Device and method for preparing oxygen 18 and heavy water by using tap water

Abstract

The invention belongs to the technical field of isotope separation, discloses a device and a method for preparing oxygen 18 and heavy water by using tap water, overcomes the defect of high energy consumption caused by a water rectification method, reduces the production cost, and is suitable for production of nuclear power and civil stable isotope oxygen 18 and heavy water. The device comprises a first large tower, a second large tower, a first tower group, a second tower group, a sixth small tower, a seventh small tower and an eighth small tower which are sequentially connected in series, the first large tower and the second large tower are used for pre-concentrating large-flow tap water entering the towers, and an intermediate material obtained at the bottoms of the towers is conveyed to the first tower group and the second tower group through a pump for moderate concentration; tower bottom concentrate is conveyed to the next-stage rectifying tower to be highly concentrated. According to the method, pre-concentration, primary concentration and concentration enrichment are carried out, intermediate products obtained at the tower bottom converge and enter a next-stage rectifying tower, then high-concentration enrichment is carried out, and finally oxy-18 water and heavy water are obtained.

Description

Technical Field

[0001] The present application belongs to the field of isotope separation technology, and in particular, relates to a device and method for preparing oxygen 18 and heavy water using tap water. Background Art

[0002] The main oxygen element in nature is 16 O. 17 O. 18 O exists in the form of three stable isotopes, with natural abundances of 99.76%, 0.037%, and 0.204% respectively. The product of the combination of hydrogen and oxygen 18 isotopes is often called heavy oxygen water or oxygen 18 water (H 2 18 O), its physical and chemical properties are basically the same as light water. Oxygen 18 is the most widely used stable isotope, and oxygen 18 water is also a special reagent for PET imaging drugs.

[0003] The application of oxygen isotopes is mainly to take advantage of their similar physical and chemical properties. Isotopes can replace each other without affecting the properties of the original substance itself. As a stable isotope, oxygen 18 has two main applications. One is to use its similar physical and chemical properties as an "isotope tracer" and apply it to research on biological metabolism, drug synthesis, physics, chemistry, biomedicine, environmental science and hydrogeology, chemical reaction mechanisms, etc.; the other is to use it as a raw material for fluorine 18 nuclides and widely used in fluorine 18 positron drug synthesis and molecular imaging research.

[0004] The separation methods of stable isotope oxygen 18 mainly include thermal diffusion, distillation, chemical exchange, electrolysis, laser, membrane separation and chromatography. However, the only method suitable for industrial production is distillation, which contains NO or O 2 Low temperature distillation and water distillation. Among them, low temperature distillation has the disadvantages of extremely high requirements for equipment and construction, high technical difficulty, and high cost. Water distillation separation mainly uses the difference in vapor pressure (volatility) between isotope molecules to achieve separation. Although water distillation has the disadvantage of high energy consumption, it has a large processing throughput, is relatively simple to operate, and is easy to automate. Summary of the invention

[0005] The purpose of this application is to provide a device and method for preparing oxygen 18 and heavy water using tap water, which overcomes the disadvantage of high energy consumption brought by the water distillation method, reduces production costs, and is suitable for the production of nuclear power and civilian stable isotope oxygen 18 and heavy water.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] In the first aspect, the present application provides a device for preparing oxygen 18 and heavy water using tap water, comprising a first large tower, a second large tower, a first tower group, a second tower group, a sixth small tower, a seventh small tower and an eighth small tower connected in series in sequence, wherein the eighth small tower is connected to an electrolytic cell through a pipeline; the first tower group comprises a first small tower, a second small tower and a third small tower connected in parallel, and the second tower group comprises a fourth small tower and a fifth small tower connected in parallel; the first large tower and the second large tower pre-concentrate a large flow of tap water entering the tower, and the intermediate material obtained at the bottom of the tower is transported to the first tower group and the second tower group by a pump for intermediate concentration, and the concentrate at the bottom of the tower is transmitted to the next-stage distillation tower for high concentration.

[0008] In some embodiments, the bottom of the first large tower is connected to the top of the second large tower, the bottom of the second large tower is connected to the top of the first tower group, the bottom of the first tower group is connected to the top of the second tower group, the bottom of the second tower group is connected to the top of the sixth small tower, the bottom of the sixth small tower is connected to the top of the seventh small tower, and the bottom of the seventh small tower is connected to the top of the eighth small tower.

[0009] In some embodiments, a first transmission pump and a first flow meter are provided on the first pipeline connecting the first large tower and the second large tower, a second transmission pump and a second flow meter are provided on the second pipeline between the second large tower and the first tower group, a third transmission pump and a third flow meter are provided on the third pipeline between the first tower group and the second tower group, a fourth transmission pump is provided on the fourth pipeline between the second tower group and the sixth small tower, and a fifth transmission pump and a fifth flow meter are provided on the fifth pipeline between the sixth small tower and the seventh small tower.

[0010] In some embodiments, a vacuum pressure gauge is provided at the top of the first large tower, which is mainly used to monitor the pressure of the distillation tower in the entire cascade process to ensure that the pressure inside the entire distillation tower is at a constant value.

[0011] In some embodiments, the electrolytic cell temperature ranges from 10°C to 25°C.

[0012] In some embodiments, the number of theoretical plates is 3000-3500.

[0013] In some embodiments, a mixed structured packing and random packing are arranged in the distillation tower.

[0014] In some embodiments, the tower body is made of 316L stainless steel, and the fillers are surface-modified regular twill wire mesh fillers and random fillers.

[0015] In a second aspect, the present application provides a method for preparing oxygen-18 and heavy water using tap water, comprising:

[0016] Step 1: Use tap water as raw material to remove particulate impurities in the tap water;

[0017] Step 2: Perform reverse osmosis on the tap water filtered in step 1 using a reverse osmosis membrane;

[0018] Step 3: using the device as described in any one of claims 1 to 8, taking the tap water after the treatment in step 2 as raw material, the raw material enters the first-stage large tower for pre-concentration, the intermediate product obtained in the tower body enters the next-stage distillation tower for primary concentration, the raw material liquid after the primary concentration in the multi-stage series distillation tower is divided into multiple streams and enters the next-stage distillation tower, and is concentrated and enriched in the multi-stage parallel distillation tower. The intermediate products obtained at the bottom of the tower converge and enter the next-stage distillation tower, and then are highly concentrated and enriched;

[0019] Step 4: passing the high-abundance heavy oxygen water obtained by distillation through an electrolytic cell to obtain high-purity oxygen-18 gas and deuterium gas at the electrode parts of the electrolytic cell;

[0020] Step 5: The high-purity oxygen-18 gas and deuterium gas obtained by electrolysis are purified, decontaminated, condensed, and then oxidized with high-purity hydrogen and high-purity oxygen through precious metal catalysis to obtain oxygen-18 water and heavy water.

[0021] In step 1, particulate impurities in tap water are removed by membrane filtration.

[0022] In step 3, the pressure is controlled at a negative pressure of 5 kPa-30 kPa, and the temperature ranges from 313 K to 353 K.

[0023] Compared with the prior art, the device and method for preparing oxygen 18 and heavy water using tap water provided in the present application have the following beneficial effects:

[0024] The method provided in the present application couples the surplus steam of nuclear power plants as energy, reduces the energy consumption caused by the water distillation method, and thus reduces the production cost. The method is suitable for the production of nuclear power and civilian stable isotope oxygen 18 and heavy water.

[0025] This application uses tap water as raw material. The raw material source is widely available, inexpensive, pollution-free, clean and environmentally friendly. The entire production process is pollution-free, harmless and environmentally friendly, and meets the country's requirements for developing new quality productivity.

[0026] Furthermore, the present application can obtain high-purity and high-abundance oxygen-18 water and heavy water through a multi-stage cascade distillation process combining filtration, reverse osmosis, series and parallel connection, electrolysis in an electrolytic cell, and a combined oxidation process. At the same time, the method is coupled with the characteristics of surplus steam in nuclear power plants, so that the surplus steam resources of nuclear power plants are fully and efficiently utilized, and the energy and environmental problems caused by high energy consumption in the distillation process are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for the technical description.

[0028] Figure 1 A schematic diagram of the structure of the device for preparing oxygen 18 and heavy water using tap water provided in this application;

[0029] Figure 2 A schematic diagram of the process technology for preparing oxygen 18 and heavy water using tap water provided in this application;

[0030] Figure 3 A flow chart of a method for preparing oxygen-18 and heavy water using tap water provided in this application. DETAILED DESCRIPTION

[0031] The following is further explained in detail through specific implementation methods.

[0032] like Figure 1 and Figure 2 As shown, the present application provides a device for preparing oxygen 18 and heavy water using tap water, including 2 large towers and 8 small towers, a total of 10 towers, and the 10 towers are connected in series, in parallel, and in series. The 2 large towers are the first large tower 1a and the second large tower 1b; the 8 small towers are the first small tower 1c, the second small tower 1d, the third small tower 1e, the fourth small tower 1f, the fifth small tower 1g, the sixth small tower 1h, the seventh small tower 1i, and the eighth small tower 1j.

[0033] The first large tower 1a and the second large tower 1b are connected in series; the first small tower 1c, the second small tower 1d, and the third small tower 1e are connected in parallel to form the first tower group; the fourth small tower 1f and the fifth small tower 1g are connected in parallel to form the second tower group; the sixth small tower 1h, the seventh small tower 1i, and the eighth small tower 1j are connected in series. The first large tower 1a, the second large tower 1b, the first tower group, the second tower group, the sixth small tower 1h, the seventh small tower 1i, and the eighth small tower 1j are connected in series in sequence, and they are connected end to end, that is, the bottom of the first large tower 1a is connected to the top of the second large tower 1b, the bottom of the second large tower 1b is connected to the top of the first tower group, the bottom of the first tower group is connected to the top of the second tower group, the bottom of the second tower group is connected to the top of the sixth small tower 1h, the bottom of the sixth small tower 1h is connected to the top of the seventh small tower 1i, and the bottom of the seventh small tower 1i is connected to the top of the eighth small tower 1j. The 10 towers are connected in series-parallel-series to form a 7-stage cascade distillation process. The prior art mainly adopts single tower cascade with gradually decreasing tower diameter, and cascade mode of first parallel connection and then series connection for tower diameter less than DN100, while the present application adopts such series-parallel-series cascade mode, which can achieve large processing flux, reduce tower pressure drop, and improve tower separation efficiency. The present application adopts 7-stage cascade to achieve oxygen-18 enrichment abundance higher than 98% and deuterium abundance higher than 99% in heavy water at one time.

[0034] The first large tower 1a and the second large tower 1b are pre-concentration sections; the first tower group and the second tower group are further concentration sections; the sixth small tower 1h, the seventh small tower 1i, and the eighth small tower 1j are high-abundance product concentration sections. The high-abundance heavy oxygen water enriched at the bottom of the eighth small tower 1j is transported to the subsequent electrolytic cell.

[0035] The first pipeline connecting the first large tower 1a and the second large tower 1b is provided with a first transmission pump 2a and a first flowmeter 3a; the top of the first large tower 1a is provided with a vacuum pressure gauge 4a, which is mainly used to monitor the pressure of the distillation tower in the entire cascade process to ensure that the pressure inside the entire distillation tower is at a constant value. The first transmission pump 2a is a flow transmission pump, and the deuterium-depleted water at the top of the tower comes out from the top of the first large tower 1a. The first flowmeter 3a is a mass flowmeter, which is mainly used to control the flow rate transmitted to the next tower, such as the top of tower 1b.

[0036] A second transfer pump 2b and a second flowmeter 3b are provided on the second pipeline between the second large tower 1b and the first tower group. A third transfer pump 2c and a third flowmeter 3c are provided on the third pipeline between the first tower group and the second tower group. A fourth transfer pump 2d and a fourth flowmeter 3d are provided on the fourth pipeline between the second tower group and the sixth small tower 1h. A fifth transfer pump 2e and a fifth flowmeter 3e are provided on the fifth pipeline between the sixth small tower 1h and the seventh small tower 1i. In addition, the steam at the top of the tower enters the bottom of the upper-level distillation tower through a pipeline. For example, the top of the second large tower 1b is connected to the bottom of the first large tower 1a by a pipeline, and the steam at the top of the second large tower 1b enters the bottom of the first large tower 1a. Figure 1 As shown, the steam at the top of the next-stage distillation tower enters the bottom of the previous-stage distillation tower through a pipeline.

[0037] Using tap water as raw material, the raw water is first filtered and reverse osmosis process to remove a small amount of suspended particles, chloride ions, sulfate ions, Na + , Ca 2+ , K + Mg 2+ Etc. to remove, so that the conductivity of the sample raw water reaches 0.1-10μS / cm, and then feed from the top of the first large tower 1a by high-position feeding. The tower body of the distillation tower (including 10 towers) is made of 316L stainless steel, and the filler is a regular twill wire mesh filler with surface modification and a random filler.

[0038] Through the two first large towers 1a and second large towers 1b connected in series, the first large towers 1a and the second large towers 1b with regular fillers as separation media are pre-concentrated, and intermediate materials are obtained in the pre-concentration section at the bottom of the second large tower 1b. The intermediate materials are transmitted into the tops of three parallel distillation towers (the first small tower 1c, the second small tower 1d and the third small tower 1e) under the flow control of the second transmission pump 2b and the second flowmeter 3b, and further concentrated materials are obtained at the bottoms of the first small tower 1c, the second small tower 1d and the third small tower 1e after gas-liquid exchange.

[0039] The input flow is then controlled by the third transmission pump 2c and the third flowmeter 3c to enter two parallel distillation towers (the fourth small tower 1f and the fifth small tower 1g) for concentration to obtain intermediate materials deuterium and oxygen 18.

[0040] The intermediate material of the concentration section is transmitted through the fourth transmission pump 2d into the high-abundance product concentration section composed of the subsequent three series-connected distillation towers (the sixth small tower 1h, the seventh small tower 1i and the eighth small tower 1j). After the final concentration and enrichment, high-abundance deuterium and oxygen-18 compound heavy oxygen water is obtained at the bottom of the eighth small tower 1j.

[0041] The high-abundance heavy oxygen water enriched at the bottom of the eighth small tower 1j is transported to the subsequent electrolyzer, and through electrolysis, high-abundance deuterium gas and oxygen 18 gas are obtained at the cathode and anode of the electrolyzer respectively; then, they are combined with purchased commercial high-purity oxygen (99.99%) and high-purity hydrogen (99.99%) for oxidation-reduction reaction under the catalysis of the precious metal Pt to obtain oxygen 18 water with an abundance greater than 97% and heavy water with an abundance greater than 99%, respectively, and stored in a special liquid storage tank. The number of theoretical plates required for the entire distillation concentration and enrichment process is 3000-3500, and the entire cascade process controls the operating pressure of the tower top to be about 13kPa-15kPa, the tower top temperature range is 45℃-60℃, and the tower bottom temperature is 55℃-70℃. The discharge of heavy oxygen water flowing out of the bottom of the tower is 100g / day-200g / day.

[0042] Furthermore, the distillation tower has a diameter range of 20mm-800mm, a tower height of 5m-30m, and a packing height of 4m-28m. The first large tower 1a and the second large tower 1a have a diameter between DN400-800, and the subsequent first and second tower groups have a diameter between DN20-400.

[0043] Furthermore, a mixed method of structured packing and random packing is adopted in the distillation tower, wherein the structured packing is a homemade twill wire mesh packing and the random packing is a Dixon packing made of metal (copper, stainless steel, phosphor bronze, etc.).

[0044] Furthermore, the pre-concentration and primary concentration distillation tower sections are composed of 1-3 single towers in series, the intermediate concentration section is composed of 2-10 distillation towers in parallel, and the high concentration enrichment section is composed of 2-4 single towers in series.

[0045] Furthermore, the electrolytic cell must be sealed to maintain a constant temperature within the range of 10°C-25°C.

[0046] Furthermore, the chemical combination process includes a noble metal catalyst (such as Pt), and the commercial hydrogen and oxygen used are high-purity gases, with gas concentrations reaching 99.99%.

[0047] like Figure 3 As shown, the present application provides a method for preparing oxygen 18 and heavy water using tap water, comprising the following steps:

[0048] Step 1: Remove particulate matter from tap water.

[0049] Using multiple membrane filtration components, tap water is used as raw material to remove a small amount of suspended solids and other particulate impurities in the tap water through membrane filtration. The filtered tap water then flows to the reverse osmosis component for reverse osmosis.

[0050] Step 2: Use a reverse osmosis membrane to perform reverse osmosis on the tap water filtered in step 1 to remove as much metal ions, chloride ions, etc. as possible in the water to reduce the impact on the performance of subsequent distillation fillers.

[0051] Step 3: Multiple distillation towers are connected in series and in parallel to form the entire cascade distillation process. The tap water after the treatment in step 2 is used as the raw material. First, the large-flux raw material enters the first-stage large tower for pre-concentration. The intermediate product obtained in the tower body enters the next-stage distillation tower for initial concentration. The raw material liquid after initial concentration in the multi-stage series distillation tower is divided into multiple streams and enters the next-stage distillation tower group. After being concentrated and enriched by multiple stages of parallel distillation towers, the intermediate products finally obtained at the bottom of the tower converge and enter the next-stage distillation tower. After being highly concentrated and enriched by multiple single-tower series distillation towers. A heavy oxygen water product enriched with deuterium and oxygen 18 is obtained at the bottom of the tower. The pressure of the entire distillation system is controlled at a negative pressure of 5kPa-30kPa, and the temperature range is 313K-353K.

[0052] Step 4: The high-abundance heavy oxygen water obtained by distillation is passed through an electrolytic cell to obtain high-purity oxygen-18 gas and deuterium gas at the electrode sites of the electrolytic cell.

[0053] Step 5: The high-purity oxygen-18 gas and deuterium gas obtained by electrolysis are respectively passed through cold trap, drying, adsorption, low-temperature cold trap, etc., purification, impurity removal, condensation and other processes, and then oxidized with commercially available high-purity hydrogen (99.99%) and high-purity oxygen (99.99%) by precious metal catalysis to obtain the final products of oxygen-18 water and heavy water.

[0054] The method provided in this application is to use a cascade distillation process technology with more than 3,000 trays in multiple coupling modes to distill tap water to prepare high-abundance oxygen 18 and high-concentration heavy water. The method uses filtration, reverse osmosis, distillation, electrolysis, and chemical combination equipment to simultaneously produce oxygen 18 and heavy water.

[0055] The present application uses tap water as raw material to prepare oxygen 18 and heavy water. First, the raw tap water (the deuterium content in the tap water is about 150ppm, and the oxygen 18 content is about 2000ppm) is transferred into the filter by a pump to remove suspended matter, colloidal matter and other particulate suspended matter in the tap water; the tap water after filtration is further purified by a reverse osmosis membrane to remove a small amount of chloride ions, sulfate ions, calcium, magnesium, potassium, sodium and other metal ions in the tap water, so that its conductivity reaches 0.1-10μS / cm. Finally, the treated and purified tap water is fed from the middle and upper part of the primary tower into the distillation tower.

[0056] The 1-2 level tower is connected in series to pre-concentrate the large flow of tap water entering the tower. The specifications of the distillation tower in the pre-concentration section are DN500-DN800, and the combination is in series. The intermediate material obtained by distillation and enrichment at the bottom of the secondary tower in the pre-concentration section is pumped to the 3-4 level tower for further moderate concentration. The 3-4 level tower is composed of 2-10 distillation towers in parallel, and the diameter specifications of the distillation tower in the further concentration section are DN100-DN400. The bottom concentrate after distillation in the 3-4 level tower is transferred to the next level distillation tower for high concentration. This part consists of 3 distillation towers with a diameter of DN20-DN150 connected in series, and the material at the top of the tower returns to the bottom of the pre-concentration section. The whole mass transfer and heat transfer process adopts the mixed assembly of structured packing and random packing. The structured packing is a homemade twill wire mesh structured packing that can be mass-produced, and the random packing is a Dixon ring packing made of metal (copper, stainless steel, phosphor bronze, etc.) after special treatment by existing methods. Both structured packing and random packing have a large specific surface area and excellent hydrophilic properties. The water contact angle is less than 1°, which can effectively improve the wetting properties of the packing surface, facilitate the spreading of gas and liquid on the packing surface, form a good liquid film, significantly improve the mass and heat transfer of gas and liquid, and facilitate the realization of D, 18 The isotope of O is enriched. At the same time, the structured packing has excellent gas-liquid flow channels, with the advantages of small pressure drop and large flux.

[0057] Random packing has efficient theoretical plates, which is conducive to the enrichment of isotopes. Due to the effect of distillation, the gas and liquid phases transfer mass and heat in the tower in a countercurrent manner, so that the deuterium and oxygen 18 in the gas phase are continuously transferred to the liquid phase for enrichment, while hydrogen and oxygen 16 are transferred to the gas phase. Finally, through the cascade process of distillation, deuterium and oxygen 18 are enriched at the bottom of the tower in the high-abundance enrichment section, and high-abundance (>97%) heavy oxygen water (D 2 18 O). Since the distillation separation process of oxygen 18 is relatively complicated, a very high theoretical number of stages is required.

[0058] The whole distillation concentration and enrichment process has an overall operating condition of a pressure range of 5kPa-30kPa, a temperature range of 323K-353K, a distillation tower diameter of DN20-DN800, a tower height of 5m-30m, and a packing height of 4m-28m. Finally, the high-abundance heavy oxygen water obtained by distillation is passed into an electrolytic cell for electrolysis to obtain high-abundance oxygen-18 gas and deuterium gas, and then commercially purchased high-purity hydrogen (99.99%) and oxygen (99.99%) are combined and oxidized under the catalysis of precious metals to obtain high-abundance oxygen-18 water and heavy water with a purity of more than 99%, which are finally stored in a liquid storage tank.

[0059] Embodiment 1:

[0060] Example 1 consists of 2 large towers and 8 small towers, a total of 10 towers, which are connected in series, parallel, and series. Among them, 1a and 1b are large towers connected in series, 1c, 1d, and 1e are three small towers in parallel, 1f and 1g are in parallel, and 1h, 1i, and 1j high-abundance concentration sections are in series. The overall process is a 7-stage cascade distillation process composed of series-parallel-series.

[0061] Using tap water as raw material, the feed rate is controlled at 150kg / h, the deuterium content is 150ppm, and the oxygen content is 2000ppm. The raw water is first filtered and reverse osmosis is used to remove a small amount of suspended particles, chloride ions, sulfate ions, and Na + , Ca 2+ , K + Mg 2+ The conductivity of the raw water sample is removed so that it reaches 0.1-10μS / cm, and then the material is fed from the top of tower 1a by high-position feeding. The distillation tower body is made of 316L stainless steel, and the fillers are regular twill wire mesh fillers with surface modification and random fillers.

[0062] Pre-concentration is carried out through two series-connected distillation towers with diameters of DN800 and DN700, tower heights of 30m, and structured packings as separation media in towers 1a and 1b. Intermediate materials are obtained in the pre-concentration section at the bottom of tower 1b and are transmitted through a 2b transmission pump and a 3b flow meter at a flow rate of 50kg / h to the tops of three parallel distillation towers 1c, 1d, and 1e. Each distillation tower has a diameter of DN400, a height of 30m, and random packings. After gas-liquid exchange, further concentrated materials are obtained at the bottom of towers 1c, 1d, and 1e. Then, the 2c transmission pump is used to control the input flow rate to 20kg / h through the 3c flowmeter to enter two parallel 1f and 1g distillation towers. The diameter of each distillation tower is DN250 and the tower height is 30m. Concentration is carried out to obtain an intermediate material with a deuterium content of 15% and an oxygen 18 content of 9.8%; the intermediate material in the concentration section is transmitted through the 2d pump to the high-abundance product concentration section composed of the subsequent three series-connected distillation towers. The diameter of each distillation tower is DN150, the tower height is 30m, and the surface-modified random packing is used as the separation medium. After the final concentration and enrichment, a high-abundance deuterium and oxygen 18 compound heavy oxygen water is obtained at the bottom of the 1j tower, in which the deuterium content is about 99.5% and the oxygen 18 content is 98.0%.

[0063] The highly abundant heavy oxygen water enriched at the bottom of the 1j tower is transported to the subsequent electrolyzer, and through electrolysis, highly abundant deuterium gas and oxygen 18 gas are obtained at the cathode and anode of the electrolyzer respectively; and then, through chemical oxidation-reduction reaction with purchased commercial high-purity oxygen (99.99%) and high-purity hydrogen (99.99%) under the catalysis of the precious metal Pt, oxygen 18 water with an abundance greater than 97% and heavy water with an abundance greater than 99% are obtained respectively, and stored in a special liquid storage tank. The number of theoretical plates required for the entire distillation concentration and enrichment process is 3,500. The entire cascade process controls the operating pressure of the top of the tower to be about 15 kPa, the top temperature range is 50°C-60°C, and the bottom temperature is 60°C-70°C. The discharge of heavy oxygen water flowing out of the bottom of the tower is 200g / day.

[0064] Example 2

[0065] Using tap water as raw material, the feed rate was controlled at 100 kg / h, the deuterium content was 150 ppm, and the oxygen content was 2000 ppm.

[0066] The raw water is first filtered and reverse osmosis process, and a small amount of suspended particles, chloride ions, sulfate ions, Na + , Ca 2+ , K + Mg 2+The conductivity of the sampled raw water is removed by high-level feeding from the top of tower 1a. The distillation tower body is made of 316L stainless steel, and the fillers are surface-modified regular twill wire mesh fillers and random fillers. Through two series-connected distillation towers, the tower diameters are DN700 and DN500, the tower heights are 30m, and the regular fillers are used as separation media 1a and 1b towers for pre-concentration. The intermediate material is obtained at the pre-concentration section at the bottom of tower 1b. Through the 2b transmission pump, the flow rate is controlled by the 3b flowmeter to control the flow rate of 30kg / h and enter the top of the three parallel distillation towers 1c, 1d, and 1e. Each distillation tower has a diameter of DN300, a tower height of 30m, and random fillers. After gas-liquid exchange, further concentrated materials are obtained at the bottom of towers 1c, 1d, and 1e.

[0067] Then, through the 2c transmission pump, the input flow rate is controlled by the 3c flowmeter to be 8kg / h and enters two parallel 1f and 1g distillation towers. The diameter of each distillation tower is DN200 and the tower height is 30m. Concentration is carried out to obtain an intermediate material with a deuterium content of 22% and an oxygen-18 content of 13%; the intermediate material of the concentration section is transmitted through the 2d pump to the high-abundance product concentration section composed of the subsequent three series-connected distillation towers. The diameter of each distillation tower is DN100, the tower height is 25m, and the surface-modified random packing is used as the separation medium. After the final concentration and enrichment, high-abundance deuterium and oxygen-18 compound heavy oxygen water is obtained at the bottom of the 1j tower, in which the deuterium content is about 99.7% and the oxygen-18 content is 98.3%.

[0068] The highly abundant heavy oxygen water enriched at the bottom of the 1j tower is transported to the subsequent electrolyzer, and through electrolysis, highly abundant deuterium gas and oxygen 18 gas are obtained at the cathode and anode of the electrolyzer respectively; and then, through chemical oxidation-reduction reaction with purchased commercial high-purity oxygen (99.99%) and high-purity hydrogen (99.99%) under the catalysis of the precious metal Pt, oxygen 18 water with an abundance greater than 98% and heavy water with an abundance greater than 99% are obtained respectively, and stored in a special liquid storage tank. The number of theoretical plates required for the entire distillation concentration and enrichment process is 3200, and the entire cascade process controls the operating pressure of the top of the tower to be about 13kPa, the top temperature range is 45℃-55℃, and the bottom temperature is 55℃-70℃. The discharge of heavy oxygen water flowing out of the bottom of the tower is 140g / day.

[0069] Example 3

[0070] Using tap water as raw material, the feed rate was controlled at 50 kg / h, the deuterium content was 150 ppm, and the oxygen content was 2000 ppm.

[0071] The raw water is first filtered and reverse osmosis process, and a small amount of suspended particles, chloride ions, sulfate ions, Na +, Ca 2+ , K + Mg 2+ The conductivity of the sampled raw water is removed so that it reaches 0.1-10μS / cm, and then the material is fed from the top of the 1a tower by high-position feeding. The distillation tower body is made of 316L stainless steel, and the fillers are surface-modified regular twill wire mesh fillers and random fillers. Through two series-connected distillation towers, the tower diameters are DN600 and DN500, the tower heights are 30m, and the regular fillers are used as separation media 1a and 1b towers for pre-concentration. The intermediate material is obtained in the pre-concentration section at the bottom of the 1b tower, and the intermediate material is transmitted to the top of the three parallel distillation towers 1c, 1d, and 1e towers through the 2b transmission pump and the 3b flowmeter at a flow rate of 20kg / h. Each distillation tower has a diameter of DN250, a tower height of 30m, and random fillers. After gas-liquid exchange, further concentrated materials are obtained at the bottom of the 1c, 1d, and 1e towers.

[0072] Then, through the 2c transmission pump, the input flow rate is controlled by the 3c flowmeter to be 6kg / h and enters two parallel 1f and 1g distillation towers. The diameter specification of each distillation tower is DN150 and the tower height is 30m. Concentration is carried out to obtain an intermediate material with a deuterium content of 23.8% and an oxygen 18 content of 14.3%; the intermediate material of the concentration section is transmitted through the 2d pump to the high-abundance product concentration section composed of the subsequent three series-connected distillation towers. The tower diameter specification of each distillation tower is DN50, the tower height is 20m, and the surface-modified random packing is used as the separation medium. After the final concentration and enrichment, high-abundance deuterium and oxygen 18 compound heavy oxygen water is obtained at the bottom of the 1j tower, in which the deuterium content is about 99.9% and the oxygen 18 content is 98.6%.

[0073] The highly abundant heavy oxygen water enriched at the bottom of the 1j tower is transported to the subsequent electrolyzer, and through electrolysis, highly abundant deuterium gas and oxygen 18 gas are obtained at the cathode and anode of the electrolyzer respectively; and then, through chemical oxidation-reduction reaction with purchased commercial high-purity oxygen (99.99%) and high-purity hydrogen (99.99%) under the catalysis of the precious metal Pt, oxygen 18 water with an abundance greater than 98% and heavy water with an abundance greater than 99% are obtained respectively, and stored in a special liquid storage tank. The number of theoretical plates required for the entire distillation concentration and enrichment process is 3,000. The entire cascade process controls the operating pressure of the top of the tower to be about 13 kPa, the top temperature range is 45°C-55°C, and the bottom temperature is 60°C-70°C. The discharge of heavy oxygen water flowing out of the bottom of the tower is 100g / day.

[0074] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A device for preparing oxygen 18 and heavy water using tap water, characterized in that: The invention comprises a first large tower (1a), a second large tower (1b), a first tower group, a second tower group, a sixth small tower (1h), a seventh small tower (1i) and an eighth small tower (1j) which are connected in series in sequence, wherein the eighth small tower (1j) is connected to an electrolytic cell via a pipeline; the first tower group comprises a first small tower (1c), a second small tower (1d) and a third small tower (1e) which are connected in parallel, and the second tower group comprises a fourth small tower (1f) and a fifth small tower (1g) which are connected in parallel; the first large tower (1a) and the second large tower (1b) pre-concentrate a large amount of tap water entering the tower, and the intermediate material obtained at the bottom of the tower is transported to the first tower group and the second tower group by a pump for intermediate concentration, and the concentrate at the bottom of the tower is transported to the next-stage distillation tower for high concentration.

2. The device for preparing oxygen 18 and heavy water using tap water according to claim 1, characterized in that: The bottom of the first large tower (1a) is connected to the top of the second large tower (1b), the bottom of the second large tower (1b) is connected to the top of the first tower group, the bottom of the first tower group is connected to the top of the second tower group, the bottom of the second tower group is connected to the top of the sixth small tower (1h), the bottom of the sixth small tower (1h) is connected to the top of the seventh small tower (1i), and the bottom of the seventh small tower (1i) is connected to the top of the eighth small tower (1j).

3. The device for preparing oxygen 18 and heavy water using tap water according to claim 1 or 2, characterized in that: A first transmission pump (2a) and a first flow meter (3a) are provided on the first pipeline connecting the first large tower (1a) and the second large tower (1b); a second transmission pump (2b) and a second flow meter (3b) are provided on the second pipeline between the second large tower (1b) and the first tower group; a third transmission pump (2c) and a third flow meter (3c) are provided on the third pipeline between the first tower group and the second tower group; a fourth transmission pump (2d) and a fourth flow meter (3d) are provided on the fourth pipeline between the second tower group and the sixth small tower (1h); and a fifth transmission pump (2e) and a fifth flow meter (3e) are provided on the fifth pipeline between the sixth small tower (1h) and the seventh small tower (1i).

4. The device for preparing oxygen 18 and heavy water using tap water according to claim 3, characterized in that: A vacuum pressure gauge (4a) is provided at the top of the first large tower (1a).

5. The device for preparing oxygen 18 and heavy water using tap water according to claim 1, characterized in that: The temperature of the electrolytic cell is in the range of 10°C to 25°C.

6. The device for preparing oxygen 18 and heavy water using tap water according to claim 1, characterized in that: The number of theoretical plates is 3000-3500.

7. The device for preparing oxygen 18 and heavy water using tap water according to claim 1, characterized in that: The distillation tower is arranged with mixed structured packing and random packing.

8. The device for preparing oxygen 18 and heavy water using tap water according to claim 1, characterized in that: The tower body is made of 316L stainless steel, and the fillers are regular twill wire mesh fillers and random fillers with surface modification.

9. A method for preparing oxygen 18 and heavy water using tap water, characterized in that: include: Step 1: Use tap water as raw material to remove particulate impurities in the tap water; Step 2: Perform reverse osmosis on the tap water filtered in step 1 using a reverse osmosis membrane; Step 3: using the device as described in any one of claims 1 to 8, taking the tap water after the treatment in step 2 as raw material, the raw material enters the first-stage large tower for pre-concentration, the intermediate product obtained in the tower body enters the next-stage distillation tower for primary concentration, the raw material liquid after the primary concentration in the multi-stage series distillation tower is divided into multiple streams and enters the next-stage distillation tower, and is concentrated and enriched in the multi-stage parallel distillation tower. The intermediate products obtained at the bottom of the tower converge and enter the next-stage distillation tower, and then are highly concentrated and enriched; Step 4: passing the high-abundance heavy oxygen water obtained by distillation through an electrolytic cell to obtain high-purity oxygen-18 gas and deuterium gas at the electrode parts of the electrolytic cell; Step 5: The high-purity oxygen-18 gas and deuterium gas obtained by electrolysis are purified, decontaminated, condensed, and then oxidized with high-purity hydrogen and high-purity oxygen through precious metal catalysis to obtain oxygen-18 water and heavy water.

10. The method for preparing oxygen 18 and heavy water using tap water according to claim 9, characterized in that: In step 1, particulate impurities in tap water are removed by membrane filtration.

11. The method for preparing oxygen 18 and heavy water using tap water according to claim 9, characterized in that: In step 3, the pressure is controlled at a negative pressure of 5 kPa-30 kPa, and the temperature ranges from 313 K to 353 K.

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