Ethylene glycol synthesizer

Abstract

The utility model provides an ethylene glycol synthesis device which comprises a carbonylation reactor, a first heat exchanger, a mixer, a second heat exchanger and a hydrogenation reactor which are sequentially connected in series, the first heat exchanger is arranged to exchange heat between a product produced by the carbonylation reactor and hydrogen, and the hydrogen is heated while the carbonylation product is cooled, so that the temperature of the carbonylation product is reduced; therefore, the heat in the carbonylation product is recycled; and meanwhile, a second heat exchanger is arranged to perform heat exchange and temperature rise on a gas-liquid mixture of dimethyl oxalate and hydrogen by utilizing a hydrogenated product, so that the heat in the hydrogenated product is recycled. And the defect of energy waste caused by the fact that heat in a reaction product is not utilized in the existing ethylene glycol production mode is overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ethylene glycol synthesis, and particularly relates to an ethylene glycol synthesis device. BACKGROUND

[0002] Ethylene glycol is a kind of colorless and odorless liquid organic substance with sweet taste, so it is also called "glycol", which is one of important basic chemical raw materials and is widely used in energy, fine chemical industry, automobile manufacturing industry and textile industry. There are many methods for synthesizing ethylene glycol, such as direct synthesis of carbon monoxide and hydrogen, formaldehyde and methanol method, dimethyl oxalate method and ethylene method. Among them, the dimethyl oxalate method has a short process and low cost, and is the most concerned coal-to-ethylene glycol technology in China in terms of technology and economy, and is also the most widely used process in coal-to-ethylene glycol production enterprises. The method uses coal as raw material, and obtains carbon monoxide and hydrogen through gasification, shift conversion, purification and separation and purification. Carbon monoxide is coupled to oxalate, and then oxalate is hydrogenated to generate ethylene glycol.

[0003] The production of ethylene glycol mainly includes the coupling reaction of methyl nitrite and CO and the hydrogenation reaction of dimethyl oxalate and hydrogen. In the above reaction process, the reaction is exothermic, and if the heat generated in the reaction process is not recovered, the energy will be wasted. The existing method is to set a corresponding steam drum to recover the heat in the form of steam. However, the reaction product still has high temperature, and the traditional method is to use a heat exchanger to cool the reaction product. The temperature of the heat exchange medium after heat exchange is low, and the low-grade heat generated is difficult to be reused, which leads to the waste of energy in this part of material. CONTENT OF THE INVENTION

[0004] The present application provides an ethylene glycol synthesis device to solve the problem of energy waste caused by the fact that the heat in the reaction product is not utilized in the existing method for producing ethylene glycol.

[0005] The present application provides an ethylene glycol synthesis device, which comprises a carbonylation reactor, a first heat exchanger, a mixer, a second heat exchanger and a hydrogenation reactor connected in series.

[0006] The carbonylation reactor is connected with a carbonylation raw material supply device, and the carbonylation reactor is connected with a carbonylation steam drum in series through a first circulating pump set to form a loop for heat exchange to the carbonylation reactor.

[0007] The hydrogenation reactor is connected with a hydrogenation steam drum in series through a second circulating pump set to form a loop for heat exchange to the hydrogenation reactor.

[0008] The carbonylation steam drum and the hydrogenation steam drum are respectively connected with a water supply device.

[0009] The shell side input end of the first heat exchanger is connected with the material output end of the carbonylation reactor, the gas output end of the shell side is connected with the tail gas collecting device, and the material output end of the shell side is connected with the mixer;

[0010] The tube side input end of the first heat exchanger is connected with the hydrogen pipeline, and the tube side output end is connected with the mixer;

[0011] The output end of the mixer is connected with the tube side input end of the second heat exchanger, the tube side output end is connected with the material input end of the hydrogenation reactor, the shell side input end is connected with the material output end of the hydrogenation reactor, and the shell side output end is connected with the post-processing device.

[0012] Optionally, the carbonylation reactor comprises at least one carbonylation reaction bed;

[0013] The hydrogenation reactor comprises at least one hydrogenation reaction bed;

[0014] The first circulating pump set comprises at least one first circulating pump;

[0015] The second circulating pump set comprises at least one second circulating pump.

[0016] Optionally, the carbonylation reactor comprises a plurality of parallel carbonylation reaction beds;

[0017] The hydrogenation reactor comprises a plurality of parallel hydrogenation reaction beds;

[0018] The first circulating pump set comprises a plurality of parallel first circulating pumps;

[0019] The second circulating pump set comprises a plurality of parallel second circulating pumps.

[0020] Optionally, the first heat exchanger comprises a cylinder arranged horizontally and end covers for closing both ends of the cylinder, and the cylinder and the end covers at both ends are respectively separated by baffles;

[0021] A plurality of heat exchange pipes are arranged in the cylinder to communicate the end covers at both ends;

[0022] A feeding port and an exhaust port are respectively arranged on the upper surface of the cylinder near the end covers at both sides, the lower surface of the cylinder is concave to form a liquid receiving space in the shape of an inverted cone, and a liquid discharge port is arranged on the lower surface;

[0023] A filter screen is arranged between the liquid receiving space of the cylinder and the lowermost heat exchange pipe, and a plurality of baffle plates are vertically arranged between the baffles at both ends;

[0024] The baffle plate near the feeding port is connected with the baffle plate near the exhaust port through a first perforated plate arranged horizontally;

[0025] The first perforated plate passes through the baffle plate.

[0026] Optionally, the mixer comprises a shell;

[0027] The horizontally arranged mixing pipe is supported and fixed in the shell by a plurality of connecting ribs, one end of the mixing pipe is a tapered throat pipe, and the other end is connected with the hydrogen gas pipeline through the hydrogen gas compressor, the upper surface of the end of the mixing pipe close to the hydrogen gas compressor is connected with the material output end of the first heat exchanger through the liquid inlet pipe;

[0028] A plurality of shunt plates connected in series are fixedly arranged in the mixing pipe, each shunt plate is twisted into a spiral shape, and the twisting directions of adjacent two shunt plates are opposite.

[0029] Optionally, a second hole plate is vertically arranged between the adjacent two shunt plates.

[0030] Optionally, the carbonylation steam drum is connected with the steam recovery pipeline through the heat pump.

[0031] The hydrogenation steam drum is also connected with the steam recovery pipeline.

[0032] The application provides an ethylene glycol synthesis device, which exchanges heat between the product produced by the carbonylation reactor and hydrogen gas through the first heat exchanger, thereby achieving the heat recovery and utilization of the carbonylation product; and the second heat exchanger is arranged to exchange heat between the hydrogenation product and the gas-liquid mixture of dimethyl oxalate and hydrogen gas, thereby achieving the heat recovery and utilization of the hydrogenation product. The device utilizes the heat in the reaction product in the ethylene glycol production process through the cooperation of the above-mentioned equipment, and overcomes the waste of energy caused by the failure to utilize the heat in the reaction product in the existing ethylene glycol production mode. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0034] Figure 1 The schematic diagram of the ethylene glycol synthesis device provided by an embodiment of the present application;

[0035] Figure 2 The structural schematic diagram of the first heat exchanger provided by an embodiment of the present application;

[0036] Figure 3 The structural schematic diagram of the mixer provided by an embodiment of the present application;

[0037] Figure 4 The structural schematic diagram of the mixer provided by another embodiment of the present application;

[0038] Figure 5 The schematic diagram of the ethylene glycol synthesis device provided for another embodiment of the application.

[0039] Explanation of reference signs:

[0040] 1, carbonylation reactor; 2, first heat exchanger; 3, mixer; 4, second heat exchanger; 5, hydrogenation reactor; 6, water supplement device; 7, treatment device; 8, heat pump; 9, steam recovery pipeline; 10, carbonylation reaction bed; 11, carbonylation raw material supply device; 12, first circulating pump unit; 13, carbonylation steam drum; 14, tail gas collection device; 20, hydrogen pipeline; 21, cylinder; 22, head; 23, baffle; 24, heat exchange pipe; 25, filter screen; 26, baffle; 27, first orifice plate; 31, shell; 32, mixing pipe; 33, hydrogen compressor; 34, liquid inlet pipe; 50, hydrogenation reaction bed; 51, second circulating pump unit; 52, hydrogenation steam drum; 121, first circulating pump; 201, feed inlet; 202, exhaust port; 203, liquid outlet; 321, flow dividing plate; 322, second orifice plate; 511, second circulating pump. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application is described clearly and completely below. Obviously, the described embodiments are some embodiments of the application, but not all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work also belong to the protection scope of the application.

[0042] As shown in Figure 1 The application provides an ethylene glycol synthesis device, which comprises, in sequence, a carbonylation reactor 1, a first heat exchanger 2, a mixer 3, a second heat exchanger 4 and a hydrogenation reactor 5;

[0043] The carbonylation reactor 1 is connected with a carbonylation raw material supply device 11, and the carbonylation reactor 1 is connected with the carbonylation steam drum 13 in sequence through the first circulating pump unit 12 to form a loop, which is used for heat exchange to the carbonylation reactor 1;

[0044] The hydrogenation reactor 5 is connected with the hydrogenation steam drum 52 in sequence through the second circulating pump unit 51 to form a loop, which is used for heat exchange to the hydrogenation reactor 5;

[0045] The carbonylation steam drum 13 and the hydrogenation steam drum 52 are respectively connected with a water supplement device 6;

[0046] The shell side input end of the first heat exchanger 2 is connected with the material output end of the carbonylation reactor 1, the gas output end of the shell side is connected with a tail gas collection device 14, and the material output end of the shell side is connected with the mixer 3.

[0047] The tube side input end of the first heat exchanger 2 is connected with the hydrogen pipeline 20, and the tube side output end is connected with the mixer 3;

[0048] The output end of the mixer 3 is connected with the tube side input end of the second heat exchanger 4, and the tube side output end is connected with the material input end of the hydrogenation reactor 5; the shell side input end is connected with the material output end of the hydrogenation reactor 5, and the shell side output end is connected with the post-processing device 7.

[0049] In use, the carbonylation raw material supply device supplies the reaction raw materials (carbon monoxide and methyl nitrite) into the carbonylation reactor 1, and the hot water in the carbonylation steam pocket 13 sucked by the first circulating pump set 12 is supplied into the heat exchange jacket of the carbonylation reactor 1 to heat the carbonylation reactor 1 to reach the reaction temperature. After the reaction starts, since the reaction of carbon monoxide and methyl nitrite is an exothermic reaction, in order to avoid the temperature in the carbonylation reactor 1 being too high, the first circulating pump set 12 needs to continuously supply the hot water (the temperature of the hot water is lower than the temperature in the carbonylation reactor 1) in the carbonylation steam pocket 13 into the carbonylation reactor 1 for heat exchange and cooling. The hot water after being cooled by absorbing heat from the carbonylation reactor 1 is raised in temperature and is input into the carbonylation steam pocket 13 again. Since the volume of the carbonylation steam pocket 13 is large, the hot water raised in temperature will expand to generate part of steam when it enters the carbonylation steam pocket 13. In actual reaction, the temperature of the water input from the carbonylation reactor 1 into the carbonylation steam pocket 13 is 110-130℃, and the steam generated by the expansion of the water can be recovered. At the same time, since the water in the carbonylation steam pocket 13 is continuously vaporized to generate steam, the water level in the carbonylation steam pocket 13 will be lowered, and therefore the hot water needs to be continuously supplied into the carbonylation steam pocket 13 by the water supply device 6. The temperature of the supplied hot water is about 100℃, which is beneficial to heat exchange and cooling of the carbonylation reactor 1.

[0050] Carbon monoxide and methyl nitrite react in the carbonylation reactor 1 to generate dimethyl oxalate and nitrogen monoxide. The dimethyl oxalate is in liquid state, and the carbon monoxide is in gaseous state. The two are in the form of gas-liquid mixture and are output from the carbonylation reactor 1. The gas-liquid mixture of the output dimethyl oxalate and nitrogen monoxide is input into the first heat exchanger 2 to exchange heat with the hydrogen input from the hydrogen pipeline 20. The hydrogen is heated and raised in temperature, while the temperature of the gas-liquid mixture of the dimethyl oxalate and nitrogen monoxide is lowered. The cooled and condensed dimethyl oxalate is input into the mixer 3, and the nitrogen monoxide is separated from the liquid dimethyl oxalate and is discharged into the tail gas collecting device 14 for centralized treatment.

[0051] The dimethyl oxalate output from the first heat exchanger 2 is mixed with the hydrogen raised in temperature and output from the first heat exchanger 2 in the mixer 3. The misty gas-liquid mixture after being heated and raised in temperature by the heat exchange with the hydrogenation reaction product output from the second heat exchanger 4 and the hydrogenation reactor 5 is easily gasified and is input into the hydrogenation reactor 5 for hydrogenation reaction.

[0052] In the hydrogenation reaction, the hot water in the hydrogenation steam drum 52 pumped by the second circulating pump set 51 is supplied into the heat exchange jacket of the hydrogenation reactor 5 to heat the hydrogenation reactor 5 to reach the reaction temperature. After the reaction starts, since the reaction between hydrogen and dimethyl oxalate is an exothermic reaction, to avoid the temperature in the hydrogenation reactor 5 being too high, the second circulating pump set 51 needs to continuously supply the hot water (the temperature of which is lower than that in the hydrogenation reactor 5) in the hydrogenation steam drum 52 into the hydrogenation reactor 5 to exchange heat and reduce the temperature. The temperature of the hot water after the heat absorption and temperature reduction of the hydrogenation reactor 5 is increased and the hot water is input into the hydrogenation steam drum 52 again. Since the volume of the hydrogenation steam drum 52 is large, the hot water with the increased temperature expands to generate part of steam when it is input into the hydrogenation steam drum 52. In the actual reaction, the temperature of the water input from the hydrogenation reactor 5 into the hydrogenation steam drum 52 is 170-200°C, and the steam generated by the expansion is output from the hydrogenation steam drum 52 to be recycled. At the same time, since the water level in the hydrogenation steam drum 52 is continuously reduced due to the steam generated by the vaporization of the hot water, the hot water needs to be continuously supplied into the hydrogenation steam drum 52 through the water supply device 6. The temperature of the supplied hot water is about 100°C, which is beneficial to the heat exchange and temperature reduction of the hydrogenation reactor 5.

[0053] The hydrogenation product (mainly ethylene glycol and reaction by-products) obtained in the hydrogenation reactor 5 is output into the second heat exchanger 4 to exchange heat with the misty gas-liquid mixture of hydrogen and dimethyl oxalate to increase the temperature. The hydrogenation product after the heat exchange is input into the post-treatment device 7 for centralized treatment.

[0054] The application provides an ethylene glycol synthesis device. The first heat exchanger 2 is arranged to exchange heat between the product obtained by the carbonylation reactor 1 and hydrogen, to heat the hydrogen while reducing the temperature of the carbonylation product, so as to recycle and utilize the heat in the carbonylation product. The second heat exchanger 4 is arranged to exchange heat between the hydrogenation product and the gas-liquid mixture of dimethyl oxalate and hydrogen, to increase the temperature, so as to recycle and utilize the heat in the hydrogenation product. The device of the application utilizes the heat in the reaction product in the ethylene glycol production process by the cooperation of the above-mentioned devices, to overcome the problem that the heat in the reaction product is not utilized in the existing ethylene glycol production mode, and the energy is wasted.

[0055] Optionally, the carbonylation reactor 1 comprises at least one carbonylation reaction bed 10.

[0056] The hydrogenation reactor 5 comprises at least one hydrogenation reaction bed 50.

[0057] The first circulating pump set 12 comprises at least one first circulating pump 121.

[0058] The second circulating pump set 51 comprises at least one second circulating pump 511.

[0059] In the present application, the carbonylation reactor 1 is the main equipment for the carbonylation reaction, in which carbon monoxide and methyl nitrate react to form dimethyl oxalate. The hydrogenation reactor 5 is the main equipment for the hydrogenation reaction, in which hydrogen and dimethyl oxalate react to form ethylene glycol.

[0060] In the present application, the first circulating pump 121 and the second circulating pump 511 are respectively used to supply the heat exchange medium to the corresponding carbonylation reactor 1 and hydrogenation reactor 5, so as to timely remove the heat generated in the reaction process and prevent the equipment from being damaged or safety accidents caused by high temperature.

[0061] As shown in Figure 1 Optionally, the carbonylation reactor 1 comprises a plurality of parallel carbonylation reactors 10.

[0062] The hydrogenation reactor 5 comprises a plurality of parallel hydrogenation reactors 50.

[0063] The first circulating pump unit 12 comprises a plurality of parallel first circulating pumps 121.

[0064] The second circulating pump unit 51 comprises a plurality of parallel second circulating pumps 511.

[0065] In the present application, the plurality of parallel carbonylation reactors 10 and hydrogenation reactors 50 can improve the reaction efficiency.

[0066] Similarly, the plurality of parallel first circulating pumps 121 and second circulating pumps 511 can further improve the heat exchange efficiency of the corresponding reaction equipment and prevent the equipment from being damaged or safety accidents caused by high temperature.

[0067] As shown in Figure 2 Optionally, the first heat exchanger 2 comprises a horizontally arranged cylinder 21 and a head 22 for closing both ends of the cylinder 21, and the cylinder 21 and the two ends of the head 22 are respectively separated by a partition plate 23.

[0068] A plurality of heat exchange pipes 24 are arranged in the cylinder 21 to connect the two ends of the head 22.

[0069] A feed inlet 201 and an exhaust outlet 202 are respectively arranged on the upper surface of the cylinder 21 near the two side heads 22, and a liquid receiving space in the form of an inverted cone is formed on the lower surface of the cylinder 21, and a liquid outlet 203 is arranged.

[0070] A filter screen 25 is arranged between the liquid receiving space of the cylinder 21 and the lowermost heat exchange pipe 24, and a plurality of baffle plates 26 are vertically arranged between the two partition plates 23.

[0071] The baffle plate 26 near the feed inlet 201 is connected to the partition plate 23 near the exhaust outlet 202 through a horizontally arranged first hole plate 27.

[0072] The first hole plate 27 is arranged through the baffle 26.

[0073] In the present application, in use, the output gaseous-liquid mixture of dimethyl oxalate and nitric oxide is input into the first heat exchanger 2 from the feed port 201, under the action of the baffle 26 and the first hole plate 27, the gaseous-liquid mixture is prolonged in the path, and exchanges heat with the hydrogen input into the heat exchange tube 24 through the hydrogen pipeline 20 in the cylinder 21 of the first heat exchanger 2, wherein the hydrogen is heated and the temperature of the gaseous-liquid mixture of dimethyl oxalate and nitric oxide is reduced, the condensed and cooled dimethyl oxalate falls into the liquid receiving space in the cylinder 21, and the nitric oxide is separated from the liquid dimethyl oxalate and discharged from the exhaust port 202 to the tail gas collecting device 14 for centralized treatment.

[0074] As shown in Figure 3 Optionally, the mixer 3 comprises a shell 31;

[0075] The shell 31 is supported and fixed by a plurality of connecting ribs, and a horizontal mixing tube 32 is arranged in the shell 31, one end of the mixing tube is a tapered throat, and the other end is connected with the hydrogen pipeline 20 through the hydrogen compressor 33, and the upper surface of the end of the mixing tube 32 close to the hydrogen compressor 33 is connected with the material output end of the first heat exchanger 2 through the liquid inlet pipe 34;

[0076] A plurality of shunt plates 321 are fixedly arranged in the mixing tube 32, each shunt plate 321 is twisted into a spiral shape, and the twisting directions of the adjacent two shunt plates 321 are opposite.

[0077] In the present application, in use, the hydrogen enters the hydrogen compressor 33 in the shell 31, is compressed and pressurized, and then enters the mixing tube 32 with the dimethyl oxalate input from the liquid inlet pipe 34, under the action of the shunt plates 321 in the tube, the hydrogen and the dimethyl oxalate are mixed, and finally are sprayed into the second heat exchanger 4 after being pressurized in the tapered section of the mixing tube 32, and are heated and warmed up, since the gaseous-liquid mixture sprayed from the mixing tube 32 is in a mist state, the mist state gaseous-liquid mixture exchanges heat with the hydrogenation reaction product produced by the hydrogenation reactor 5 after being warmed up, and is easily gasified and input into the hydrogenation reactor 5 for hydrogenation reaction.

[0078] As shown in Figure 4 Optionally, a second hole plate 322 is vertically arranged between the adjacent two shunt plates 321.

[0079] The second hole plate 322 is arranged in the present application to increase the turbulence of the fluid, so as to promote the mixing of the hydrogen and the dimethyl oxalate.

[0080] As shown in Figure 5As shown, the carbonylation water tank 13 is connected to the steam recovery pipeline 9 through the heat pump 8.

[0081] The hydrogenation water tank 52 is also connected to the steam recovery pipeline 9.

[0082] In this application, the water temperature input from the carbonylation reactor 1 to the carbonylation water tank 13 is 110-130°C, and the steam generated by the expansion of the water is output from the carbonylation water tank 13. Since the steam generated here has a low temperature, it is input into the heat pump 8 to generate high-grade steam, which is recovered into the steam recovery pipeline 9 for use.

[0083] The water temperature input from the hydrogenation reactor 5 to the hydrogenation water tank 52 is 170-200°C, and the steam generated by the expansion of the water is output from the hydrogenation water tank 52. Since the steam generated here has a high temperature and can be directly recovered for use, the steam generated here is directly recovered from the hydrogenation water tank 52 into the steam recovery pipeline 9 for use.

[0084] The present application provides an ethylene glycol synthesis device, and the working process is as follows:

[0085] In use, the carbonylation raw material supply device supplies the reaction raw materials (carbon monoxide and methyl nitrite) into the carbonylation reactor 1, and the hot water in the carbonylation water tank 13 sucked by the first circulating pump set 12 is introduced into the heat exchange jacket of the carbonylation reactor 1 to heat the carbonylation reactor 1 to reach the reaction temperature. After the reaction starts, since the reaction of carbon monoxide and methyl nitrite is an exothermic reaction, in order to avoid the temperature in the carbonylation reactor 1 being too high, the first circulating pump set 12 needs to continuously supply the hot water in the carbonylation water tank 13 into the carbonylation reactor 1 for heat exchange and cooling. The hot water after being cooled by absorbing heat in the carbonylation reactor 1 is input into the carbonylation water tank 13 again. Since the volume of the carbonylation water tank 13 is large, the hot water with a higher temperature will expand to generate part of steam when it enters the carbonylation water tank 13. In actual reaction, the water temperature input from the carbonylation reactor 1 to the carbonylation water tank 13 is 110-130°C, and the steam generated by the expansion of the water is output from the carbonylation water tank 13. Since the steam generated here has a low temperature, it is input into the heat pump 8 to generate high-grade steam, which is recovered into the steam recovery pipeline 9 for use. At the same time, since the water level in the carbonylation water tank 13 is lowered due to the continuous vaporization of the hot water to generate steam, the hot water needs to be continuously supplemented into the carbonylation water tank 13 through the water supplementing device 6. The temperature of the supplemented hot water is about 100°C, which is beneficial to heat exchange and cooling of the carbonylation reactor 1.

[0086] The carbon monoxide and the methyl nitrite react in the plurality of carbonylation reaction beds 10 of the carbonylation reactor 1 to generate dimethyl oxalate and nitrogen monoxide, wherein the dimethyl oxalate is in liquid state and the carbon monoxide is in gaseous state, and the two are in the form of gas-liquid mixture and are output from the carbonylation reactor 1, the output gas-liquid mixture of the dimethyl oxalate and the carbon monoxide is input into the first heat exchanger 2 from the feed port 201, under the action of the baffle 26 and the first perforated plate 27, the travel path of the gas-liquid mixture is prolonged, and the gas-liquid mixture exchanges heat with the hydrogen input via the hydrogen pipeline 20 in the heat exchange tube 24 in the barrel 21 of the first heat exchanger 2, wherein the hydrogen is heated and warmed, while the temperature of the gas-liquid mixture of the dimethyl oxalate and the carbon monoxide is reduced, the condensed and cooled dimethyl oxalate falls into the liquid receiving space in the barrel 21, and the nitrogen monoxide is separated from the liquid dimethyl oxalate and is discharged from the exhaust port 202 to the tail gas collecting device 14 for centralized treatment.

[0087] The dimethyl oxalate output from the first heat exchanger 2 is mixed with the warmed hydrogen output from the first heat exchanger 2 in the mixer 3. During the mixing, the hydrogen enters the hydrogen compressor 33 in the shell 31, is compressed and pressurized, and then enters the mixing tube 32 with the dimethyl oxalate input from the liquid inlet pipe 34, under the action of the flow divider 321 and the second perforated plate 322 in the tube, the hydrogen and the dimethyl oxalate are mixed, and finally, after being pressurized by passing through the tapered section of the mixing tube 32, the gas-liquid mixture is sprayed into the second heat exchanger 4 for heating and warming. Since the gas-liquid mixture sprayed from the mixing tube 32 is in mist form, it exchanges heat with the hydrogenation reaction product generated by the hydrogenation reactor 5 in the second heat exchanger 4, and after being warmed, the mist-shaped gas-liquid mixture is easily vaporized and input into the hydrogenation reactor 5 for hydrogenation reaction.

[0088] In the hydrogenation reaction, the hot water in the hydrogenation steam pocket 52 pumped by the second circulating pump set 51 is supplied into the heat exchange jacket of the hydrogenation reactor 5 to heat the hydrogenation reactor 5 to the reaction temperature. After the reaction starts, since the reaction between hydrogen and dimethyl oxalate is an exothermic reaction, to avoid the temperature in the hydrogenation reactor 5 being too high, the second circulating pump set 51 needs to continuously supply the hot water in the hydrogenation steam pocket 52 into the hydrogenation reactor 5 to exchange heat and reduce the temperature. The hot water after being cooled by absorbing heat in the hydrogenation reactor 5 is supplied into the hydrogenation steam pocket 52 again. Since the hydrogenation steam pocket 52 has a large volume, the hot water with a higher temperature expands to generate some steam when it is supplied into the hydrogenation steam pocket 52. In the actual reaction, the water supplied from the hydrogenation reactor 5 into the hydrogenation steam pocket 52 has a temperature of 170-200°C, and the steam generated by the expansion of the water has a high temperature and can be directly recycled. Therefore, the steam generated in the hydrogenation steam pocket 52 can be directly recycled into the steam recycling pipeline 9 for use. At the same time, since the water in the hydrogenation steam pocket 52 continuously vaporizes to generate steam, the water level in the hydrogenation steam pocket 52 decreases, and therefore the hot water needs to be continuously supplied into the hydrogenation steam pocket 52 by the water supply device 6. The temperature of the supplied hot water is about 100°C, which is beneficial to the heat exchange and temperature reduction of the hydrogenation reactor 5.

[0089] The hydrogenation product (mainly ethylene glycol and reaction by-products) obtained in the hydrogenation reactor 5 is output from the multiple hydrogenation reaction beds 50 in the hydrogenation reactor 5 into the second heat exchanger 4 to exchange heat with the misty gas-liquid mixture of hydrogen and dimethyl oxalate and increase the temperature. The hydrogenation product after the heat exchange is supplied into the post-treatment device 7 for centralized treatment.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can modify the technical solutions described in the above embodiments, or make equivalent replacements to some or all of the technical features. Such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An apparatus for synthesizing ethylene glycol, characterized in that, It includes a carbonylation reactor (1), a first heat exchanger (2), a mixer (3), a second heat exchanger (4), and a hydrogenation reactor (5) connected in series. The carbonylation reactor (1) is connected to the carbonylation raw material supply device (11). The carbonylation reactor (1) is also connected in series with the carbonylation steam drum (13) through the first circulating pump unit (12) to form a loop for heat exchange to the carbonylation reactor (1). The hydrogenation reactor (5) is connected in series with the hydrogenation steam drum (52) via the second circulating pump unit (51) to form a loop for heat exchange to the hydrogenation reactor (5); The carbonylation steam drum (13) and the hydrogenation steam drum (52) are also connected to the water replenishment device (6); The shell-side input end of the first heat exchanger (2) is connected to the material output end of the carbonylation reactor (1), the gas output end of the shell side is connected to the tail gas collection device (14), and the material output end of the shell side is connected to the mixer (3). The tube-side input end of the first heat exchanger (2) is connected to the hydrogen pipeline (20), and the tube-side output end is connected to the mixer (3); The output end of the mixer (3) is connected to the tube side input end of the second heat exchanger (4), and the tube side output end is connected to the material input end of the hydrogenation reactor (5); the shell side input end is connected to the material output end of the hydrogenation reactor (5), and the shell side output end is connected to the post-processing device (7).

2. The ethylene glycol synthesis apparatus according to claim 1, characterized in that, The carbonylation reactor (1) includes at least one carbonylation reaction bed (10); The hydrogenation reactor (5) includes at least one hydrogenation reaction bed (50); The first circulating pump unit (12) includes at least one first circulating pump (121); The second circulating pump unit (51) includes at least one second circulating pump (511).

3. The ethylene glycol synthesis apparatus according to claim 2, characterized in that, The carbonylation reactor (1) comprises multiple parallel carbonylation reaction beds (10); The hydrogenation reactor (5) includes multiple parallel hydrogenation reaction beds (50); The first circulating pump unit (12) includes a plurality of first circulating pumps (121) connected in parallel; The second circulating pump unit (51) includes a plurality of second circulating pumps (511) connected in parallel.

4. The ethylene glycol synthesis apparatus according to claim 1, characterized in that, The first heat exchanger (2) includes a horizontally arranged cylinder (21) and end caps (22) for sealing both ends of the cylinder (21), and the cylinder (21) and the end caps (22) at both ends are separated by partitions (23); Multiple heat exchange tubes (24) are installed inside the cylinder (21) to connect the end caps (22) at both ends; The upper surface of the cylinder (21) near the two end caps (22) is provided with a feed inlet (201) and an exhaust outlet (202), respectively. The lower surface is convex to form an inverted cone-shaped liquid receiving space and is provided with a drain outlet (203). A filter screen (25) is provided between the liquid receiving space of the cylinder (21) and the lowest heat exchange tube (24); multiple baffles (26) are vertically arranged between the partitions (23) at both ends; The baffle (26) near the feed inlet (201) is connected to the partition (23) near the exhaust port (202) by a horizontally arranged first perforated plate (27); The first orifice plate (27) is disposed through the baffle plate (26).

5. The ethylene glycol synthesis apparatus according to claim 1, characterized in that, The mixer (3) includes a housing (31); The housing (31) is supported and fixed by multiple connecting ribs. A horizontally arranged mixing tube (32) is fixed inside the housing (31). One end of the mixing tube is a tapered throat tube and is connected to the tube input end of the second heat exchanger (4). The other end is connected to the hydrogen pipeline (20) through the hydrogen compressor (33). The upper surface of the mixing tube (32) near the hydrogen compressor (33) is connected to the material output end of the first heat exchanger (2) through the liquid inlet pipe (34). The mixing tube (32) is fixedly provided with multiple connected diverter plates (321), each of which is twisted into a spiral shape, and the twisting directions of two adjacent diverter plates (321) are opposite.

6. The ethylene glycol synthesis apparatus according to claim 5, characterized in that, A second perforated plate (322) is vertically arranged between two adjacent flow dividers (321).

7. The ethylene glycol synthesis apparatus according to any one of claims 1 to 6, characterized in that, The carbonyl steam drum (13) is connected to the steam recovery pipeline (9) via a heat pump (8); The hydrogenated steam drum (52) is also connected to the steam recovery pipeline (9).

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