Self-heating reactor for preparing ethylene glycol through dimethyl oxalate hydrogenation

Abstract

A first preheating section, a shell pass reaction section, a tube pass reaction section and a second preheating section are sequentially and coaxially arranged from top to bottom, an upper sealing head is arranged at the top end of the first preheating section and provided with a reaction gas inlet a, and a lower sealing head is arranged at the bottom end of the second preheating section and provided with a reaction gas inlet b. The lower sealing head is provided with a reaction gas outlet b; a preheating gas inlet g and a preheating gas outlet h are respectively formed in the second preheating section cylinder, a preheating gas inlet i and a preheating gas outlet j are respectively formed in the first preheating section cylinder, and a reaction preheating gas inlet c and a reaction preheating gas outlet d are respectively formed in the tube pass reaction section cylinder; and a reaction gas inlet e and a reaction gas outlet f are respectively formed in the shell pass reaction section cylinder. According to the utility model, the temperature required by the reaction can be maintained by utilizing the heat generated by the reaction, and good response matching property and operation reliability can be maintained under complicated working conditions such as randomness and volatility of operation load, so that the device has important significance on solving the response matching property and operation reliability of chemical production in a green electricity scene.

Description

Technical Field

[0001] The utility model relates to an autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol, belonging to the field of autothermal reaction equipment. Background Art

[0002] In modern chemical industry, ethylene glycol is an extremely important organic chemical raw material with a wide range of application fields. It is widely used in the production of polyester fibers, polyester plastics, antifreeze agents, lubricants and other chemical products. The traditional production method of ethylene glycol mainly relies on the petroleum route. However, the limited nature and price volatility of petroleum resources bring many uncertainties to this route. At the same time, the petroleum route often produces a large amount of pollutants during the production process, putting great pressure on the environment. In contrast, hydrogenating dimethyl oxalate to ethylene glycol has many advantages. First of all, dimethyl oxalate can be synthesized through the coal-based route, and China's rich coal resources provide a stable raw material guarantee for this process. Secondly, this process is relatively environmentally friendly and produces less pollutants.

[0003] In the production process of ethylene glycol, the chemical reaction process and the reactor are the central links in the chemical production process, and a chemical production process often revolves around the reaction process. In many chemical reaction processes, appropriate temperature conditions need to be provided to promote the reaction. Traditional reactors often require external energy sources for heating or heat extraction, and there are problems such as high energy consumption, low heat exchange efficiency and high cost. To solve the above problems, this new type of autothermal reactor came into being. This autothermal reactor is a device that can use the heat generated by the reaction itself to maintain the reaction temperature, and it is usually used for chemical reactions that need to be carried out at a specific temperature. The design of this autothermal reactor is based on specific chemical reaction principles, and through reasonable structures and operating conditions, the reaction can generate enough heat to maintain the required temperature. Summary of the Utility Model

[0004] The utility model provides an autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol, which can use the heat generated by the reaction itself to maintain the temperature required for the reaction, and at the same time can achieve an efficient and energy-saving reaction process for complex working conditions such as randomness and volatility of the operation load.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] An autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol, comprising an upper head, a lower head, a tube-side reaction section, a shell-side reaction section, a first preheating section, and a second preheating section. The first preheating section, the shell-side reaction section, the tube-side reaction section, and the second preheating section are coaxially arranged in sequence from top to bottom. An upper head is provided at the top end of the first preheating section, and a reaction gas inlet a is provided on the upper head. A lower head is provided at the bottom end of the second preheating section, and a reaction gas outlet b is provided on the lower head;

[0007] A preheating gas inlet g and a preheating gas outlet h are respectively provided on the cylinder body of the second preheating section. A preheating gas inlet i and a preheating gas outlet j are respectively provided on the cylinder body of the first preheating section. A reaction preheating gas inlet c and a reaction preheating gas outlet d are respectively provided on the cylinder body of the tube-side reaction section. A reaction gas inlet e and a reaction gas outlet f are respectively provided on the cylinder body of the shell-side reaction section;

[0008] There is a flow connection between the preheating gas outlet h and the reaction preheating gas inlet c, between the reaction preheating gas outlet d and the reaction gas inlet e, and between the reaction gas outlet f and the preheating gas inlet i;

[0009] Furthermore, the tube-side reaction section is that a number of heat exchange tubes are arranged in the shell, and a catalyst is filled in the heat exchange tubes to form a tube-side reaction cavity, and heat exchange materials are filled between the outside of the heat exchange tubes and the shell to form a shell-side preheating cavity;

[0010] The shell-side reaction section is that a number of heat exchange tubes are arranged in the shell, and a catalyst is filled between the outside of the heat exchange tubes and the shell to form a reaction cavity, and a tube-side preheating cavity is formed inside the heat exchange tubes;

[0011] The first preheating section and the second preheating section have the same structure. A number of heat exchange tubes are arranged in the shell, and heat exchange materials are placed between the outside of the heat exchange tubes and the shell to form a shell-side preheating cavity, and a tube-side preheating cavity is formed inside the heat exchange tubes;

[0012] Furthermore, the diameter of the shell is 500 mm, the height of the tube-side reaction section is 4000 mm, the height of the shell-side reaction section is 4000 mm, and the heights of the first preheating section and the second preheating section are both 2000 mm;

[0013] 290 heat exchange tubes are evenly arranged in the tube-side reaction section, the shell-side reaction section, the first preheating section, and the second preheating section, and all the heat exchange tubes are arranged parallel to the central axis direction;

[0014] Furthermore, a number of baffle plates are respectively arranged in the tube-side reaction section, the shell-side reaction section, the first preheating section, and the second preheating section, and the baffle plates are installed perpendicular to the central axis direction;

[0015] Furthermore, the first preheating section and the shell-side reaction section, the shell-side reaction section and the tube-side reaction section, and the tube-side reaction section and the second preheating section are connected by cylinder connection sections;

[0016] Furthermore, an energy control mechanism is provided, which includes a temperature sensing element and a control element. The energy control mechanism is connected to the autothermal reactor. The temperature sensing element monitors the temperature in the reaction chamber and the preheating chamber. When the temperature in the tube of the autothermal reactor reaches a preset temperature, the energy control mechanism introduces cold shock gas into the cylinder connecting section according to the temperature sensing element to suppress the excessively high reaction temperature.

[0017] Through the above technical solution, compared with the prior art, the utility model has the following beneficial effects:

[0018] 1. The autothermal reactor for hydrogenating dimethyl oxalate to produce ethylene glycol provided by the utility model adopts a combination of a tube-side reaction section, a shell-side reaction section and a preheating section. The size of each bed section is designed according to the characteristics of the reaction of hydrogenating dimethyl oxalate to produce ethylene glycol. The distribution ratio of each bed section can be adjusted according to different feed flow rates, so as to maintain good response matching and operation reliability under complex working conditions such as randomness and volatility of operating loads;

[0019] 2. The autothermal reactor for hydrogenating dimethyl oxalate to produce ethylene glycol provided by the utility model has a preheating chamber in the structure that has the ability to quickly absorb and store heat, and is particularly suitable for the intermittent, fluctuating, and random characteristics of raw gas in green electricity scenarios;

[0020] 3. The autothermal reactor for hydrogenating dimethyl oxalate to produce ethylene glycol provided by the utility model can realize heat transfer between the reaction gas and the raw gas, avoid deactivation of the catalyst due to overheating, and at the same time can heat the raw gas to the catalytic reaction activity temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 It is a schematic diagram of the structure of an autothermal reactor for hydrogenating dimethyl oxalate to produce ethylene glycol in a preferred embodiment provided by the utility model;

[0023] Figure 2 This is the design method of the autothermal reactor provided by the utility model;

[0024] Figure 3 This is an example diagram of the micro-segment volume ΔV of a bed segment in an autothermal reactor selected in the autothermal reactor design method provided by the utility model.

[0025] In the figure: 100 is a reaction gas inlet a, 101 is a reaction gas outlet b, 102 is a reaction preheating gas inlet c, 103 is a reaction preheating gas outlet d, 104 is a reaction gas inlet e, 105 is a reaction gas outlet f, 106 is a preheating gas inlet g, 107 is a preheating gas outlet h, 108 is a preheating gas inlet i, and 109 is a preheating gas outlet j;

[0026] The upper head is 200, the lower head is 201, the cylindrical connection section is 202, the tube-side reaction section is 204, the shell-side reaction section is 205, the first preheating section is 206, the second preheating section is 207, the shell is 300, the heat exchange tubes are 301, the catalyst is 302, the baffle is 303, and the heat exchange material is 304. Detailed implementation mode

[0027] Now, the present utility model will be further described in detail with reference to the accompanying drawings. In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "left side", "right side", "upper part", "lower part", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model 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. "First", "second", etc. do not represent the importance of the components, so it cannot be understood as a limitation to the present utility model. The specific dimensions adopted in this embodiment are only for illustrating the technical solution by way of example and do not limit the protection scope of the present utility model.

[0028] As generated in the background technology, the existing reactors for hydrogenating dimethyl oxalate to ethylene glycol have the following two disadvantages: there are certain limitations in coping with flow fluctuations, and they cannot effectively adapt to the dynamic changes of the flow, thus affecting the efficiency and quality of ethylene glycol production; there is also room for further improvement in the energy utilization efficiency to better meet the requirements of energy conservation and emission reduction.

[0029] The self-heating reactor provided in this application for hydrogenating dimethyl oxalate to ethylene glycol, as Figure 1 shown, includes an upper head 200, a lower head 201, a tube-side reaction section 204, a shell-side reaction section 205, a first preheating section 206, and a second preheating section 207. The first preheating section, the shell-side reaction section, the tube-side reaction section, and the second preheating section are coaxially arranged in sequence from top to bottom. An upper head is provided at the top of the first preheating section, and a reaction gas inlet a100 is provided on the upper head. A lower head is provided at the bottom of the second preheating section, and a reaction gas outlet b101 is provided on the lower head; a preheating gas inlet g106 and a preheating gas outlet h107 are respectively provided on the cylinder of the second preheating section, a preheating gas inlet i108 and a preheating gas outlet j109 are respectively provided on the cylinder of the first preheating section, a reaction preheating gas inlet c102 and a reaction preheating gas outlet d103 are respectively provided on the cylinder of the tube-side reaction section, and a reaction gas inlet e104 and a reaction gas outlet f105 are respectively provided on the cylinder of the shell-side reaction section; there is a flow connection between the preheating gas outlet h and the reaction preheating gas inlet c, between the reaction preheating gas outlet d and the reaction gas inlet e, and between the reaction gas outlet f and the preheating gas inlet i.

[0030] The structure provided in this application for the hydrogenation of dimethyl oxalate to ethylene glycol adopts a combined form of a tube-side reaction section, a shell-side reaction section, and a preheating section. This is because the design method followed in this application is to use a two-stage stochastic programming optimization model solution method, that is, as Figure 2 shown, the so-called two-stage includes two stages. In the first stage, the combined form of the bed section is initially determined, the sizes of each bed section are designed according to the characteristics of different reactions, the production process is optimized based on the flow uncertainty parameters and different bed structures, the distribution ratio of the feed entering each bed section is adjusted under different feed flows, and the best configuration of the combined form is further confirmed considering the target product content and equipment cost; in the second stage, the production process of the autothermal reactor formed by each combination in the first stage is optimized according to the feed flow rates obtained under different probability conditions throughout the year to obtain the optimal solution.

[0031] In the first stage, considering that the operable temperature range of catalyst 302 during the hydrogenation of dimethyl oxalate to ethylene glycol is between 190 - 210 °C, the catalyst operating temperature is set as T, the upper limit of the catalyst operating temperature is T max , and the lower limit of the catalyst operating temperature is T min , so T max -T min < 50 °C, and preferably the autothermal reactor is set as a combined form of a tube-side reaction section, a shell-side reaction section, and a preheating section.

[0032] For further adjustment and confirmation, based on the balance relationship between the feed flow rate of each bed section, the target product flow rate, and the catalyst volume, the target product flow rate and the catalyst volume of each bed section are obtained through the balance relationship, and it is confirmed that the target product content Y(R) of the designed combined form is the largest; a further design of this application is that the tube-side reaction section is provided with a number of heat exchange tubes 301 inside the shell 300, and heat exchange materials 304 are placed between the outside of the heat exchange tubes and the shell to form a shell-side preheating cavity, and catalysts are filled inside the heat exchange tubes to form a tube-side reaction cavity; the shell-side reaction section is provided with a number of heat exchange tubes inside the shell, and catalysts are filled between the outside of the heat exchange tubes and the shell to form a shell-side reaction cavity, and a tube-side preheating cavity is formed inside the heat exchange tubes; the structures of the first preheating section and the second preheating section are the same, and both are provided with a number of heat exchange tubes inside the shell, and heat exchange materials are placed between the outside of the heat exchange tubes and the shell to form a shell-side preheating cavity, and a tube-side preheating cavity is formed inside the heat exchange tubes.

[0033] In the autothermal reactor for the hydrogenation of dimethyl oxalate to ethylene glycol, the heat exchange material needs to have good thermal conductivity, high-temperature resistance, corrosion resistance, and certain strength and mechanical properties. Therefore, as long as the heat exchange material meets the above requirements, it can be used, such as commonly used copper, aluminum, high-temperature resistant alloys, etc.; the selection of the catalyst usually focuses on copper-based catalysts to exert the maximum efficacy of the catalyst.

[0034] Specifically, the gas treatment volume is about 10848 Nm3 / h, the shell diameter of the entire autothermal reactor is 500mm, the height of the tube-side reaction section is 4000mm, the height of the shell-side reaction section is 4000mm, the height of the first preheating section and the second preheating section are both 2000mm; 290 heat exchange tubes are evenly arranged in the tube-side reaction section, the shell-side reaction section, the first preheating section and the second preheating section, and all heat exchange tubes are arranged parallel to the central axis. The temperature range of the reaction gas inlet a and the reaction preheating gas inlet c is 120-180°C, preferably 130-150°C.

[0035] The structural composition of the tube-side reaction section, shell-side reaction section, first preheating section and second preheating section is confirmed through the balance relationship, which includes reaction dynamic balance, material balance and energy balance. In other words, the balance reaction formulas of several combination types are combined under the flow rate of the highest probability scenario throughout the year to obtain the export target product content and the volume of each bed section. Which type has the largest target product content Y(R) is then combined with the equipment cost to finally determine the combination type.

[0036] Specifically, dimethyl oxalate and hydrogen are converted into ethylene glycol under the action of a catalyst by the following reaction:

[0037] CH3OOCCOOCH3+4H2=HOCH2CH2OH+2CH3OH Where, ΔH=-198.2KJ / mol. First, the differential simultaneous calculation process in each bed layer is provided:

[0038] Taking exothermic reaction as an example, the exothermic reaction satisfies the formula: aA+bB=rR+sS, A and B are reaction raw materials, R is the target product, S is the reaction by-product, and a, b, s, r are the stoichiometric coefficients of the reactants and products respectively.

[0039] like Figure 3 As shown, the micro-segment volume ΔV of a bed section in the autothermal reactor is selected for calculation. Since the micro-segment volume ΔV is small enough, the micro-segment kinetic equation can be determined by the micro-segment inlet reaction temperature and the inlet concentration of each substance in the micro-segment reaction. That is, the temperature change of the micro-segment has almost no effect on the reaction rate.

[0040] The reaction dynamic equilibrium equation of the micro-segment is:

[0041] J=J(T in ,P A,in ,P B,in ,P R,in ,P S,in ) (1)

[0042] ΔG(R,out)=J×ΔV (2)

[0043] In Formulas (1) and (2), J is the reaction rate of the micro-segment, and T in is the inlet reaction temperature of the micro-segment, and T in needs to satisfy the logical constraint condition T min ≤T in , P A,in , P B,in , P R,in , P S,in are the inlet concentrations of each substance in the micro-segment, ΔG(R,out) is the flow rate of the target product generated in the micro-segment, and ΔV is the volume of the micro-segment.

[0044] Substitute the reaction rate J of the micro-segment into the material balance equation,

[0045]

[0046] In Formula (3), F(A+B,out) is the molar flow rate of the reaction raw material at the outlet of the micro-segment, and F(A+B,in) is the molar flow rate of the reaction raw material at the inlet of the micro-segment. In Formula (3), given the feed composition and concentration of the reaction raw material in the micro-segment, the outlet composition can be solved, and further the outlet concentrations P A,out , P B,out , P R,out , P S,out of each substance in the micro-segment can be obtained.

[0047] Next, based on the concentrations calculated from Formula (3), the enthalpy of the outlet substances, and the enthalpy of the inlet substances, combined with the reaction heat, substitute into the energy balance equation to solve for the outlet temperature T out of the micro-segment and the inlet temperature T cold,in of the cold raw material gas. Specifically,

[0048] The energy balance equation is:

[0049]

[0050] ΣF(c,out)H c,out -∑F(c,in)H c,in =-ΔH-K×ΔS×ΔT m (5)

[0051] K×ΔS×ΔT m =∑[F(cold,c,in)×Cp(cold,c)](T cold，out -T cold，in ) (6)

[0052] In Formulas (4), (5), and (6), ΔH is the reaction heat of the micro-segment, ΔH r is the reaction heat of the target product, F(c,out) is the flow rate of each outlet substance in the micro-segment, Hc，out is the enthalpy of each outlet material of the micro-segment, that is, the outlet temperature T of the micro-segment out function, F(c, in) is the flow rate of each inlet substance in the micro-segment, H c，in is the enthalpy of each inlet substance in the micro-segment, that is, the micro-segment inlet reaction temperature T in function, K is the total heat transfer coefficient, ΔS is the micro-segmented heat transfer area, F(cold, c, in) is the feed amount of each inlet substance of the cold raw gas, Cp(cold, c) is the isobaric heat capacity of each substance in the cold raw gas, T cold,out is the outlet temperature of the cold raw gas, T cold,in is the inlet temperature of the cold raw gas;

[0053] In formulas (5) and (6), In formula (7), d is the diameter of the bed segment where the micro-segment is located;

[0054] In formula (8), T out is the outlet temperature of each micro-segment, T in is the reaction temperature of each micro-segment inlet; by combining formulas (5), (6), (7) and (8), through repeated iterations and calculations, the micro-segment outlet temperature T is finally calculated. out And the cold raw gas inlet temperature T cold，in ; So far, the key parameters of the outlet material composition and temperature of this micro-segment have been obtained. The key parameters include the outlet temperature T out , the inlet temperature of cold raw gas T cold，in , outlet concentration of each substance in the micro-segment P A，out , P B，out , P R，out , P S，out , the outlet molar flow rate of the micro-segmented reaction raw materials F(A+B,out). These key parameters are used as the input for the inlet calculation of the next micro-segment.

[0055] By integrating the above process until T out Does not meet T out ≤T max , and obtain the target product flow rate G(R,out) of each bed section and the catalyst volume V of each bed section.

[0056] Next, calculations are performed between each bed layer segment.

[0057] When the bed sections in the autothermal reactor are connected, it is assumed that the flow between section i and section j is connected (it should be emphasized here that it is determined according to the connection between the bed sections under actual working conditions. If there is no connection, the flow between section i and section j is 0), satisfying:

[0058] F(bi, in) = F(bj,i, out) + F(cpi, in) (9)

[0059]

[0060] In equations (9) and (10), F(bi, ib) is the molar flow rate at the inlet of section i, F(bj, i, out) is the molar flow rate returned from section j to section i, F(cpi, in) is the molar flow rate of fresh feed in section i, F(bi, out) is the molar flow rate at the outlet of section i, and G(Ri, out) is the flow rate of the target product in section i;

[0061] Based on equations (9)-(10), the flow rate of the target product G(R, out) at the outlet of the last autothermal reactor section is calculated;

[0062] Substitute the calculated flow rate of the target product G(R, out) at the outlet of the last autothermal reactor section into the objective function to obtain the content of the target product Y(R) in the designed combined type. The objective function is:

[0063]

[0064] In equation (11), Y(R) is the content of the target product, G(R, out) is the total flow rate of the target product, F(b, in) is the total molar flow rate at the inlet, and a, b, s, r are the stoichiometric coefficients of the reactants and products respectively.

[0065] So far, it can be basically determined that the combined type of tube-side reaction section, shell-side reaction section and preheating section adopted for the structure of hydrogenation of dimethyl oxalate to ethylene glycol meets the requirements.

[0066] In the second stage, considering the flow rates under scenarios with different probabilities throughout the year, based on equations (1)-(10) under the logical constraint conditions T min ≤ T in 、T out ≤ T max If a solution can be obtained under the setting, it proves that the designed combined type can adapt to this flow rate. As for the staged feed, 10 distributed feeds are sampled through the weighted random distribution function and solved respectively, and the maximum of the objective function (i.e., equation 11) is taken as the optimal solution. Finally, it is verified whether the initially determined combined type meets the actual working condition requirements.

[0067] The implementation process of the self-heating reactor provided by this application is as follows: when the temperatures of the preheated gas inlet g and the reaction gas inlet a are 140 °C, the reaction gas inlet a passes through the tube side of the first preheating section, is preheated to 162 °C by the reaction gas in the shell, then passes through the cylinder connection section 202, and is redistributed into the tube side of the shell-side reaction section. After being preheated to the activation temperature of 190 °C by the reaction gas in the shell, it passes through the cylinder connection section and is redistributed into the tube of the tube-side reaction section. After contacting the catalyst, ethylene glycol is generated by reaction. The reaction-generated gas passes through the cylinder connection section, is redistributed into the tube side of the second preheating section, preheats the raw material gas in the preheating cavity of the shell, and then exits the self-heating reactor through the reaction gas outlet b; the preheated gas inlet g passes through the shell side of the second preheating section, is preheated to 162 °C by the reaction gas in the tube side, enters the shell preheating cavity of the tube-side reaction section, is preheated to the activation temperature of 190 °C by the reaction gas in the tube, enters the shell side of the shell-side reaction section, and after contacting the catalyst, ethylene glycol is generated by reaction. The reaction-generated gas enters the shell preheating cavity of the tube-side reaction section, preheats the raw material gas in the tube side, and then exits the reactor through the preheated gas outlet j.

[0068] In the self-heating reactor provided by this application for hydrogenating dimethyl oxalate to ethylene glycol, in the face of complex working conditions such as fluctuations and intermittences in the flow rate of the raw material gas, it can maintain good reaction performance and reliable operation performance. In order to further improve the performance of the reactor and the high efficiency and stability of the reaction, a number of baffle plates 303 are respectively arranged in the tube-side reaction section, the shell-side reaction section, the first preheating section, and the second preheating section. The baffle plates can change the flow direction of the fluid, increase the turbulence degree of the fluid, thereby increasing the heat transfer coefficient and enhancing the heat transfer effect; a number of baffle plates are evenly arranged during installation, and can also guide the uniform distribution of the fluid, avoiding the situation of too high or too low local flow velocity, and ensuring the uniformity and stability of the reaction. The baffle plates are installed perpendicular to the central axis direction, and a number of baffle plates are staggeredly arranged parallel to each other. This installation method can also provide support for the reactor with internal heat exchange tubes, preventing the heat exchange tubes from bending or deforming due to fluid flow or external factors.

[0069] It can be seen from Figure 1 that the first preheating section is connected to the shell-side reaction section, the shell-side reaction section is connected to the tube-side reaction section, and the tube-side reaction section is connected to the second preheating section through the cylinder connection section. In actual use, the cylinder connection section can also not be set.

[0070] For further design, an energy control mechanism is also provided, which includes a temperature sensing element and a control element. The energy control mechanism is connected to the self-heating reactor. The temperature sensing element monitors the temperatures in the reaction cavity and the preheating cavity. When the temperature in the tube of the self-heating reactor reaches the preset temperature, the energy control mechanism injects cold gas into the cylinder connection section according to the temperature sensing element to suppress the too high reaction temperature, so as to maintain the temperature stability of the preheating cavity. Through precise energy control, the reaction efficiency and stability are further improved.

[0071] Those skilled in the art can understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the field to which this application belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as such here.

[0072] As used in this application, the meaning of "and / or" includes both the case where each exists alone and the case where both exist simultaneously.

[0073] As used in this application, the meaning of "connection" can be a direct connection between components or an indirect connection between components through other components.

[0074] Taking the above-mentioned ideal embodiments of the present utility model as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An autothermal reactor for hydrogenating dimethyl oxalate to produce ethylene glycol, characterized in that: It comprises an upper head, a lower head, a tube-side reaction section, a shell-side reaction section, a first preheating section and a second preheating section, wherein the first preheating section, the shell-side reaction section, the tube-side reaction section and the second preheating section are coaxially arranged in sequence from top to bottom, an upper head is arranged at the top end of the first preheating section, and a reaction gas inlet a is arranged on the upper head, and a lower head is arranged at the bottom end of the second preheating section, and a reaction gas outlet b is arranged on the lower head; The second preheating section cylinder is provided with a preheating gas inlet g and a preheating gas outlet h, respectively; the first preheating section cylinder is provided with a preheating gas inlet i and a preheating gas outlet j, respectively; the tube-side reaction section cylinder is provided with a reaction preheating gas inlet c and a reaction preheating gas outlet d, respectively; the shell-side reaction section cylinder is provided with a reaction gas inlet e and a reaction gas outlet f; There is flow communication between the preheating gas outlet h and the reaction preheating gas inlet c, between the reaction preheating gas outlet d and the reaction gas inlet e, and between the reaction gas outlet f and the preheating gas inlet i.

2. The autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol according to claim 1, characterized in that: The tube-side reaction section is a shell in which a plurality of heat exchange tubes are arranged, catalysts are filled in the heat exchange tubes to form a tube-side reaction chamber, and heat exchange materials are filled between the outside of the heat exchange tubes and the shell to form a shell-side preheating chamber; The shell-side reaction section is a shell in which a plurality of heat exchange tubes are arranged, catalysts are filled between the outside of the heat exchange tubes and the shell to form a shell-side reaction chamber, and a tube-side preheating chamber is formed inside the heat exchange tubes; The first preheating section and the second preheating section have the same structure, both of which are to arrange a plurality of heat exchange tubes in the shell, place heat exchange materials between the outside of the heat exchange tubes and the shell to form a shell-side preheating cavity, and form a tube-side preheating cavity in the heat exchange tubes.

3. The autothermal reactor for hydrogenating dimethyl oxalate to produce ethylene glycol according to claim 2, characterized in that: The shell diameter is 500mm, the tube-side reaction section height is 4000mm, the shell-side reaction section height is 4000mm, and the first preheating section and the second preheating section height are both 2000mm; 290 heat exchange tubes are evenly arranged in the tube-side reaction section, the shell-side reaction section, the first preheating section and the second preheating section, and all the heat exchange tubes are arranged parallel to the central axis.

4. The autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol according to claim 2, characterized in that: A plurality of baffles are respectively arranged in the tube-side reaction section, the shell-side reaction section, the first preheating section and the second preheating section, and the baffles are installed perpendicular to the central axis direction.

5. The autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol according to claim 1, characterized in that: The first preheating section and the shell-side reaction section, the shell-side reaction section and the tube-side reaction section, and the tube-side reaction section and the second preheating section are connected through a cylinder connecting section.

6. The autothermal reactor for hydrogenating dimethyl oxalate to ethylene glycol according to claim 5, characterized in that: An energy control mechanism is also provided, which includes a temperature sensing element and a control element. The energy control mechanism is connected to the autothermal reactor. The temperature sensing element monitors the temperature in the reaction chamber and the preheating chamber. When the temperature in the tube of the autothermal reactor reaches a preset temperature, the energy control mechanism, based on the temperature sensing element, introduces cold shock gas into the connecting section of the cylinder to suppress the excessively high reaction temperature.

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