by a multi-stage hollow fiber degassing membrane of a hydrogen treatment system and then sent to a hydrogen buffer tank. The crude material is condensed, distilled, and melt crystallized to obtain the target product 2,2'-bipyridine.
[0010] At the same time, hydrogen reduction is used to prepare the catalyst for 2,2'-bipyridine: the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged and then sent to the 2,2'-bipyridine production system containing the catalyst, the catalyst is reduced, and the hydrogen is recovered and sent back to the hydrogen treatment system, and then purified by a multi-stage hollow fiber degassing membrane for recycling.
[0011] Furthermore, in the industrial chain production method of 2,2'-bipyridine, in step 1, methanol is pressurized and pumped into the formaldehyde production system, and the heat of the hydrogen in the catalyst reduction section of the 2,2'-bipyridine production system is used to exchange heat with the methanol, and after the methanol is gasified, the methanol is sent to a fixed bed reactor equipped with a catalyst according to the production volume requirement, and countercurrently contacts the catalyst bed to carry out oxidation and dehydrogenation reactions of the methanol, and the generated formaldehyde mixed gas is pressurized, cooled, and subjected to gas-liquid separation before being sent to a hydrogen treatment system.
[0012] Furthermore, in the industrial chain production method of 2,2'-bipyridine, in step 1, methanol is fed into a 520-580°C fixed bed reactor containing a catalyst, countercurrently contacting the catalyst bed to carry out oxidation and dehydrogenation reactions of methanol, and the ratio of methanol gas to oxygen is 3-6:1.
[0013] Furthermore, in the industrial chain production method of 2,2'-bipyridine, in step 1, methanol is fed into a 530-570°C fixed bed reactor containing a catalyst, countercurrently contacting the catalyst bed to carry out oxidation and dehydrogenation reactions of methanol, and the ratio of methanol gas to oxygen is 4-5:1.
[0014] Furthermore, in the industrial chain production method of 2,2'-bipyridine, the hollow fiber degassing membrane material in step 1 is preferably polyimide, cellulose acetate, or polysulfone resin.
[0015] Furthermore, in the industrial chain production method of 2,2'-bipyridine, the ratio of the adsorbent loading amount in the bottom, middle and upper parts of the composite adsorption bed in step 1 is 3:1:1.
[0016] Furthermore, in the industrial chain production method of 2,2'-bipyridine, in step 3, the heat of hydrogen in the catalyst reduction section of the 2,2'-bipyridine production system is used to exchange heat with pyridine from the pyridine production system. Under the conditions of a pressure of 0.8-1.2 MPa, an air velocity of 0.5-1 h-1, and a reaction temperature of 160-240°C, pyridine is contacted with the catalyst for a coupling reaction to prepare 2,2'-bipyridine. After condensation, the reaction liquid is separated into light components and heavy components by a crude distillation tower. The light components enter a distillation tower group to recover pyridine, and the heavy components enter a melt crystallizer for crystallization and sweating purification to obtain 2,2-bipyridine.
[0017] Furthermore, in the industrial chain production method of 2,2'-bipyridine, in step 3, the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged, and then passed through a flow meter at a volume space velocity of 300-1000h -1 The catalyst is sent to a 2,2'-bipyridine production system to reduce the catalyst.
[0018] The present invention also provides an industrial chain production system of 2,2'-bipyridine, including a formaldehyde production system, a hydrogen treatment system, a pyridine production system, a 2,2'-bipyridine production system, a hydrogen buffer tank and a pressure swing adsorption purification device.
[0019] When preparing formaldehyde, a formaldehyde production system is used to oxidize methanol to prepare a formaldehyde mixed gas, and the formaldehyde mixed gas is treated and sent to a hydrogen treatment system, where the hydrogen is purified by a multi-stage hollow fiber degassing membrane in the hydrogen treatment system, wherein the formaldehyde mixed gas first passes through a hollow fiber degassing membrane with a membrane pore size between 0.25-0.35nm, and hydrogen and nitrogen are permeated out by using the partial pressure difference on both sides of the hollow fiber degassing membrane, and a residual gas containing formaldehyde gas is obtained, and then the hydrogen and nitrogen are permeated through a hollow fiber degassing membrane with a membrane pore size of less than 0.25nm to complete the hydrogen purification.
[0020] The purified hydrogen is sent to a hydrogen buffer tank, and the residual gas containing formaldehyde gas is sent to a pressure swing adsorption purification device to remove impurities to obtain formaldehyde gas, and the formaldehyde gas is sent to a pyridine production system, wherein the pressure swing adsorption purification device is layered with a composite adsorption bed, a zeolite molecular sieve adsorbent containing crystalline metasilicate containing alkaline earth elements is filled at the bottom of the composite adsorption bed, a silica gel adsorbent is filled in the middle of the composite adsorption bed, and activated alumina is filled in the upper part of the composite adsorption bed, and the residual gas passes through the bottom, middle and upper parts of the composite adsorption bed in turn to remove impurities from the formaldehyde gas.
[0021] When preparing pyridine, acetaldehyde gas and formaldehyde gas are preheated in the pyridine production system and then reacted with ammonia gas to obtain pyridine, which is then fed into the 2,2'-bipyridine production system.
[0022] When preparing 2,2'-bipyridine, a pyridine reaction is used to prepare 2,2'-bipyridine in a 2,2'-bipyridine production system under the action of a catalyst to obtain a crude product and hydrogen. The hydrogen is purified by a multi-stage hollow fiber degassing membrane of a hydrogen treatment system and then sent to a hydrogen buffer tank. The crude material is condensed, distilled, and melt crystallized to obtain the target product 2,2'-bipyridine.
[0023] At the same time, when hydrogen is used to reduce the catalyst for preparing 2,2'-bipyridine, the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged and then sent to the 2,2'-bipyridine production system containing the catalyst to reduce the catalyst, and the recovered hydrogen is sent back to the hydrogen treatment system for recycling after purification by a multi-stage hollow fiber degassing membrane.
[0024] The benefits of the present invention are:
[0025] The hydrogen produced in the methanol production formaldehyde section and the by-product hydrogen produced in the bipyridine production section are recycled and utilized. The hydrogen is highly purified through a multi-stage hollow fiber degassing membrane. At the same time, the formaldehyde gas is removed by a pressure swing adsorption purification device to provide raw materials for downstream production, which not only saves equipment investment, but also reduces production costs.
[0026] At the same time, it can circulate hydrogen to the catalyst reduction section to ensure the activity of the catalyst.
[0027] In summary, the present invention uses industrialized and cheap methanol as raw material to directly extend downstream formaldehyde to prepare pyridine with acetaldehyde, wherein formaldehyde and pyridine can be sold as mature products, and pyridine can also be extended to prepare 2,2'-bipyridine, ensuring the formation of a complete industrial chain. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a schematic diagram of the process flow of the method of the present invention.
[0029] Figure 2 The present invention is a schematic diagram of purifying hydrogen by using a multi-stage hollow fiber degassing membrane.
[0030] Figure 3 The present invention is a schematic diagram of a composite adsorption bed filler in a pressure swing adsorption purification device. DETAILED DESCRIPTION
[0031] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.
[0032] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.
[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0034] Example 1
[0035] The present invention provides an industrial chain production method for 2,2'-bipyridine, comprising:
[0036] Step 1: Formaldehyde preparation: Methanol is oxidized in a formaldehyde production system to prepare a formaldehyde mixed gas. In the specific implementation, methanol can be pumped into the formaldehyde production system under pressure, and the heat of hydrogen in the catalyst reduction section of the 2,2'bipyridine production system is used to exchange heat with methanol. After methanol is gasified, methanol and air are sent to a fixed bed reactor equipped with a catalyst through a flame arrester according to production requirements. The temperature of the fixed bed reactor is adjusted to 520-580°C, preferably 530-570°C, so that methanol gas and air are countercurrently contacted with the catalyst bed to carry out oxidation and dehydrogenation reactions of methanol. The ratio of methanol gas to oxygen is 3-6:1, preferably 4-5:1. After the formaldehyde mixed gas is generated, the formaldehyde mixed gas is pressurized, cooled, and subjected to gas-liquid separation before being sent to a hydrogen treatment system.
[0037] After the formaldehyde mixed gas is treated, it is sent to the hydrogen treatment system, and the hydrogen is purified by the multi-stage hollow fiber degassing membrane in the hydrogen treatment system. The hollow fiber degassing membrane can use the pressure of the mixed gas itself and the dense skin layer of the degassing membrane to achieve air permeability and liquid impermeability. The partial pressure difference on both sides of the membrane is used as the driving force to separate and obtain high-concentration hydrogen. The hollow fiber degassing membrane material is preferably polyimide, cellulose acetate, polysulfone resin and other materials. Figure 2The formaldehyde mixed gas as the raw gas first passes through the hollow fiber degassing membrane with a membrane pore size between 0.25-0.35nm, and the partial pressure difference on both sides of the hollow fiber degassing membrane is used to permeate hydrogen and nitrogen, and the residual gas containing formaldehyde gas is obtained, and then the hydrogen and nitrogen are passed through the hollow fiber degassing membrane with a membrane pore size of less than 0.25nm to permeate hydrogen, completing the hydrogen purification.
[0038] The purified hydrogen is sent to a hydrogen buffer tank, and the residual gas containing formaldehyde is sent to a pressure swing adsorption purification device to remove impurities to obtain dry formaldehyde gas with a content of not less than 98%. The formaldehyde gas is sent to a pyridine production system, wherein the residual gas passes through the bottom, middle and upper parts of the composite adsorption bed in turn to remove impurities of the formaldehyde gas. The composite adsorption bed is layered in the pressure swing adsorption purification device, and combined with Figure 3 , a zeolite molecular sieve adsorbent containing alkaline earth elements and crystalline metasilicate is loaded at the bottom of the composite adsorption bed to preferentially adsorb impurity gases such as CO, CH4, N2, and O2, a silica gel adsorbent is loaded in the middle of the composite adsorption bed to remove moisture again and remove the remaining hydrocarbons and CO2 and other components, and activated alumina is loaded on the top of the composite adsorption bed, mainly for gas drying. The adsorbent loading ratio of the bottom, middle, and top of the composite adsorption bed is adjusted according to the implementation in (1-4):1:1, for example, it can be 1:1:1, 3:1:1, 4:1:1, etc.
[0039] Step 2: Preparation of pyridine: In the pyridine production system, acetaldehyde gas and formaldehyde gas are preheated and reacted with ammonia gas to obtain pyridine, which is then fed into the 2,2'-bipyridine production system.
[0040] Step 3: Preparation of 2,2'-bipyridine: In the 2,2'-bipyridine production system, 2,2'-bipyridine is prepared by pyridine reaction under the action of a catalyst to obtain a crude product and hydrogen. The hydrogen is purified by a multi-stage hollow fiber degassing membrane of a hydrogen treatment system and then sent to a hydrogen buffer tank. The crude material is condensed, distilled, and melt crystallized to obtain the target product 2,2'-bipyridine. The heat of the hydrogen in the catalyst reduction section of the 2,2'-bipyridine production system can be used to exchange heat with the pyridine from the pyridine production system. Under the conditions of a pressure of 0.8-1.2 MPa, an air velocity of 0.5-1 h-1, and a reaction temperature of 160-240°C, pyridine is contacted with a catalyst for a coupling reaction to prepare 2,2'-bipyridine. After condensation, the reaction liquid is separated into light components and heavy components by a crude distillation tower. The light components enter the distillation tower group to recover pyridine, and the heavy components enter the melt crystallizer for crystallization and sweating purification to obtain 2,2-bipyridine.
[0041] At the same time, the catalyst for preparing 2,2' bipyridine by hydrogen reduction is: the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged, and then sent to the 2,2' bipyridine production system containing the catalyst, the catalyst is reduced, and the recovered hydrogen is sent back to the hydrogen treatment system, and then purified by a multi-stage hollow fiber degassing membrane for recycling. The hydrogen in the hydrogen buffer tank can be pressurized and heat-exchanged, and then passed through a flow meter at a volume space velocity of 300-1000h -1 The catalyst is sent to a 2,2'-bipyridine production system to reduce the catalyst.
[0042] Example 2
[0043] The present invention also provides an industrial chain production system of 2,2'-bipyridine, including a formaldehyde production system, a hydrogen treatment system, a pyridine production system, a 2,2'-bipyridine production system, a hydrogen buffer tank and a pressure swing adsorption purification device.
[0044] When preparing formaldehyde, a formaldehyde production system is used to oxidize methanol to prepare a formaldehyde mixed gas, and the formaldehyde mixed gas is treated and sent to a hydrogen treatment system, where the hydrogen is purified by a multi-stage hollow fiber degassing membrane in the hydrogen treatment system, wherein the formaldehyde mixed gas first passes through a hollow fiber degassing membrane with a membrane pore size between 0.25-0.35nm, and hydrogen and nitrogen are permeated out by using the partial pressure difference on both sides of the hollow fiber degassing membrane, and a residual gas containing formaldehyde gas is obtained, and then the hydrogen and nitrogen are permeated through a hollow fiber degassing membrane with a membrane pore size of less than 0.25nm to complete the hydrogen purification.
[0045] The purified hydrogen is sent to a hydrogen buffer tank, and the residual gas containing formaldehyde gas is sent to a pressure swing adsorption purification device to remove impurities to obtain formaldehyde gas, and the formaldehyde gas is sent to a pyridine production system, wherein the pressure swing adsorption purification device is layered with a composite adsorption bed, a zeolite molecular sieve adsorbent containing crystalline metasilicate containing alkaline earth elements is filled at the bottom of the composite adsorption bed, a silica gel adsorbent is filled in the middle of the composite adsorption bed, and activated alumina is filled in the upper part of the composite adsorption bed, and the residual gas passes through the bottom, middle and upper parts of the composite adsorption bed in turn to remove impurities from the formaldehyde gas.
[0046] When preparing pyridine, acetaldehyde gas and formaldehyde gas are preheated in the pyridine production system and then reacted with ammonia gas to obtain pyridine, which is then fed into the 2,2'-bipyridine production system.
[0047] When preparing 2,2'-bipyridine, a pyridine reaction is used to prepare 2,2'-bipyridine in a 2,2'-bipyridine production system under the action of a catalyst to obtain a crude product and hydrogen. The hydrogen is purified by a multi-stage hollow fiber degassing membrane of a hydrogen treatment system and then sent to a hydrogen buffer tank. The crude material is condensed, distilled, and melt crystallized to obtain the target product 2,2'-bipyridine.
[0048] At the same time, when hydrogen is used to reduce the catalyst for preparing 2,2'-bipyridine, the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged and then sent to the 2,2'-bipyridine production system containing the catalyst to reduce the catalyst, and the recovered hydrogen is sent back to the hydrogen treatment system for recycling after purification by a multi-stage hollow fiber degassing membrane.
[0049] The above-mentioned contents such as material transmission or reaction process between subsystems in the system of the present invention are based on the same concept as the embodiment of the method of the present invention. For specific contents, please refer to the description in the embodiment of the method of the present invention, and will not be repeated here.
[0050] Similarly, the system of the present invention recycles hydrogen produced in the formaldehyde section of methanol production and by-product hydrogen produced in the bipyridine production section, and mainly purifies hydrogen to a high degree through a multi-stage hollow fiber degassing membrane, and simultaneously uses a pressure swing adsorption purification device to remove impurities from formaldehyde gas, thereby providing raw materials for downstream production, which not only saves equipment investment, but also reduces production costs.
[0051] At the same time, it can circulate hydrogen to the catalyst reduction section to ensure the activity of the catalyst.
[0052] In summary, the system of the present invention utilizes industrialized and cheap methanol as raw material, directly extends downstream formaldehyde, and prepares pyridine with acetaldehyde, wherein formaldehyde and pyridine can be sold as mature products, and pyridine can also be extended to prepare 2,2'-bipyridine, ensuring the formation of a complete industrial chain.
[0053] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.
Claims
1. A method for producing an industrial chain of 2,2'-bipyridine, characterized in that include: Step 1: Formaldehyde preparation: Methanol is oxidized in a formaldehyde production system to prepare a formaldehyde mixed gas, the formaldehyde mixed gas is treated and then sent to a hydrogen treatment system, and hydrogen is purified through a multi-stage hollow fiber degassing membrane in the hydrogen treatment system, wherein the formaldehyde mixed gas first passes through a hollow fiber degassing membrane with a membrane pore size between 0.25-0.35nm, and hydrogen and nitrogen are permeated out by using the partial pressure difference on both sides of the hollow fiber degassing membrane, and a residual gas containing formaldehyde gas is obtained, and then hydrogen and nitrogen are permeated through a hollow fiber degassing membrane with a membrane pore size of less than 0.25nm to complete hydrogen purification. The purified hydrogen is sent to a hydrogen buffer tank, and the residual gas containing formaldehyde gas is sent to a pressure swing adsorption purification device to remove impurities to obtain formaldehyde gas, and the formaldehyde gas is sent to a pyridine production system, wherein the pressure swing adsorption purification device is layered with a composite adsorption bed, a zeolite molecular sieve adsorbent containing crystalline metasilicate containing alkaline earth elements is filled at the bottom of the composite adsorption bed, a silica gel adsorbent is filled in the middle of the composite adsorption bed, and activated alumina is filled in the upper part of the composite adsorption bed, and the residual gas passes through the bottom, middle and upper parts of the composite adsorption bed in turn to remove impurities from the formaldehyde gas. Step 2: Preparation of pyridine: In the pyridine production system, acetaldehyde gas and formaldehyde gas are preheated and reacted with ammonia gas to obtain pyridine, which is then fed into the 2,2'-bipyridine production system. Step 3: Preparation of 2,2'-bipyridine: In the 2,2'-bipyridine production system, 2,2'-bipyridine is prepared by pyridine reaction under the action of a catalyst to obtain a crude product and hydrogen. The hydrogen is purified by a multi-stage hollow fiber degassing membrane of a hydrogen treatment system and then sent to a hydrogen buffer tank. The crude material is condensed, distilled, and melt crystallized to obtain the target product 2,2'-bipyridine. At the same time, hydrogen reduction is used to prepare the catalyst for 2,2'-bipyridine: the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged and then sent to the 2,2'-bipyridine production system containing the catalyst, the catalyst is reduced, and the hydrogen is recovered and sent back to the hydrogen treatment system, and then purified by a multi-stage hollow fiber degassing membrane for recycling.
2. The industrial chain production method of 2,2'-bipyridine according to claim 1 is characterized in that in step 1, methanol is pumped into the formaldehyde production system under pressure, and the heat of the hydrogen in the catalyst reduction section of the 2,2'-bipyridine production system is used to exchange heat with the methanol, and after the methanol is gasified, the methanol is sent to a fixed bed reactor equipped with a catalyst according to the production volume requirement, and countercurrently contacts the catalyst bed to carry out oxidation and dehydrogenation reactions of the methanol, and the generated formaldehyde mixed gas is pressurized, cooled, and subjected to gas-liquid separation before being sent to a hydrogen treatment system.
3. The industrial chain production method of 2,2'-bipyridine according to claim 2 is characterized in that in step 1, methanol is fed into a 520-580°C fixed bed reactor containing a catalyst, countercurrently contacts the catalyst bed to carry out oxidation and dehydrogenation reactions of methanol, and the ratio of methanol gas to oxygen is 3-6:
1.
4. The industrial chain production method of 2,2'-bipyridine according to claim 3 is characterized in that in step 1, methanol is fed into a 530-570°C fixed bed reactor equipped with a catalyst, countercurrently contacts the catalyst bed to carry out oxidation and dehydrogenation reactions of methanol, and the ratio of methanol gas to oxygen is 4-5:
1.
5. The industrial chain production method of 2,2'-bipyridine according to claim 1, characterized in that In step 1, the hollow fiber degassing membrane material is preferably polyimide, cellulose acetate, or polysulfone resin.
6. The industrial chain production method of 2,2'-bipyridine according to claim 1, characterized in that the adsorbent loading ratio of the bottom, middle and upper parts of the composite adsorption bed in step 1 is (1-4):1:
1.
7. The industrial chain production method of 2,2'-bipyridine according to claim 1, characterized in that In step 3, the heat of hydrogen in the catalyst reduction section of the 2,2'-bipyridine production system is used to exchange heat with pyridine from the pyridine production system. Under the conditions of a pressure of 0.8-1.2 MPa, an air velocity of 0.5-1 h-1, and a reaction temperature of 160-240° C., pyridine is contacted with the catalyst for a coupling reaction to prepare 2,2'-bipyridine. After condensation, the reaction liquid is separated into light components and heavy components by a crude distillation tower. The light components enter a distillation tower group to recover pyridine, and the heavy components enter a melt crystallizer for crystallization and sweating purification to obtain 2,2-bipyridine.
8. The industrial chain production method of 2,2'-bipyridine according to claim 1, characterized in that in step 3, the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged, and then passed through a flow meter at a volume space velocity of 300-1000h -1 The catalyst is sent to a 2,2'-bipyridine production system to reduce the catalyst.
9. A 2,2'-bipyridine industrial chain production system, characterized by It includes formaldehyde production system, hydrogen processing system, pyridine production system, 2,2' bipyridine production system, hydrogen buffer tank and pressure swing adsorption purification device. When preparing formaldehyde, a formaldehyde production system is used to oxidize methanol to prepare a formaldehyde mixed gas, and the formaldehyde mixed gas is treated and sent to a hydrogen treatment system, where the hydrogen is purified by a multi-stage hollow fiber degassing membrane in the hydrogen treatment system, wherein the formaldehyde mixed gas first passes through a hollow fiber degassing membrane with a membrane pore size between 0.25-0.35nm, and hydrogen and nitrogen are permeated out by using the partial pressure difference on both sides of the hollow fiber degassing membrane, and a residual gas containing formaldehyde gas is obtained, and then the hydrogen and nitrogen are permeated through a hollow fiber degassing membrane with a membrane pore size of less than 0.25nm to complete the hydrogen purification. The purified hydrogen is sent to a hydrogen buffer tank, and the residual gas containing formaldehyde gas is sent to a pressure swing adsorption purification device to remove impurities to obtain formaldehyde gas, and the formaldehyde gas is sent to a pyridine production system, wherein the pressure swing adsorption purification device is layered with a composite adsorption bed, a zeolite molecular sieve adsorbent containing crystalline metasilicate containing alkaline earth elements is filled at the bottom of the composite adsorption bed, a silica gel adsorbent is filled in the middle of the composite adsorption bed, and activated alumina is filled in the upper part of the composite adsorption bed, and the residual gas passes through the bottom, middle and upper parts of the composite adsorption bed in turn to remove impurities from the formaldehyde gas. When preparing pyridine, acetaldehyde gas and formaldehyde gas are preheated in the pyridine production system and then reacted with ammonia gas to obtain pyridine, which is then fed into the 2,2'-bipyridine production system. When preparing 2,2'-bipyridine, a pyridine reaction is used to prepare 2,2'-bipyridine in a 2,2'-bipyridine production system under the action of a catalyst to obtain a crude product and hydrogen. The hydrogen is purified by a multi-stage hollow fiber degassing membrane of a hydrogen treatment system and then sent to a hydrogen buffer tank. The crude material is condensed, distilled, and melt crystallized to obtain the target product 2,2'-bipyridine. At the same time, when hydrogen is used to reduce the catalyst for preparing 2,2'-bipyridine, the hydrogen in the hydrogen buffer tank is pressurized and heat-exchanged and then sent to the 2,2'-bipyridine production system containing the catalyst to reduce the catalyst, and the recovered hydrogen is sent back to the hydrogen treatment system for recycling after purification by a multi-stage hollow fiber degassing membrane.