Adsorption separation device and method for heavy water purification and application

Abstract

The invention belongs to the technical field of water isotope separation and purification, and particularly relates to an adsorption separation device and method for heavy water purification and application. The adsorption separation device comprises a main adsorption tower and an auxiliary adsorption tower, temperature-sensitive solid adsorbents capable of selectively adsorbing protium water are arranged in the main adsorption tower and the auxiliary adsorption tower, independent slot waveguide antennas are arranged on the outer surfaces of the side walls, and each slot waveguide antenna is connected with an independent microwave emission source; tower top feed ports of the main adsorption tower and the auxiliary adsorption tower are connected with a raw material feed pipeline, tower top discharge ports of the main adsorption tower and the auxiliary adsorption tower are connected with a light water discharge pipeline through an independent control valve group, tower bottom feed ports of the main adsorption tower and the auxiliary adsorption tower are connected with a nitrogen purging pipeline through an independent control valve group, and tower bottom discharge ports of the main adsorption tower and the auxiliary adsorption tower are connected with a heavy water discharge pipeline through an independent control valve group. The adsorption separation device is high in separation efficiency, low in process energy consumption, environmentally friendly, free of pollution, low in production cost and suitable for separating high-purity heavy water from low-concentration heavy water or raw material water.

Description

Technical Field

[0001] The invention belongs to the technical field of water isotope separation and purification, and specifically relates to an adsorption separation device, method and application for heavy water purification. Background Art

[0002] Deuterated water (D 2 O), a water isotope with a molecular weight lower than that of conventional water (H 2 O)(MW≈18.0153) is about 11% higher, so it is called heavy water. The main use of high-purity heavy water is as a moderator in nuclear reactors to reduce the speed of neutrons in the process of nuclear fission. It can also be used as a raw material for nuclear fusion reactions. In addition, deuterium gas obtained by decomposing high-purity heavy water is also widely used in semiconductor processing, medical testing, lighting systems, chemical tracing, weapons manufacturing and other fields, so heavy water is a very important strategic resource. However, due to the extremely low abundance of deuterium in nature (only 0.015%), it is very difficult to obtain and purify heavy water. At present, the industrial production of heavy water usually adopts electrolysis, hydrogen sulfide-water double heat exchange method, and distillation method.

[0003] The hydrogen sulfide-water double heat exchange method belongs to the chemical exchange method. Its principle is to rely on temperature to affect the distribution ratio of hydrogen isotopes between the gas and liquid phases, and to use the countercurrent of hydrogen sulfide and water on the catalyst to enrich deuterated water in the liquid phase. U.S. Patent US3685966A published in 1972 describes this production method in detail. However, due to the excessive toxicity of hydrogen sulfide gas and severe corrosion to equipment, this method is gradually being eliminated and replaced by the hydrogen-water double heat exchange method. The disadvantages of the hydrogen-water double heat exchange method are that the separation coefficient is low, the water consumption is large, and the energy consumption is huge after multi-stage separation. In addition, the large amount of precious metal catalysts used make the cost of producing heavy water by this method high.

[0004] The principle of preparing heavy water by electrolysis is that deuterated water (D 2 O) compared to protinated water (H 2O) is not easy to be electrolyzed, and the protium water in the raw water is removed by electrolysis, so that the deuterated water is enriched in the electrolyte in large quantities, thereby obtaining concentrated heavy water. The current mainstream electrolysis process is alkaline electrolysis, and the cathode is made of low-carbon steel or nickel, platinum, and the anode material is mostly nickel or nickel-plated steel. However, using ordinary water to directly produce heavy water by electrolysis, energy consumption is extremely large and the yield is very low, and a large amount of alkaline electrolyte will pollute the environment. Therefore, the electrolysis method is often used in conjunction with a distillation method or a chemical exchange method to further purify the heavy water after the latter is concentrated. For example, patent CN116516372A proposes a device and method for electrolyzing and concentrating low-purity heavy water and producing high-purity deuterium gas at the same time. However, the separation factor of the electrolysis method is generally around 10, which is relatively low. Therefore, multi-stage electrolysis is usually required to gradually purify heavy water, so the production cost of using electrolysis to prepare heavy water is very high.

[0005] The distillation method uses the difference in vapor pressure between water isotopes to separate heavy water from light water. Concentrated deuterated water is obtained by multi-stage distillation of raw water. For example, U.S. Patent US2999795A and Japanese Patent JPS5640401A describe in detail the distillation method for concentrating heavy water. Although the distillation method is simpler in process, less polluting in the process, and lower in maintenance cost than the chemical exchange method and the electrolysis method, the separation factor of the distillation method is relatively low, only 1.03 to 1.06. Therefore, the heavy water production process relying on the distillation method requires the use of multi-stage distillation towers in series to vaporize a large amount of raw water, resulting in the disadvantages of huge equipment size, large construction investment, large water consumption, and high energy consumption in the distillation method.

[0006] Adsorption separation is widely used in the separation and purification of gas phase mixtures or liquid phase mixtures due to its advantages of high selectivity, low energy consumption, renewable use of adsorbents, and low pollution. For the production of heavy water, most of the current adsorption processes are for the separation of hydrogen isotopes, and then the hydrogen isotopes are oxidized to obtain heavy water. For example, patents CN112851954A, CN113262650A, CN114618300A, and CN114653343A introduce adsorption materials and preparation methods for efficient separation of hydrogen isotopes. Patent CN115382393A introduces a hydrogen isotope gas separation device. However, the adsorption separation of hydrogen isotopes requires extremely low temperatures to obtain good separation efficiency: for example, the separation factor of protium / deuterium is 10 at 20K, but it is only about 2 when the temperature rises to 77K. On the contrary, the desorption process of the target molecule needs to be carried out in a high temperature environment, so in actual production, the adsorption equipment needs to be repeatedly placed in a high temperature and extremely low temperature environment, which greatly increases the difficulty and cost of equipment manufacturing; at the same time, the maintenance of the low temperature environment requires the consumption of a large amount of liquid nitrogen, making the cost of producing heavy water by hydrogen isotope adsorption at low temperature relatively high. Therefore, the development of a hydrogen isotope adsorption separation process at room temperature is crucial to reducing the cost of heavy water production.

[0007] In summary, based on the common problems of high process energy consumption, high production cost, low separation efficiency, process pollution, etc. in the current heavy water production process, it is urgent to develop a new green and efficient heavy water separation process and equipment to improve separation efficiency, reduce process energy consumption, reduce production costs, and solve process pollution. Summary of the invention

[0008] In view of the problems of high process energy consumption, high production cost, low separation efficiency, process pollution, etc. in the existing heavy water production technology, the present invention provides an adsorption separation device, method and application for heavy water purification.

[0009] Specifically, the present invention provides the following technical solutions:

[0010] An adsorption separation device for heavy water purification comprises: a main adsorption tower and a secondary adsorption tower;

[0011] The main adsorption tower and the auxiliary adsorption tower are equipped with a temperature-sensitive solid adsorbent capable of selectively adsorbing protium water in water isotope molecules; independent slot waveguide antennas are arranged on the outer surfaces of the side walls of the main adsorption tower and the auxiliary adsorption tower, and each slot waveguide antenna is connected to an independent microwave emission source;

[0012] The top feed ports of the main adsorption tower and the auxiliary adsorption tower are connected to the raw material feed pipeline through an independent control valve group; the top discharge ports of the main adsorption tower and the auxiliary adsorption tower are connected to the light water discharge pipeline through an independent control valve group;

[0013] The bottom feed ports of the main adsorption tower and the auxiliary adsorption tower are connected to the nitrogen purge pipeline through an independent control valve group; the bottom discharge ports of the main adsorption tower and the auxiliary adsorption tower are connected to the heavy water discharge pipeline through an independent control valve group.

[0014] The adsorption separation device provided by the present invention, when performing the adsorption operation, after the raw material (water or low-concentration heavy water) enters the main adsorption tower and the auxiliary adsorption tower, the light water (hydrogenated water) in the water is selectively adsorbed by the temperature-sensitive solid adsorbent at normal temperature and pressure, the light water component in the raw material is removed, the heavy water component is enriched at the bottom of the tower, and high-purity heavy water is discharged through the heavy water discharge pipeline. When performing the desorption operation, the microwave emission source can input microwaves into the main adsorption tower and the auxiliary adsorption tower through the slot waveguide antenna for heating, and the light water vapor is discharged through the light water discharge pipeline at the top of the tower at 373k and normal pressure. At the same time, the nitrogen purge pipeline can provide inert protective gas during microwave heating desorption to prevent the high temperature generated by microwave heating from causing the adsorption material to catch fire or explode. The adsorption tower in this device is divided into a main adsorption tower and a sub-adsorption tower. During actual operation, the two towers perform adsorption and desorption operations alternately. When the adsorbent in the main adsorption tower is saturated with adsorption, it is switched to the sub-tower for adsorption, and the microwave emission source of the main adsorption tower is turned on for desorption. Compared with the traditional single-tower adsorption process, continuous operation can be achieved.

[0015] In the present invention, the temperature-responsive solid adsorbent refers to the one that can preferentially adsorb protium hydrogenated water in water isotope molecules at low temperatures, and at high temperatures, the pore expansion of the adsorbent causes the adsorbed protium hydrogenated water to be desorbed from the pores.

[0016] Preferably, the main adsorption tower and the auxiliary adsorption tower adopt a quasi-optical resonant cavity structure to achieve uniform distribution of the electric field.

[0017] Preferably, the inner surfaces of the main adsorption tower and the auxiliary adsorption tower are provided with a polytetrafluoroethylene layer, an enamel coating or a quartz coating.

[0018] Preferably, the solid adsorbent is a temperature-responsive porous coordination polymer or a temperature-responsive metal-organic framework material.

[0019] Furthermore, the solid adsorbent is made of a microwave absorbing material. Studies have shown that when the solid adsorbent is made of a microwave absorbing material, microwave selective heating preferentially heats the solid adsorbent, resulting in a better effect.

[0020] Preferably, the slot waveguide antenna is arranged on the outer surface of the side wall of the adsorption tower, and the slot width of the slot waveguide antenna at different heights is set to 1 / 6 to 1 / 4 of the microwave wavelength to control the microwave input amount at different positions, thereby achieving uniform distribution of the electric field in the adsorption tower.

[0021] Preferably, a cavity temperature measurement system is also included, which is used to monitor the temperature of the internal solid adsorbent when the adsorption tower is performing a desorption operation, and to adjust the output power of the microwave emission source when the temperature is too high, thereby avoiding high temperature damage to the adsorption material.

[0022] Further preferably, the cavity temperature measurement system is composed of a multi-point temperature measurement optical fiber and a fiber optic spectrometer, and the multi-point temperature measurement optical fiber is vertically arranged in the adsorption tower to achieve temperature measurement of the adsorbent at different heights.

[0023] Preferably, a product filter and a product condenser are sequentially arranged on the light water discharge pipeline and the heavy water discharge pipeline along the material flow direction.

[0024] Preferably, a computer control system is also included, and the control valve groups on the raw material feed pipeline, the light water discharge pipeline, the heavy water discharge pipeline, and the nitrogen purge pipeline, the cavity temperature measurement system, and the microwave emission source are connected to the computer control system through a control circuit. During the adsorption-desorption process, the computer control system controls the action of the control valve groups on each pipeline to achieve the switching of the feed and discharge of the main adsorption tower and the auxiliary adsorption tower. At the same time, during the desorption process, the computer control system analyzes the signal sent back by the cavity temperature measurement system, monitors the temperature in the adsorption tower in real time, and appropriately adjusts the output power of the microwave emission source.

[0025] The present invention also provides an adsorption separation method using the above-mentioned adsorption separation device, wherein the adsorption and desorption of the main adsorption tower and the auxiliary adsorption tower are performed alternately, and the method comprises the following steps:

[0026] (1) When the main adsorption tower is performing adsorption operation and the auxiliary adsorption tower is performing desorption operation, the computer control system first opens the control valve group of the raw material feed pipeline at the top of the main adsorption tower and the control valve group of the heavy water discharge pipeline at the bottom of the main adsorption tower, allowing the raw material (water or low-concentration heavy water) to enter the main adsorption tower from the top of the main adsorption tower;

[0027] (2) When the raw material flows through the solid adsorbent, the protium water molecules therein will be preferentially adsorbed by the solid adsorbent, while the deuterium water molecules will not be adsorbed by the solid adsorbent, thereby increasing the concentration of heavy water in the bottom discharge of the main adsorption tower;

[0028] (3) The heavy water flowing out of the bottom of the main adsorption tower is filtered by a product filter on the heavy water discharge pipeline, and then enters a product condenser for further cooling to become a heavy water product;

[0029] (4) When the solid adsorbent in the main adsorption tower is saturated with adsorption, the computer control system performs a desorption operation on the main adsorption tower. First, the computer control system closes the control valve group on the raw material feed pipeline at the top of the main adsorption tower and the control valve group on the heavy water discharge pipeline at the bottom of the tower, and opens the control valve group on the raw material feed pipeline at the top of the auxiliary adsorption tower and the control valve group on the heavy water discharge pipeline at the bottom of the tower, allowing the raw material to enter the auxiliary adsorption tower;

[0030] (5) After the raw material enters the auxiliary adsorption tower, the computer control system will open the control valve group on the light water discharge pipeline at the top of the main adsorption tower and the control valve group on the nitrogen purge pipeline at the bottom of the tower to allow nitrogen to enter the main adsorption tower, and then turn on the microwave emission source of the main adsorption tower to input microwaves into the main adsorption tower for desorption. The light water vapor generated by desorption enters the light water discharge pipeline through nitrogen purge, and becomes a light water discharge product after being filtered by the product filter and cooled by the product condenser;

[0031] (6) When the auxiliary adsorption tower is saturated with adsorption, the computer control system switches the raw material feed back to the main adsorption tower for adsorption operation and performs the same desorption operation on the auxiliary adsorption tower.

[0032] The present invention also provides application of the above-mentioned adsorption separation device or the above-mentioned adsorption separation method in the field of heavy water separation and purification.

[0033] The beneficial effects of the present invention are at least:

[0034] 1) The present invention provides an adsorption separation device and method for heavy water purification, wherein the adsorption tower is divided into a main adsorption tower and a secondary adsorption tower, and the two towers alternately perform adsorption and desorption operations, which can achieve continuous operation compared to the traditional single-tower adsorption process;

[0035] 2) The present invention provides an adsorption separation device and method for heavy water purification. A temperature-responsive solid adsorbent is used in the adsorption tower, which can directly selectively adsorb and separate water isotope molecules at room temperature and pressure, and the separation factor can reach 200. Compared with the hydrogen isotope adsorption method, the present invention does not need to use a large amount of liquid nitrogen to create an extremely low temperature environment, which greatly saves process energy consumption; compared with the chemical exchange method, the present invention does not need to use expensive precious metal catalysts, which reduces the production cost of heavy water; compared with the electrolysis method, the present invention does not need to consume a large amount of electricity and a large amount of alkaline electrolyte, and the production process is more energy-saving and green and environmentally friendly; compared with the distillation method, the present invention has the advantages of high separation efficiency, convenient operation, simple equipment, and low process energy consumption, and has the potential for large-scale application;

[0036] 3) The present invention provides an adsorption separation device and method for heavy water purification, which uses microwave heating for desorption operation. The microwave selective heating can directly heat the adsorbent or the water molecules in the adsorbent, thereby accelerating the desorption process. Compared with the traditional high-temperature steam or electric heating method, the microwave heating desorption treatment is more efficient, the desorption is more thorough, and the energy consumption is lower, which effectively solves the problem of incomplete desorption and damage to the adsorbent in the traditional heating method;

[0037] 4) The present invention provides an adsorption separation device and method for heavy water purification, which uses a slot waveguide antenna to uniformly feed the microwaves generated by a microwave emission source into an adsorption tower. Compared with the traditional single-port feeding mode, the electric field distribution is more uniform and the heating is more uniform;

[0038] 5) The present invention provides an adsorption separation device and method for heavy water purification, which uses water or low-concentration heavy water as the only operating medium of the adsorption separation device, does not require the use of other additives or auxiliary agents, and the process is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of an adsorption separation device in a specific implementation manner;

[0040] Among them, 1 is a light water product condenser, 2 is a light water product filter, 3 is a first control valve group, 4 is a second control valve group, 5 is a main adsorption tower, 6 is a first slot waveguide antenna, 7 is a first cavity temperature measurement system, 8 is a first microwave emission source, 9 is a third control valve group, 10 is a fourth control valve group, 11 is a fifth control valve group, 12 is a sixth control valve group, 13 is a seventh control valve group, 14 is a heavy water product filter, 15 is a heavy water product condenser, 16 is a second microwave emission source, 17 is a second slot waveguide antenna, 18 is a computer control system, 19 is an auxiliary adsorption tower, 20 is a second cavity temperature measurement system, 21 is an eighth control valve group, 22 is a ninth control valve group, 23 is a raw material feed pipeline, 24 is a light water discharge pipeline, 25 is a heavy water discharge pipeline, and 26 is a nitrogen purge pipeline. DETAILED DESCRIPTION

[0041] For a better understanding of the present invention, the present invention is further described in detail below in conjunction with embodiments, but the scope of protection claimed by the present invention is not limited to the scope represented by the embodiments.

[0042] The raw materials used in the present invention, unless otherwise specified, are all conventional commercially available products. The methods used in the present invention, unless otherwise specified, are all conventional methods in the art. The quality of each substance used in the present invention is the conventional quality.

[0043] An adsorption separation device for heavy water purification, such as Figure 1As shown, it includes: a main adsorption tower 5 and a secondary adsorption tower 19;

[0044] The main adsorption tower 5 and the auxiliary adsorption tower 19 are filled with a temperature-sensitive solid adsorbent capable of selectively adsorbing protium-containing water in water isotope molecules;

[0045] A first slot waveguide antenna 6 is provided on the outer surface of the side wall of the main adsorption tower 5, and the first slot waveguide antenna 6 is connected to the first microwave emission source 8; a second slot waveguide antenna 17 is provided on the outer surface of the side wall of the auxiliary adsorption tower 19, and the second slot waveguide antenna 17 is connected to the second microwave emission source 16;

[0046] The tower top feed port is connected to the raw material feed pipeline 23 through the second control valve group 4 and the eighth control valve group 21 respectively; the tower top discharge ports of the main adsorption tower 5 and the auxiliary adsorption tower 19 are connected to the light water discharge pipeline 24 through the first control valve group 3 and the ninth control valve group 22 respectively;

[0047] The bottom feed ports of the main adsorption tower 5 and the auxiliary adsorption tower 19 are connected to the nitrogen purge pipeline 26 through the fourth control valve group 10 and the sixth control valve group 12, respectively, and the nitrogen purge pipeline 26 is also provided with a third control valve group 9; the bottom discharge ports of the main adsorption tower 5 and the auxiliary adsorption tower 19 are connected to the heavy water discharge pipeline 25 through the fifth control valve group 11 and the seventh control valve group 13, respectively;

[0048] The main adsorption tower 5 and the auxiliary adsorption tower 19 are used as microwave cavities, and the structure is a quasi-optical resonant cavity structure to achieve uniform distribution of the electric field;

[0049] The inner surfaces of the main adsorption tower 5 and the auxiliary adsorption tower 19 are provided with a polytetrafluoroethylene layer to reduce the corrosion of the inner wall of the cavity by high-temperature water vapor during the desorption process and to prevent the burrs on the inner wall of the metal cavity from causing microwave ignition.

[0050] The adsorption separation device also includes a first cavity temperature measurement system 7 and a second cavity temperature measurement system 20 composed of a multi-point temperature measurement optical fiber and an optical fiber spectrometer. The two multi-point temperature measurement optical fibers are closely arranged in the main adsorption tower 5 and the auxiliary adsorption tower 19, respectively, to achieve temperature measurement of the adsorbent at different heights;

[0051] The first slot waveguide antenna 6 and the second slot waveguide antenna 17 are respectively and closely connected and arranged on the outer surfaces of the side walls of the main adsorption tower 5 and the auxiliary adsorption tower 19 to achieve uniform distribution of the electric field in the adsorption tower;

[0052] The light water discharge pipeline 24 is provided with a light water product filter 2 and a light water product condenser 1 in sequence along the material flow direction; the heavy water discharge pipeline 25 is provided with a heavy water product filter 14 and a heavy water product condenser 15 in sequence along the material flow direction;

[0053] The connection between the main adsorption tower 5 and the auxiliary adsorption tower 19 and the raw material feed pipeline and control valve group, the light water discharge pipeline and control valve group, the cavity temperature measurement system, the slot waveguide antenna, the heavy water discharge pipeline and control valve group, and the nitrogen purge pipeline and control valve group meets the electromagnetic wave shielding requirements, and microwave leakage will not occur;

[0054] When the adsorption separation device performs an adsorption operation, after the raw water or low-concentration heavy water enters the main adsorption tower 5 and the auxiliary adsorption tower 19, the light water (hydrogenated water) in the water is selectively adsorbed by the temperature-sensitive solid adsorbent at normal temperature and pressure, the light water component in the raw material is removed, the heavy water component is enriched at the bottom of the tower, and high-purity heavy water is discharged through the heavy water discharge pipeline 25. When performing a desorption operation, the microwave emission sources 8 and 16 can input microwaves into the adsorption tower through the slot waveguide antennas 6 and 17, and the adsorbent or the water molecules in the adsorbent can be directly and rapidly heated by microwave selective heating, thereby accelerating the desorption process. At high temperature and normal pressure, the light water vapor is cooled into liquid light water through the light water discharge pipeline 25 and then discharged.

[0055] The adsorption tower is divided into two adsorption towers, a main adsorption tower 5 and a secondary adsorption tower 19. In actual operation, the two towers alternately perform adsorption and desorption operations. When the adsorbent in the main adsorption tower 5 is saturated with adsorption, the computer control system switches to the secondary adsorption tower 19 for adsorption, and turns on the first microwave emission source 8 of the main adsorption tower 5 to desorb the main adsorption tower 5.

[0056] The adsorption separation device also includes a computer control system 18. The control valve groups on each pipeline, the first cavity temperature measurement system 7 and the second cavity temperature measurement system 20, and the first microwave emission source 8 and the second microwave emission source 16 are connected to the computer control system 18 through a control circuit. During the adsorption process, the computer control system 18 controls the action of the control valve groups on each pipeline to realize the switching of the inlet and outlet materials. During the desorption process, the computer control system 18 analyzes the signals sent back by the first cavity temperature measurement system 7 and the second cavity temperature measurement system 20, respectively, and monitors the temperatures in the main adsorption tower 5 and the auxiliary adsorption tower 19 in real time, and appropriately adjusts the output power of the first microwave emission source 8 and the second microwave emission source 16.

[0057] The specific steps of the adsorption separation method using the above-mentioned adsorption separation device are as follows:

[0058] (1) The adsorption and desorption of the main adsorption tower 5 and the auxiliary adsorption tower 19 are performed alternately. When the main adsorption tower 5 performs the adsorption operation and the auxiliary adsorption tower 19 performs the desorption operation, the computer control system 18 first opens the second control valve group 4 of the raw material feed pipeline 23 at the top of the main adsorption tower 5 and the fifth control valve group 11 of the heavy water discharge pipeline 25 at the bottom of the tower, so that the raw material water or low-concentration heavy water feed liquid enters the main adsorption tower 5 from the top of the main adsorption tower 5;

[0059] (2) When water isotopes flow through the solid adsorbent, protium water molecules will be preferentially adsorbed by the adsorbent, while deuterium water molecules will not be adsorbed by the solid adsorbent, thereby increasing the concentration of heavy water in the bottom discharge of the main adsorption tower 5;

[0060] (3) The heavy water flowing out of the bottom of the main adsorption tower 5 is filtered by the heavy water product filter 14 on the heavy water discharge pipeline 25, and then enters the heavy water product condenser 15 for further cooling to become a heavy water product;

[0061] (4) When the solid adsorbent in the main adsorption tower 5 is saturated, the computer control system 18 performs a desorption operation on the main adsorption tower 5. First, the computer control system 18 closes the second control valve group 4 on the raw material feed pipeline 23 at the top of the main adsorption tower 5 and the fifth control valve group 11 on the heavy water discharge pipeline 25 at the bottom of the tower, and opens the eighth control valve group 21 on the raw material feed pipeline 23 at the top of the auxiliary adsorption tower 19 and the seventh control valve group 13 on the heavy water discharge pipeline 25 at the bottom of the tower, so that the raw material enters the auxiliary adsorption tower 19;

[0062] (5) After the raw material enters the auxiliary adsorption tower 19, the computer control system 18 opens the first control valve group 3 on the light water discharge pipeline 24 at the top of the main adsorption tower and the third control valve group 9 and the fourth control valve group 10 on the nitrogen purge pipeline 26 at the bottom of the tower to allow nitrogen to enter the main adsorption tower 5, and then opens the first microwave emission source 8 of the main adsorption tower 5 to input microwaves into the main adsorption tower 5 for desorption. The light water vapor generated by desorption enters the light water discharge pipeline 24 through nitrogen purge, and becomes a light water discharge product after being filtered by the light water product filter 2 and cooled by the light water product condenser 1;

[0063] (6) When the auxiliary adsorption tower 19 is saturated with adsorption, the computer control system 18 switches the raw material feed back to the main adsorption tower 5 for adsorption operation, and performs the same desorption operation on the auxiliary adsorption tower 19.

[0064] When the adsorption separation method is performing the desorption operation, in order to prevent the microwave from being idle, when it is detected that there is no water vapor discharged from the light water discharge pipeline 24, the microwave emission source will be automatically turned off, and nitrogen will be used to continuously purge the adsorbent to cool down to 293K.

[0065] Specifically, the relevant process operations and tests are as follows:

[0066] Example 1

[0067] The above-mentioned adsorption separation device and adsorption separation method are used to separate and purify heavy water. The detailed process parameters are as follows:

[0068] First, a temperature-responsive porous coordination polymer (PCPs) was synthesized: 19.20 g of dimethyl 5-iodoisophthalate, 9.66 g of iminostilbene, 1.19 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 32.58 g of cesium carbonate, 1.37 g of tris(dibenzylideneacetone)dipalladium (0) and 200 ml of toluene were placed in a flask and isolated from oxygen for 24 hours. The reaction product was then purified and separated to obtain a light yellow solid, which was recorded as reaction product 1. Subsequently, 10 g of reaction product 1 was added to 200 ml of a solution composed of THF and methanol in a volume ratio of 1:1, and 200 ml of a 2 mol / L NaOH aqueous solution was added thereto to react for 16 hours. The solid generated by the reaction was dried under reduced pressure at 60°C to obtain a temperature-responsive porous coordination polymer (PCPs).

[0069] The prepared PCPs material was filled into the main and auxiliary adsorption towers, and the adsorption saturation time was set to 4 hours. During the desorption operation, the maximum microwave output power was set to 3KW, the adsorption temperature was 293K, the desorption temperature was set to 373K, and the working pressure was normal pressure. TPD spectroscopy was used to analyze the low-concentration heavy water feed gas and the light water discharge after 4 hours. The results are shown in Table 1 below.

[0070] Table 1

[0071]

[0072] It can be found that as the feed H 2 The increase of O component content and the H 2 O also gradually increased, but was always higher than H in the raw gas. 2 O content. It was also found that deuterated water (D 2 O) is significantly lower than D in low-concentration heavy water raw gas. 2 O content, which indicates that the temperature-responsive solid adsorbent (PCPs) can effectively absorb light water (H 2 O) molecules were selectively adsorbed, so that D 2 The O content is improved, indicating that the device and method can effectively purify and separate heavy water.

[0073] Example 2

[0074] The above-mentioned adsorption separation device and adsorption separation method are used to separate and purify heavy water. The detailed process parameters are as follows:

[0075] First, a temperature-responsive metal organic framework material (MOFs) was synthesized: 19.20 g of 5-iodoisophthalic acid dimethyl ester, 9.76 g of iminodibenzyl, 1.19 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, 32.58 g of cesium carbonate, 1.37 g of tris(dibenzylideneacetone)dipalladium (0) and 200 ml of toluene were placed in a flask and isolated from oxygen for 24 hours. The reaction product was then purified and separated to obtain a light yellow solid, which was recorded as reaction product 2. Subsequently, 10 g of reaction product 2 was added to 200 ml of a solution composed of THF and methanol in a volume ratio of 1:1, and 200 ml of a 2 mol / L NaOH aqueous solution was added thereto to react for 16 hours. The solid generated by the reaction was dried under reduced pressure at 60°C to obtain a temperature-responsive metal organic framework material (MOFs).

[0076] The prepared MOFs material was filled into the main and auxiliary adsorption towers, and the adsorption saturation time was set to 3 hours. During the desorption operation, the maximum microwave output power was set to 2.5KW, the adsorption temperature was 293K, the desorption temperature was set to 373K, and the working pressure was normal pressure. TPD spectroscopy was used to analyze the low-concentration heavy water feed gas and the light water discharge after 3 hours. The results are shown in Table 2 below.

[0077] Table 2

[0078]

[0079] It can be found that as the feed H 2 The increase of O component content and the H 2 O also gradually increased, but was always higher than H in the raw gas. 2 O content. It was also found that deuterated water (D 2 O) is significantly lower than D in low-concentration heavy water raw gas. 2 O content, which indicates that the temperature-responsive metal-organic framework materials (MOFs) are sensitive to light water (H 2 O) molecules were selectively adsorbed, so that D 2 The O content is improved, indicating that the device and method can effectively purify and separate heavy water.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adsorption separation device for heavy water purification, characterized in that: include: Main adsorption tower and auxiliary adsorption tower; The main adsorption tower and the auxiliary adsorption tower are equipped with a temperature-sensitive solid adsorbent capable of selectively adsorbing protium water in water isotope molecules; independent slot waveguide antennas are arranged on the outer surfaces of the side walls of the main adsorption tower and the auxiliary adsorption tower, and each slot waveguide antenna is connected to an independent microwave emission source; The top feed ports of the main adsorption tower and the auxiliary adsorption tower are connected to the raw material feed pipeline through an independent control valve group; the top discharge ports of the main adsorption tower and the auxiliary adsorption tower are connected to the light water discharge pipeline through an independent control valve group; The bottom feed ports of the main adsorption tower and the auxiliary adsorption tower are connected to the nitrogen purge pipeline through an independent control valve group; the bottom discharge ports of the main adsorption tower and the auxiliary adsorption tower are connected to the heavy water discharge pipeline through an independent control valve group.

2. The adsorption separation device according to claim 1, characterized in that: The main adsorption tower and the auxiliary adsorption tower adopt a quasi-optical resonant cavity structure.

3. The adsorption separation device according to claim 1 or 2, characterized in that: The inner surfaces of the main adsorption tower and the auxiliary adsorption tower are provided with a polytetrafluoroethylene layer, an enamel coating or a quartz coating.

4. The adsorption separation device according to claim 1 or 2, characterized in that: The solid adsorbent is a temperature-responsive porous coordination polymer or a temperature-responsive metal organic framework material.

5. The adsorption separation device according to claim 1 or 2, characterized in that: It also includes a cavity temperature measurement system, which is used to monitor the temperature of the solid adsorbent when the adsorption tower is performing a desorption operation.

6. The adsorption separation device according to claim 1 or 2, characterized in that: The light water discharge pipeline and the heavy water discharge pipeline are provided with a product filter and a product condenser in sequence along the material flow direction.

7. The adsorption separation device according to claim 1 or 2, characterized in that: It also includes a computer control system. The control valve groups on the raw material feed pipeline, light water discharge pipeline, heavy water discharge pipeline, and nitrogen purge pipeline, the cavity temperature measurement system, and the microwave emission source are connected to the computer control system through a control circuit.

8. An adsorption separation method using the adsorption separation device according to any one of claims 1 to 7, characterized in that: The adsorption and desorption of the main adsorption tower and the auxiliary adsorption tower are carried out alternately, including the following steps: (1) When the main adsorption tower is performing adsorption operation and the auxiliary adsorption tower is performing desorption operation, the computer control system first opens the control valve group of the raw material feed pipeline at the top of the main adsorption tower and the control valve group of the heavy water discharge pipeline at the bottom of the main adsorption tower, allowing the raw material to enter the main adsorption tower from the top of the main adsorption tower; (2) When the raw material flows through the solid adsorbent, the protium water molecules therein will be preferentially adsorbed by the solid adsorbent, while the deuterium water molecules will not be adsorbed by the solid adsorbent, thereby increasing the concentration of heavy water in the bottom discharge of the main adsorption tower; (3) The heavy water flowing out of the bottom of the main adsorption tower is filtered by a product filter on the heavy water discharge pipeline, and then enters a product condenser for further cooling to become a heavy water product; (4) When the solid adsorbent in the main adsorption tower is saturated with adsorption, the computer control system performs a desorption operation on the main adsorption tower. First, the computer control system closes the control valve group on the raw material feed pipeline at the top of the main adsorption tower and the control valve group on the heavy water discharge pipeline at the bottom of the tower, and opens the control valve group on the raw material feed pipeline at the top of the auxiliary adsorption tower and the control valve group on the heavy water discharge pipeline at the bottom of the tower, allowing the raw material to enter the auxiliary adsorption tower; (5) After the raw material enters the auxiliary adsorption tower, the computer control system will open the control valve group on the light water discharge pipeline at the top of the main adsorption tower and the control valve group on the nitrogen purge pipeline at the bottom of the tower to allow nitrogen to enter the main adsorption tower, and then turn on the microwave emission source of the main adsorption tower to input microwaves into the main adsorption tower for desorption. The light water vapor generated by desorption enters the light water discharge pipeline through nitrogen purge, and becomes a light water discharge product after being filtered by the product filter and cooled by the product condenser; (6) When the auxiliary adsorption tower is saturated with adsorption, the computer control system switches the raw material feed back to the main adsorption tower for adsorption operation and performs the same desorption operation on the auxiliary adsorption tower.

9. Use of the adsorption separation device according to any one of claims 1 to 7 or the adsorption separation method according to claim 8 in the field of heavy water separation and purification.

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