阅读说明：本技术 一种双同位素低温同步分离装置及分离方法 (Double-isotope low-temperature synchronous separation device and separation method ) 是由 何晖 袁士豪 李剑锋 李冬锋 朱程浩 任美凤 康玉茹 吴秀杰 韩小磊 包汉波 孙 于 2020-05-09 设计创作，主要内容包括：一种双同位素低温同步分离装置,它至少由空分氧气净化系统和空分氮气净化系统,<Sup>18</Sup>O同位素和<Sup>15</Sup>N同位素同步低温精馏系统,<Sup>18</Sup>O同位素和<Sup>15</Sup>N同位素分子裂解重组系统三部分构成；所述空分氧气净化系统和空分氮气净化系统至少包括空分氧气净化装置和空分氮气净化装置分别集合成的组合塔,以及空分氧气净化装置和空分氮气净化装置的下塔底部设有再沸器,空分氧气净化装置和空分氮气净化装置的冷凝蒸发器,本发明结合规整填料和散堆填料各自特点,前几级级联塔设置双层金属丝网波纹填料,后几级级联塔设置矩形螺旋圈填料,既保证了装置原料量处理能力较好,同时装置精馏效率也较高。在系统中设置有同位素分子裂解重组催化系统,提高了目标同位素丰度和产量。(A dual-isotope low-temperature synchronous separation device at least comprises an air separation oxygen purification system and an air separation nitrogen purification system, 18 o isotope and 15 an N isotope synchronous low-temperature rectification system, 18 o isotope and 15 the N isotope molecule cracking recombination system comprises three parts; the air separation oxygen purification system and the air separation nitrogen purification system at least comprise a combined tower which is respectively integrated by an air separation oxygen purification device and an air separation nitrogen purification device, and a reboiler is arranged at the bottom of the lower tower of the air separation oxygen purification device and the air separation nitrogen purification deviceThe invention relates to a condensation evaporator of an air separation nitrogen purification device, which combines the characteristics of regular packing and random packing, wherein the front cascade towers are provided with double-layer wire mesh corrugated packing, and the rear cascade towers are provided with rectangular spiral coil packing, thereby ensuring better raw material quantity processing capacity of the device and higher rectification efficiency of the device. An isotope molecule cracking recombination catalysis system is arranged in the system, so that the abundance and the yield of the target isotope are improved.)

1. A dual-isotope low-temperature synchronous separation device at least comprises an air separation oxygen purification system and an air separation nitrogen purification system,¹⁸o isotope and¹⁵an N isotope synchronous low-temperature rectification system,¹⁸o isotope and¹⁵the N isotope molecule cracking recombination system comprises three parts; it is characterized in that the air separation oxygen purification system and the air separation nitrogen purification system at least comprise a combined tower formed by respectively integrating an air separation oxygen purification device and an air separation nitrogen purification device, an air separation oxygen purification device and an air separation nitrogen purification deviceA reboiler is arranged at the bottom of the lower tower of the air separation nitrogen purification device, condensation evaporators of the air separation oxygen purification device and the air separation nitrogen purification device, condensers at the tops of the upper towers of the air separation oxygen purification device and the air separation nitrogen purification device, and a pressure reducing valve;¹⁸o isotope and¹⁵the N isotope synchronous cryogenic rectification system at least comprises¹⁸O isotope and¹⁵the system comprises an N isotope multi-stage rectifying tower, a liquid oxygen nitrogen reboiler, an oxygen and nitrogen condensation evaporator and a liquid nitrogen condenser;¹⁸o isotope and¹⁵the N isotope atom cracking recombination system at least comprises an oxygen/nitrogen molecule cracking recombination catalytic device and a catalytic electric heater, wherein the combined tower of the air separation oxygen purification device and the air separation nitrogen purification device is divided into an upper tower and a lower tower, wherein the upper tower filters out light component impurities, the lower tower filters out heavy component impurities, the pressure of the lower tower is higher than that of the upper tower, the steam rising from the top of the lower tower is used as a heat source to boil the accumulated liquid at the bottom of the upper tower through the difference of boiling points, the upper towers of the air separation oxygen purification device and the air separation nitrogen purification device are subjected to pressure reduction operation to remove the light component impurities such as hydrogen, the lower towers of the air separation oxygen purification device and the air separation nitrogen purification device are subjected to low-temperature rectification to filter out the heavy component impurities, and the content of the.

2. The dual-isotope low-temperature synchronous separation device according to claim 1, characterized in that the inlet of the air separation nitrogen purification device (16) is connected with air separation nitrogen (33), the top of the lower tower (98) of the air separation nitrogen purification device (16) is connected with the bottom of the air separation nitrogen condensation evaporator (99), the upper air outlet of the lower tower (98) of the air separation nitrogen purification device (16) is connected with the inlet of a pressure reducing valve (90), the outlet of the pressure reducing valve (90) is connected with the feed inlet of an upper tower (96) of an air separation nitrogen purification device (16), the bottom of the upper tower (96) of the air separation nitrogen purification device (16) is connected with the top of an air separation nitrogen condensation evaporator (99), the bottom of a lower tower (98) of the air separation nitrogen purification device (16) is connected with the top of a lower tower reboiler (109), the top of the upper tower (96) of the air separation nitrogen purification device (16) is connected with the bottom of an upper tower top condenser (101), and the outlet of the air separation nitrogen purification device (16) is connected with the mass flow rate of high-purity raw material nitrogen.An inlet of the preparation device (18) and an outlet of the high-purity raw material nitrogen mass flow controller (18) are connected with a first-stage cascade¹⁵The middle raw material inlet of the N isotope lean removing tower (1) is cascaded in the first stage¹⁵The waste gas at the top of the N isotope lean removing tower (1) is exhausted to the atmosphere, and the first stage is cascaded¹⁵The bottom of the N isotope lean removing tower (1) is connected with a first-stage cascade¹⁸O isotope and¹⁵the top of the N isotope condensation evaporator (2), the outlet of the condensation evaporator (2) is connected with the second cascade¹⁵The middle raw material inlet of the N isotope lean removing tower (5) is cascaded in the second stage¹⁵The top waste gas (36) of the N isotope lean removing tower (5) is connected with the first-stage cascade¹⁵The return air port of the N isotope lean removing tower (1) is cascaded in the second stage¹⁵The bottom of the N isotope lean removing tower (5) is connected with a second-stage cascade¹⁸O isotope and¹⁵the top of the N isotope condensation evaporator (6), the outlet of the condensation evaporator (6) is connected with the next cascade¹⁵The raw material inlet of the N isotope lean removing tower is cascaded in the second stage¹⁵The return air port of the N isotope lean removing tower (5) is connected with the next stage of cascade¹⁵A top gas outlet of the N isotope lean removal tower, the first stage is cascaded¹⁵The top of the N isotope lean removing tower (1) is connected with a first-stage cascade¹⁵The bottom of the N isotope condenser (13) is cascaded in the second stage¹⁵The top of the N isotope lean removing tower (5) is connected with a second-stage cascade¹⁵The bottom of the N isotope condenser (14) is provided with a product discharge hole of the second-stage cascade tower¹⁸O isotope and¹⁵a recombination catalytic device (32) for cracking N isotope molecules.

3. The dual-isotope low-temperature synchronous separation device according to claim 1, characterized in that the inlet of the air separation oxygen purification device (17) is connected with air separation oxygen (41), the top of the lower tower (58) of the air separation oxygen purification device (17) is connected with the bottom of the air separation oxygen condensation evaporator (79), the upper air outlet of the lower tower (58) of the air separation oxygen purification device (17) is connected with the inlet of a pressure reducing valve (60), the outlet of the pressure reducing valve (60) is connected with the feed inlet of the upper tower (56) of the air separation oxygen purification device (17), and the bottom of the upper tower (56) of the air separation oxygen purification device (17) is connected with the air separationThe top of the generator (79), the bottom of the lower tower (58) of the air separation oxygen purification device (17) is connected with the top of the lower tower reboiler (59), the top of the upper tower (56) of the air separation oxygen purification device (17) is connected with the bottom of the upper tower condenser (100), the outlet of the air separation oxygen purification device (17) is connected with the inlet of the high-purity raw material oxygen mass flow controller (19), and the outlet of the high-purity raw material oxygen mass flow controller (19) is connected with the first-stage cascade¹⁸The middle raw material inlet of the O isotope lean removing tower (3) is cascaded in the first stage¹⁸The waste gas at the top of the O isotope lean removing tower (3) is exhausted to the atmosphere, and the first stage is cascaded¹⁸The bottom of the O isotope lean removing tower (3) is connected with a first-stage cascade¹⁸An O isotope lean removal tower nitrogen reboiler (4) and a first-stage cascade¹⁸The top of the O isotope lean removing tower (3) is connected with a first-stage cascade¹⁸O isotope and¹⁵the bottom of the N isotope condensation evaporator (2) is cascaded in the first stage¹⁸The outlet of a nitrogen reboiler (4) of the O isotope lean removal tower is connected with the second-stage cascade¹⁸The middle raw material inlet of the O isotope lean removing tower (7) is cascaded in the second stage¹⁸The top of the O isotope lean removing tower (7) is connected with a second-stage cascade¹⁸O isotope and¹⁵the bottom of the N isotope condensation evaporator (6) is cascaded in the second stage¹⁸The top of the O isotope lean removal tower (7) is exhausted and connected with a first-stage cascade¹⁸The return air port of the O isotope lean removing tower (3) is cascaded in the second stage¹⁸The bottom of the O isotope lean removing tower (7) is connected with a second-stage cascade¹⁸An O isotope lean removal tower nitrogen reboiler (8) and a first and second-stage cascade¹⁸The outlet of a nitrogen reboiler (8) of the O isotope lean removal tower is connected with the next stage of cascade¹⁸And a raw material inlet of the O isotope dephenolizing tower.

4. The dual-isotope cryo-synchronous separation device of claim 1, wherein the dual isotopes are separated in parallel¹⁸O isotope and¹⁵product discharge port arrangement of N isotope multi-stage rectifying tower¹⁸O isotope and¹⁵the N isotope molecule cracking recombination catalytic device (32), the nitrogen inlet of the isotope molecule cracking recombination catalytic device (32) is connected with the second-stage cascade¹⁵N isotopes and cascades¹⁸The outlet of the O isotope condensation evaporator and the oxygen inlet of the isotope molecule cracking recombination catalytic device (32) are connected with the second cascade¹⁸The outlet of the nitrogen reboiler of the O isotope lean removal tower is connected with the inlet of the catalyzed nitrogen outlet valve (20) through the nitrogen outlet of the isotope molecule cracking recombination catalytic device (32), and the outlet of the catalyzed nitrogen outlet valve (20) is connected with the last-stage cascade¹⁵The raw material inlet of the N isotope concentration tower (9) is cascaded at the last stage¹⁵The top of the N isotope concentration tower (9) is connected with an upper-stage cascade¹⁵N isotope lean-removing tower gas return port, last stage cascade¹⁵The bottom of the N isotope concentration tower (9) is connected with the last stage cascade¹⁸O isotope and¹⁵top of N isotope condensing evaporator (10) and final stage cascade¹⁵The top of the N isotope concentration tower (9) is connected with the last stage cascade¹⁵The bottom of the N isotope condenser (15), an oxygen outlet of the isotope molecule cracking recombination catalytic device (32) is connected with an inlet of a catalyzed oxygen outlet valve (21), and an outlet of the catalyzed oxygen outlet valve (21) is connected with a final-stage cascade¹⁸The raw material inlet of an O isotope concentration tower (11) is cascaded at the last stage¹⁸The top of the O isotope concentration tower is connected with an upper-stage cascade¹⁸The return air port of the O isotope lean removing tower is cascaded at the last stage¹⁸The bottom of the O isotope concentration tower (11) is connected with the last stage cascade¹⁸The top of a nitrogen reboiler (12) of an O isotope lean removal tower is cascaded at the last stage¹⁸The top of the O isotope concentration tower (11) is connected with the last stage cascade¹⁸O isotope and¹⁵n isotope condensing evaporator (10).

5. The dual isotope cryogenic synchronous separation plant of claim 3, wherein the first stage cascade is characterized by¹⁸The nitrogen outlet of the O isotope lean-removing tower nitrogen reboiler (4) is connected with the inlet of a stop valve (24), the outlet of the stop valve (24) is exhausted to the atmosphere, and the second stage is cascaded¹⁸The nitrogen outlet of the O isotope lean-removing tower nitrogen reboiler (8) is connected with the inlet of a stop valve (26), the outlet of the stop valve (26) is exhausted to atmosphere, and the last stage is connected with the reboiler¹⁸The nitrogen outlet of the O isotope lean-removing tower nitrogen reboiler (12) is connected with the inlet of a stop valve (28), and the outlet of the stop valve (28) is largeGas, the first stage is cascaded¹⁸The nitrogen inlet of the O isotope lean-removing tower nitrogen reboiler (4) is connected with the outlet of the stop valve (23), and the second stage is cascaded¹⁸The nitrogen inlet of a nitrogen reboiler (8) of the O isotope lean removal tower is connected with the outlet of a stop valve (25) and is connected with the final stage¹⁸The nitrogen inlet of the O isotope lean-separating tower nitrogen reboiler (12) is connected with the outlet of a stop valve (27), the inlet of the stop valve (23), the inlet of the stop valve (25) and the inlet of the stop valve (27) are connected with the outlets of air-cooled nitrogen buffer devices (22), and the first-stage cascade is connected with the outlets of the air-cooled nitrogen buffer devices (22)¹⁸An O isotope lean removal tower nitrogen reboiler (4) and a second-stage cascade¹⁸O isotope dephenolization tower nitrogen reboiler (8) and final stage combination¹⁸And the nitrogen reboiler (12) of the O isotope dephenolizing tower takes air separation cold nitrogen as a heat source.

6. A separation method using the dual isotope cryo-simultaneous separation apparatus of any one of claims 1 to 5, the method comprising:

a. before the system is started, corresponding purging is required to be carried out on oxygen and nitrogen pipelines of the system, a valve (90) and a mass flow controller (18) are opened, air in the corresponding nitrogen pipelines is replaced by normal-pressure nitrogen (108 Kpa (A)), when the dew point of a purge gas outlet is as low as minus 170 ℃, purging is stopped, the valve (90) and the mass flow controller (18) are closed, a valve (60) and a mass flow controller (19) are opened, air in the corresponding oxygen pipelines is replaced by normal-pressure oxygen (108 Kpa (A)), when the dew point of the purge gas outlet is as low as minus 170 ℃, purging is stopped, and the valve (60) and the mass flow controller (19) are closed;

b. the system is started, firstly, air separation nitrogen (33) enters an air separation nitrogen purification device (16) lower tower (98), a valve (90) is opened, the air separation nitrogen enters an air separation nitrogen purification device (16) upper tower (96), the air separation nitrogen purification device (16) upper tower (96) condenser (101) is started, the air separation nitrogen is liquefied, liquid is accumulated at the bottom of the upper tower (96), when the liquid accumulated at the bottom of the upper tower (96) reaches a specified liquid level, a lower tower (98) reboiler (109) is started, ascending steam of the lower tower (98) serves as a reboiling heat source at the bottom of the upper tower (96), and air separation nitrogen purification is establishedThe rectification is balanced, when the air-separated nitrogen impurities are detected to be qualified, the high-purity raw material nitrogen mass flow controller (18) is slowly opened, and the high-purity nitrogen (34) enters the first-stage cascade connection¹⁵The N isotope lean removing tower (1) is started to start the first stage cascade¹⁵N isotope condenser (13), high-purity nitrogen liquefaction, first-stage cascade¹⁵Liquid accumulated at the bottom of the N isotope delignification tower (1);

C. starting an air separation oxygen pipeline, enabling air separation oxygen (41) to enter a lower tower (58) of an air separation oxygen purification device (17), opening a valve (60), enabling the air separation oxygen to enter an upper tower (56) of the air separation oxygen purification device (17), starting an upper tower (58) condenser (100) of the air separation oxygen purification device (17), liquefying the air separation oxygen, adding liquid at the bottom of the upper tower (56), starting a reboiler (59) of the lower tower (58) when the liquid at the bottom of the upper tower (56) reaches a specified liquid level, using ascending steam of the lower tower (58) as a reboiling heat source at the bottom of the upper tower (56), establishing air separation oxygen purification rectification balance, slowly opening a high-purity raw material oxygen mass flow controller (19) after air separation oxygen impurities are detected to be qualified, and enabling the high-purity oxygen (42¹⁸An O isotope depreciation tower (3) and high-purity oxygen (42) cascaded in the first stage¹⁸The top of the O isotope lean removal tower (3) is cascaded through a first stage¹⁸O isotope and¹⁵n isotope condensing evaporator (2) evaporating first-stage cascade¹⁵The bottom of the N isotope depreciation tower (1) is accumulated liquid, high-purity oxygen (42) is condensed at the same time, and the first stage is cascaded¹⁸The accumulated liquid at the bottom of the O isotope lean removal tower (3) is slowly opened by a stop valve (23), and air-cooled nitrogen (50) enters the first-stage cascade¹⁸An O isotope dephenolization tower nitrogen reboiler (4) used as a heat source to evaporate the first-stage cascade¹⁸The accumulated liquid at the bottom of the O isotope lean removal tower (3) establishes a first-stage cascade¹⁸O isotope lean removal tower (3) and first stage cascade¹⁵The rectification balance of the N isotope lean removal tower (1) is cascaded in the first stage¹⁸The waste gas at the top of the O isotope lean removing tower (3) is emptied, and the first stage is cascaded¹⁵Exhausting waste gas at the top of the N isotope lean removing tower (1), opening a valve (24), cooling air-cooled nitrogen (50), and exhausting air (51);

d. when the first stage is cascaded¹⁸O isotope lean removal tower (3) and first stage cascade¹⁵The rectification balance of the N isotope lean removing tower (1) is established, and after products at the bottom of each tower are analyzed to be qualified, the first-stage cascade connection is carried out firstly¹⁵Qualified products (35) at the bottom of the N isotope lean removing tower (1) pass through a first-stage cascade¹⁸O isotope and¹⁵the air outlet of the N isotope condensation evaporator (2) enters the second-stage cascade¹⁵The N isotope lean removing tower (5) starts the second stage cascade¹⁵N isotope condenser (14), first stage cascade¹⁵Qualified products (35) at the bottom of the N isotope lean removing tower (1) are liquefied and accumulated in the second-stage cascade¹⁵The bottom of the N isotope lean removing tower (5) is cascaded in the first stage¹⁸Qualified products (43) at the bottom of the O isotope lean removing tower (3) pass through a first-stage cascade¹⁸The outlet of a nitrogen reboiler (4) of the O isotope lean removal tower enters a second-stage cascade¹⁸An O isotope lean removing tower (7) and a first stage cascade¹⁸Qualified products (43) at the bottom of the O isotope lean removing tower (3) are cascaded in the second stage¹⁸The top of the O isotope lean removing tower (7) is cascaded through a second stage¹⁸O isotope and¹⁵n isotope condensing evaporator (6) evaporating second-stage cascade¹⁵Liquid nitrogen at the bottom of the N isotope lean removing tower (5) and a first-stage cascade¹⁸Qualified products (43) at the bottom of the O isotope lean removing tower (3) are liquefied and accumulated in the second-stage cascade¹⁸The bottom of the O isotope lean removal tower (7) is slowly opened by a stop valve (25), and the cold nitrogen (52) of the air separation enters the second-stage cascade¹⁸An O isotope depletion tower nitrogen reboiler (8) used as a heat source to evaporate the second-stage cascade¹⁸The bottom liquid of the O isotope lean removal tower (7) establishes a second-stage cascade¹⁸O isotope lean removal tower (7) and second-stage cascade¹⁵The rectification balance of the N isotope lean removing tower (5) is in the second stage cascade connection¹⁸The waste gas (44) at the top of the O isotope lean removing tower (7) returns to the first-stage cascade¹⁸An O isotope lean removing tower (3) and a second stage cascade¹⁵The waste gas (36) at the top of the N isotope lean removing tower (5) returns to the first-stage cascade¹⁵The N isotope lean removing tower (1) is opened with a valve (26), and after the air-cooled nitrogen (52) is cooled (53)Venting to atmosphere when the second stage is cascaded¹⁸O isotope lean removal tower (7) and second-stage cascade¹⁵The rectification balance of the N isotope lean removing tower (5) is established, and the next stage is started after the products at the bottom of each tower are qualified by analysis¹⁸O isotope and¹⁵n isotope cascade tower, wherein the product oxygen (45) enters the next cascade¹⁸The product nitrogen (37) enters the next stage of cascade connection¹⁵An N isotope depolitising tower; cascade of the next stage¹⁸The waste gas (46) at the top of the O isotope lean removing tower returns to the second-stage cascade¹⁸An O isotope lean removing tower (7) and the next stage is cascaded¹⁵The top exhaust gas (38) of the N isotope lean removal tower returns to the second stage cascade¹⁵An N isotope depolitising tower (5);

e. turning on the electric heater (73), from the second stage¹⁵The N isotope product enters a catalyst (75) pipeline and is subjected to the target reaction under the high-temperature catalysis action¹⁵The abundance of N isotope molecules is improved, after the catalysis is finished, a valve (20) is opened, and the final cascade after the catalysis is finished¹⁵The raw material gas (39) of the N isotope rectifying tower enters the final stage cascade¹⁵N isotope rectifying tower (9) starting the last stage cascade¹⁵N isotope condenser (15), last stage cascade¹⁵N isotope rectifying tower raw material gas (39) is cascaded at the last stage¹⁵N isotope rectifying tower (9) is condensed at the top and accumulated in the last stage cascade¹⁵The bottom of the N isotope rectifying tower (9) is closed by a valve (20), and residual nitrogen in the isotope molecule cracking recombination catalytic device (32) is discharged from the second stage¹⁸The O isotope product enters a catalyst (75) pipeline and is subjected to high-temperature catalysis to obtain a target¹⁸The abundance of O isotope molecules is improved, after the catalysis is finished, a valve (21) is opened, and the final cascade after the catalysis is finished¹⁸The raw gas (47) of the O isotope rectifying tower enters the final stage cascade¹⁸An O isotope rectifying tower (11) in the final stage¹⁸The top of the O isotope rectifying tower (11) is cascaded through the last stage¹⁸O isotope and¹⁵n isotope condensing evaporator (10) evaporation final stage cascade¹⁵Liquid nitrogen at the bottom of the N isotope rectifying tower (9) and the last stage is cascaded¹⁸Raw gas (47) liquid of O isotope rectifying towerIs combined and accumulated in the final cascade¹⁸The bottom of an O isotope rectifying tower (11) is slowly opened, and air separation cold nitrogen (54) enters a final stage cascade¹⁸An O isotope deparaffinization tower nitrogen reboiler (12) as a heat source evaporation last-stage cascade¹⁸Liquid oxygen at the bottom of the O isotope rectifying tower (11) establishes the last stage cascade¹⁵N isotope rectifying tower and final stage cascade¹⁸The rectification of the O isotope rectifying tower is balanced, after the rectification is balanced,¹⁵n isotope products (40),¹⁸The O isotope product (49) enters a product filling system, a valve (28) is opened, and air is exhausted after the air-cooled nitrogen (54) is cooled (55).

7. The separation method of dual-isotope low-temperature synchronous separation according to claim 6, characterized in that the air separation oxygen is 200Kpa, 97K, V/V ≧ 99.6%, the nitrogen is 300Kpa, 88K, V/V ≧ 99.9%, both of which are purified by a purification device to remove light/heavy impurities, and the lower column (58) of the purification column is used for purifying oxygen: 200KPa, 97K; nitrogen gas: 300Kpa, 88K to remove heavy component impurities, and purifying oxygen on an upper tower (56): 135KPa, 92.8K; nitrogen gas: 230Kpa and 84.6K remove light component impurities to obtain high-purity oxygen and nitrogen with the purity of more than 5n as isotope rectification feed gases.

8. The separation method of dual-isotope low-temperature synchronous separation according to claim 6, characterized in that the first stage of cascade tower employs a structured packing tower with a length-diameter ratio less than or equal to 0.04, the subsequent stages employ a structured packing tower with a length-diameter ratio less than or equal to 0.02, and the last stages employ a rectangular spiral random packing tower with a length-diameter ratio less than or equal to 0.02.

9. The separation method of the dual-isotope low-temperature synchronous separation according to claim 6, characterized in that the isotope raw material gas is kept still in the catalyst for 36-48 hours within a temperature zone of 680-730K, and the total length of the catalyst is 50-70 m.

10. The separation method of dual-isotope cryosynchrony separation of claim 6, wherein the separation method is characterized in that⁵N isotope and¹⁸the O isotope rectification cascade tower is operated by total reflux, a cold source at the top is 80K normal pressure liquid nitrogen, and nitrogen gas 674KPa and 98K are boiled at the bottom.

Technical Field

The invention relates to a method for realizing low-temperature separation¹⁸O isotope and¹⁵n isotope synchronous separation technology and device, in particular to synchronous separation of oxygen by cryogenic rectification technology¹⁸In O isotope and nitrogen¹⁵N isotope utilization¹⁸O isotope raw material oxygen is used as heat source for evaporation¹⁵N isotope as raw material liquid nitrogen at the same time¹⁸O isotope raw material oxygen condensing and liquefying¹⁸And (4) rectifying reflux liquid by using an O isotope. The invention has great economic value and scientific research utilization value¹⁸O isotope and¹⁵an N isotope.

Background

Isotopes have important applications in the fields of national defense, space exploration, medical science and the like, and extraction thereof is quite difficult. The isotope cryogenic rectification separation technology is the top technology in the cryogenic low-temperature field, and the development of the isotope low-temperature separation technology has great significance at the strategic level. At present, domestic¹⁸O isotope and¹⁵the N isotope market is basically monopolized by America, Japan and Europe. The invention develops the original¹⁸O isotope and¹⁵n isotope synchronous integrated rectification process and device, output¹⁸O isotope and¹⁵an N isotope. The invention proposes¹⁸O isotope and¹⁵n isotope low-temperature synchronous separation method and device capable of simultaneously separating¹⁸O isotope and¹⁵the N isotope has large raw material processing amount,¹⁸o isotope and¹⁵the extraction rate of the N isotope is high, and the method is particularly suitable for industrial isotope production.

Disclosure of Invention

In order to realize the technical vacancy in the aspect of isotope industrial production in China, the invention develops¹⁸O isotope and¹⁵the N isotope synchronous rectification process and device take oxygen and nitrogen produced by air separation as raw materials to produce the N isotope synchronous rectification device with strategic significance¹⁸O isotope and¹⁵an N isotope.

The invention aims to realize the technical proposal that the double-isotope low-temperature synchronous separation device at least comprises an air separation oxygen purification system and an air separation nitrogen purification system,¹⁸o isotope and¹⁵an N isotope synchronous low-temperature rectification system,¹⁸o isotope and¹⁵the N isotope molecule cracking recombination system comprises three parts; the air separation oxygen purification system and the air separation nitrogen purification system at least comprise a combined tower which is respectively integrated by an air separation oxygen purification device and an air separation nitrogen purification device, and the air separation oxygen purification device and the air separationA reboiler is arranged at the bottom of the lower tower of the nitrogen purification device, condensation evaporators of the air separation oxygen purification device and the air separation nitrogen purification device, condensers at the tops of the upper towers of the air separation oxygen purification device and the air separation nitrogen purification device, and a pressure reducing valve;¹⁸o isotope and¹⁵the N isotope synchronous cryogenic rectification system at least comprises¹⁸O isotope and¹⁵the system comprises an N isotope multi-stage rectifying tower, a liquid oxygen nitrogen reboiler, an oxygen and nitrogen condensation evaporator and a liquid nitrogen condenser;¹⁸o isotope and¹⁵the N isotope atom cracking recombination system at least comprises an oxygen/nitrogen molecule cracking recombination catalytic device and a catalytic electric heater, wherein the combined tower is divided into an upper tower and a lower tower, wherein the upper tower filters light component impurities, the lower tower filters heavy component impurities, the pressure of the lower tower is higher than that of the upper tower, steam rising from the top of the lower tower is used as a heat source through boiling point difference to boil the accumulated liquid at the bottom of the upper tower, the upper towers of the air separation oxygen purification device and the air separation nitrogen purification device are operated under reduced pressure to remove light component impurities such as hydrogen, the lower towers of the air separation oxygen purification device and the air separation nitrogen purification device filter heavy component impurities through low-temperature rectification, and the content of the heavy component impurities such as hydrocarbon can be reduced to below 1 ppm.

Preferably, the method comprises the following steps: the air separation nitrogen purification device is connected with the air separation nitrogen, the bottom of the air separation nitrogen condensation evaporator is connected with the top of the lower tower of the air separation nitrogen purification device, the inlet of a pressure reducing valve is connected with the gas outlet at the upper part of the lower tower of the air separation nitrogen purification device, the outlet of the pressure reducing valve is connected with the upper tower feed inlet of the air separation nitrogen purification device, and the top of the air separation nitrogen condensation evaporator is connected with the bottom of the upper tower of the. The bottom of the lower tower of the air separation nitrogen purification device is connected with the top of the lower tower reboiler, the top of the upper tower of the air separation nitrogen purification device is connected with the bottom of the upper tower condenser, the outlet of the air separation nitrogen purification device is connected with the inlet of a high-purity raw material nitrogen mass flow controller, and the outlet of the high-purity raw material nitrogen mass flow controller is connected with the first-stage cascade¹⁵The raw material inlet at the middle part of the N isotope poverty removing tower. First stage of cascade¹⁵And exhausting the waste gas at the top of the N isotope depletion tower to the atmosphere. First stage of cascade¹⁵The bottom of the N isotope lean elimination tower is connected with a first-stage cascade¹⁸O isotope and¹⁵condensing the N isotope on the top of the evaporatorThe outlet of the evaporator is connected with the second cascade¹⁵The raw material inlet at the middle part of the N isotope poverty removing tower. Second stage of cascade¹⁵The top waste gas of the N isotope lean removal tower is connected with the first-stage cascade¹⁵And an N isotope lean removal tower return air port. Second stage of cascade¹⁵The bottom of the N isotope lean elimination tower is connected with a second-stage cascade¹⁸O isotope and¹⁵the outlet of the condensing evaporator is connected with the next stage of cascade¹⁵The raw material inlet of the N isotope lean removing tower is cascaded in the second stage¹⁵The return air port of the N isotope lean removal tower is connected with the next stage of cascade¹⁵A top gas outlet of the N isotope lean removal tower, the first stage is cascaded¹⁵The top of the N isotope lean removal tower is connected with a first-stage cascade¹⁵N isotope condenser bottom, second stage cascade¹⁵The top of the N isotope lean removal tower is connected with a second-stage cascade¹⁵The bottom of the N isotope condenser is provided with a product discharge port of the second-stage cascade tower¹⁸O isotope and¹⁵n isotope molecule cracking recombination catalytic unit.

Preferably, the method comprises the following steps: the air separation oxygen purification device is characterized in that an inlet of the air separation oxygen purification device is connected with air separation oxygen, the bottom of the lower tower of the air separation oxygen purification device is connected with the bottom of an air separation oxygen condensation evaporator, an upper gas outlet of the lower tower of the air separation oxygen purification device is connected with an inlet of a pressure reducing valve, an outlet of the pressure reducing valve is connected with an upper tower feed inlet of the air separation oxygen purification device, and the bottom of the upper tower of the air separation oxygen purification device. The bottom of the lower tower of the air separation oxygen purification device is connected with the top of the reboiler of the lower tower, the top of the upper tower of the air separation oxygen purification device is connected with the bottom of the condenser at the top of the upper tower, the outlet of the air separation oxygen purification device is connected with the inlet of the high-purity raw material oxygen mass flow controller, and the outlet of the high-purity raw material oxygen mass flow controller is connected with the outlet of the¹⁸The middle raw material inlet of the O isotope poverty removing tower. First stage of cascade¹⁸And exhausting the waste gas at the top of the O isotope depletion tower to the atmosphere. First stage of cascade¹⁸The bottom of the O isotope lean elimination tower is connected with a first-stage cascade¹⁸A reboiler of nitrogen gas in an O isotope lean removal tower and a first-stage cascade¹⁸The top of the O isotope lean-removing tower is connected with a first-stage cascade¹⁸O isotope and¹⁵n isotope condensing evaporator bottom. First stageCouplet¹⁸The outlet of the nitrogen reboiler of the O isotope lean removal tower is connected with the second-stage cascade¹⁸The middle raw material inlet of the O isotope poverty removing tower. Second stage of cascade¹⁸The top of the O isotope lean-removing tower is connected with a second-stage cascade¹⁸O isotope and¹⁵n isotope condensing evaporator bottom, second stage cascade¹⁸The top of the O isotope lean removal tower is connected with a first-stage cascade¹⁸And an O isotope element de-lean tower gas return port. Second stage of cascade¹⁸The bottom of the O isotope lean elimination tower is connected with a second-stage cascade¹⁸A reboiler of nitrogen for an O isotope lean removal tower and a first and second cascade¹⁸The outlet of the nitrogen reboiler of the O isotope lean removal tower is connected with the next stage of cascade¹⁸And a raw material inlet of the O isotope dephenolizing tower.

Preferably, the method comprises the following steps: the second stage¹⁸O isotope and¹⁵product discharge port arrangement of N isotope multi-stage rectifying tower¹⁸O isotope and¹⁵the N isotope molecule cracking recombination catalytic device is characterized in that a nitrogen inlet of the isotope molecule cracking recombination catalytic device is connected with a second-stage cascade¹⁵N isotopes and cascades¹⁸The outlet of the O isotope condensation evaporator and the oxygen inlet of the isotope molecule cracking recombination catalytic device are connected with the second cascade¹⁸The nitrogen outlet of the isotope molecule cracking recombination catalytic device is connected with the inlet of a catalyzed nitrogen outlet valve, and the outlet of the catalyzed nitrogen outlet valve is connected with the last-stage cascade¹⁵Raw material inlet and final stage cascade of N isotope concentration tower¹⁵The top of the N isotope concentration tower is connected with an upper-stage cascade¹⁵And an N isotope lean removal tower return air port. Last stage cascade¹⁵N isotope concentration tower bottom connection last stage cascade¹⁸O isotope and¹⁵and N isotope condensing the top of the evaporator. Last stage cascade¹⁵N isotope concentration tower top connected last stage cascade¹⁵The bottom of the N isotope condenser. The oxygen outlet of the isotope molecule cracking recombination catalytic device is connected with the inlet of a catalyzed oxygen outlet valve, and the outlet of the catalyzed oxygen outlet valve is connected with the last-stage cascade¹⁸Raw material inlet of O isotope concentration tower and final stage cascade¹⁸The top of the O isotope concentration tower is connected with an upper-stage cascade¹⁸Return air port of O isotope lean removing tower. Last stage cascade¹⁸The bottom of the O isotope concentration tower is connected with the last-stage cascade¹⁸The top of a nitrogen reboiler of an O isotope lean removal tower is cascaded at the last stage¹⁸O isotope concentration tower top connected last stage cascade¹⁸O isotope and¹⁵n isotope condensing evaporator bottom.

Preferably, the method comprises the following steps: the first stage of cascade¹⁸And a nitrogen outlet of the nitrogen reboiler of the O isotope lean removal tower is connected with an inlet of a stop valve, and an outlet of the stop valve exhausts the atmosphere. Second stage of cascade¹⁸The nitrogen outlet of the nitrogen reboiler of the O isotope lean-removing tower is connected with the inlet of a stop valve, the outlet of the stop valve exhausts the atmosphere, and the last stage is connected with the reboiler¹⁸The nitrogen outlet of the nitrogen reboiler of the O isotope lean-rejection tower is connected with the inlet of a stop valve, the outlet of the stop valve is exhausted to the atmosphere, and the first stage is cascaded¹⁸The nitrogen inlet of the nitrogen reboiler of the O isotope lean removal tower is connected with the outlet of the stop valve, and the second stage is cascaded¹⁸The nitrogen inlet of the nitrogen reboiler of the O isotope lean removal tower is connected with the outlet of the stop valve and the last-stage connection¹⁸The nitrogen inlet of the nitrogen reboiler of the O isotope lean-removing tower is connected with the outlet of the stop valve, the inlet of the stop valve and the inlet of the stop valve are connected with the outlets of the air separation cold nitrogen buffer device, and the first stage is cascaded¹⁸O isotope lean removal tower nitrogen reboiler and second-stage cascade¹⁸Nitrogen reboiler and final cascade of O isotope lean removing tower¹⁸And the nitrogen reboiler of the O isotope lean removal tower takes air separation cold nitrogen as a heat source.

The separation method of the present invention comprises:

a. before the system is started, the oxygen and nitrogen pipelines of the system need to be correspondingly purged, a valve and a mass flow controller are opened, air in the corresponding nitrogen pipeline is replaced by normal-pressure nitrogen (108 Kpa (A)), when the dew point of a purge gas outlet is as low as-170 ℃, purging is stopped, and the valve and the mass flow controller are closed. Opening the valve and the mass flow controller, replacing air in the corresponding oxygen pipeline with normal pressure oxygen (108 Kpa (A)), stopping purging when the dew point of a purge gas outlet is as low as-170 ℃, and closing the valve and the mass flow controller.

b. The system is started, firstly, the air separation nitrogen enters the lower tower of the air separation nitrogen purification device, and the valve is openedAnd the door, the air separation nitrogen enters the air separation nitrogen purification device to be fed into the tower, the air separation nitrogen purification device is fed into the tower feeding condenser, the air separation nitrogen is liquefied, and the liquid is accumulated at the bottom of the tower. When the liquid accumulated at the bottom of the upper tower reaches a specified liquid level, a lower tower reboiler is opened, ascending steam of the lower tower is used as a reboiling heat source at the bottom of the upper tower, air separation nitrogen purification rectification balance is established, when air separation nitrogen impurities are detected to be qualified, a high-purity raw material nitrogen mass flow controller is slowly opened, and high-purity nitrogen enters a first-stage cascade¹⁵And (4) an N isotope depoliferation tower. Enabling first level cascading¹⁵N isotope condenser, high-purity nitrogen liquefaction, first-stage cascade¹⁵And accumulating liquid at the bottom of the N isotope depreciation tower.

C. The air separation oxygen pipeline is started, the air separation oxygen enters the lower tower of the air separation oxygen purification device, the valve is opened, the air separation oxygen enters the upper tower of the air separation oxygen purification device, the upper tower condenser of the air separation oxygen purification device is started, the air separation oxygen is liquefied, and effusion is arranged at the bottom of the upper tower. When the liquid accumulated at the bottom of the upper tower reaches a specified liquid level, a lower tower reboiler is opened, the ascending steam of the lower tower is used as a reboiling heat source at the bottom of the upper tower, the air separation oxygen purification rectification balance is established, when the air separation oxygen impurities are detected to be qualified, a high-purity raw material oxygen mass flow controller is slowly opened, and the high-purity oxygen enters a first-stage cascade connection¹⁸O isotope lean-removing tower, high-purity oxygen cascaded in the first stage¹⁸The top of the O isotope lean removing tower is cascaded through a first stage¹⁸O isotope and¹⁵n isotope condensing evaporator evaporation first-stage cascade¹⁵The bottom of the N isotope depreciation tower is accumulated liquid, high-purity oxygen is condensed at the same time, and the first stage is cascaded¹⁸And accumulating liquid at the bottom of the O isotope depletion tower. Slowly opening a stop valve, and allowing air-separated cold nitrogen to enter a first-stage cascade¹⁸O isotope element de-lean tower nitrogen reboiler as heat source for evaporating first-stage cascade¹⁸The bottom liquid of the O isotope lean-eliminating tower is accumulated to establish a first-stage cascade¹⁸O isotope depletion tower and first stage cascade¹⁵And (4) balancing the rectification of the N isotope deparsation tower. First stage of cascade¹⁸The waste gas at the top of the O isotope lean removal tower is emptied, and the first stage is cascaded¹⁵And exhausting the waste gas at the top of the N isotope depletion tower. And opening a valve, and discharging the cooled air-separated nitrogen gas to the atmosphere.

d. When the first stage isCouplet¹⁸O isotope depletion tower and first stage cascade¹⁵The rectification balance of the N isotope lean-removing tower is established, and after the products at the bottom of each tower are analyzed to be qualified, the first-stage cascade is firstly carried out¹⁵Qualified products at the bottom of the N isotope lean-removing tower are cascaded through the first stage¹⁸O isotope and¹⁵the outlet of the N isotope condensation evaporator enters the second-stage cascade¹⁵And (4) an N isotope depoliferation tower. Enabling second stage cascading¹⁵N isotope condensers, first-stage cascade¹⁵Qualified products at the bottom of the N isotope lean-removing tower are liquefied and accumulated in the second-stage cascade¹⁵Bottom of N isotope depolistication tower, first stage cascade¹⁸Qualified products at the bottom of the O isotope lean-removing tower are cascaded through the first stage¹⁸The outlet of a nitrogen reboiler of the O isotope lean removal tower enters a second-stage cascade¹⁸And (4) an O isotope depreciation tower. First stage of cascade¹⁸Qualified products at the bottom of the O isotope lean-removing tower are cascaded in the second stage¹⁸The top of the O isotope lean removing tower is cascaded through a second stage¹⁸O isotope and¹⁵n isotope condensing evaporator evaporation second-stage cascade¹⁵The bottom of the N isotope lean column is filled with liquid nitrogen, and the first stage is cascaded¹⁸Qualified products at the bottom of the O isotope lean-removing tower are liquefied and accumulated in the second-stage cascade¹⁸The bottom of the O isotope dephenolizing tower. Slowly opening a stop valve, and allowing air-separated cold nitrogen to enter a second-stage cascade¹⁸O isotope element de-lean tower nitrogen reboiler as heat source evaporation second-stage cascade¹⁸The bottom liquid of the O isotope lean-eliminating tower is accumulated to establish a second-stage cascade¹⁸O isotope depletion tower and second stage cascade¹⁵And (4) balancing the rectification of the N isotope deparsation tower. Second stage of cascade¹⁸Returning the waste gas at the top of the O isotope lean removal tower to the first-stage cascade¹⁸O isotope lean-removing tower, second-stage cascade¹⁵Returning the waste gas from the top of the N isotope lean removal tower to the first-stage cascade¹⁵And (4) an N isotope depoliferation tower. Opening a valve, cooling the air by cold nitrogen and then exhausting the air, and when the second stage is cascaded¹⁸O isotope depletion tower and second stage cascade¹⁵The rectification balance of the N isotope lean-removing tower is established, and the next stage is started after the products at the bottoms of the N isotope lean-removing tower are qualified by analysis¹⁸O isotope and¹⁵an N isotope cascade tower. Wherein the product oxygen enters the next stage of cascade connection¹⁸O is the same asThe nitrogen enters the next stage of cascade connection¹⁵An N isotope depolitising tower; cascade of the next stage¹⁸The waste gas at the top of the O isotope lean removal tower returns to the second-stage cascade¹⁸The next stage of the O isotope lean removing tower is cascaded¹⁵The waste gas at the top of the N isotope lean removal tower returns to the second-stage cascade¹⁵And (4) an N isotope depoliferation tower.

e. Turning on the electric heater, from the second stage¹⁵The N isotope product enters a catalyst pipeline and is subjected to the target reaction under the high-temperature catalysis action¹⁵The abundance of N isotope molecules is improved. After the catalysis is finished, the valve is opened, and the final-stage cascade after the catalysis is finished¹⁵The raw gas of N isotope rectifying tower enters the final stage cascade¹⁵N isotope rectification column, starting the last stage cascade¹⁵N isotope condensers, last-stage cascades¹⁵N isotope rectification tower raw gas is cascaded at last stage¹⁵N isotope rectifying tower top condensing and accumulating in last stage cascade¹⁵And the bottom of the N isotope rectifying tower. Closing the valve, and exhausting the residual nitrogen in the isotope molecule cracking recombination catalytic device from the second stage¹⁸The O isotope product enters a catalyst pipeline to be subjected to high-temperature catalysis to obtain a target¹⁸The abundance of O isotope molecules is improved. After the catalysis is finished, the valve is opened, and the final-stage cascade after the catalysis is finished¹⁸The raw gas of the O isotope rectifying tower enters the final stage cascade¹⁸O isotope rectifying tower cascaded at last stage¹⁸The top of the O isotope rectifying tower is cascaded through the last stage¹⁸O isotope and¹⁵n isotope condensation evaporator evaporation final stage cascade¹⁵Liquid nitrogen at the bottom of N isotope rectifying tower, and final cascade¹⁸The raw material gas of the O isotope rectifying tower is liquefied and accumulated in the last stage cascade¹⁸And (4) the bottom of the O isotope rectifying tower. Slowly opening the valve, and allowing air-separated cold nitrogen to enter the final-stage cascade¹⁸O isotope element de-lean tower nitrogen reboiler as heat source evaporation last-stage cascade¹⁸Liquid oxygen at the bottom of the O isotope rectifying tower is used for establishing the final cascade¹⁵N isotope rectifying tower and final stage cascade¹⁸And (4) balancing the rectification of the O isotope rectifying tower. After the rectification is balanced, the mixture is distilled,¹⁵n isotope product,¹⁸O isotope product goes to product filling system. The valve is opened, and the air is cooled by cold nitrogen and then dischargedAnd (4) qi.

Preferably, the method comprises the following steps: the air separation oxygen is 200Kpa, 97K, V/V is larger than or equal to 99.6 percent, the nitrogen is 300Kpa, 88K, V/V is larger than or equal to 99.9 percent, the air separation oxygen and the nitrogen are purified by a purification device to remove light/heavy component impurities, and the air separation oxygen is purified by a lower tower of an oxygen tower: 200KPa, 97K; nitrogen gas: 300Kpa and 88K remove heavy component impurities, and purifying the oxygen on the tower: 135KPa, 92.8K; nitrogen gas: 230Kpa and 84.6K remove light component impurities to obtain high-purity oxygen and nitrogen with the purity of more than 5n as isotope rectification feed gases.

Preferably, the method comprises the following steps: the first stage cascade tower adopts a structured packing tower with the length-diameter ratio less than or equal to 0.04, and the subsequent stages adopt a structured packing tower with the length-diameter ratio less than or equal to 0.02. The last stages adopt a rectangular spiral random packing tower with the length-diameter ratio less than or equal to 0.02.

Preferably, the method comprises the following steps: and standing the isotope raw material gas in a temperature zone of 680-730K for 36-48 h in the catalyst. The total length of the catalyst is 50-70 m.

Preferably, the method comprises the following steps: the above-mentioned⁵N isotope and¹⁸the O isotope rectification cascade tower is operated by total reflux, a cold source at the top is 80K normal pressure liquid nitrogen, and nitrogen gas 674KPa and 98K are boiled at the bottom.

The invention relates to a method and a device for synchronously separating double isotopes at low temperature and production¹⁵N isotope and¹⁸an isotope of O. The invention is to¹⁸O isotope and¹⁵the low-temperature enrichment of N isotope is integrated into a set of equipment so as to¹⁸O isotope and¹⁵the low-temperature rectification of the N isotope is carried out synchronously, and the isotope rectification efficiency is greatly improved. The invention utilizes the difference of the boiling points of nitrogen and oxygen under a certain pressure to perform condensation evaporation on the nitrogen and the oxygen¹⁸Cryogenic O-isotope rectification plant and¹⁵the N isotope low-temperature rectification device is combined and utilized¹⁸Evaporating oxygen at the top of the O isotope low-temperature rectifying tower as a heat source¹⁵N isotope low-temperature rectification tower bottom liquid nitrogen, and oxygen condensation¹⁸And (3) rectifying reflux liquid at low temperature by using the O isotope.¹⁸The reboiling heat source at the bottom of the O isotope cryogenic rectification tower is air separation cold nitrogen, and the cold energy of the air separation equipment is fully utilized. The invention¹⁸O isotope and¹⁵the N isotope cryogenic rectification device adopts a plurality of cascade front-back series designs, and each stageThe multi-column tube tower is connected in parallel. By combining the respective characteristics of regular packing and random packing, the two-layer wire mesh corrugated packing is arranged in the front cascade tower stages, and the rectangular spiral coil packing is arranged in the rear cascade tower stages, so that the raw material quantity processing capacity of the device is better, and the rectification efficiency of the device is higher. An isotope molecule cracking recombination catalysis system is arranged in the system, so that the abundance and the yield of the target isotope are improved.

Drawings

FIG. 1 is a schematic view of the present invention;

FIG. 2 is a schematic view of the air separation oxygen/nitrogen purification apparatus of FIG. 1;

FIG. 3 is a view of FIG. 1¹⁸O isotope and¹⁵an N isotope synchronous cryogenic rectification cascade diagram;

FIG. 4 is a drawing showing¹⁸O isotope and¹⁵schematic diagram of the N isotope cracking recombination catalytic device.

Detailed Description

The invention will be described in detail with reference to the accompanying drawings, wherein a dual isotope low temperature synchronous separation device as shown in figure 1 at least comprises an air separation oxygen purification system and an air separation nitrogen purification system,¹⁸o isotope and¹⁵an N isotope synchronous low-temperature rectification system,¹⁸o isotope and¹⁵the N isotope molecule cracking recombination system comprises three parts; the air separation oxygen purification system and the air separation nitrogen purification system at least comprise a combined tower formed by respectively integrating an air separation oxygen purification device and an air separation nitrogen purification device, a reboiler arranged at the bottom of the lower tower of the air separation oxygen purification device and the air separation nitrogen purification device, condensation evaporators of the air separation oxygen purification device and the air separation nitrogen purification device, a condenser arranged at the top of the upper tower of the air separation oxygen purification device and the air separation nitrogen purification device, and a pressure reducing valve;¹⁸o isotope and¹⁵the N isotope synchronous cryogenic rectification system at least comprises¹⁸O isotope and¹⁵the system comprises an N isotope multi-stage rectifying tower, a liquid oxygen nitrogen reboiler, an oxygen and nitrogen condensation evaporator and a liquid nitrogen condenser;¹⁸o isotope and¹⁵the N isotope atom cracking and recombining system at least comprises an oxygen/nitrogen molecule cracking and recombining catalytic device and a catalystThe combined tower is divided into an upper tower and a lower tower, wherein the upper tower filters light component impurities, the lower tower filters heavy component impurities, the lower tower has higher pressure than the upper tower, steam rising from the top of the lower tower is used as a heat source through boiling point difference to boil liquid accumulated at the bottom of the upper tower, the upper towers of the air separation oxygen purification device and the air separation nitrogen purification device are subjected to reduced pressure operation to remove light component impurities such as hydrogen, the lower towers of the air separation oxygen purification device and the air separation nitrogen purification device filter heavy component impurities through low-temperature rectification, and the content of the heavy component impurities such as hydrocarbon can be reduced to below 1ppm,

the 16 access connection air separation nitrogen gas 33 of air separation nitrogen gas purification device, the 99 bottoms of air separation nitrogen gas condensation evaporimeter are connected at the top of tower 98 under the 16 nitrogen gas purification device that air separate, and the 90 import of relief pressure valve are connected to the 98 upper portion gas outlets of tower under the 16 nitrogen gas purification device that air separate, the 90 exit linkage air separation nitrogen gas purification device 16 goes up the 96 feed inlets of tower, and the 16 nitrogen gas purification device that air separate 96 tops of tower 96 bottom connection air separation nitrogen gas condensation evaporimeter are gone up to the pressure valve. The bottom of a lower tower 98 of an air separation nitrogen purification device 16 is connected with the top of a lower tower reboiler 109, the top of an upper tower 96 of the air separation nitrogen purification device 16 is connected with the bottom of an upper tower top condenser 101, an outlet of the air separation nitrogen purification device 16 is connected with an inlet of a high-purity raw material nitrogen mass flow controller 18, and an outlet of the high-purity raw material nitrogen mass flow controller 18 is connected with a first-stage cascade¹⁵The middle raw material inlet of the N isotope lean removing tower 1. First stage of cascade¹⁵And exhausting the top waste gas of the N isotope depletion tower 1 to the atmosphere. First stage of cascade¹⁵The bottom of the N isotope lean removing tower 1 is connected with a first-stage cascade¹⁸O isotope and¹⁵the top of the N isotope condensation evaporator 2, the outlet of the condensation evaporator 2 is connected with the second-stage cascade¹⁵The middle raw material inlet of the N isotope lean removing tower 5. Second stage of cascade¹⁵The top waste gas 36 of the N isotope lean removing tower 5 is connected with the first-stage cascade¹⁵The return air port of the N isotope lean removing tower 1. Second stage of cascade¹⁵The bottom of the N isotope lean removing tower 5 is connected with a second-stage cascade¹⁸O isotope and¹⁵the top of the N isotope condensation evaporator 6, the outlet of the condensation evaporator 6 is connected with the next stage cascade¹⁵The raw material inlet of the N isotope lean removing tower is cascaded in the second stage¹⁵The return air port of the N isotope lean removing tower 5 is connected with the next stageCouplet¹⁵A top gas outlet of the N isotope lean removal tower, the first stage is cascaded¹⁵The top of the N isotope lean removing tower 1 is connected with a first-stage cascade¹⁵Bottom of N isotope condenser 13, second stage cascade¹⁵The top of the N isotope lean removing tower 5 is connected with a second-stage cascade¹⁵The bottom of the N isotope condenser 14, and the product discharge port of the second-stage cascade tower is arranged¹⁸O isotope and¹⁵the N isotope molecule cracking recombination catalysis device 32.

The inlet of the air separation oxygen 41 air separation oxygen purification device 17 is connected with the air separation oxygen 41 the top of the lower tower 58 of the air separation oxygen purification device 17 is connected with the bottom of the air separation oxygen condensation evaporator 79, the upper air outlet of the lower tower 58 of the air separation oxygen purification device 17 is connected with the inlet of the pressure reducing valve 60, the outlet of the pressure reducing valve 60 is connected with the feed inlet of the upper tower 56 of the air separation oxygen purification device 17, and the bottom of the upper tower 56 of the air separation oxygen purification device 17 is connected with the top of the air. The bottom of a lower tower 58 of the air separation oxygen purification device 17 is connected with the top of a lower tower reboiler 59, the top of an upper tower 56 of the air separation oxygen purification device 17 is connected with the bottom of an upper tower top condenser 100, the outlet of the air separation oxygen purification device 17 is connected with the inlet of a high-purity raw material oxygen mass flow controller 19, and the outlet of the high-purity raw material oxygen mass flow controller 19 is connected with a first-stage cascade¹⁸The middle raw material inlet of the O isotope lean removing tower 3. First stage of cascade¹⁸And exhausting the waste gas at the top of the O isotope depreciation tower 3. First stage of cascade¹⁸The bottom of the O isotope lean removing tower 3 is connected with a first-stage cascade¹⁸An O isotope lean removal tower nitrogen reboiler 4 which is cascaded in the first stage¹⁸The top of the O isotope lean removing tower 3 is connected with a first-stage cascade¹⁸O isotope and¹⁵the N isotope condenses the bottom of the evaporator 2. First stage of cascade¹⁸The outlet of a nitrogen reboiler 4 of the O isotope lean removal tower is connected with the second-stage cascade¹⁸The middle raw material inlet of the O isotope lean removing tower 7. Second stage of cascade¹⁸The top of the O isotope lean removing tower 7 is connected with a second-stage cascade¹⁸O isotope and¹⁵the bottom of the N isotope condensation evaporator 6 is cascaded in the second stage¹⁸The top of the O isotope lean removal tower 7 is connected with a first-stage cascade¹⁸The return air port of the O isotope lean removing tower 3. Second stage of cascade¹⁸The bottom of the O isotope lean removing tower 7 is connected with the secondCascaded stages¹⁸An O isotope lean removal tower nitrogen reboiler 8 and a second-stage cascade¹⁸The outlet of an O isotope lean removal tower nitrogen reboiler 8 is connected with the next stage of cascade¹⁸And a raw material inlet of the O isotope dephenolizing tower.

The second stage¹⁸O isotope and¹⁵product discharge port arrangement of N isotope multi-stage rectifying tower¹⁸O isotope and¹⁵an N isotope molecule cracking recombination catalytic device 32, wherein a nitrogen inlet of the isotope molecule cracking recombination catalytic device 32 is connected with a second-stage cascade¹⁵N isotopes and cascades¹⁸The outlet of the O isotope condensation evaporator and the oxygen inlet of the isotope molecule cracking recombination catalytic device 32 are connected with the second cascade¹⁸An outlet of a nitrogen reboiler of the O isotope lean removal tower is connected with a nitrogen outlet of the isotope molecule cracking recombination catalytic device 32 which is connected with an inlet of a catalyzed nitrogen outlet valve 20, and an outlet of the catalyzed nitrogen outlet valve 20 is connected with a final-stage cascade¹⁵N isotope concentration tower 9 raw material inlet, last stage cascade¹⁵The top of the N isotope concentration tower 9 is connected with an upper-stage cascade¹⁵And an N isotope lean removal tower return air port. Last stage cascade¹⁵The bottom of the N isotope concentration tower 9 is connected with the last stage cascade¹⁸O isotope and¹⁵the N isotope condenses the top of the evaporator 10. Last stage cascade¹⁵The top of the N isotope concentration tower 9 is connected with the last stage cascade¹⁵The bottom of the N isotope condenser 15. The oxygen outlet of the isotope molecule cracking recombination catalytic device 32 is connected with the inlet of the catalyzed oxygen outlet valve 21, the outlet of the catalyzed oxygen outlet valve 21 is connected with the final-stage cascade¹⁸Raw material inlet and final stage cascade of O isotope concentration tower 11¹⁸The top of the O isotope concentration tower is connected with an upper-stage cascade¹⁸And an O isotope element de-lean tower gas return port. Last stage cascade¹⁸The bottom of the O isotope concentration tower 11 is connected with the last stage cascade¹⁸The top of a nitrogen reboiler 12 of an O isotope lean removal tower is cascaded at the last stage¹⁸The top of the O isotope concentration tower 11 is connected with the last stage cascade¹⁸O isotope and¹⁵the N isotope condenses the bottom of the evaporator 10.

The first stage of cascade¹⁸And a nitrogen outlet of the O isotope lean removal tower nitrogen reboiler 4 is connected with an inlet of a stop valve 24, and an outlet of the stop valve 24 is exhausted to the atmosphere. Second oneCascaded stages¹⁸The nitrogen outlet of the O isotope lean-removing tower nitrogen reboiler 8 is connected with the inlet of a stop valve 26, the outlet of the stop valve 26 exhausts the atmosphere, and the last stage is connected with the last stage¹⁸The nitrogen outlet of the O isotope lean removal tower nitrogen reboiler 12 is connected with the inlet of a stop valve 28, the outlet of the stop valve 28 exhausts the atmosphere, and the first stage cascade is connected with the nitrogen outlet of the reboiler 12¹⁸The nitrogen inlet of the O isotope lean-removing tower nitrogen reboiler 4 is connected with the outlet of the stop valve 23, and the second stage is cascaded¹⁸The nitrogen inlet of an O isotope lean column nitrogen reboiler 8 is connected with the outlet of a stop valve 25 and is connected with the final stage¹⁸The nitrogen inlet of the O isotope lean-separating tower nitrogen reboiler 12 is connected with the outlet of a stop valve 27, the inlet of the stop valve 23, the inlet of the stop valve 25 and the inlet of the stop valve 27 are connected with the outlets of an air-separation cold-cut nitrogen buffer device 22, and the first-stage cascade connection is performed¹⁸O isotope lean removal tower nitrogen reboiler 4, second-stage cascade¹⁸O isotope dephenolization tower nitrogen reboiler 8, last stage connection¹⁸The nitrogen reboiler 12 of the O isotope lean removing tower takes air separation cold nitrogen as a heat source.

Examples of the invention

The invention relates to¹⁸O isotope and¹⁵the method and the device for synchronously separating the N isotopes at low temperature take air separation oxygen and air separation nitrogen as raw material sources, and the raw material gases are used as the raw material gases of a rectification system after impurity removal. Before the device is started, all valves are closed. Before the system is started, the tightness of the system needs to be tested, and the leakage point of a system pipeline is ensured to be avoided. And then an electric control system of the detector is detected to ensure that electrical equipment such as the instrument and the like works normally.

Before the system is started, the oxygen and nitrogen pipelines of the system need to be correspondingly purged. Referring to fig. 1 and 2, the valve 90 and the mass flow controller 18 are opened, the air in the corresponding nitrogen line is replaced by normal pressure nitrogen (108 kpa (a)), when the dew point of the purge gas outlet is as low as-170 ℃, the purge is stopped, and the valve 90 and the mass flow controller 18 are closed. Opening the valve 60 and the mass flow controller 19, replacing air in the corresponding oxygen pipeline with normal pressure oxygen (108 Kpa (A)), stopping purging when the dew point of a purge gas outlet is as low as-170 ℃, and closing the valve 60 and the mass flow controller 19.

The system is started, firstly, the air separation nitrogen 33 enters the lower tower 98 of the air separation nitrogen purification device 16, the valve 90 is opened, the air separation nitrogen enters the upper tower 96 of the air separation nitrogen purification device 16, the upper tower 98 of the air separation nitrogen purification device 16 is started, the air separation nitrogen is liquefied, and liquid is accumulated at the bottom of the upper tower 96. When the liquid accumulated at the bottom of the upper tower 96 reaches a specified liquid level, a reboiler 109 of the lower tower 98 is started, the ascending steam of the lower tower 98 is used as a reboiling heat source at the bottom of the upper tower 96, and air separation nitrogen purification rectification balance is established.

Further, when the air-separated nitrogen impurities are detected to be qualified, the high-purity raw material nitrogen mass flow controller 18 is slowly opened, and the high-purity nitrogen 34 enters the first-stage cascade connection¹⁵An N isotope depreciation tower 1. Enabling first level cascading¹⁵N isotope condenser 13, high purity nitrogen liquefaction, first stage cascade¹⁵The bottom of the N isotope depreciation tower 1 is accumulated liquid.

And starting an air separation oxygen pipeline, enabling the air separation oxygen 41 to enter a lower tower 58 of the air separation oxygen purification device 17, opening a valve 60, enabling the air separation oxygen to enter an upper tower 56 of the air separation oxygen purification device 17, starting an upper tower 58 of the air separation oxygen purification device 17, condensing the air separation oxygen, and liquefying effusion at the bottom of the upper tower 56. When the liquid accumulation at the bottom of the upper tower 56 reaches a specified liquid level, a reboiler 59 of the lower tower 58 is started, and the ascending steam of the lower tower 58 is used as a reboiling heat source at the bottom of the upper tower 56, so that the air separation oxygen purification rectification balance is established.

Further, when the air-separated oxygen impurities are detected to be qualified, the high-purity raw material oxygen mass flow controller 19 is slowly opened, and the high-purity oxygen 42 enters the first-stage cascade connection¹⁸The O isotope lean removing tower 3, high-purity oxygen 42 are cascaded in the first stage¹⁸The top of the O isotope lean removing tower 3 is cascaded through a first stage¹⁸O isotope and¹⁵n isotope condensing evaporator 2 evaporating first-stage cascade¹⁵The bottom of the N isotope lean removing tower 1 is accumulated liquid, high-purity oxygen 42 is condensed at the same time, and the first stage is cascaded¹⁸The bottom liquid of the O isotope depreciation tower 3. Slowly opening the stop valve 23, and allowing the air separation cold nitrogen 50 to enter the first stage of cascade connection¹⁸An O isotope element de-lean tower nitrogen reboiler 4 used as a heat source to evaporate the first-stage cascade¹⁸The accumulated liquid at the bottom of the O isotope lean removal tower 3 establishes a first-stage cascade¹⁸O isotope depletion tower 3 and first stage cascade¹⁵The rectification of the N isotope dephenolizing tower 1 is balanced. First stage of cascade¹⁸O parityThe waste gas at the top of the vegetable lean removal tower 3 is emptied, and the first stage is cascaded¹⁵And exhausting the waste gas at the top of the N isotope dephenolizing tower 1. The valve 24 is opened, and the cold air 50 is cooled and then 51 exhausted to the atmosphere.

To pair¹⁸O isotope and¹⁵the synchronous rectification separation of N isotope is further explained. When the first stage is cascaded¹⁸O isotope depletion tower 3 and first stage cascade¹⁵The rectification balance of the N isotope lean removing tower 1 is established, and after products at the bottom of each tower are analyzed to be qualified, the first-stage cascade is firstly carried out¹⁵Qualified products 35 at the bottom of the N isotope lean removing tower 1 are cascaded through a first stage¹⁸O isotope and¹⁵the gas outlet of the N isotope condensation evaporator 2 enters the second-stage cascade¹⁵And an N isotope depreciation tower 5. Enabling second stage cascading¹⁵N isotope condenser 14, first stage cascade¹⁵Qualified products 35 at the bottom of the N isotope lean removing tower 1 are liquefied and accumulated in a second-stage cascade¹⁵The bottom of the N isotope depreciation tower 5.

Further, the first stage is cascaded¹⁸Qualified products 43 at the bottom of the O isotope lean removing tower 3 pass through a first-stage cascade¹⁸The outlet of a nitrogen reboiler 4 of the O isotope lean removal tower enters a second-stage cascade¹⁸And an O isotope depreciation tower 7. First stage of cascade¹⁸Qualified products 43 at the bottom of the O isotope lean removing tower 3 are cascaded in the second stage¹⁸The top of the O isotope lean removing tower 7 passes through a second-stage cascade¹⁸O isotope and¹⁵n isotope condensing evaporator 6 evaporating second-stage cascade¹⁵The liquid nitrogen at the bottom of the N isotope lean removing tower 5 is cascaded in the first stage¹⁸Qualified products 43 at the bottom of the O isotope lean removing tower 3 are liquefied and accumulated in the second-stage cascade¹⁸The bottom of the O isotope depreciation tower 7. The stop valve 25 is slowly opened, and the cold nitrogen 52 enters the second cascade¹⁸An O isotope dephenolization tower nitrogen reboiler 8 used as a heat source for evaporating the second-stage cascade¹⁸The accumulated liquid at the bottom of the O isotope lean removal tower 7 establishes a second-stage cascade¹⁸O isotope depolitisation column 7 and second stage cascade¹⁵The rectification of the N isotope lean removing tower 5 is balanced. Second stage of cascade¹⁸The waste gas 44 at the top of the O isotope lean removing tower 7 returns to the first-stage cascade¹⁸O isotope lean-removing tower 3, second-stage cascade¹⁵The top waste gas 36 of the N isotope lean removing tower 5 returnsFirst stage of cascade¹⁵An N isotope depreciation tower 1. Valve 26 is opened and the cooled air 53 is vented to atmosphere after air separation of cold nitrogen 52.

When the second stage is cascaded¹⁸O isotope depolitisation column 7 and second stage cascade¹⁵The rectification balance of the N isotope lean removing tower 5 is established, and the next stage is started after the products at the bottom of each tower are analyzed to be qualified¹⁸O isotope and¹⁵an N isotope cascade tower. Wherein the product oxygen 45 enters the next stage of cascade connection¹⁸The product nitrogen 37 enters the next stage of cascade connection¹⁵An N isotope depolitising tower; cascade of the next stage¹⁸The waste gas 46 at the top of the O isotope lean removing tower returns to the second-stage cascade¹⁸O isotope lean-removing tower 7, the next stage is cascaded¹⁵The top waste gas 38 of the N isotope lean removing tower returns to the second-stage cascade¹⁵And (4) an N isotope depoliferation tower.

Referring to fig. 3, the present invention is provided with n stages of cascaded towers connected in series, wherein the first m stages adopt structured packing, and the primary product can be produced in large quantity by utilizing the characteristic of large flux in the structured packing tower; the later (n-m) stage cascade tower adopts random packing, and utilizes the characteristic of high rectification efficiency of the random packing to quickly enrich the high-abundance product isotopes.

Further, for each stage of cascade tower, a plurality of tube tower is arranged in parallel, wherein the first stage of cascade tower is provided with m₁The tube-row towers are connected in parallel, and the second-stage cascade tower is provided with m₂The column-tube towers are connected in parallel, and the m-th cascade tower is provided with m_mThe tube-array towers are connected in parallel, and the final-stage concentration tower is a single tube-array tower.

Referring to FIG. 4, in order to save raw material consumption and improve rectification efficiency, a raw material inlet of a last-stage cascade tower is provided¹⁸O isotope and¹⁵the N isotope molecule cracking recombination catalysis device 32. The catalytic device 32 (the outer layer is wrapped with the heat preservation cotton 74) heats the nitrogen/oxygen to a certain temperature zone through the electric heater 73, and the oxygen molecules/nitrogen molecules are cracked and recombined under the action of the catalyst 75, so that the abundance of target isotope molecules can be improved.

Further, the electric heater 73 is turned on, from the second stage¹⁵The N isotope product enters a catalyst 75 pipeline and is subjected to the target reaction under the high-temperature catalysis action¹⁵The abundance of N isotope molecules is improved. After the catalysis is completed, the valve 20 is opened, and the final-stage cascade after the catalysis is completed¹⁵The raw material gas 39 of the N isotope rectifying tower enters the final stage cascade¹⁵N isotope rectification column, starting the last stage cascade¹⁵N isotope condenser 15, last stage cascade¹⁵N isotope rectifying tower raw material gas 39 is cascaded at last stage¹⁵N isotope rectifying tower 9 top is condensed and accumulated in the last stage cascade¹⁵The bottom of the N isotope rectifying tower 9. The valve 20 is closed and the remaining nitrogen in the catalytic device 32 for isotopic molecule cleavage recombination is evacuated.

Further, from the second stage¹⁸The O isotope product enters a catalyst 75 pipeline and is subjected to high-temperature catalysis to obtain a target¹⁸The abundance of O isotope molecules is improved. After the catalysis is completed, the valve 21 is opened, and the final-stage cascade after the catalysis is completed¹⁸The raw material gas 47 of the O isotope rectifying tower enters the final stage cascade¹⁸O isotope rectifying tower 11, cascaded at last stage¹⁸The top of the O isotope rectifying tower 11 is cascaded through the last stage¹⁸O isotope and¹⁵n isotope condensing evaporator 10 evaporation final stage cascade¹⁵Liquid nitrogen at the bottom of N isotope rectifying tower 9, and the last stage is cascaded¹⁸The raw material gas 47 of the O isotope rectifying tower is liquefied and accumulated in the final stage cascade¹⁸And the bottom of the O isotope rectifying tower 11. The valve 27 is slowly opened, and the cold nitrogen 54 enters the final cascade¹⁸O isotope dephenolization tower nitrogen reboiler 12 as heat source evaporation last stage cascade¹⁸Liquid oxygen at the bottom of the O isotope rectifying tower 11 establishes the final stage cascade¹⁵N isotope rectifying tower and final stage cascade¹⁸And (4) balancing the rectification of the O isotope rectifying tower. After the rectification is balanced, the mixture is distilled,¹⁵40 portions of N isotope product,¹⁸O-isotope product 49 goes to the product filling system. The valve 28 is opened and the cooled air 54 is vented 55 to atmosphere.

The following steps are required: air separation oxygen (200 Kpa, 97K, V/V ≧ 99.6%) and nitrogen (300 Kpa, 88K, V/V ≧ 99.9%) are purified by a purification device to remove light/heavy component impurities. The lower tower 58 (oxygen: 200KPa, 97K; nitrogen: 300KPa, 88K) of the purification tower is used for removing heavy component impurities, and the upper tower 56 (oxygen: 135KPa, 92.8K; nitrogen: 230KPa, 84.6K) of the purification tower is used for removing light component impurities, so that high-purity oxygen with the purity of more than 5n and nitrogen are obtained to be used as isotope rectification feed gases.

The following steps are required: the first stage cascade tower adopts a regular packed tower with the length-diameter ratio less than or equal to 0.04, and the subsequent stages adopt a regular packed tower with the length-diameter ratio less than or equal to 0.02. The last stages adopt a rectangular spiral random packing tower with the length-diameter ratio less than or equal to 0.02.

The following steps are required: and standing the isotope raw material gas in a temperature zone of 680-730K for 36-48 h in the catalyst. The total length of the catalyst is 50-70 m.

The following steps are required:¹⁵n isotope and¹⁸the O isotope rectification cascade tower is operated by total reflux, a cold source at the top is 80K normal pressure liquid nitrogen, and nitrogen gas 674KPa and 98K are boiled at the bottom.

The invention relates to a method and a device for synchronously separating double isotopes at low temperature, which take air separation nitrogen and oxygen as raw materials for production¹⁵N isotope and¹⁸an isotope of O. The invention relates to a device¹⁸O isotope and¹⁵the low-temperature enrichment process of the N isotope is synchronously carried out, and the isotope production efficiency is greatly improved. The invention utilizes the difference of the boiling points of nitrogen and oxygen under a certain pressure to perform condensation evaporation on the nitrogen and the oxygen¹⁸Cryogenic O-isotope rectification plant and¹⁵the N isotope low-temperature rectification device is combined and utilized¹⁸Evaporating oxygen at the top of the O isotope low-temperature rectifying tower as a heat source¹⁵N isotope low-temperature rectification tower bottom liquid nitrogen, and oxygen condensation¹⁸And (3) rectifying reflux liquid at low temperature by using the O isotope.¹⁸The reboiling heat source at the bottom of the O isotope cryogenic rectification tower is air separation cold nitrogen, and the cold energy of the air separation equipment is fully utilized.