Deuterium production equipment

Abstract

To provide deuterium production equipment capable of producing high-purity deuterium with high utilization efficiency of heavy water.SOLUTION: The deuterium production equipment comprises a raw material tank capable of storing heavy water, a deuterium generation section connected to the raw material tank via a first pipe, and a dehumidification section for dehumidifying gas discharged from the raw material tank or gas generated in the deuterium generation section. The dehumidification section is connected with a return line for returning heavy water recovered in the dehumidification section to the raw material tank.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a deuterium production facility. [Background technology]

[0002] There are known devices for producing hydrogen gas by electrolysis of water. For example, Patent Document 1 discloses a device including a water supply tank and a water electrolysis module including an anode chamber for generating oxygen gas and a cathode chamber for generating hydrogen gas. The device of Patent Document 1 is configured to supply water in excess of the amount required for electrolysis to the anode side of the water electrolysis module, discharge a gas-liquid mixed fluid containing water that has not been electrolyzed and oxygen gas from the water electrolysis module, and supply the water contained in the fluid again to the anode side of the water electrolysis module.

[0003] Patent Document 2 discloses a hydrogen generation device including an electrolytic cell and a dehumidifier. The hydrogen generation device of Patent Document 2 supplies hydrogen gas containing moisture extracted from the hydrogen generation device to a dehumidifier, which dehumidifies the hydrogen gas to obtain dry hydrogen as a product gas. The device of Patent Document 2 includes an adsorption column as a dehumidifier. Moist hydrogen gas containing moisture and hydrogen gas discharged from the adsorption column in a regeneration process of the adsorption column is returned to the hydrogen gas line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-183556 A [Patent Document 2] JP 2020-189282 A Summary of the Invention [Problem to be solved by the invention]

[0005] When producing hydrogen by electrolysis of water, it has been desirable to improve the recovery efficiency of the product hydrogen gas. On the other hand, since the raw material water is easily available and inexpensive, there has been little progress in studying how to recover the water discharged from the electrolysis device as an unreacted raw material. However, when producing deuterium by electrolysis of heavy water, the raw material heavy water is in limited supply and expensive. For this reason, it is desirable not only to improve the recovery efficiency of the product deuterium gas, but also to reduce the loss of raw material and use all of the heavy water.

[0006] In view of this current situation, one of the objects of the present disclosure is to provide a deuterium production facility that can highly efficiently utilize heavy water and produce high-purity deuterium. [Means for solving the problem]

[0007] The deuterium production equipment according to the present disclosure includes a raw material tank capable of storing heavy water, a deuterium generation unit connected to the raw material tank via a first pipe, and a dehumidification unit for dehumidifying a gas discharged from the raw material tank or a gas generated in the deuterium generation unit. A return line for returning the heavy water recovered in the dehumidification unit to the raw material tank is connected to the dehumidification unit.

[0008] The heavy water production facility according to the present disclosure includes a raw material tank capable of storing heavy water, a deuterium generation unit connected to the raw material tank via a first pipe, a first dehumidification unit connected to the deuterium generation unit via a second pipe, a third pipe connecting the first dehumidification unit to the outside, and a heavy water separation unit connected to the first dehumidification unit via a fourth pipe. The production facility includes a fifth pipe connecting the heavy water separation unit and the second pipe, and a sixth pipe connecting the heavy water separation unit and the raw material tank.

[0009] The deuterium production equipment according to the present disclosure includes a raw material tank capable of storing heavy water, and a deuterium generation unit connected to the raw material tank via a first pipe. A ninth pipe that exhausts gas from the raw material tank is connected to the raw material tank. A second dehumidification unit including a plurality of dehumidifiers capable of adsorbing and desorbing heavy water is connected downstream of the ninth pipe. The production equipment includes a tenth pipe that branches off from the ninth pipe and connects to the raw material tank. Effect of the Invention

[0010] According to the deuterium production facility of the present disclosure, deuterium production facility is provided that has high utilization efficiency of heavy water and is capable of producing high-purity deuterium. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration of a deuterium production facility according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an explanatory diagram showing the configuration of a deuterium production facility according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is an explanatory diagram showing the configuration of a deuterium production facility according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Outline of the embodiment] First, an overview of the deuterium production facility according to the present disclosure will be listed and described. The deuterium production equipment according to the present disclosure includes a raw material tank capable of storing heavy water, a deuterium generation unit connected to the raw material tank via a first pipe, and a dehumidification unit for dehumidifying a gas discharged from the raw material tank or a gas generated in the deuterium generation unit. A return line for returning the heavy water recovered in the dehumidification unit to the raw material tank is connected to the dehumidification unit.

[0013] As the use of deuterium expands, a stable supply of deuterium (D2) gas is desired. One method for producing deuterium is to electrolyze heavy water (D2O) to obtain deuterium (D2) gas. Electrolysis of heavy water can be carried out roughly in the same equipment and under the same conditions as electrolysis of light water (H2O). However, since the price of the raw material, heavy water, is much higher than that of light water, it is desirable to improve the efficiency of heavy water use as much as possible. At the same time, deuterium gas used in semiconductor manufacturing and other applications is required to be highly pure.

[0014] As studies on deuterium production equipment progressed, it was considered to recover heavy water, which had previously been discharged unused outside the equipment, and return it to the raw material tank. Specifically, the following two types of heavy water were identified as the heavy water to be recovered. First, heavy water contained as heavy water in the generated deuterium gas and adsorbed and removed in a dehumidifier. Second, heavy water as saturated water vapor contained in nitrogen gas or oxygen gas circulated in the gas phase of the raw material tank.

[0015] The heavy hydrogen (D2) manufacturing equipment according to the present disclosure includes a dehumidification unit for dehumidifying the gas circulated in the gas phase of the raw material tank or the gas generated in the deuterium generation unit, and the dehumidification unit is connected to a return line for returning the heavy water recovered in the dehumidification unit to the raw material tank. The heavy water is returned to the raw material tank through the return line and reused as a raw material for deuterium. With this configuration, the heavy water that was conventionally discharged outside the device without being used can be recovered and used as a raw material. This improves the efficiency of heavy water utilization. In addition, by connecting the raw material tank, the deuterium generation unit, the dehumidification unit, and the return line with a series of piping, the heavy water can be recovered within the closed system of the manufacturing equipment and returned to the raw material tank. This prevents impurities from entering from outside the system, and allows high-purity deuterium gas to be manufactured.

[0016] In the heavy hydrogen production facility, the dehumidification unit may include a dehumidification device capable of adsorbing and desorbing heavy moisture. A dehumidification device that adsorbs and desorbs heavy moisture can easily recover heavy moisture by desorbing the heavy moisture, and can regenerate the dehumidification device by desorption and reuse it. In addition, a dehumidification device that adsorbs and desorbs heavy moisture has a known configuration, and the effects of the present disclosure can be efficiently obtained by utilizing a known configuration.

[0017] The heavy water production facility according to the present disclosure includes a raw material tank capable of storing heavy water, a deuterium generation unit connected to the raw material tank via a first pipe, a first dehumidification unit connected to the deuterium generation unit via a second pipe, a third pipe connecting the first dehumidification unit to the outside, and a heavy water separation unit connected to the first dehumidification unit via a fourth pipe. The production facility includes a fifth pipe connecting the heavy water separation unit and the second pipe, and a sixth pipe connecting the heavy water separation unit and the raw material tank.

[0018] In the above manufacturing equipment, the dehumidification section and the heavy water separation section are connected via a pipe (fourth pipe). Also, the deuterium gas separated in the heavy water separation section is returned to the upstream of the dehumidification section via a pipe (fifth pipe), and the heavy water separated in the heavy water separation section is returned to the raw material tank via a pipe (sixth pipe). With this configuration, the heavy water and deuterium can be separated from the mixed fluid of heavy water and deuterium discharged from the dehumidification section, and the heavy water and deuterium can be reused.

[0019] In the deuterium production equipment, the first dehumidification unit may include a plurality of dehumidification devices capable of adsorbing and desorbing heavy moisture, a first switching unit, and a second switching unit. The first switching unit is connected to the second piping and is capable of switching between a state in which a first dehumidification device of the plurality of dehumidification devices is connected to the deuterium generation unit and a state in which a second dehumidification device of the plurality of dehumidification devices is connected to the deuterium generation unit. The second switching unit is connected to the third piping and is capable of switching between a state in which a first dehumidification device of the plurality of dehumidification devices is connected to the outside and a state in which a second dehumidification device of the plurality of dehumidification devices is connected to the outside. The first dehumidification unit may include a seventh piping branched off from downstream of the second switching unit and connected to the second switching unit.

[0020] According to this configuration, in the first dehumidification section, one of the first and second dehumidification devices can perform adsorption (dehumidification) while the other dehumidification device can perform desorption (regeneration) at the same time. Therefore, it is possible to continuously produce deuterium while exerting the effects of the present disclosure, and the production efficiency is also excellent.

[0021] In the deuterium production facility, a pump may be provided in the fifth pipe. With this configuration, the deuterium gas recovered by desorption in the dehumidification unit and separated in the heavy water separation unit can be pressurized and merged into the second pipe, making it possible to produce deuterium more efficiently.

[0022] In the deuterium production facility, a cooling unit may be provided in the second pipe, and the cooling unit may be connected to the raw material tank via an eighth pipe. With this configuration, a part of the heavy water content can be recovered from the wet deuterium gas flowing through the second pipe before the gas reaches the dehumidifier and returned to the raw material tank. Also, the amount of heavy water content adsorbed in the dehumidifier can be reduced. With these configurations, deuterium can be produced more efficiently.

[0023] The deuterium production facility according to the present disclosure includes a raw material tank capable of storing heavy water, and a deuterium generation unit connected to the raw material tank via a first pipe. A ninth pipe that exhausts gas from the raw material tank is connected to the raw material tank. A second dehumidification unit including a plurality of dehumidification devices capable of adsorbing and desorbing heavy water is connected downstream of the ninth pipe. The production facility includes a tenth pipe that connects the second dehumidification unit and the raw material tank.

[0024] According to the above manufacturing equipment, the gas discharged from the raw material tank passes through the dehumidifier. According to this configuration, deuterium equivalent to the saturated water vapor contained in the gas in the raw material tank can be recovered by the dehumidifier. Furthermore, the heavy water vapor recovered by the dehumidifier is returned to the raw material tank through a pipe (tenth pipe). In other words, the saturated water vapor contained in the gas in the raw material tank can be recovered and used as a raw material for deuterium. Furthermore, it is possible to recover the heavy water vapor and return it to the raw material tank in a closed system, which makes it possible to produce high-purity deuterium while avoiding the introduction of impurities.

[0025] In the deuterium production facility, an eleventh pipe connecting the second dehumidification unit and the outside may be connected downstream of the second dehumidification unit. The second dehumidification unit may include a third switching unit and a fourth switching unit. The third switching unit is connected to the ninth pipe and is capable of switching between a state in which a third dehumidification unit of the multiple dehumidification units is connected to the raw material tank and a state in which a fourth dehumidification unit of the multiple dehumidification units is connected to the raw material tank. The fourth switching unit is connected to the eleventh pipe and is capable of switching between a state in which the third dehumidification unit of the multiple dehumidification units is connected to the outside and a state in which the fourth dehumidification unit of the multiple dehumidification units is connected to the outside. The eleventh pipe may include a twelfth pipe branching off from downstream of the fourth switching unit and connecting to the fourth switching unit.

[0026] According to these configurations, one of the third and fourth dehumidifiers can perform adsorption (dehumidification) while the other dehumidifier can simultaneously perform desorption (regeneration). Therefore, it is possible to continuously produce heavy water while exerting the effects of the present disclosure, and the production efficiency is also excellent. In addition, it is possible to regenerate the dehumidifier without introducing gas from outside the device. Therefore, the effect of producing high-purity deuterium while avoiding the introduction of impurities can be more reliably obtained.

[0027] [Specific example of embodiment] Next, an example of a specific embodiment of the deuterium production equipment according to the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference symbols, and their description will not be repeated. In this specification, in the deuterium production equipment, the side closer to the raw material tank is referred to as the "upstream side", and the side closer to the product gas outlet or the exhaust outlet to the outside of the equipment is referred to as the "downstream side". However, in the operation of the equipment, the flow direction of the fluid flowing through each part of the equipment is not limited to this, and the flow direction of the fluid is switched depending on the process.

[0028] (Deuterium production facility) (Embodiment 1) Fig. 1 is an explanatory diagram showing the configuration of a deuterium production equipment 1 according to an embodiment of the present disclosure. With reference to Fig. 1, the deuterium production equipment 1 includes a raw material tank 10 that stores heavy water (D2O) in a liquid state, a deuterium generation unit 20, a dehumidification unit 30 as a first dehumidification unit, and a return line 40. The production equipment 1 can recover heavy water mixed into the deuterium gas generated in the deuterium generation unit 20 and return it to the raw material tank 10. The production equipment 1 can also recover deuterium gas used to recover the heavy water.

[0029] The raw material tank 10 and the deuterium generating unit 20 are connected via a pipe 71 serving as a first pipe. The deuterium generating unit 20 includes an electrolysis device. In the deuterium generating unit 20, heavy water serving as a raw material is electrolyzed to generate deuterium (D2) and oxygen. The deuterium generated in the deuterium generating unit 20 flows through a pipe 72 serving as a second pipe as a wet deuterium gas (wet D2) containing deuterium gas and unreacted heavy water that has passed through the deuterium generating unit. The pipe 72 connects between the deuterium generating unit 20 and the dehumidifying unit 30. In the dehumidifying unit 30, deuterium is removed from the wet deuterium gas. Note that a line (not shown) is connected to the deuterium generating unit 20, and oxygen generated in the deuterium generating unit 20 can be taken out via the line.

[0030] The dehumidifying section 30 includes dehumidifiers 31 and 32 capable of adsorbing and desorbing heavy moisture. Specifically, the dehumidifiers 31 and 32 may be columns filled with an adsorbent such as zeolite, silica gel, or alumina. The dehumidifiers 31 and 32 are arranged in parallel to each other. Arranged in parallel to each other means that a pipe that passes through the dehumidifier 31 without passing through the dehumidifier 32 can be configured, and a pipe that passes through the dehumidifier 32 without passing through the dehumidifier 31 can be configured.

[0031] The dehumidification unit 30 includes a first switching unit 51 connected to a pipe 72. The first switching unit 51 includes four switching valves. By opening and closing the switching valves of the first switching unit 51, it is possible to switch between a state in which the dehumidification device 31 as a first dehumidification device is connected to the deuterium generation unit 20 via the pipe 72 and a state in which the dehumidification device 32 as a second dehumidification device is connected to the deuterium generation unit 20 via the pipe 72.

[0032] A pipe 73 serving as a third pipe is connected to the downstream side of the dehumidification unit 30. Deuterium gas (product gas) dehumidified in the dehumidification unit 30 is taken out of the manufacturing apparatus through the pipe 73. The dehumidification unit 30 includes a second switching unit 52 connected to the pipe 73. The second switching unit 52 includes four switching valves. By opening and closing the switching valves of the second switching unit 52, it is possible to switch between a state in which the dehumidification device 31 is connected to the outside and a state in which the dehumidification device 32 is connected to the outside. The pipe 73 includes a pipe 77 serving as a seventh pipe that branches off from the downstream of the second switching unit 52 and connects to the second switching unit 52.

[0033] By providing the dehumidification section 30 with the dehumidifiers 31, 32, the first switching section 51, and the second switching section 52, it is possible to perform dehumidification with one dehumidifier (e.g., the dehumidifier 31) while simultaneously regenerating the other dehumidifier (e.g., the dehumidifier 32). A temperature adjustment device (not shown) is provided for dehumidification and regeneration. Although an example including two dehumidifiers 31, 32 has been described as an example of the embodiment, the dehumidification section of the deuterium production facility according to the present disclosure may be configured to include even more dehumidifiers, for example, 3, 4, 6, etc. The dehumidification and regeneration steps will be described later.

[0034] The dehumidification section 30 is connected to the heavy water separation section 50 via a pipe 74 as a fourth pipe. The pipe 74 is connected to the first switching section 51. When the dehumidification devices 31 and 32 are regenerated, deuterium gas containing heavy water desorbed from the dehumidification devices 31 and 32 is taken out through the pipe 74. The heavy water separation section 50 is connected to the pipe 72 via a pipe 75 as a fifth pipe. The heavy water separation section 50 is connected to the raw material tank 10 via a pipe 76 as a sixth pipe. The heavy water separation section 50 includes a cooling condensation device 57 and a gas-liquid separation device 58. The cooling condensation device 57 may be, for example, a heat exchanger. The gas-liquid separation device 58 may include, for example, a separator. The separator may include, for example, a centrifugal separation type gas-liquid separator or a float type gas-liquid separator. Since the regeneration of the dehumidifiers 31 and 32 is performed at a high temperature of, for example, about 250° C., the desorbed heavy water becomes gas or heavy water vapor, and is discharged as a mixed gas with deuterium gas, which is a gas for regeneration. The mixed gas is cooled in the cooling and condensing device 57, and the heavy water contained in the mixed gas is condensed to become liquid heavy water. Next, the heavy water and the deuterium gas are separated in the gas-liquid separator 58. The deuterium gas, which is a gas, separated in the gas-liquid separator 58 is supplied to the pipe 72 through the pipe 75. The heavy water, which is a liquid, separated in the gas-liquid separator 58 is returned to the raw material tank 10 through the pipe 76. With these configurations, both the heavy water desorbed from the dehumidifier and the deuterium gas used in the regeneration process can be recovered and reused.

[0035] A pump 91 is provided in the pipe 75, which can pressurize the deuterium gas and allow it to join the pipe 72. A check valve is provided in the pipe 72 to regulate the direction in which the deuterium gas flows.

[0036] (Embodiment 2) FIG. 2 is an explanatory diagram showing a configuration of a deuterium production facility 100 according to an embodiment of the present disclosure. Referring to FIG. 2, the deuterium production facility 100 includes a raw material tank 110 for accommodating liquid heavy water, a deuterium generating unit 120, a dehumidifying unit 160 as a second dehumidifying unit, and a pipe 140 as a return line. In the production facility 100, heavy water is accommodated in the raw material tank 110. In addition, the gas phase in the raw material tank 110 is purged with an inert gas such as nitrogen gas or argon gas, or oxygen gas, in order to prevent the heavy water as a raw material from being mixed with light water or other impurities (hereinafter, the gas circulated in the gas phase of the raw material tank may be referred to as a tank circulation gas). The production facility 100 can recover heavy water vapor equivalent to the saturated water vapor contained in the tank circulation gas circulated in the raw material tank 110, and return the heavy water to the raw material tank 110 as heavy water.

[0037] The manufacturing equipment 100 includes a deuterium generating unit 120 connected to the raw material tank 110 via a pipe 171 as a first pipe. The deuterium generating unit 120 includes, for example, an electrolysis device. In the deuterium generating unit 120, heavy water is electrolyzed to generate deuterium and oxygen. The generated deuterium is taken out through a pipe (not shown). A pipe 179 as a ninth pipe is also connected to the raw material tank 110. It is preferable that the pipe 179 is connected to the upper part (upper part in the vertical direction) of the raw material tank 110 so that gas can be taken out from the gas phase part of the raw material tank 110. A dehumidification unit 160 is connected to the downstream side of the pipe 179. A tank circulation gas containing heavy water vapor of a saturated water vapor content flows through the pipe 179. The tank circulation gas taken out from the raw material tank 110 through the pipe 179 is dehumidified by the dehumidification unit 160.

[0038] A pipe 181 serving as an eleventh pipe is connected to the downstream side of the dehumidification section 160. The tank circulating gas dehumidified in the dehumidification section 160 is discharged through the pipe 181 to the outside of the manufacturing apparatus.

[0039] The dehumidification unit 160 includes a dehumidifier 163 as a third dehumidifier capable of adsorbing and desorbing heavy moisture, and a dehumidifier 164 as a fourth dehumidifier. Specifically, the dehumidifiers 163 and 164 may be columns filled with an adsorbent such as zeolite, silica gel, or alumina. The dehumidifiers 163 and 164 are arranged in parallel with each other. The dehumidification unit 160 also includes a third switching unit 153 and a fourth switching unit 154. The third switching unit 153 is connected to a pipe 179. The third switching unit 153 includes four switching valves. By opening and closing the switching valve of the third switching unit 153, it is possible to switch between a state in which the dehumidifier 163 is connected to the raw material tank 110 via the pipe 179 and a state in which the dehumidifier 164 is connected to the raw material tank 110 via the pipe 179.

[0040] Fourth switching unit 154 is connected to pipe 181. Fourth switching unit 154 includes four switching valves. Opening and closing the switching valves of fourth switching unit 154 makes it possible to switch between a state in which dehumidifier 163 is connected to the outside and a state in which dehumidifier 164 is connected to the outside. In addition, pipe 181 includes pipe 182 as a twelfth pipe that branches off from downstream of fourth switching unit 154 and connects to fourth switching unit 154.

[0041] The dehumidification section 160 is connected to the heavy water separation section 150 through a pipe 180 as a tenth pipe. The pipe 180 is connected to the third switching section 153 of the dehumidification section 160. When the dehumidification devices 163, 164 are regenerated, the tank circulation gas containing the heavy water desorbed from the dehumidification devices 163, 164 is sent to the heavy water separation section 150 through the pipe 180. The heavy water separation section 150 is connected to the raw material tank 110 through the pipe 140 which is a return line. The heavy water separation section 150 includes a cooling condensation device 157 and a gas-liquid separation device 158. Since the regeneration of the dehumidification devices 163, 164 is performed at a high temperature of, for example, about 250°C, the heavy water desorbed from the dehumidification devices becomes gas or heavy water vapor, and is discharged as a mixed gas with the tank circulation gas used as the regeneration gas. For example, the mixed gas is cooled in a cooling condensing device 151 which is a heat exchanger, and the heavy water contained in the mixed gas becomes liquid heavy water. The heavy water and the tank circulating gas are separated in a gas-liquid separator 158. The tank circulating gas separated in the gas-liquid separator 158 is discharged to the outside of the facility through a pipe 185 which is a discharge line. The heavy water separated in the gas-liquid separator 158 is returned to the raw material tank 110 through a pipe 140. With this configuration, the heavy water discharged from the raw material tank as the saturated water vapor contained in the tank circulating gas can be reused as a raw material.

[0042] (Embodiment 3) Fig. 3 is an explanatory diagram showing the configuration of a deuterium production facility 200 according to an embodiment of the present disclosure. With reference to Fig. 3, the deuterium production facility 200 includes a raw material tank 210, a deuterium generation unit 220 including an electrolysis device, a first dehumidification unit 230 for dehumidifying moist deuterium gas extracted from the deuterium generation unit 220, and a second dehumidification unit 260 for dehumidifying heavy water in the tank circulating gas extracted from the raw material tank 210. Of the configuration of the production facility 200, some of the configurations common to the above-mentioned production facility 1 and production facility 100 will not be described.

[0043] (Deuterium line) The raw material tank 210 and the deuterium generation unit 220 are connected by a pipe 271 as a first pipe. The deuterium generation unit 220 and the dehumidification unit 230 are connected via a pipe 272 as a second pipe. The first dehumidification unit 230 is connected to the heavy water separation unit 250 via a pipe 274 as a fourth pipe. The heavy water separation unit 250 is connected to the pipe 272 as the second pipe via a pipe 275 as a fifth pipe, and is also connected to the raw material tank 210 via a pipe 276 as a sixth pipe. With these configurations, the heavy water recovered from the dehumidification unit 230 can be returned to the raw material tank 210, and the deuterium gas used for regenerating the dehumidification unit 230 is also recovered.

[0044] A pump 292 is provided midway along the pipe 271, and the heavy water as the raw material can be pressurized and sent to the deuterium generating unit 220. The deuterium generating unit 220 is connected to a pipe 272 which is an extraction line for deuterium gas, and a pipe 283 which is an extraction line for oxygen generated in the deuterium generating unit 220. The pipe 283 is connected to the raw material tank 210.

[0045] A check valve C1 and a cooling unit 255 are provided in the pipe 272. The cooling unit 255 is connected to the raw material tank 210 via a pipe 278 serving as an eighth pipe. A gas-liquid mixed fluid containing heavy water as an unreacted raw material flows through the pipe 272. This wet deuterium gas is cooled in the cooling unit 255, and the heavy water condensed in the cooling unit 255 is collected in the raw material tank 210 through the pipe 278.

[0046] Wet deuterium gas (Wet D2) from which some of the heavy water has been removed by being cooled in the cooling unit 255 is sent to the dehumidification unit 230 through the pipe 272. The dehumidification unit 230 includes a dehumidification unit 231 as a first dehumidification unit, a dehumidification unit 232 as a second dehumidification unit, a first switching unit 251 including switching valves V1 to V4, and a second switching unit 252 including switching valves V5 to V8. The dehumidification units 231 and 232 are arranged in parallel with each other. The first switching unit 251 is arranged upstream of the dehumidification units 231 and 232. The first switching unit 251 is connected to the pipe 272. The first switching unit 251 is connected to the pipe 274. The second switching unit 252 is arranged downstream of the dehumidification units 231 and 232. The second switching unit 252 is connected to a pipe 273 which is an extraction line for dry deuterium gas (Dry D2) which is the product gas. The dehumidification unit 230 includes a pipe 277 which serves as a seventh pipe which branches off from the downstream of the second switching unit 252 and connects to the second switching unit 252. A valve V10 which is a flow control valve, a flow meter FG, and a switching valve V9 are provided midway along the pipe 277.

[0047] The heavy water separation section 250 includes a cooling condensation device 257 and a gas-liquid separation device 258. Specifically, the cooling condensation device 257 may be a heat exchanger. The configuration of the heavy water separation section 250 is similar to that of the heavy water separation section 50 in the manufacturing equipment 1. The deuterium gas separated in the heavy water separation section 250 is sent to the pipe 272 through the pipe 275. The pipe 275 is provided with a pump 291 and a check valve C2. The pipe 272 is provided with a pressure gauge PG. The heavy water separated in the heavy water separation section 250 is collected in the raw material tank 210 through the pipe 276.

[0048] (Method for recovering and reusing heavy water and deuterium from the deuterium generating unit) A method for recovering heavy water and deuterium in the above-mentioned equipment will now be described. Deuterium as a raw material is supplied from the raw material tank 210 to the deuterium generating unit 220. The pressure of the deuterium is adjusted to a predetermined pressure (for example, about 0.8 MPa) by the pump 292. Deuterium and oxygen are generated by electrolyzing the deuterium in the deuterium generating unit 220. An appropriate electrolysis device can be selected as the deuterium generating unit, and specifically, for example, it includes a solid polymer water electrolysis cell. Deuterium generated by electrolysis of the deuterium is supplied to the cooling unit 255 in the form of a gas-liquid mixed deuterium together with unreacted deuterium that has permeated the solid polymer membrane of the deuterium generating unit 220. The cooling unit 255 is a gas-liquid separator, and specifically, for example, a heat exchanger. Cooling water is supplied to the cooling unit 255 to cool the gas-liquid mixed water. The temperature of the cooling water may be, for example, 5°C to 30°C, preferably 5°C to 25°C, and more preferably 5°C to 10°C. The gas-liquid heavy water mixture is cooled in the cooling section 255 , and the condensed heavy water is collected in the raw material tank 210 through a pipe 278 .

[0049] The wet deuterium gas (Wet D2) from which excess heavy water has been removed in the cooling section 255 is supplied to the dehumidification section 230 through the pipe 272. Specifically, the dehumidifiers 231, 232 in the dehumidification section 230 include a dehumidification cylinder unit containing an adsorbent, for example. As the adsorbent, a porous material that adsorbs moisture, such as zeolite, silica gel, or alumina, is used. One of the dehumidifiers 231, 232 is used to dry the wet deuterium gas, and the other is simultaneously regenerated. The dehumidifiers 231, 232 are used by switching between drying and regeneration according to a predetermined standard (for example, at regular intervals or at regular flow rates).

[0050] Here, a case will be described where the dehumidifier 231 is used for drying and the dehumidifier 232 is used for regeneration. By opening the switching valve V1 of the first switching unit 251 and the switching valve V7 of the second switching unit 252, the pipe 272, the dehumidifier 231, and the pipe 273 are communicated. In this state, the dehumidifier 231 is used for drying the wet deuterium gas. The wet deuterium gas that has passed through the dehumidifier 231 is dehumidified to a dew point of about −80° C., and is taken out of the device as dry deuterium gas (Dry D2), which is a product gas, through the pipe 273. In addition, by opening the flow control valve V10 and the switching valves V9 and V6, a part of the dry deuterium gas flowing through the pipe 273 is introduced into the dehumidifier 232 and is used for regeneration of the dehumidifier 232. The flow control valve V10 may be, for example, a needle valve. The opening of the flow control valve V10 is adjusted to adjust the amount of dry deuterium gas used in the regeneration process. The amount of dry deuterium gas used in the regeneration process is preferably 10% or less of the dry deuterium gas flowing through the pipe 273, and more preferably 3% to 5%. In the regeneration process, it is preferable to heat the dehumidifier 232 to about 250°C using a heater. By opening the switching valve V4, the dehumidifier 232 and the pipe 274 are communicated, and the gas used for dehumidification by the dehumidifier 232 is introduced into the heavy water separation section 250 through the pipe 274.

[0051] In the regeneration step, the heavy water adsorbed on the adsorbent of the dehumidifier 232 is desorbed, and the dry deuterium gas introduced into the dehumidifier 232 becomes deuterium gas containing heavy water. This deuterium gas containing heavy water is introduced into the heavy water separation section 250 through the pipe 274 and passes through the cooling condensation device 257 of the heavy water separation section 250. The cooling condensation device 257 is cooled with a refrigerant such as water or antifreeze. The cooling temperature is not limited as long as the required performance is obtained, but is preferably 4°C or higher, which is the freezing point of heavy water, and may be 10°C or lower. In the cooling condensation device 257, the heavy water contained in the deuterium gas containing heavy water is condensed, thereby obtaining heavy water and deuterium gas containing heavy water equivalent to the saturated water vapor at the cooling temperature (for example, 10°C). In the gas-liquid separator 258, the heavy water and the deuterium gas are separated, and the heavy water is collected in the raw material tank 210 through the pipe 276. The deuterium gas is pressurized to a predetermined pressure (for example, 0.8 MPa) by a pump 291 through a pipe 275 and then fed into a pipe 272 .

[0052] The above-mentioned equipment and method make it possible to use the entire amount of deuterium gas as a product without releasing it into the atmosphere, and the only loss of heavy water vapor is that contained in the product deuterium, which has a dew point of about -80° C. In addition, the above-mentioned equipment makes it possible to recover and reuse deuterium and deuterium gas in a closed system, preventing the intrusion of impurities from outside the equipment, and enabling the stable production of high-purity deuterium gas.

[0053] (Inert gas, oxygen line) The raw material tank 210 is connected to a pipe 284 for introducing an inert gas (e.g., nitrogen gas) to be circulated in the gas phase part of the raw material tank 210, and a pipe 283. The pipe 284 is equipped with a flow meter FG, and an appropriate amount of nitrogen gas is supplied according to the amount of heavy water in the raw material tank 210. A gas-liquid mixture of oxygen gas generated in the deuterium generation part 220 and unreacted heavy water is sent to the raw material tank 210 through the pipe 283.

[0054] A pipe 279 as a ninth pipe is connected to the raw material tank 210, and the gas circulated in the gas phase part of the raw material tank 210 is taken out through the pipe 279. The gas passing through the raw material tank 210 contains heavy water with a saturated water vapor content according to the temperature of the raw material tank. The pipe 279 is connected to the dehumidification part 260 as a second dehumidification part. The second dehumidification part 260 is connected to the heavy water separation part 350 through the pipe 280 as a tenth pipe. The heavy water separation part 350 is connected to the raw material tank 210 through the pipe 240 as a return line. The heavy water separation part 350 is also connected to the pipe 279 through the pipe 285. A pump 293 and a check valve C4 are provided in the middle of the pipe 285. With these configurations, the heavy water recovered in the regeneration process of the dehumidification part 260 can be returned to the raw material tank 210. Also, the gas used for regeneration of the dehumidification part 260 is supplied to the dehumidification part 260 again.

[0055] The dehumidification section 260 includes two dehumidifiers 263, 264 arranged in parallel, a third switching section 253, and a fourth switching section 254. The third switching section 253 is arranged upstream of the dehumidifiers 263, 264, and includes four switching valves V1' to V4'. The fourth switching section 254 is arranged downstream of the dehumidifiers 263, 264, and includes four switching valves V5' to V8'. The dehumidification section 260 includes a pipe 282 as a twelfth pipe that branches from downstream of the fourth switching section 254 and connects to the fourth switching section 254. A valve V10' that is a flow control valve, a flowmeter FG, and a switching valve V9' are provided in the middle of the pipe 282. The configuration of the dehumidification section 260 is generally similar to that of the dehumidification section 160 and the dehumidification section 230, and therefore overlapping descriptions will not be repeated. The dehumidifying section 260 is connected to a pipe 281 which is an eleventh pipe connected to the outside of the device. Through the pipe 281, the inert gas and the oxygen gas are released to the outside of the facility.

[0056] The heavy water separation section 350 includes a cooling condensation device 357 and a gas-liquid separation device 358. Specifically, the cooling condensation device 357 may be a heat exchanger. The configuration of the heavy water separation section 350 is generally similar to that of the heavy water separation sections 150 and 250, and therefore overlapping descriptions will not be repeated. The heavy water separated in the heavy water separation section 350 is collected in the raw material tank 210 through the pipe 240.

[0057] (Method of recovering and reusing heavy water from the gas phase of the raw material tank) A method for recovering heavy water in the above-mentioned facility will now be described. The gas extracted from the gas phase of the raw material tank 210 through the pipe 279 is dehumidified in the dehumidifier 260 and then discharged outside the facility through the pipe 281. The gas supplied to the dehumidifier 260 contains an inert gas (e.g., nitrogen gas) and oxygen gas, as well as heavy water vapor equivalent to saturated water vapor. The heavy water vapor is adsorbed by the dehumidifier 263 or 264 of the dehumidifier 260, dehumidified to a dew point of about -80°C, and then discharged through the pipe 281. One of the dehumidifiers 263, 264 is used to dry the gas in the gas phase of the tank, and the other is regenerated at the same time. The dehumidifiers 263, 264 are used by switching between drying and regeneration according to a predetermined standard (e.g., at regular intervals or at regular flow rates).

[0058] The gas drying and dehumidification device regeneration in the dehumidification section 260 can be performed in the same manner as that performed in the dehumidification section 230, and a duplicated description will not be repeated. For regeneration of the dehumidifier, the dehumidified tank circulation gas supplied to the dehumidifier 260 through the pipe 282 and the fourth switching unit 254 is used as a drying gas. In the regeneration process, the heavy water adsorbed to the adsorbent of the dehumidifier 263 (or the dehumidifier 264) is desorbed, and the drying gas introduced into the dehumidifier 263 (or the dehumidifier 264) becomes a gas containing heavy water. This gas containing heavy water is introduced into the heavy water separation unit 350 through the pipe 280 and passes through the cooling condensation unit 357 of the heavy water separation unit 350. In the cooling condensation unit 357, the heavy water contained in the gas containing heavy water is condensed, thereby obtaining heavy water and a gas containing heavy water equivalent to the saturated water vapor at a cooling temperature (for example, 10°C). In the gas-liquid separator 358, the heavy water and the gas are separated, and the heavy water is collected in the raw material tank 210 through the pipe 240. The gas is pressurized to a predetermined pressure (for example, 0.1 MPa) by pump 293 through pipe 285, and then sent to pipe 279, where it is dehumidified again by dehumidifying section 260.

[0059] The above-mentioned equipment and method make it possible to recover heavy water mixed as saturated water vapor in the gas present in the gas phase of the raw material tank, and the only heavy water lost is that contained in the exhausted dry gas at a dew point of about -80°C. Furthermore, the above-mentioned equipment makes it possible to recover and reuse deuterium in a closed system, preventing the intrusion of impurities from outside the equipment, and enabling the stable production of high-purity deuterium gas.

[0060] The embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0061] 1, 100, 200 Manufacturing equipment, 10, 110, 210 Raw material tank, 20, 120, 220 Deuterium generation section, 30, 130, 230, 160, 260 Dehumidification section, 31, 32, 163, 164, 231, 232, 263, 264 Dehumidification device, 40 Return line, 50, 150, 250, 350 Heavy water separation section, 51, 251 First switching section, 52, 252 Second switching section, 57, 157, 257, 357 Cooling and condensing device, 58, 158, 258, 358 Gas-liquid separator, 71, 72, 73, 74, 75, 76, 77, 79, 140, 171, 179, 180, 181, 182, 185, 240, 271, 272, 273, 274, 275, 276, 278, 279, 280, 281, 282, 283, 284, 285 Piping, 91, 291, 292, 293 Pump, 153, 253 Third switching section, 154, 254 Fourth switching section, 255 Cooling section.

Claims

1. a raw material tank capable of containing heavy water; a deuterium generating unit connected to the source tank via a first pipe; a dehumidification unit for dehumidifying the gas discharged from the raw material tank or the gas generated in the deuterium generation unit; Equipped with The dehumidification unit includes: A return line is connected to return the heavy water recovered in the dehumidification unit to the raw material tank. Deuterium production facility.

2. The dehumidification unit includes a dehumidification device capable of adsorbing and desorbing heavy moisture. The facility for producing deuterium according to claim 1 .

3. a raw material tank capable of containing heavy water; a deuterium generating unit connected to the source tank via a first pipe; a first dehumidification unit connected to the deuterium generation unit via a second pipe; A third pipe connecting the first dehumidification unit and the outside; a heavy water separation unit connected to the first dehumidification unit via a fourth pipe; Equipped with a fifth pipe connecting the heavy water separation unit and the second pipe; a sixth pipe connecting the heavy water separation unit and the raw material tank; Including, Deuterium production facility.

4. The first dehumidification unit includes: A plurality of dehumidifiers capable of adsorbing and desorbing heavy moisture; a first switching unit connected to the second pipe and capable of switching between a state in which a first dehumidifier of the plurality of dehumidifiers is connected to the deuterium generation unit and a state in which a second dehumidifier of the plurality of dehumidifiers is connected to the deuterium generation unit; a second switching unit connected to the third pipe and capable of switching between a state in which a first dehumidifier of the plurality of dehumidifiers is connected to the outside and a state in which a second dehumidifier of the plurality of dehumidifiers is connected to the outside, A seventh pipe branching off from downstream of the second switching unit and connecting to the second switching unit, The facility for producing deuterium according to claim 3.

5. A pump is provided in the fifth pipe. The facility for producing deuterium according to claim 3 or 4.

6. A cooling section is provided in the second piping, The cooling unit is connected to the raw material tank via an eighth pipe. The facility for producing deuterium according to claim 3 or 4.

7. a raw material tank capable of containing heavy water; a deuterium generating unit connected to the source tank via a first pipe; Equipped with a ninth pipe for discharging gas from the raw material tank is connected to the raw material tank; A second dehumidification unit including a plurality of dehumidification devices capable of adsorbing and desorbing heavy moisture is connected downstream of the ninth pipe, A tenth pipe is provided to connect the second dehumidification unit and the raw material tank. Deuterium production facility.

8. an eleventh pipe is connected downstream of the second dehumidification unit to connect the second dehumidification unit to the outside; The second dehumidification unit includes: a third switching unit connected to the ninth pipe and capable of switching between a state in which a third dehumidifier of the plurality of dehumidifiers is connected to the raw material tank and a state in which a fourth dehumidifier of the plurality of dehumidifiers is connected to the raw material tank; a fourth switching unit connected to the eleventh pipe and capable of switching between a state in which a third dehumidifier of the plurality of dehumidifiers is connected to the outside and a state in which a fourth dehumidifier of the plurality of dehumidifiers is connected to the outside, The 11th pipe includes a 12th pipe branching off from downstream of the fourth switching unit and connecting to the fourth switching unit. The facility for producing deuterium according to claim 7.

9. a first dehumidification unit connected to the deuterium generation unit via a second pipe; A third pipe connecting the first dehumidification unit and the outside; a heavy water separation unit connected to the first dehumidification unit via a fourth pipe; Equipped with a fifth pipe connecting the heavy water separation unit and the second pipe; a sixth pipe connecting the heavy water separation unit and the raw material tank; Including, The facility for producing deuterium according to claim 7 or 8.

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