阅读说明：本技术 一种利用水合物法的氦精制装置 (Helium refining device using hydrate method ) 是由 贾文龙 蒲兼林 李长俊 张财功 李俊逸 王静 于 2020-12-23 设计创作，主要内容包括：本发明专利公开了一种利用水合物法的氦精制装置,涉及天然气提氦技术领域,包括粗氦气换热器、脱氢反应器、粗氦气冷却器、第一水合物生成塔、第二水合物生成塔、水合物分解器、氦气压缩机、氦气冷却器等设备。本发明采用催化氧化法脱氢和水合物法脱氮,不同于传统氦精制装置,脱氢单元生成的水在脱氮单元得到利用,从而去掉脱水装置,减少设备投资,并通过添加四丁基溴化铵溶液降低氮气水合物的生成压力,使整个装置的运行压力比传统氦精制装置低,从而降低装置能耗。本发明克服了传统氦精制装置投资和能耗成本大的缺点,且利用脱氢粗氦气为粗氦气换热器和水合物分解器供热,实现能量多级重复利用。(The invention discloses a helium refining device by using a hydrate method, which relates to the technical field of natural gas stripping helium and comprises a crude helium heat exchanger, a dehydrogenation reactor, a crude helium cooler, a first hydrate generation tower, a second hydrate generation tower, a hydrate decomposer, a helium compressor, a helium cooler and the like. The invention adopts catalytic oxidation dehydrogenation and hydrate denitrification, is different from the traditional helium refining device, utilizes the water generated by the dehydrogenation unit in the denitrification unit, thereby removing a dehydration device, reducing the equipment investment, reducing the generation pressure of nitrogen hydrate by adding tetrabutylammonium bromide solution, lowering the operation pressure of the whole device compared with the traditional helium refining device, and reducing the energy consumption of the device. The invention overcomes the defects of large investment and energy consumption cost of the traditional helium refining device, and supplies heat to the crude helium heat exchanger and the hydrate decomposer by using the dehydrogenation crude helium gas, thereby realizing the multi-stage reutilization of energy.)

1. The helium refining device utilizing the hydrate method is characterized by comprising a crude helium refining unit and a TBAB solution recovery unit, wherein the crude helium refining unit comprises a crude helium heat exchanger (1), a dehydrogenation reactor (2), a crude helium cooler (3), a first hydrate generation tower (4), a second hydrate generation tower (5), a hydrate decomposer (6), a helium compressor (7) and a helium cooler (8), crude helium enters from a cold gas inlet of the crude helium heat exchanger (1), a cold gas outlet of the crude helium heat exchanger (1) is connected with the dehydrogenation reactor (2), the dehydrogenation reactor (2) is connected with a hot gas inlet of the crude helium heat exchanger (1), a hot gas outlet of the crude helium heat exchanger (1) is connected with the crude helium cooler (3), and a connecting pipeline of the crude helium heat exchanger (1) and the crude helium cooler (3) exchanges heat through the hydrate decomposer (6) The system comprises a crude helium cooler (3), a first hydrate generation tower (4), a second hydrate generation tower (5), a nitrogen accelerator solution (TBAB) and a TBAB solution, wherein the top outlet of the first hydrate generation tower (4) is connected with the lower end inlet of the second hydrate generation tower (5), nitrogen in the crude helium is mixed with the TBAB solution in the first hydrate generation tower (4) and the second hydrate generation tower (5) to generate nitrogen hydrate rapidly, the bottom outlet of the first hydrate generation tower (4) is connected with a hydrate decomposer (6), the bottom outlet of the second hydrate generation tower (5) is connected with the hydrate decomposer (6), and the TBAB solution recovery unit comprises a buffer tank (15), a TBAB solution cooler (16), a pump (17) and a second flow rate regulating unitThe device comprises a throttle valve (19) and a third flow regulating valve (20), wherein an outlet at the top of the second hydrate generation tower (5) is connected with a helium compressor (7), the helium compressor (7) is connected with a helium cooler (8), cooled high-purity helium is output, the hydrate decomposer (6) is connected with an external heat exchange pipeline, and N decomposed by the hydrate decomposer (6)₂Defeated outward, TBAB solution that hydrate decomposer (6) decomposed gets into buffer tank (15), buffer tank (15) are connected with TBAB solution cooler (16), TBAB solution cooler (16) are connected with pump (17), pump (17) and first hydrate generate tower (4) upper end import, second hydrate generate tower (5) upper end access connection, can realize the reuse of TBAB solution.

2. The apparatus for refining helium by using the hydrate method according to claim 1, wherein the nitrogen hydrate accelerator is tetrabutylammonium bromide (TBAB) solution which can greatly reduce the formation pressure of the nitrogen hydrate.

3. A helium refining plant using hydrate process according to claim 1, characterized in that said dehydrogenated crude helium is sequentially fed into a first hydrate formation tower (4) and a second hydrate formation tower (5), and the nitrogen gas forms hydrates in the towers, thereby realizing the separation of nitrogen gas and helium gas.

4. A helium purification apparatus using a hydrate method according to claim 1, wherein the buffer tank (15) is connected to a second flow rate control valve (19) and a third flow rate control valve (20), water is replenished through the second flow rate control valve (19), and the hydrate formation promoter TBAB is replenished through the third flow rate control valve (20).

Technical Field

The invention relates to the technical field of helium extraction from natural gas, in particular to a helium refining device by using a hydrate method

Background

Helium is an important strategic resource, has an extremely low boiling point (4.2K), a critical temperature (5.15K) and a critical pressure (0.226MPa), and can easily realize ultralow-temperature cooling which cannot be realized by other low-temperature liquids, so that the helium plays an irreplaceable role in the technical fields of aerospace, nuclear weapons, submarines, saturated diving operation, nuclear magnetic resonance, semiconductors and the like, and becomes one of essential important raw materials for national defense, military industry and high-tech development. Therefore, how to extract helium from the nature is an important issue of great attention. However, the content of helium in nature is very low, the content of helium in the atmosphere is only 0.0005%, and the content of helium in natural gas of many oil and gas fields is higher than 0.1% and is ten million times higher than that of helium in the air. At present, the natural gas helium extraction process is the mainstream process for extracting helium globally.

The natural gas helium stripping process is mainly divided into a decarburization unit, a dehydration unit, a demethanization unit and a helium refining unit, wherein the helium refining unit is an important gas purification unit and determines whether helium can meet product requirements. Therefore, a need exists for an efficient and energy efficient helium purification apparatus. Among helium refining processes, catalytic oxidation dehydrogenation, membrane separation purification and pressure swing adsorption denitrification are the most widely used processes, such as patent publications CN111547691A and CN110844893A, which can improve the purity of helium and increase the recovery rate of helium, but have three limitations, specifically expressed as the following three aspects: firstly, water generated by the catalytic oxidation device is difficult to utilize, a deep dehydration unit needs to be established for treatment, and the equipment investment is increased; secondly, the membrane separation method is used for primarily purifying crude helium in a helium refining device, and the load of a pressure swing adsorption device is reduced so as to reduce energy consumption, but the separation capacity of a single-stage membrane is limited, a multi-stage membrane unit needs to be designed or the pressure difference between two sides of the membrane needs to be increased so as to ensure the purity of the helium, and the material cost and the energy consumption cost are still higher; thirdly, the pressure swing adsorption method needs to establish a multi-stage adsorption device to ensure the denitrification efficiency, the process flow is complex, meanwhile, because the adsorption device has the upper limit of adsorption capacity, in order to enable the device to continuously operate, a plurality of devices are needed to be alternately used, the requirement on the precision of equipment is also provided, the equipment investment and the operation cost are increased, and the adsorption pressure of the pressure swing adsorption device is often higher, which means that the power requirement of a compressor is higher, and the helium extraction energy consumption is higher. Analysis shows that the helium refining device has the problem of poor economic benefit. The device fully considers the defects of the traditional helium refining device, simplifies the oxidative dehydrogenation process by adopting a hydrate method, removes a dehydration unit, has lower denitrification operation pressure of a multistage hydrate generation tower, does not need to be used alternately, reduces the requirement on equipment, overcomes the problems of complex flow and large investment and energy consumption of the traditional helium refining device, and improves the economic benefit of natural gas helium stripping while ensuring the purity of helium.

Disclosure of Invention

The purpose of the invention is: the device can realize high-efficiency purification of crude helium by adopting catalytic oxidation dehydrogenation and hydrate denitrification, simplifies the oxidative dehydrogenation process, reduces the investment, realizes hydrate denitrification, reduces the energy loss and ensures that the extracted helium meets the requirements of related national products.

The technical scheme adopted by the invention for solving the technical problem is as follows: a helium purification apparatus using a hydrate method, comprising a crude helium purification unit and a TBAB solution recovery unit: the crude helium refining unit comprises a crude helium heat exchanger 1, a dehydrogenation reactor 2, a crude helium cooler 3, a first hydrate generation tower 4, a second hydrate generation tower 5, a hydrate decomposer 6, a helium compressor 7 and a helium cooler 8, wherein crude helium enters a cold air inlet of the crude helium heat exchanger 1 for heat exchange and temperature rise, a cold air outlet of the crude helium heat exchanger 1 is connected with the dehydrogenation reactor 2, the crude helium removes impurity hydrogen in the dehydrogenation reactor 2, the dehydrogenation reactor 2 is connected with a hot air inlet of the crude helium heat exchanger 1, the heated dehydrogenation crude helium serves as hot air to supply heat for the crude helium, a hot air outlet of the crude helium heat exchanger 1 is connected with the crude helium cooler 3, a connecting pipeline of the crude helium heat exchanger 1 and the crude helium cooler 3 exchanges heat through the hydrate decomposer 6, and the dehydrogenation crude helium passes through the crude helium cooler 3, The hydrate decomposer 6 is further cooled to meet the temperature condition of hydrate generation, the crude helium cooler 3 is connected with an inlet at the lower end of the first hydrate generation tower 4, and an outlet at the top of the first hydrate generation tower 4 and a second hydrate generation tower are connectedThe lower end of a tower forming tower 5 is connected with an inlet, nitrogen in the crude helium gas generates hydrate in a first hydrate generating tower 4 and a second hydrate generating tower 5, the top outlet of the second hydrate generating tower 5 is connected with a helium gas compressor 7, the helium gas compressor 7 is connected with a helium gas cooler 8, the storage requirement of a gas cylinder of high-purity helium gas is met after pressurization and temperature reduction, and the high-purity helium gas is output; the TBAB solution recovery unit comprises a buffer tank 15, a TBAB solution cooler 16, a pump 17, a second flow regulating valve 19 and a third flow regulating valve 20, wherein an outlet at the bottom of the first hydrate generation tower 4 and an outlet at the bottom of the second hydrate generation tower 5 are connected with a hydrate decomposer 6, generated hydrate slurry enters the hydrate decomposer 6 to be decomposed, the hydrate decomposer 6 is connected with an external heat exchange pipeline, and N decomposed by the hydrate decomposer 6₂The TBAB solution decomposed by the hydrate decomposer 6 enters the buffer tank 15, the loss of the TBAB solution exists in the decomposition process in the hydrate decomposer 6, the buffer tank 15 is connected with a second flow regulating valve 19 and a third flow regulating valve 20, water and TBAB respectively enter the buffer tank through the second flow regulating valve 19 and the third flow regulating valve 20, the buffer tank 15 is connected with a TBAB solution cooler 16, the temperature of the TBAB solution is reduced to the generation temperature of the nitrogen hydrate, the TBAB solution cooler 16 is connected with a pump 17, the pump 17 is connected with an upper end inlet of the first hydrate generation tower 4 and an upper end inlet of the second hydrate generation tower 5, and the TBAB solution is pumped into the first hydrate generation tower 4 and the second hydrate generation tower 5 to realize cyclic utilization.

Preferably, a start-up heater 9 is connected between the crude helium heat exchanger 1 and the dehydrogenation reactor 2, no hot gas flows into the crude helium heat exchanger 1 during first start-up, the crude helium is heated by the start-up heater 9, a first stop valve 10 is connected in front of the start-up heater 9, and a pipeline where the start-up heater 9 and the first stop valve 10 are located is connected in parallel with a pipeline where the second stop valve 11 is located.

Preferably, the dehydrogenation reactor 2 is provided with H after₂/O₂On-line analyzer 12, crude helium from dehydrogenation reactor 2 is passed through H₂/O₂On-line analyzer 12 detecting if H₂、O₂The concentration reaches the standard and passes through the third stop valve 13And when the output is not up to the standard, the mixed gas flows back to the dehydrogenation reactor 2 through the fourth stop valve 14, and the first flow regulating valve 18 is regulated during the backflow to control the oxygen input amount, so that the dehydrogenation is qualified.

Preferably, the crude helium heat exchanger 1 is a shell-and-tube heat exchanger, the crude helium cooler 3 is an air-cooled cooler, the helium compressor 7 is a membrane press, the helium cooler 8 is a shell-and-tube cooler, the start-up heater 9 is an electric heater, the buffer tank 15 is a vertical tank, the TBAB solution cooler 16 is a plate cooler, the pump 17 is a centrifugal immersed pump, and a hydrate formation accelerator added to the first hydrate generation tower 4 and the second hydrate generation tower 5 is tetrabutylammonium bromide (TBAB), so that the generation pressure of the nitrogen hydrate can be greatly reduced.

Preferably, a gas dryer is not arranged behind the dehydrogenation reactor 2, and water generated in the dehydrogenation reactor 2 enters the first hydrate generation tower 4 along with the dehydrogenated crude helium.

Preferably, the TBAB solution is directly introduced into the first hydrate formation tower 4 and the second hydrate formation tower 5, which can effectively prevent the hydrates from forming in front of the first hydrate formation tower 4 and blocking pipelines.

Preferably, the TBAB solution can greatly reduce the generation pressure of the nitrogen hydrate, the nitrogen and water have lower pressure in the dehydrogenation unit and are not contacted with the TBAB solution, the hydrate generation condition is not met, the process pressure does not need to be controlled, and the process is simplified.

Preferably, the heating mode of the medium in the external heat exchange pipeline is photo-thermal + air source + electric heating, and the medium and the hydrate decomposer 6 are subjected to heat exchange and temperature reduction and then are circulated to the external heating treatment.

Due to the adoption of the technical scheme, the invention can achieve the following beneficial effects:

(1) the fluid pressure of the dehydrogenation unit is lower than the generation pressure of the nitrogen hydrate, water generated by a catalytic oxidation method can be introduced into the first hydrate generation tower 4 along with the crude helium, a dehydration device is not required to be established, no hydrate is generated, the process is simplified, and the equipment investment is reduced;

(2) the pressure required by the denitrification by the hydrate method is low, and the energy consumption is low;

(3) the dehydrogenated crude helium gas provides heat for the crude helium gas heat exchanger 1 and the hydrate decomposer 6, so that the multi-stage recycling of energy is realized;

(4) the device has simple flow, high economic benefit and low investment cost.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic flow diagram of the present invention.

In the figure: 1 crude helium heat exchanger, 2 dehydrogenation reactor, 3 crude helium cooler, 4 first hydrate generation tower, 5 second hydrate generation tower, 6 hydrate decomposer, 7 helium compressor, 8 helium cooler, 9 start-up heater, 10 first stop valve, 11 second stop valve, 12H₂/O₂The system comprises an online analyzer, a 13 third stop valve, a 14 fourth stop valve, a 15 buffer tank, a 16TBAB solution cooler, a 17 pump, an 18 first flow regulating valve, a 19 second flow regulating valve and a 20 third flow regulating valve.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

A helium refining device using a hydrate method comprises a crude helium heat exchanger 1, a dehydrogenation reactor 2, a crude helium cooler 3, a first hydrate generation tower 4, a second hydrate generation tower 5, a hydrate decomposer 6, a helium compressor 7, a helium cooler 8, a start-up heater 9, a first stop valve 10, a second stop valve 11, a 12H₂/O₂The system comprises an online analyzer, a 13 third stop valve, a 14 fourth stop valve, a 15 buffer tank, a 16TBAB solution cooler, a 17 pump, an 18 first flow regulating valve, a 19 second flow regulating valve and a 20 third flow regulating valve.

The specific implementation mode is as follows: as can be seen from the attached figure 1 in the specification, the main components of the crude helium comprise 25.22% of nitrogen, 72.55% of helium and 2.23% of hydrogen, when the gas is started for the first time, the first stop valve 10 is opened, the second stop valve 11 is closed, and the temperature of the crude helium (2.8MPa, 45 ℃) is raised to 120 ℃ through the start-up heaterMixing with oxygen passing through the first flow regulating valve 18, introducing into a dehydrogenation reactor 2, catalytically reacting hydrogen and oxygen in the dehydrogenation reactor 2 to generate water to obtain crude dehydrogenation helium gas containing water, raising the temperature of the gas at the outlet of the dehydrogenation reactor 2 to 200 ℃ after the reaction, and installing H at the outlet of the dehydrogenation reactor 2₂/O₂And if the concentration of the hydrogen and the oxygen is not up to standard through analysis, the on-line analyzer 12 opens the fourth stop valve 14, closes the third stop valve 13, and makes the hydrogen and the oxygen flow back to the dehydrogenation reactor 2, adjusts the first flow regulating valve 18 to control the oxygen introduction amount during the back flow, opens the third stop valve 13 if the concentration is up to standard, closes the fourth stop valve 14, makes the hydrogen and the oxygen flow enter the crude helium heat exchanger 1 to exchange heat with the crude helium, reduces the temperature of the dehydrogenated crude helium to 126 ℃ after the heat exchange, closes the first stop valve 10 after the temperature of the gas at the cold air outlet of the crude helium heat exchanger 1 is increased to 120 ℃, opens the second stop valve 11, and the crude helium directly enters the dehydrogenation reactor 2 through the second stop valve 11.

After the crude helium gas cooled by the crude helium gas heat exchanger 1 exchanges heat through the hydrate decomposer 6 and the crude helium gas cooler 3 is cooled to 10 ℃, the crude helium gas enters the first hydrate generation tower 4 from the lower end thereof, the mixed gas is in countercurrent contact with an excessive TBAB solution (the mass fraction is 10%) entering from the upper end of a first hydrate generation tower 4 in the tower, the nitrogen hydrate generation pressure is reduced to 2.39MPa, about 80% of nitrogen generates hydrate, helium gas coming out of the top end of the first hydrate generation tower 4 and nitrogen which is not completely converted enter the lower end of a second hydrate generation tower 5, contacting with excessive TBAB solution (mass fraction is 10%) from bottom to top, wherein nitrogen completely generates hydrate, helium from the top of the second hydrate generation tower 5 is pressurized to 15MPa by a helium compressor 7 and then cooled to 40 ℃ by a helium cooler 8, the cooled high-purity helium is output, and hydrate slurry of the first hydrate tower 4 and the second hydrate tower 5 flows into a hydrate decomposer 6 from the bottom of the towers.

Dehydrogenation crude helium and an external heat exchange pipeline provide heat for the heat exchange of the hydrate decomposer 6, the hydrate is heated in the hydrate decomposer 6 and then decomposed into nitrogen and TBAB solution, the nitrogen is output, the TBAB solution enters the buffer tank 15, the TBAB solution lost in the decomposition process is supplemented in the buffer tank 15, the flow of supplementing water is controlled by adjusting the second flow adjusting valve 19, the flow of supplementing TBAB is controlled by adjusting the third flow adjusting valve 20, the temperature is reduced to 10 ℃ through the TBAB solution cooler 16 after the buffer, and the buffer is sent to the upper end of the first hydrate generation tower 4 and the upper end of the second hydrate generation tower 5 through the pump 17 for cyclic utilization.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.