Two-stage coal-to-ethylene glycol hydrogenation reactor and use method thereof

Abstract

The invention provides a two-stage coal-to-ethylene glycol hydrogenation reactor and a use method thereof, and relates to the technical field of chemical production. A traditional tubular reactor has the problems of short service life caused by coking of an upper-layer catalyst, activity waste of a lower-layer catalyst and the like. According to the scheme, a two-section tubular reactor is adopted, the material is 304, the inner diameter phi is 38, the upper part of the reactor is a first reactor section, the lower part of the reactor is a second reactor section, and a mixed gas distributor is arranged between the first reactor section and the second reactor section. And the reactor first section and the reactor second section are designed to be two-section type cooling water feeding design of cooling water feeding and cooling water returning. The upper and lower two-section feeding and two-section cooling design can adjust the feeding amount according to working conditions, slow down coking at the upper part of a bed layer, prolong the service life of a catalyst, fully utilize the activity of the catalyst at the lower section, improve the heat exchange effect, guarantee safe operation, effectively optimize the reaction process and conditions, and improve the efficiency and economical efficiency of the coal-to-ethylene glycol hydrogenation process.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and specifically relates to a two-stage coal-to-ethylene glycol hydrogenation reactor and a use method thereof. Background Art

[0002] As an important chemical production technology, coal-to-ethylene glycol process plays an important role in the current energy and chemical industry. Its process flow and reaction principle are summarized as follows: Fresh hydrogen and liquid dimethyl oxalate are vaporized and mixed in the DMO evaporation tower and then enter the hydrogenation reactor to react and generate ethylene glycol and methanol under the action of a Cu-based catalyst.

[0003] The first step of the hydrogenation reaction: (COOCH3)2+2H2——HOCH2COOCH3+CH3OH (1) The second step of hydrogenation reaction: HCH2COOCH3+2H2——HOCH2CH2OH+CH3OH (2) (1) + (2) Overall reaction equation: (COOCH3)2+4H2——HOCH2CH2OH+2CH3OH (3) (3) Further hydrogenation main side reaction formula: HOCH2CH2OH+H2——CH3CH2OH+H2O (4) (4) The reaction formula is converted into dimethyl oxalate, and the reaction formula is: (COOCH3)2+5H2——CH3CH2OH+ 2CH3OH+ H2O (5) Ethanol and ethylene glycol undergo a carbonization reaction: HOCH2CH2OH+CH3CH2OH——HOCH2CHOHCH2CH3+H2O (6) Ethylene glycol is a basic chemical raw material widely used in many fields such as polyester fiber, antifreeze, and plastics. With the continuous growth of market demand for ethylene glycol, coal-to-ethylene glycol technology has been widely studied and applied in my country due to its advantage of abundant raw material coal resources. In the coal-to-ethylene glycol process, dimethyl oxalate (DMO) is first used as a key intermediate product for hydrogenation reaction to produce ethylene glycol. The process usually involves the mixing of fresh hydrogen and liquid dimethyl oxalate, which are first vaporized and mixed in the DMO evaporation tower to form a uniform mixed gas before entering the hydrogenation reactor for reaction. In the existing coal-to-ethylene glycol hydrogenation process, the generally short catalyst life is a prominent problem. The average catalyst life of products from different process packages and different catalyst manufacturers is about 12 months. In some cases where the operation is poor, the catalyst life is only 6 months, and even in units with better operation, the catalyst life can only reach 18 months. The main reason for the short catalyst life is that the upper catalyst of the shell-and-tube reactor is prone to coking. As the reaction proceeds, the reactor pressure difference gradually rises, which seriously affects the effective space velocity of the catalyst bed, causing the residence time and distribution of the reaction materials in the catalyst bed to change, thereby affecting the reaction effect. Moreover, the coking situation will become more serious as the operation time increases. When the coking reaches a certain level, the reactor cannot meet the normal reaction requirements and must be loaded down or even replaced with a catalyst. For those cases where the operation is good and the catalyst life can reach more than 12 months, there are also obvious problems. Although the overall catalyst operation time is acceptable, the upper catalyst of the reactor is seriously coked, while the activity of the lower catalyst can still meet the reaction requirements. However, due to the limitations of the overall operating conditions such as the increase in the reactor pressure difference, enterprises usually have to take measures when the reactor pressure difference rises to a certain level. Some units choose to remove the upper catalyst head, and more units directly choose to replace the new catalyst. This practice not only leads to parking and affects the production of ethylene glycol, but also causes the waste of some catalysts that still have good activity, fails to give full play to the potential of the entire catalyst bed, and increases production costs. The existing process faces many challenges in the control of the reaction process. On the one hand, it is difficult to achieve an ideal state in the control of the feed amount. If the feed amount in one section is not appropriate, such as too much or too little, it will lead to more side reactions. Excessive feed may aggravate side reactions such as hydrogenation of ethylene glycol to produce ethanol, thereby increasing the amount of by-products such as ethanol and butanediol; it will also lead to aggravated coking; too little feed may affect the reaction efficiency and product yield. On the other hand, the control of key parameters such as temperature and pressure in the reactor is not accurate enough. Due to the exothermic reaction, the temperature distribution in the reactor is uneven, and local overheating or overcooling is prone to occur, which not only affects the selectivity of the reaction, but also further aggravates the deactivation and coking problems of the catalyst. At the same time, pressure fluctuations will also have an adverse effect on the reaction, affecting the balance and rate of the reaction, and thus affecting the production quality and efficiency of ethylene glycol. Summary of the invention

[0004] The present invention provides a two-stage coal-to-ethylene glycol hydrogenation reactor and a method for using the same, in order to solve the technical problems existing in the prior art of the traditional coal-to-ethylene glycol process, that is, the catalyst life of the upper layer of the shell-and-tube reactor is short, the surface of the reactor is prone to coking, resulting in insufficient catalyst reaction, and the reaction process and conditions of the traditional reactor are difficult to control, resulting in reduced production quality and efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: A two-stage coal-to-ethylene glycol hydrogenation reactor, the reactor is divided into an upper and lower part, the upper part is the reactor section one, the lower part is the reactor section two, a mixed gas distributor is arranged between the reactor section one and the reactor section two, the upper end of the reactor section one is arranged with a first feed inlet, and the upper end of the reactor section two is arranged with a second feed inlet.

[0006] A first-stage heater and a first-stage feed valve are arranged on the feed pipeline of the first-stage feed port, a second-stage heater and a second-stage feed valve are arranged on the feed pipeline of the second-stage feed port, and both the first-stage feed valve and the second-stage feed valve are connected to the PLC control system.

[0007] The feed pipeline of the first feed inlet and the feed pipeline of the second feed inlet are connected to a centrifugal pump together.

[0008] A feed pipeline of a feed inlet is connected to an outlet pipeline of a compressor, and the compressor is used to input hydrogen into the reactor and drive gas phase circulation.

[0009] The lower end of the second section of the reactor is the discharge pipe of the reactor, the discharge pipe is connected to the inlet pipe of the separation tank, a cooling device is arranged on the discharge pipe, a material collection monitoring device is arranged on the outlet pipe of the separation tank, and the material collection monitoring device is connected to the PLC control system.

[0010] The outlet pipe of the separation tank is connected to the inlet pipe of the compressor, the pipes between the compressor, the reactor and the separation tank are connected to form a circulation loop, and the compressor is connected to the PLC control system.

[0011] The first reactor section and the second reactor section are both provided with cooling water supply pipes and cooling water return pipes.

[0012] A method for using a two-stage coal-to-ethylene glycol hydrogenation reactor comprises the following steps: loading a catalyst into a first stage and a second stage of the reactor, inputting dimethyl oxalate and hydrogen into the first stage and the second stage of the reactor through a first feed port and a second feed port, wherein the dimethyl oxalate and the hydrogen generate ethylene glycol under the action of the catalyst, and the ethylene glycol further reacts with the hydrogen to generate 1,2-butanediol; the product in the first stage of the reactor and a mixed gas of dimethyl oxalate and hydrogen enter the second stage of the reactor through a mixed gas distributor, and the mixed gas continues to react under the action of the catalyst in the second stage of the reactor.

[0013] The cooling device on the discharge pipe of the reactor condenses the mixed gas output by the reactor into liquid. After cooling, the mixed gas still contains gas. After the gas-liquid mixture is separated in the separation tank, the gas enters the compressor and the liquid is transported to the intermediate tank area through the outlet pipe of the separation tank.

[0014] The material collection monitoring device monitors the liquid component data in the separation tank outlet pipe in real time, and sends this data to the PLC control system. The PLC control system controls the opening of the first-stage feed valve and the second-stage feed valve according to the data.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The two-stage coal-to-ethylene glycol hydrogenation reactor disclosed in the present invention is different from the traditional reactor in that the reactor is divided into two sections, an upper section and an lower section, and feed ports are respectively set, so that the feed amount of the first and second sections of the reactor can be adjusted according to a certain proportion according to the operating conditions. The problem that the catalyst layer of one section of the reactor is always in the high-load area in the traditional upper feeding method is avoided, and the reaction materials can be more reasonably distributed, so that the catalysts in the upper and lower sections can work under appropriate loads, thereby improving the overall reaction efficiency. The upper and lower two-stage feeding method effectively slows down the generation of coking on the upper part of the bed. Since the feed amount of the upper and lower sections can be flexibly controlled, the coking phenomenon of the upper catalyst caused by the local high-concentration material is reduced, thereby extending the service life of the catalyst. For the situation where the activity of the lower catalyst in the traditional reactor is not fully utilized, this design can also better balance the use of the upper and lower catalysts, and give full play to the activity of the entire catalyst bed.

[0016] Furthermore, a heater and a feed valve are provided on the feed pipeline, wherein the first stage heater and the second stage heater can preheat the materials entering the first stage and the second stage of the reactor respectively, so that the reactants reach a suitable reaction temperature. The valve is connected to the PLC control system to achieve precise control of the feed. The PLC control system can automatically adjust the opening of the first stage feed valve and the second stage feed valve according to the actual conditions of the reaction, such as reaction rate, temperature, pressure and other parameters, so as to accurately control the amount of material entering each section of the reactor, and avoid affecting the reaction quality and efficiency due to excessive or insufficient feed. This solves the problem that the reaction process and conditions of the traditional reactor are difficult to control.

[0017] Furthermore, the centrifugal pump can provide stable power for the feed of the reactor, ensuring that the material can enter the reactor smoothly. At the same time, the connection of the first reactor and the second reactor to a centrifugal pump can achieve the coordination of material transportation to a certain extent, making the pressure and other parameters of the material before entering different reaction sections more stable and balanced, which is conducive to the stable operation of the entire reaction system.

[0018] Further, a compressor is used to transport hydrogen into the reactor to ensure that hydrogen can enter a reactor section with sufficient pressure. Hydrogen is an important reactant in the coal-to-ethylene glycol reaction, and suitable hydrogen pressure and flow are crucial for the reaction. The hydrogen is formed into a gas phase cycle in the reactor by the compressor, and the hydrogen can be fully mixed with dimethyl oxalate and participate in the reaction, which is conducive to improving the yield of ethylene glycol. The compressor, the reactor and the separation tank form a circulation loop, which can make the unreacted gas such as hydrogen re-enter the compressor, and then return to the reactor to react, thereby improving the utilization rate of raw materials, reducing the waste of raw materials, reducing production costs, and also helping to improve the yield of products such as ethylene glycol.

[0019] Furthermore, a cooling device is provided on the discharge pipe of the reactor, which can condense the mixed gas outputted from the reactor into liquid, facilitating subsequent separation and collection. The material collection monitoring device can monitor the liquid component data in the outlet pipe of the separation tank in real time, and feed the data back to the PLC control system. The PLC control system controls the opening of the feed valve according to the data, realizing a closed-loop system from discharge monitoring to feed control. This helps to ensure the stability of product quality, and can adjust the reaction process in time according to the actual situation of the product, thereby improving production quality and efficiency.

[0020] Furthermore, both the first and second stages of the reactor are provided with cooling water pipes and cooling return pipes, and the provision of cooling water pipes can effectively control the temperature of each stage of the reactor. In the coal-to-ethylene glycol reaction process, some reaction steps may generate a large amount of heat, and the cooling water pipes and cooling return pipes can promptly remove excess heat to prevent the temperature in the reactor from being too high. This is very important for maintaining the activity and stability of the catalyst, because high temperature may cause catalyst deactivation or accelerate surface coking, and this cooling system can avoid these problems and extend the service life of the catalyst.

[0021] Furthermore, the present invention discloses a method for using a two-stage coal-to-ethylene glycol hydrogenation reactor, wherein a catalyst is loaded in the first and second stages of the reactor, and dimethyl oxalate and hydrogen are fed in two stages to generate ethylene glycol under the action of the catalyst, and further generate products such as ethanol and 1,2-butanediol. This method can fully utilize the activity of the upper and lower stage catalysts, avoid the problem of decreased overall reaction efficiency caused by premature deactivation of the upper catalyst in a traditional reactor, improve the overall utilization rate of the catalyst, extend the catalyst replacement cycle, and reduce production costs.

[0022] Furthermore, the PLC control system controls the opening of the first and second stage feed valves according to the monitored gas composition data in the first and second stages of the reactor, and then controls the feed rate of the first and second stages of the reactor, thus achieving precise control of the reaction process. During the reaction process, the feed amount is adjusted in time according to the changes in the gas composition monitored in real time, so that the reaction is always kept in the best state, thus achieving dynamic regulation of the reaction process.

[0023] Furthermore, the cooling device condenses the mixed gas into liquid, which is convenient for subsequent separation operations. After the gas-liquid mixture is separated in the separation tank, the gas can be recycled and the liquid is transported to the intermediate tank area. This separation process can effectively collect the product and realize the recycling of raw materials, improving the economy and efficiency of the entire production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 : Schematic diagram of the comparison between the two-stage coal-to-ethylene glycol hydrogenation reactor and the traditional reactor; Figure 2 : Control logic diagram of two-stage coal-to-ethylene glycol hydrogenation reactor.

[0025] Explanation of reference numerals: 1. First stage heater; 2. Second stage heater; 3. First stage reactor; 4. Second stage reactor; 5. Compressor; 6. Cooling device; 7. Separation tank; 8. First stage feed valve; 9. Second stage feed valve; 10. Centrifugal pump; 11. Material collection monitoring device; 12. PLC control system; 13. Mixed gas distributor. DETAILED DESCRIPTION

[0026] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] See also Figure 1 and Figure 2 , which is a schematic diagram comparing the structure of the two-stage coal-to-ethylene glycol hydrogenation reactor in the present invention with the structure of the traditional coal-to-ethylene glycol hydrogenation reactor, as shown Figure 1 As shown in (a), the conventional coal-to-ethylene glycol hydrogenation reactor is an integral one-stage tube-in-tube type, and the reactor has only one feed, which is arranged at the upper end of the reactor; the reactor is provided with a set of cooling water supply pipes and cooling water return pipes; Figure 1 As shown in (b), the structure of the two-stage coal-to-ethylene glycol hydrogenation reactor of the present invention is a two-stage tube-in-tube type distributed up and down, with the upper part being the first reactor 3 and the lower part being the second reactor 4. A mixed gas distributor 13 is arranged between the first reactor 3 and the second reactor 4. Both the first reactor 3 and the second reactor 4 are provided with a cooling circulation system consisting of a separate cooling water supply pipe and a cooling water return pipe. Both the first reactor 3 and the second reactor 4 of the present invention are provided with a feed port, realizing two-stage feeding. The feed port of the first stage 3 of the reactor is the first feed port, and the feed port of the second stage 4 of the reactor is the second feed port. A first stage heater 1 is installed on the feed pipe of the first feed port, and a second stage heater 2 is installed on the feed pipe of the second feed port. The feed pipes of the first feed port and the second feed port are connected to a centrifugal pump 10. The discharge pipe below the second stage 4 of the reactor is connected to the inlet pipe of the separation tank 7, and a cooling device 6 is arranged on the discharge pipe. A material collection monitoring device 11 is arranged on the outlet pipe of the separation tank 7, and the material collection monitoring device 11 is connected to the PLC control system 12. The outlet pipe of the separation tank 7 is connected to the inlet pipe of the compressor 5. The pipe connection between the compressor 5, the reactor and the separation tank 7 forms a circulation loop. The compressor 5 allows hydrogen to form a gas phase circulation in this circulation loop, and fresh hydrogen is added to the reactor through the outlet pipe of the compressor 5. The PLC control system 12 is connected to the first-stage feed valve 8 and the second-stage feed valve 9 . The PLC control system 12 adjusts the opening of the first-stage feed valve 8 and the second-stage feed valve 9 according to the data monitored by the material collection monitoring device 11 .

[0029] The present embodiment provides a two-stage coal-to-ethylene glycol hydrogenation reactor and a method for using the same. The two-stage coal-to-ethylene glycol hydrogenation reactor provided in the present technical solution divides a traditional one-stage reactor into two sections, the first section 3 of the reactor is provided with a first feed port, the second section 4 of the reactor is provided with a second feed port, and both the first section 3 of the reactor and the second section 4 of the reactor are provided with a cooling upper water pipe and a cooling return water pipe, which form a cooling circulation system of the reactor; between the first section 3 of the reactor and the second section 4 of the reactor is a mixed gas distributor 13, and the crude ethylene glycol generated by the reaction of the first section 3 of the reactor and the mixed gas of the intermediate product and hydrogen are evenly diffused with the dimethyl oxalate fed into the second section 4 of the reactor and the mixed gas distributor 13 and then enter the second section 4 of the reactor together.

[0030] In this embodiment, as a further preference, the lower end of the reactor section 4 is the discharge pipe of the reactor, the discharge pipe is connected to the inlet pipe of the separation tank 7, and a cooling device 6 is provided on the discharge pipe. The mixed gas generated by the reactor is condensed into liquid through the cooling device 6 on the discharge pipe. During the condensation process, there is still gas that is not completely condensed. Therefore, after condensation by the cooling device 6, a gas-liquid mixture will be output, and the gas-liquid mixture is separated by the separation tank 7, the liquid is transported to the intermediate tank area, and the gas is transported to the compressor 5. A material collection monitoring device 11 is provided on the outlet pipe of the separation tank 7. The material collection monitoring device 11 adopts a high-precision gas component analysis sensor, which can monitor the liquid component data of the mixed gas generated after the reactor reaction in real time and accurately. The material collection monitoring device 11 is connected to the PLC control system 12, and the material collection monitoring device 11 monitors the liquid component data output by the separation tank 7 in real time, and sends the real-time monitored liquid component data to the PLC control system 12. The PLC control system 12 calculates the data to determine whether the feed of the reactor section 4 is excessive. The centrifugal pump 10 transports liquid dimethyl oxalate to the feed pipe of the first feed port and the feed pipe of the second feed port. The liquid dimethyl oxalate is heated by the first heater 1 and the second heater 2 in the two feed pipes, evaporates to form dimethyl oxalate gas, and then mixes with hydrogen to enter the first reactor 3 and the second reactor 4 for coal-to-ethylene glycol hydrogenation reaction.

[0031] The specific implementation steps of a two-stage coal-to-ethylene glycol hydrogenation reactor are as follows: In this embodiment, the overall material of the two-stage coal-to-ethylene glycol hydrogenation reactor is 304 stainless steel. The reactor is a two-stage shell-and-tube reactor distributed up and down. The inner diameter of the reactor shell and tube is φ38mm. The height ratio of the first and second stages of the two-stage reactor in this embodiment should be comprehensively calculated and considered. The height ratio of the first and second stages can be adjusted according to actual needs. In actual applications, the height of the second stage of the reactor should be greater than the height of the first stage of the reactor to avoid over-reaction in the first stage of the reactor.

[0032] Before the reactor is used, the entire device is comprehensively inspected to ensure that there is no leakage in the reactor and no blockage in the tubes, and the catalyst is loaded into the reactor section 1 3 and the reactor section 2 4. After the loading is completed, the resistance of the catalyst bed in the reactor section 1 3 and the reactor section 2 4 is checked to ensure that it is within the normal range. The entire circulation system consisting of the reactor, the separation tank 7 and the compressor 5 is replaced with nitrogen for a period of time to ensure that there are no other air impurities in the reactor. The cooling circulation system of the cooling upper water pipe and the cooling return water pipe is opened. The cooling circulation system is provided with an initial flow rate. The cooling water makes the temperature of the reactor reach the predetermined initial reaction temperature under the condition of the initial flow rate. Start the compressor 5, which drives the system to circulate hydrogen and input it into the reactor. The hydrogen passes through the reactor and the separation tank 7 and returns to the compressor 5 to form a hydrogen gas phase cycle. The centrifugal pump 10 is started to adjust the feed load of the first stage reactor 3 and the second stage reactor 4 from low to high, and the dimethyl oxalate liquid is transported to the feed pipe of the first stage reactor 3 and the feed pipe of the second stage reactor 4. The dimethyl oxalate solution is heated and evaporated into dimethyl oxalate gas under the action of the first stage heater 1 and the second stage heater 2 arranged on the feed pipe of the first stage reactor 3 and the feed pipe of the second stage reactor 4; the compressor 5 allows the hydrogen to enter the second stage reactor 4 from the first stage reactor 3 through the first feed port of the reactor, and finally transport the hydrogen to the compressor 5 through the separation tank 7 to circulate the hydrogen.

[0033] Dimethyl oxalate and hydrogen react in the first stage 3 of the reactor and the second stage 4 of the reactor under the action of the catalyst to generate methyl glycolate and methanol, methyl glycolate further reacts with hydrogen to generate ethylene glycol, ethylene glycol further reacts with hydrogen to generate ethanol, and ethylene glycol and ethanol react to generate 1,2-butanediol; the PLC control system 12 controls the opening of the first stage feed valve 8 and the second stage feed valve 9 according to the result of calculation and judgment of the data collected by the material collection monitoring device 11; the PLC control system 12 is provided with a methyl glycolate content threshold and a 1,2-butanediol content threshold. In the liquid component data monitored by the material collection monitoring device 11, if the real-time content value of methyl glycolate is greater than or equal to the methyl glycolate content threshold, the PLC control system 12 determines that the reaction is not complete in the first stage 3 of the reactor and the second stage 4 of the reactor, and the PLC control system 12 controls the first stage feed valve 8 and the second stage feed valve 9 to increase the opening, otherwise, the opening of the first stage feed valve 8 and the second stage feed valve 9 remains unchanged. If the real-time content value of 1,2-butanediol is greater than or equal to the 1,2-butanediol content threshold, the PLC control system 12 determines that the reaction in the first stage 3 and the second stage 4 of the reactor is excessive. At this time, the PLC control system 12 controls the first stage feed valve 8 and the second stage feed valve 9 to reduce the opening, and at the same time, controls the compressor 5 to increase the power to speed up the circulation speed of hydrogen in the reactor, thereby driving the flow speed of the reaction gas in the reactor, so that the reaction in the first stage 3 and the second stage 4 of the reactor is accelerated, otherwise, the opening of the first stage feed valve 8 and the second stage feed valve 9 and the power of the compressor 5 remain unchanged. If dimethyl oxalate exists in the liquid component data monitored by the material collection monitoring device 11, it means that the catalyst bed in the reactor is penetrated, the reactor is over-fed, and the reaction is not completely reacted. At this time, the PLC control system 12 controls the first stage feed valve 8 and the second stage feed valve 9 to reduce the opening. The PLC control system 12 controls the feed rate of the reactor section 1 3 and the reactor section 2 4 by monitoring the real-time data, and further controls the feed amount in the reactor to ensure that the feed of the reactor section 3 can react completely with the catalyst, that is, its feed can satisfy the entire activity cycle of the catalyst, while ensuring that the feed amount of the reactor section 2 4 is not excessive, so as to avoid the phenomenon of excessive feed to the reactor and coking on the catalyst surface.

[0034] In another preferred embodiment of the present invention, the staff sets a temperature threshold for the reactor. During the reaction process, the temperature monitor monitors the temperature data in the reactor in real time. When the temperature is greater than or equal to the temperature threshold, the flow rate of the cooling water is controlled to increase and the cooling is accelerated. Otherwise, the cooling water of the water circulation system is restored to the initial flow rate.

[0035] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A two-stage coal-to-ethylene glycol hydrogenation reactor, characterized in that: The reactor is divided into two parts, the upper part is the reactor section one (3), and the lower part is the reactor section two (4). A mixed gas distributor (13) is arranged between the reactor section one (3) and the reactor section two (4). The upper end of the reactor section one (3) is provided with a first feed inlet, and the upper end of the reactor section two is provided with a second feed inlet.

2. A two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 1, characterized in that: A first-stage heater (1) and a first-stage feed valve (8) are provided on the feed pipeline of the first-stage feed port, and a second-stage heater (2) and a second-stage feed valve (9) are provided on the feed pipeline of the second-stage feed port. Both the first-stage feed valve (8) and the second-stage feed valve (9) are connected to a PLC control system (12).

3. A two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 2, characterized in that: The feed pipeline of the first feed inlet and the feed pipeline of the second feed inlet are connected to a centrifugal pump (10) together.

4. A two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 3, characterized in that: A feed pipe of a feed inlet is connected to an outlet pipe of a compressor (5), and the compressor (5) is used to feed hydrogen into the reactor.

5. A two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 1, characterized in that: The lower end of the second section (4) of the reactor is a discharge pipe of the reactor, the discharge pipe is connected to the inlet pipe of the separation tank (7), a cooling device (6) is arranged on the discharge pipe, and a material collection monitoring device (11) is arranged on the outlet pipe of the separation tank (7), and the material collection monitoring device (11) is connected to a PLC control system (12).

6. A two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 5, characterized in that: The outlet pipe of the separation tank (7) is connected to the inlet pipe of the compressor (5), the pipes between the compressor (5), the reactor and the separation tank (7) are connected to form a circulation loop, and the compressor (5) is connected to the PLC control system (12).

7. A two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 1, characterized in that: The reactor section 1 (3) and the reactor section 2 (4) are both provided with a cooling water supply pipe and a cooling water return pipe.

8. A method for using a two-stage coal-to-ethylene glycol hydrogenation reactor, based on the two-stage coal-to-ethylene glycol hydrogenation reactor according to any one of claims 1 to 7, characterized in that: The method of use is as follows: loading a catalyst into the first reactor section (3) and the second reactor section (4), inputting dimethyl oxalate and hydrogen into the first reactor section (3) and the second reactor section (4) through a first feed port and a second feed port, dimethyl oxalate and hydrogen generate ethylene glycol under the action of the catalyst, and ethylene glycol further reacts with hydrogen to generate 1,2-butanediol; the product in the first reactor section (3) and the mixed gas of dimethyl oxalate and hydrogen enter the second reactor section (4) through a mixed gas distributor (13), and the mixed gas continues to react under the action of the catalyst in the second reactor section (4).

9. The method for using a two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 8, characterized in that: The cooling device (6) on the discharge pipe of the reactor condenses the mixed gas output from the reactor into liquid. After the mixed gas is cooled, gas still exists. After the gas-liquid mixture is separated by the separation tank (7), the gas enters the compressor (5) and the liquid is transported to the intermediate tank area through the outlet pipe of the separation tank (7).

10. The method for using a two-stage coal-to-ethylene glycol hydrogenation reactor according to claim 9, characterized in that: The material collection monitoring device (11) monitors the liquid component data in the outlet pipe of the separation tank (7) in real time, and sends the data to the PLC control system (12). The PLC control system (12) controls the opening of the first-stage feed valve (8) and the second-stage feed valve (9) according to the data.

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