Reaction device and method for producing phosgene based on carbon dioxide as a chemical raw material

Abstract

The present application relates to a reaction device and method for producing phosgene based on carbon dioxide as a chemical raw material. In the electromagnetic induction heating reaction furnace, carbon dioxide reacts with carbon to produce carbon monoxide. The flue gas discharged from the electromagnetic induction heating reaction furnace enters the heat exchange device to exchange heat with the carbon dioxide raw gas. The flue gas discharged from the heat exchange device is treated by dust collection and purification to obtain carbon monoxide. The carbon monoxide reacts with chlorine gas generated by the chlor-alkali process to produce phosgene. Before entering the electromagnetic induction heating reaction furnace, the carbon dioxide is preheated to a temperature of 1000-1200 DEG C by using an electromagnetic induction preheating device, and then is blown into the electromagnetic induction heating reaction furnace. The heating method adopted by the present application is electromagnetic induction heating, which is a non-contact heating method, has the characteristics of high efficiency, rapidness, accurate control, and is not easy to introduce impurities.

Description

Technical Field

[0001] This invention relates to a reaction apparatus and method for producing phosgene from carbon dioxide as a chemical raw material, belonging to the field of phosgene preparation technology. Background Technology

[0002] Carbon dioxide is a major greenhouse gas and also an important carbon resource. Converting carbon dioxide into value-added chemicals is one of the important technological approaches to achieve carbon dioxide emission reduction. However, due to the lack of industrially applicable carbon dioxide resource utilization technologies, it is currently impossible to convert carbon dioxide into value-added chemicals on a large scale, with high efficiency and low cost. Therefore, developing new industrially applicable carbon dioxide resource utilization technologies is a major practical problem that energy and environmental science urgently needs to solve.

[0003] Phosgene is an important organic reaction intermediate, widely used in pesticides, pharmaceuticals, engineering plastics, dyes, papermaking and other fields. Currently, in industry, carbon monoxide and chlorine are commonly used as raw materials to produce phosgene (Cl2 + CO = COCl2). Cl2 mainly comes from the chlor-alkali process (electrolysis of water and sodium chloride), and CO mainly comes from coal chemical industry. This method has a long process flow, large equipment footprint, complex raw material gas purification process and serious pollution. Therefore, it is of great significance to develop a new phosgene synthesis process. Summary of the Invention

[0004] To address the problems and shortcomings of existing technologies, this invention proposes a reaction apparatus for producing phosgene from carbon dioxide as a basic chemical raw material. The apparatus mainly includes an electromagnetic induction heating reactor, a heat exchange device, and a carbon dioxide feed gas preheating device. Using this reaction apparatus and method, carbon dioxide reacts with carbon to generate carbon monoxide flue gas. The carbon monoxide flue gas enters the heat exchange device, where it exchanges heat with the carbon dioxide feed gas, effectively utilizing the waste heat of the carbon monoxide flue gas. After cooling and purification treatment, the carbon monoxide flue gas reacts with chlorine generated in the chlor-alkali process to produce phosgene.

[0005] The electromagnetic induction heating reactor of this invention has an internal vertical metal tube. The metal tube material, meeting the technical requirements, is one of molybdenum, tungsten, vanadium, niobium, nickel, and iron, or an alloy thereof. The outer wall of the metal tube is wrapped with a high-temperature resistant asbestos insulation layer. A spiral gas conduit is located outside the high-temperature resistant asbestos insulation layer. The heat exchange gas conduit material, meeting the technical requirements, is one of aluminum nitride, magnesium oxide, silicon nitride, and corundum. Carbon dioxide raw material gas flows through the gas conduit to reduce the surface temperature of the electromagnetic induction heating reactor. An electromagnetic induction coil is wound around the outside of the electromagnetic induction heating reactor. The electromagnetic induction coil is connected to alternating current, and the alternating current flowing through the coil heats the metal tube, supplementing the heat energy for the endothermic reaction (CO2 + C = 2CO + endothermic) inside the reactor. The electromagnetic induction coil of the electromagnetic induction heating reactor of this application is divided into three independent sections, with the upper section temperature controlled at 700℃~900℃, the middle section temperature at 900℃~1000℃, and the lower section temperature at 1000℃~1200℃. The electromagnetic induction heating reactor is equipped with a carbon feed hopper and a carbon sealing chamber at the top. The carbon feed materials that meet the technical requirements are coal, coke, straw, and sawdust, as well as mixtures thereof. The bottom of the carbon feed hopper is equipped with a baffle. When the amount of carbon feed in the hopper reaches a certain value, the baffle at the bottom of the hopper is opened, allowing the carbon feed to fall into the carbon sealing chamber. The baffle at the bottom of the hopper then closes. When the amount of carbon feed in the carbon sealing chamber reaches a certain value, the baffle at the bottom of the carbon sealing chamber is opened, allowing the carbon feed to fall into the reactor. The baffle at the bottom of the carbon sealing chamber then closes. The electromagnetic induction heating reactor has two ash locks at the bottom, with an ash bin between them. Ash generated during the reaction falls onto the ash lock at the bottom of the reactor. When the ash accumulates to a certain amount, the ash lock at the top of the ash bin opens, allowing the ash to fall into the bin. The ash lock at the top of the ash bin then closes. When the amount of ash in the ash bin reaches a certain level, the ash lock at the bottom of the ash bin opens, allowing the ash to be discharged from the bottom. The ash lock at the bottom of the ash bin is then immediately closed. The electromagnetic induction heating reactor has a carbon dioxide gas inlet on the bottom side and a carbon monoxide flue gas outlet on the upper side.

[0006] The carbon monoxide flue gas heat exchange device of this invention has a high-temperature gas inlet connected to the carbon monoxide flue gas outlet of an electromagnetic induction heating reactor. Within the heat exchange device, the carbon monoxide flue gas exchanges heat with the carbon dioxide feedstock gas, effectively utilizing the waste heat in the carbon monoxide flue gas. The carbon monoxide flue gas discharged from the heat exchange device, after dust collection and purification, is used to synthesize phosgene.

[0007] The carbon dioxide feedstock gas preheating device of this invention comprises a vertical refractory circular tube inside, containing a metal ball with a diameter of 3-8 cm. The metal ball material, meeting the technical requirements, is one of molybdenum, tungsten, vanadium, niobium, nickel, and iron, or an alloy thereof. The outer wall of the refractory circular tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral gas conduit is installed outside the insulation layer. The gas conduit material, meeting the technical requirements, is one of aluminum nitride, magnesium oxide, silicon nitride, and corundum. Carbon dioxide feedstock gas flows through the tube to reduce the surface temperature of the carbon dioxide feedstock gas preheating device. An electromagnetic induction coil is wound around the outside of the vertical refractory circular tube and is connected to alternating current. The carbon dioxide feedstock gas preheating device has a carbon dioxide gas inlet at the bottom and a high-temperature carbon dioxide gas outlet at the top. In the feedstock gas preheating device, the carbon dioxide feedstock gas is heated to 1000℃-1200℃ and bottom-blown into an electromagnetic induction heating reactor to be used as feedstock gas for producing carbon monoxide.

[0008] An application method for a system for producing phosgene from carbon dioxide-based chemical raw materials, the specific steps of which are as follows: Step 1: Carbon blocks are added into the vertical metal tube of the electromagnetic induction heating reactor through the carbon raw material feeding hopper and the carbon enclosed chamber, until the reaction chamber volume reaches two-thirds. Step 2: Divide the carbon dioxide raw material gas into three parts. One part is fed into the heat exchange device, one part is fed into the spiral gas duct of the electromagnetic induction heating reactor, and one part is fed into the spiral gas duct of the carbon dioxide raw material gas preheating device. The three parts of carbon dioxide gas after heating are combined and fed into the carbon dioxide raw material gas preheating device to heat the carbon dioxide raw material gas to 1000℃~1200℃. Step 3: The carbon dioxide raw material gas heated to 1000℃~1200℃ is introduced into the vertical metal tube of the electromagnetic induction heating reactor to react with the carbon blocks in the reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step four: Add carbon blocks to the feeding hopper of the electromagnetic induction heating reactor to allow them to enter the reactor and replenish the carbon consumed by the chemical reaction. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor, it enters the heat exchange device, where it transfers heat to the carbon dioxide raw material gas. After dust collection and purification, the dust and sulfur-containing impurities in the carbon monoxide flue gas are removed. The resulting carbon monoxide enters the phosgene synthesis device, where it reacts with the chlorine gas generated by the chlor-alkali process to produce phosgene.

[0009] Beneficial effects of the present invention

[0010] (1) Traditional phosgene chemical process uses coal as the basic chemical raw material to produce carbon monoxide. The method proposed in this application uses carbon dioxide and carbon as raw materials to produce carbon monoxide. As can be seen from the chemical reaction equation (CO2+C=2CO), the method proposed in this application can reduce carbon dioxide emissions. That is, only 0.5 moles of carbon are needed to produce 1 mole of carbon monoxide, while the traditional method requires 1 mole of carbon.

[0011] (2) Photo / electrocatalytic reduction of carbon dioxide is a widely studied technology for the utilization of carbon dioxide resources. However, this method has problems such as complex electrolytic cell structure, unstable electrode performance, low carbon dioxide conversion efficiency, and small production scale, which prevents large-scale industrial application. Compared with the photo / electrochemical reduction of carbon dioxide, the method proposed in this invention has the advantages of high efficiency, low cost, and strong industrial applicability, and maximizes the utilization of thermal energy, thus having broad prospects for industrial application.

[0012] (3) Unlike traditional resistance heating and fuel combustion heating, the heating method used in this invention is electromagnetic induction heating. This method is a non-contact heating method with the characteristics of high efficiency, speed and precise control, and it is not easy to introduce impurities.

[0013] (4) Carbon dioxide is a major greenhouse gas and also an important carbon resource. Converting carbon dioxide into useful chemicals and realizing the recycling of carbon resources is one of the important technical ways to achieve carbon dioxide emission reduction. However, to date, no new industrial technology can convert carbon dioxide into useful chemicals on a large scale, with high efficiency and low cost. The method proposed in this application can continuously, stably and efficiently convert carbon dioxide into carbon monoxide, and then synthesize phosgene, which has good industrial applicability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the system for producing phosgene from carbon dioxide as a chemical raw material according to the present invention. In the diagram: 1-Electromagnetic induction heating reactor, 2-Carbon dioxide raw material gas preheating device, 3-Heat exchange device. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example 1

[0016] like Figure 1 As shown, the reaction apparatus for producing phosgene from carbon dioxide as a chemical raw material includes an electromagnetic induction heating reactor 1, a heat exchange device 2, and a carbon dioxide raw material gas preheating device 3.

[0017] The electromagnetic induction heating reactor contains a vertical iron pipe, 1.8 meters high, 0.28 meters in inner diameter, and 0.02 meters thick. The outer wall of the pipe is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral aluminum nitride gas duct is located outside the insulation layer. An electromagnetic induction coil is wound around the outermost part of the reactor. Alternating current is passed through the coil, and by controlling the frequency and current intensity, the iron pipe is heated, providing heat energy for the endothermic reaction within the reactor. The electromagnetic induction coil is divided into three independent sections, with the upper section temperature controlled at 700℃, the middle section at 900℃, and the lower section at 1000℃. A carbon dioxide gas inlet is located on the lower side of the reactor, and a flue gas outlet is located on the upper side. The top of the reactor has a carbon feed hopper and a carbon sealing chamber, while the bottom has two ash locks and one ash silo, with the ash silo located between the two ash locks.

[0018] The carbon monoxide flue gas discharged from the electromagnetic induction heating reactor enters the heat exchange device, where it exchanges heat with the carbon dioxide feed gas. The low-temperature flue gas discharged from the heat exchange device, after dust collection and purification, enters the phosgene reactor, where it reacts with chlorine from the chlor-alkali process to generate phosgene.

[0019] Before entering the electromagnetic induction heating reactor, carbon dioxide is preheated to 1000℃ using a carbon dioxide feed gas preheating device, and then bottom-blown into the reactor. The preheating device contains a vertical, circular tube made of 1.9 meters long, with an inner diameter of 0.19 meters and a wall thickness of 0.04 meters. A 3-centimeter diameter iron ball is placed inside the tube. The outer wall of the refractory tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral aluminum nitride gas conduit is located outside the insulation layer. Carbon dioxide feed gas flows through the conduit to reduce the surface temperature of the preheating device. An electromagnetic induction coil is wound around the outside of the vertical refractory tube. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the iron ball is heated, providing thermal energy for the carbon dioxide. The preheating device has a carbon dioxide gas inlet at the bottom and a high-temperature carbon dioxide gas outlet at the top.

[0020] The specific implementation steps are as follows: Step 1: Carbon blocks (coke) are added into the vertical iron pipe of the electromagnetic induction heating reactor through the carbon raw material feeding hopper and the carbon enclosed chamber, until the reaction chamber volume reaches two-thirds. Step two involves dividing the carbon dioxide feedstock gas into three parts. One part is fed into a heat exchanger to exchange heat with the carbon monoxide flue gas, lowering its temperature to below 50°C. Another part is fed into a spiral gas duct of an electromagnetic induction heating reactor to reduce its surface temperature to below 60°C. The third part is fed into a spiral gas duct of a carbon dioxide feedstock gas preheating device to further reduce the reactor's surface temperature to below 70°C. The three heated portions of carbon dioxide gas are then combined and fed into the carbon dioxide feedstock gas preheating device, where they are heated to 1000°C. Step 3: The carbon dioxide raw material gas heated to 1000℃ is introduced into the vertical iron pipe of the electromagnetic induction heating reactor to react with the carbon block in the electromagnetic induction heating reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step four: continuously add coke to the electromagnetic induction heating reactor to replenish the carbon consumed by the chemical reaction. The ash generated during the reaction is discharged from the bottom of the electromagnetic induction heating reactor. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor, it enters the heat exchange device to exchange heat with the carbon dioxide raw material gas. Then, the dust in the carbon monoxide flue gas is removed by the centrifugal dust collector. In the desulfurization reactor, zinc oxide is used to remove sulfides and mercaptans from the flue gas. The resulting gas reacts with chlorine to generate phosgene. The required chlorine comes from the chlor-alkali process.

[0021] In this embodiment, the conversion rate of carbon dioxide to carbon monoxide in the electromagnetic induction heating reactor reaches 96%. This device can continuously, stably, and efficiently convert carbon dioxide into carbon monoxide. Example 2

[0022] like Figure 1 As shown, the reaction apparatus for producing phosgene from carbon dioxide as a chemical raw material includes an electromagnetic induction heating reactor 1, a heat exchange device 2, and a carbon dioxide raw material gas preheating device 3.

[0023] The electromagnetic induction heating reactor contains a vertical iron / nickel alloy tube, 1.7 meters high, 0.28 meters in inner diameter, and 0.025 meters thick. The outer wall of the iron / nickel alloy tube is wrapped with a high-temperature resistant asbestos insulation layer. A spiral magnesium oxide gas duct is located outside the insulation layer. An electromagnetic induction coil is wound around the outermost part of the reactor. Alternating current is passed through the coil. By controlling the frequency and current intensity of the alternating current, the iron / nickel alloy is heated, providing thermal energy for the endothermic reaction within the reactor. The electromagnetic induction coil is divided into three independent sections, with the upper section temperature controlled at 800℃, the middle section at 1000℃, and the lower section at 1200℃. A carbon dioxide gas inlet is located on the lower side of the reactor, and a carbon monoxide flue gas outlet is located on the upper side. The top of the reactor has a carbon feed hopper and a carbon sealing chamber, while the bottom has two ash locks and one ash bin, with the ash bin located between the two ash locks.

[0024] The carbon monoxide flue gas discharged from the electromagnetic induction heating reactor enters the heat exchange device, where it exchanges heat with the carbon dioxide feed gas. The low-temperature flue gas discharged from the heat exchange device, after dust collection and purification, enters the phosgene reactor, where it reacts with chlorine from the chlor-alkali process to generate phosgene.

[0025] Before entering the electromagnetic induction heating reactor, carbon dioxide is preheated to 1200℃ using a carbon dioxide feed gas preheating device, and then bottom-blown into the reactor. The preheating device contains a vertical, circular tube made of 1.8 meters long, with an inner diameter of 0.21 meters and a wall thickness of 0.035 meters. Inside the tube are iron / nickel alloy spheres with a diameter of 8 centimeters. The outer wall of the refractory tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral magnesia gas conduit is located outside the insulation layer. Carbon dioxide feed gas flows through the conduit to reduce the surface temperature of the preheating device. An electromagnetic induction coil is wound around the outside of the vertical refractory tube. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the iron / nickel alloy spheres are heated, providing thermal energy for the carbon dioxide. The preheating device has a carbon dioxide gas inlet at the bottom and a high-temperature carbon dioxide gas outlet at the top.

[0026] The specific implementation steps are as follows: Step 1: Carbon blocks (anthracite) are added into the vertical iron / nickel alloy tube of the electromagnetic induction heating reactor through the carbon raw material feeding hopper and the carbon enclosed chamber, until the reactor volume reaches two-thirds. Step two involves dividing the carbon dioxide feedstock gas into three parts. One part is fed into a heat exchanger to exchange heat with the carbon monoxide flue gas, lowering its temperature to below 60°C. Another part is fed into a spiral magnesium oxide gas conduit in an electromagnetic induction heating reactor to reduce its surface temperature to below 70°C. The third part is fed into a spiral gas conduit in a carbon dioxide feedstock gas preheating device to further reduce the reactor's surface temperature to below 60°C. The three portions of carbon dioxide gas are then combined and fed into the carbon dioxide feedstock gas preheating device, where they are heated to 1200°C. Step 3: The carbon dioxide raw material gas heated to 1200℃ is introduced into the vertical iron / nickel alloy tube of the electromagnetic induction heating reactor to react with the carbon block in the electromagnetic induction heating reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step 4: Anthracite is continuously added to the electromagnetic induction heating reactor to replenish the carbon consumed by the chemical reaction. The ash generated during the reaction is discharged from the bottom of the electromagnetic induction heating reactor. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor, it enters the heat exchange device to exchange heat with the carbon dioxide raw material gas. Then, the dust in the carbon monoxide flue gas is removed by the electrostatic precipitator. In the desulfurization reactor, zinc oxide is used to remove sulfides and mercaptans from the flue gas. The resulting gas reacts with chlorine to generate phosgene. The required chlorine comes from the chlor-alkali process.

[0027] In this embodiment, the conversion rate of carbon dioxide to carbon monoxide in the electromagnetic induction heating reactor reaches 98%. This device can continuously, stably, and efficiently convert carbon dioxide into carbon monoxide. Example 3

[0028] like Figure 1 As shown, the reaction apparatus for producing phosgene from carbon dioxide as a chemical raw material includes an electromagnetic induction heating reactor 1, a heat exchange device 2, and a carbon dioxide raw material gas preheating device 3.

[0029] The electromagnetic induction heating reactor contains a vertical iron / molybdenum alloy tube, 2.1 meters high, 0.30 meters in inner diameter, and 0.022 meters thick. The outer wall of the iron / molybdenum alloy tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral corundum gas duct is located outside the insulation layer. An electromagnetic induction coil is wound around the outermost part of the reactor. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the iron / molybdenum alloy tube is heated, providing thermal energy for the endothermic reaction within the reactor. The electromagnetic induction coil is divided into three independent sections, with the upper section temperature controlled at 700℃, the middle section at 900℃, and the lower section at 1000℃. A carbon dioxide gas inlet is located on the lower side of the reactor, and a flue gas outlet is located on the upper side. The top of the reactor has a carbon feed hopper and a carbon sealing chamber, while the bottom has two ash locks and one ash silo, with the ash silo located between the two ash locks.

[0030] The carbon monoxide flue gas discharged from the electromagnetic induction heating reactor enters the heat exchange device, where it exchanges heat with the carbon dioxide feed gas. The low-temperature flue gas discharged from the heat exchange device, after dust collection and purification, enters the phosgene reactor, where it reacts with chlorine from the chlor-alkali process to generate phosgene.

[0031] Before entering the electromagnetic induction heating reactor, carbon dioxide is preheated to 1000℃ using a carbon dioxide feed gas preheating device, and then bottom-blown into the reactor. The carbon dioxide feed gas preheating device contains a vertical, circular tube made of 1.75 meters long, with an inner diameter of 0.25 meters and a wall thickness of 0.035 meters. Inside the tube are iron / molybdenum alloy spheres with a diameter of 8 centimeters. The outer wall of the circular refractory tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral corundum gas conduit is located outside the insulation layer. Carbon dioxide feed gas flows through the conduit to reduce the surface temperature of the preheating device. An electromagnetic induction coil is wound around the outside of the vertical refractory tube. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the iron / molybdenum alloy spheres are heated, providing thermal energy for the carbon dioxide. The carbon dioxide feed gas preheating device has a carbon dioxide gas inlet at the bottom and a high-temperature carbon dioxide gas outlet at the top.

[0032] The specific implementation steps are as follows: Step 1: Carbon blocks (chopped straw) are added into the vertical iron / molybdenum alloy tube of the electromagnetic induction heating reactor through the carbon raw material feeding hopper and the carbon sealed chamber, until the reaction chamber volume reaches two-thirds. Step two involves dividing the carbon dioxide feedstock gas into three parts. One part is fed into a heat exchanger to exchange heat with the carbon monoxide flue gas, lowering its temperature to below 55°C. Another part is fed into a spiral gas duct of an electromagnetic induction heating reactor to reduce its surface temperature to below 65°C. The third part is fed into a spiral gas duct of a carbon dioxide feedstock gas preheating device to further reduce the reactor's surface temperature to below 50°C. The three heated portions of carbon dioxide gas are then combined and fed into the carbon dioxide feedstock gas preheating device, where they are heated to 1000°C. Step 3: Carbon dioxide raw material gas heated to 1000℃ is introduced into the vertical iron / molybdenum alloy tube of the electromagnetic induction heating reactor to react with the carbon block in the electromagnetic induction heating reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step 4: Continuously add chopped straw to the electromagnetic induction heating reactor to replenish the carbon consumed by the chemical reaction. The ash generated during the reaction is discharged from the bottom of the electromagnetic induction heating reactor. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor, it enters the heat exchange device to exchange heat with the carbon dioxide raw material gas. Then, the dust in the carbon monoxide flue gas is removed by the bag dust collector. In the desulfurization reactor, zinc oxide is used to remove sulfides and mercaptans from the flue gas. The resulting gas reacts with chlorine to generate phosgene. The required chlorine comes from the chlor-alkali process.

[0033] In this embodiment, the conversion rate of carbon dioxide to carbon monoxide in the electromagnetic induction heating reactor reaches 98%. This device can continuously, stably, and efficiently convert carbon dioxide into carbon monoxide. Example 4

[0034] like Figure 1 As shown, the reaction apparatus for producing phosgene from carbon dioxide as a chemical raw material includes an electromagnetic induction heating reactor 1, a heat exchange device 2, and a carbon dioxide raw material gas preheating device 3.

[0035] The electromagnetic induction heating reactor contains a vertical iron / tungsten alloy tube, 1.6 meters high, 0.23 meters in inner diameter, and 0.03 meters thick. The outer wall of the iron / tungsten alloy tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral silicon nitride gas duct is located outside the insulation layer. An electromagnetic induction coil is wound around the outermost part of the reactor. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the iron / tungsten alloy tube is heated, providing thermal energy for the endothermic reaction within the reactor. The electromagnetic induction coil is divided into three independent sections, with the upper section temperature controlled at 800℃, the middle section at 1000℃, and the lower section at 1100℃. A carbon dioxide gas inlet is located on the lower side of the reactor, and a flue gas outlet is located on the upper side. The top of the reactor has a carbon feed hopper and a carbon sealing chamber, while the bottom has two ash locks and one ash bin, with the ash bin located between the two ash locks.

[0036] The carbon monoxide flue gas discharged from the electromagnetic induction heating reactor enters the heat exchange device, where it exchanges heat with the carbon dioxide feed gas. The low-temperature carbon monoxide flue gas discharged from the heat exchange device, after dust collection and purification, enters the phosgene reactor, where it reacts with chlorine from the chlor-alkali process to generate phosgene.

[0037] Before entering the electromagnetic induction heating reactor, carbon dioxide is preheated to 1100℃ using a carbon dioxide feed gas preheating device, and then bottom-blown into the reactor. The preheating device contains a vertical, circular tube made of 1.7 meters long, with an inner diameter of 0.18 meters and a wall thickness of 0.035 meters. Inside the tube are iron / tungsten alloy spheres with a diameter of 5 centimeters. The outer wall of the refractory tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral silicon nitride gas conduit is located outside the insulation layer. Carbon dioxide feed gas flows through the conduit to reduce the surface temperature of the preheating device. An electromagnetic induction coil is wound around the outside of the vertical refractory tube. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the iron / tungsten alloy spheres are heated, providing thermal energy for the carbon dioxide. The preheating device has a carbon dioxide gas inlet at the bottom and a high-temperature carbon dioxide gas outlet at the top.

[0038] The specific implementation steps are as follows: Step 1: Carbon blocks (coke + straw) are added into the vertical iron / tungsten alloy tube of the electromagnetic induction heating reactor through the carbon raw material feeding hopper and the carbon sealed chamber, reaching two-thirds of the reaction chamber volume. Step two involves dividing the carbon dioxide feedstock gas into three parts. One part is fed into a heat exchanger to exchange heat with the carbon monoxide flue gas, lowering its temperature to below 60°C. Another part is fed into a spiral silicon nitride gas duct of an electromagnetic induction heating reactor to reduce its surface temperature to below 65°C. The third part is fed into a spiral silicon nitride gas duct of a carbon dioxide feedstock gas preheating device to further reduce the reactor's surface temperature to below 60°C. The three portions of carbon dioxide gas are then combined and fed into the carbon dioxide feedstock gas preheating device, where they are heated to 1100°C. Step 3: The carbon dioxide raw material gas heated to 1100℃ is introduced into the vertical iron / tungsten alloy tube of the electromagnetic induction heating reactor to react with the carbon block in the electromagnetic induction heating reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step four: Carbon blocks are continuously added to the electromagnetic induction heating reactor to replenish the carbon consumed by the chemical reaction. The ash generated during the reaction is discharged from the bottom of the electromagnetic induction heating reactor. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor, it enters the heat exchange device to exchange heat with the carbon dioxide raw material gas. Then, the dust in the carbon monoxide flue gas is removed by the centrifugal dust collector. In the desulfurization reactor, zinc oxide is used to remove sulfides and mercaptans from the flue gas. The resulting gas reacts with chlorine to generate phosgene. The required chlorine comes from the chlor-alkali process.

[0039] In this embodiment, the conversion rate of carbon dioxide to carbon monoxide in the electromagnetic induction heating reactor reaches 97%. This device can continuously, stably, and efficiently convert carbon dioxide into carbon monoxide. Example 5

[0040] like Figure 1 As shown, the reaction apparatus for producing phosgene from carbon dioxide as a chemical raw material includes an electromagnetic induction heating reactor 1, a heat exchange device 2, and a carbon dioxide raw material gas preheating device 3.

[0041] The electromagnetic induction heating reactor contains a vertical tungsten tube, 1.7 meters high, 0.26 meters in inner diameter, and 0.024 meters thick. The outer wall of the tungsten tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral silicon carbide gas duct is located outside the insulation layer. An electromagnetic induction coil is wound around the outermost part of the reactor. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the tungsten tube is heated, providing thermal energy for the endothermic reaction within the reactor. The electromagnetic induction coil is divided into three independent sections, with the upper section temperature controlled at 900℃, the middle section at 1000℃, and the lower section at 1100℃. A carbon dioxide gas inlet is located on the lower side of the reactor, and a flue gas outlet is located on the upper side. The top of the reactor has a carbon feed hopper and a carbon sealing chamber, while the bottom has two ash locks and one ash bin, with the ash bin located between the two ash locks.

[0042] The carbon monoxide flue gas discharged from the electromagnetic induction heating reactor enters the heat exchange device, where it exchanges heat with the carbon dioxide feed gas. The low-temperature flue gas discharged from the heat exchange device, after dust collection and purification, enters the phosgene reactor, where it reacts with chlorine from the chlor-alkali process to generate phosgene.

[0043] Before entering the electromagnetic induction heating reactor, carbon dioxide is preheated to 1100℃ using a carbon dioxide feed gas preheating device, and then bottom-blown into the reactor. The carbon dioxide feed gas preheating device contains a vertical, circular tube made of 1.8 meters long, with an inner diameter of 0.23 meters and a wall thickness of 0.042 meters. A 6-centimeter diameter tungsten ball is placed inside the tube. The outer wall of the refractory tube is wrapped with a high-temperature resistant asbestos insulation layer, and a spiral silicon carbide gas conduit is located outside the insulation layer. Carbon dioxide feed gas flows through the conduit to reduce the surface temperature of the preheating device. An electromagnetic induction coil is wound around the outside of the vertical refractory tube. Alternating current is passed through the coil, and by controlling the frequency and current intensity of the alternating current, the tungsten ball is heated, providing thermal energy for the carbon dioxide. The carbon dioxide feed gas preheating device has a carbon dioxide gas inlet at the bottom and a high-temperature carbon dioxide gas outlet at the top.

[0044] The specific implementation steps are as follows: Step 1: Carbon blocks (anthracite + wood chips) are added into the vertical tungsten tube of the electromagnetic induction heating reactor through the carbon raw material feeding hopper and the carbon enclosed chamber, until the reaction chamber volume is two-thirds full. Step two involves dividing the carbon dioxide feedstock gas into three parts. One part is fed into a heat exchanger to exchange heat with the carbon monoxide flue gas, lowering its temperature to below 50°C. Another part is fed into a spiral silicon carbide gas duct of an electromagnetic induction heating reactor to reduce its surface temperature to below 60°C. The third part is fed into a spiral silicon carbide gas duct of a carbon dioxide feedstock gas preheating device to further reduce the reactor's surface temperature to below 60°C. The three heated portions of carbon dioxide gas are then combined and fed into the carbon dioxide feedstock gas preheating device, where they are heated to 1100°C. Step 3: The carbon dioxide raw material gas heated to 1100℃ is introduced into the vertical tungsten tube of the electromagnetic induction heating reactor to react with the carbon block in the electromagnetic induction heating reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step four: Carbon blocks are continuously added to the electromagnetic induction heating reactor to replenish the carbon consumed by the chemical reaction. The ash generated during the reaction is discharged from the bottom of the electromagnetic induction heating reactor. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor, it enters the heat exchange device to exchange heat with the carbon dioxide raw material gas. Then, the dust in the carbon monoxide flue gas is removed by the gravity dust collection device. In the desulfurization reactor, zinc oxide is used to remove sulfides and mercaptans from the flue gas. The resulting gas reacts with chlorine to generate phosgene. The required chlorine comes from the chlor-alkali process.

[0045] In this embodiment, the conversion rate of carbon dioxide to carbon monoxide in the electromagnetic induction heating reactor reaches 97%. This device can continuously, stably, and efficiently convert carbon dioxide into carbon monoxide.

[0046] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A reaction apparatus for producing phosgene from carbon dioxide as a basic chemical feedstock, characterized in that: It includes an electromagnetic induction heating reactor (1), a heat exchange device (2), and a carbon dioxide raw material gas preheating device (3). The electromagnetic induction heating reactor (1) is equipped with a vertical metal tube. The outer wall of the metal tube is wrapped with a high-temperature resistant asbestos insulation layer. A spiral gas duct is provided outside the high-temperature resistant asbestos insulation layer. Carbon dioxide raw material gas flows through the tube to reduce the surface temperature of the electromagnetic induction heating reactor. An electromagnetic induction coil is wound around the outside of the spiral gas duct. The electromagnetic induction coil is connected to AC power. A carbon dioxide gas inlet is provided on the lower side of the electromagnetic induction heating reactor (1), and a flue gas outlet is provided on the upper side. A carbon raw material feeding hopper and a carbon sealing chamber are provided at the top of the electromagnetic induction heating reactor (1). Two ash locks and one ash slag hopper are provided at the bottom of the electromagnetic induction heating reactor (1). The ash slag hopper is located between the two ash locks. The high-temperature gas inlet of the heat exchange device (2) is connected to the flue gas outlet of the electromagnetic induction heating reactor (1). The low-temperature flue gas discharged from the heat exchange device (2) is used to synthesize phosgene after dust collection and purification. The heat exchange medium of the heat exchange device (2) is carbon dioxide raw material gas. Before carbon dioxide enters the electromagnetic induction heating reactor, it is heated to 1000℃~1200℃ by a carbon dioxide raw material gas preheating device (3), and then blown into the electromagnetic induction heating reactor (1) from the bottom. The carbon dioxide raw material gas preheating device (3) is equipped with a vertical refractory material circular tube inside, and a metal ball with a diameter of 3~8 cm is placed inside the tube. The outer wall of the refractory material circular tube is wrapped with a high-temperature resistant asbestos insulation layer. A spiral gas duct is set on the outside of the insulation layer. Carbon dioxide raw material gas flows through the tube to reduce the surface temperature of the carbon dioxide raw material gas preheating device (3). An electromagnetic induction coil is wound around the outside of the vertical refractory material circular tube. The electromagnetic induction coil is connected to the alternating current. The bottom of the carbon dioxide raw material gas preheating device (3) is equipped with a carbon dioxide gas inlet and the top is equipped with a high-temperature carbon dioxide gas outlet. The reaction device system also includes a phosgene synthesis device. The flue gas discharged from the heat exchange device (2) is collected and purified before entering the phosgene reaction device. Chlorine produced by the chlor-alkali process also enters the phosgene reaction device.

2. The reaction apparatus for producing phosgene from carbon dioxide-based chemical raw materials according to claim 1, characterized in that: The metal tubes in the electromagnetic induction heating reactor (1) and the metal balls in the carbon dioxide raw material gas preheating device (3) are made of molybdenum, tungsten, vanadium, niobium, nickel, iron, or an alloy thereof.

3. The reaction apparatus for producing phosgene from carbon dioxide-based chemical raw materials according to claim 1, characterized in that: The spiral gas conduit material of the electromagnetic induction heating reactor (1) and the carbon dioxide raw material gas preheating device (3) is one of aluminum nitride, silicon carbide, magnesium oxide, silicon nitride or corundum.

4. The reaction apparatus for producing phosgene from carbon dioxide-based chemical raw materials according to claim 1, characterized in that: The electromagnetic induction heating reactor (1) has an electromagnetic induction coil divided into three independent sections. The temperature of the upper section is controlled at 700℃~900℃, the temperature of the middle section is controlled at 900℃~1000℃, and the temperature of the lower section is controlled at 1000℃~1200℃.

5. A method for applying the reaction apparatus for producing phosgene from carbon dioxide-based chemical raw materials according to claim 1, characterized in that... The specific steps are as follows: Step 1: Load carbon blocks into the electromagnetic induction heating reactor (1) to fill two-thirds of the reaction chamber volume; Step 2: Divide the carbon dioxide raw material gas into three parts. One part is fed into the heat exchange device (2), one part is fed into the spiral gas duct of the reactor (1), and one part is fed into the spiral gas duct of the carbon dioxide raw material gas preheating device (3). The three parts of carbon dioxide gas after heating are combined and sent into the carbon dioxide raw material gas preheating device (3) to heat the carbon dioxide raw material gas to 1000℃~1200℃. Step 3: The carbon dioxide raw material gas heated to 1000℃~1200℃ is introduced into the vertical metal tube of the electromagnetic induction heating reactor (1) to react with the carbon block in the electromagnetic induction heating reactor to generate carbon monoxide flue gas. The ash generated during the reaction is discharged from the bottom of the reactor. Step four: Add carbon blocks to the feeding hopper of the electromagnetic induction heating reactor to allow them to enter the reactor and replenish the carbon consumed by the chemical reaction. Step 5: After the carbon monoxide flue gas is discharged from the electromagnetic induction heating reactor (1), it enters the heat exchange device (2) to transfer heat to the carbon dioxide raw material gas. After dust collection and purification, the dust and sulfur-containing impurities in the carbon monoxide flue gas are removed. The resulting carbon monoxide enters the phosgene synthesis device and reacts with the chlorine generated by the chlor-alkali process to generate phosgene.

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