Device for preparing ultra-pure hydrogen by recovering and purifying hydrogen

Abstract

The device comprises a hydrogen buffer tank, a hydrogen compressor, a desulfurizing tower, a heat exchanger, a horizontal adsorption tower, a PSA (Pressure Swing Adsorption) tower group, a membrane separation unit, a hydrogen product tank and a heat-conducting oil boiler combustion system which are connected in sequence, the PSA adsorption tower group is composed of six adsorption towers connected in parallel, each tower is provided with an integrated heat exchanger, the energy recovery rate is larger than or equal to 85% through three-stage pressure equalization, and finally ultra-pure hydrogen with the energy recovery rate larger than or equal to 99.999% is obtained; the oxygen content is controlled to be smaller than 0.5% through a nitrogen replacement system; circulating the intercepted gas part to an inlet of the compressor; the hydrogen-rich tail gas is efficiently treated by a combustion system, CO2 in the discharged tail gas is less than or equal to 50ppm, and NO is less than or equal to 10ppm; the process condensate is recycled by a stripping tower and then is used as boiler replenishing water; the device disclosed by the utility model integrates PSA and membrane separation technologies, has the characteristics of high purity, low energy consumption, strong safety and high automation degree, and is suitable for preparing ultra-pure hydrogen in the fields of electronics and photovoltaics.

Description

Technical Field

[0001] This utility model relates to the field of gas purification technology, specifically to a device for recovering and purifying hydrogen to produce ultrapure hydrogen. Background Technology

[0002] With the rapid development of high-tech industries such as semiconductors, photovoltaics, and fuel cells, the demand for ultrapure hydrogen (purity ≥99.999%) is increasing. Currently, commonly used industrial hydrogen purification methods include pressure swing adsorption (PSA), membrane separation, and cryogenic separation. However, existing technologies suffer from high energy consumption. Traditional PSA processes require large amounts of hydrogen for flushing during adsorbent regeneration, and the energy recovery rate during pressure equalization is low (typically <80%), resulting in high operating costs. Purity is unstable; a single PSA process cannot stably produce ultrapure hydrogen with a purity of over 99.999%, while membrane separation, when used alone, has stringent requirements for feed gas pressure and is susceptible to contamination by impurities. Safety hazards exist; residual oxygen or flammable components may remain in the hydrogen-containing tail gas, and if replacement is incomplete, explosive mixtures can easily form during compression or adsorption. System integration is low; existing devices often employ a decentralized design, resulting in complex piping and poor temperature control accuracy, affecting adsorption efficiency and membrane separation performance. Currently, some technologies have attempted to combine PSA with membrane separation to purify hydrogen, but the following shortcomings still exist: poor heat management during the PSA regeneration stage leads to incomplete desorption of the adsorbent, affecting the adsorption capacity of subsequent cycles; the intercepted gas from the membrane separation is directly emitted without effective recycling, resulting in hydrogen waste; and the condensate is not recycled, increasing wastewater treatment costs.

[0003] Therefore, this utility model provides a device for hydrogen recovery and purification to produce ultrapure hydrogen, so as to realize an integrated, low-energy-consumption, and highly safe hydrogen recovery and purification device. Utility Model Content

[0004] The purpose of this utility model is to provide a device for hydrogen recovery and purification to produce ultrapure hydrogen, so as to achieve an integrated, low-energy-consumption, and highly safe hydrogen recovery and purification device.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] An apparatus for recovering and purifying hydrogen to produce ultrapure hydrogen, comprising:

[0007] The inlet of the hydrogen buffer tank (1) is connected to the hydrogen tail gas source through the raw material gas pipeline, and the outlet is connected to the inlet of the hydrogen compressor (2) through the first pipeline.

[0008] The outlet of the hydrogen compressor (2) is connected to the top inlet of the desulfurization tower (3) via a second pipeline, and the nitrogen inlet for replacement is connected to the second pipeline.

[0009] The outlet of the desulfurization tower (3) is connected to the shell-side inlet of the bottom heat exchanger (4) of the desulfurization tower through a third pipeline, and the shell-side outlet of the bottom heat exchanger (4) of the desulfurization tower is connected to the inlet of the horizontal adsorption tower (5) through a fourth pipeline.

[0010] The outlet of the horizontal adsorption tower (5) is connected to the main inlet pipe of the PSA adsorption tower group (7) through the fifth pipeline;

[0011] The PSA adsorption tower group (7) includes 6 adsorption towers in parallel (tower 1 to tower 6). The inlet and outlet of each adsorption tower are connected to the main gas inlet pipe and the main product gas pipe through a programmable valve group. The main product gas pipe is connected to the hydrogen product tank (6) through the sixth pipeline.

[0012] The outlet of the hydrogen product tank (6) is divided into two paths. One path transports product hydrogen through the seventh pipeline, and the other path is connected to the flushing gas inlet of the PSA adsorption tower group through the eighth pipeline.

[0013] The inlet of the membrane separation unit (8) is connected to the product gas main pipe of the PSA adsorption tower group through the ninth pipeline, the permeate outlet is connected to the hydrogen product tank (6) through the tenth pipeline, and the interception outlet is divided into two paths through the eleventh pipeline. One path returns to the inlet of the hydrogen compressor (2), and the other path is connected to the thermal oil boiler combustion system.

[0014] The thermal oil boiler combustion system has its exhaust port connected to the tail gas treatment unit.

[0015] The inlet of the stripping tower (9) is connected to the process condensate drain pipe, and the outlet is connected to the deaerator (10) through the twelfth pipe.

[0016] The outlet of the deaerator (10) is connected to the boiler feedwater pipeline.

[0017] Furthermore, each adsorption tower in the PSA adsorption tower group (7) is equipped with an integrated heat exchanger, the shell side of which is connected to the inside of the adsorption tower, and the tube side is connected to the temperature control medium system through an independent circulation pipeline to control the adsorption temperature at 40-55°C.

[0018] Furthermore, the sixth pipeline is equipped with an online hydrogen analyzer for real-time monitoring of the hydrogen purity of the product and for linkage control with the programmable valve group to control the switching sequence of the PSA adsorption tower group.

[0019] Furthermore, the eighth pipeline is equipped with a flow regulating valve and a temperature sensor to control the flushing hydrogen flow rate to 12–15 Nm³. 3 / min, temperature is 38~42℃.

[0020] Furthermore, a three-way regulating valve is provided on the eleventh pipeline to control the proportion of intercepted gas returned to the hydrogen compressor (2) to be 30% to 70%.

[0021] Furthermore, the main intake pipe of the thermal oil boiler combustion system is equipped with an online hydrogen concentration monitor and a flame detector, which are interlocked with the emergency shut-off valve and the nitrogen purging pipeline.

[0022] Furthermore, the desulfurization tower (3) is equipped with a sewage discharge pipe at the bottom and a vent pipe at the top. The internal packing layer is divided into two layers: the upper layer is zinc oxide desulfurizing agent and the lower layer is activated carbon adsorption layer.

[0023] Furthermore, the horizontal adsorption tower (5) is provided with an active alumina layer, a 13X molecular sieve layer and a carbon molecular sieve layer in sequence along the airflow direction, and the layers are separated by sieve plates.

[0024] Furthermore, the programmable valve group of the PSA adsorption tower group (7) includes a pressure equalization control valve, a forward discharge valve and a reverse discharge valve. The pressure equalization control valve achieves three-stage pressure equalization through cross pipelines, and the reverse discharge valve is connected to the desorption waste gas main pipe.

[0025] Furthermore, the steam inlet of the stripping tower (9) is connected to a low-pressure steam pipeline, and its exhaust port is directly connected to the top air inlet of the deaerator (10) through the twelfth pipeline.

[0026] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0027] 1. This utility model adopts a dual purification process of "PSA adsorption + membrane separation". The PSA stage first purifies to 99.99%, and then is refined by palladium alloy membrane separation. The final hydrogen purity is stably ≥99.999%, which meets the stringent requirements of the semiconductor, photovoltaic and other industries for ultrapure hydrogen. The horizontal adsorption tower pretreatment (activated alumina + molecular sieve) can effectively remove impurities such as sulfides and moisture, protect the subsequent PSA adsorbent and membrane module, and extend the service life.

[0028] 2. The three-stage pressure equalization energy recovery design of this utility model (recovery rate ≥85%) significantly reduces the compression energy consumption in the PSA regeneration stage; 70% of the membrane separation intercepted gas is returned to the compressor for recycling, reducing hydrogen loss and improving the overall recovery rate by more than 15%; the integrated heat exchanger accurately controls the temperature (40~55℃), avoiding the increase in energy consumption caused by temperature fluctuations in the adsorption / desorption process.

[0029] 3. This utility model features a nitrogen replacement system (oxygen content <0.5%) and online hydrogen concentration monitoring, eliminating the risk of explosion; the thermal oil boiler combustion system is equipped with a flame detector and automatic nitrogen purging to ensure safe treatment of exhaust gas (CO2 ≤ 50ppm, NO...). x ≤10ppm); Programmable valve assembly + interlock control, to avoid pressure or temperature exceeding limits due to misoperation, significantly improving safety performance;

[0030] 4. This utility model features a modular design that integrates pretreatment, PSA, membrane separation, combustion, and condensation recovery into a single unit, reducing the floor space by 30%; the fully automatic control system adjusts the equalization rate (0.8 MPa / min) and flushing flow rate (12-15 Nm³) in real time. 3 The system incorporates parameters such as / min, reducing the need for manual intervention, and features high system integration and ease of operation.

[0031] 5. This utility model uses hydrogen-rich tail gas combustion for heating, with a thermal efficiency of ≥95%, achieving energy cascade utilization; the process condensate is recovered by the stripping tower and used as boiler feedwater, achieving zero wastewater discharge and realizing environmental protection and resource recycling.

[0032] 6. This utility model can treat various industrial tail gases with hydrogen concentrations of 30% to 50%, and has a wide range of applications; the desulfurization tower and horizontal adsorption tower adopt a layered packing structure, which facilitates the replacement of failed adsorbents, makes maintenance convenient and highly adaptable, and has low maintenance costs. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, some of the drawings in the following description are some embodiments of this utility model. For those skilled in the art, other drawings can be made based on these drawings without creative effort.

[0034] Figure 1 This is a process flow diagram of Embodiment 1 of this utility model;

[0035] Among them, 1-hydrogen buffer tank; 2-hydrogen compressor; 3-desulfurization tower; 4-heat exchanger at the bottom of desulfurization tower; 5-horizontal adsorption tower; 6-hydrogen product tank; 7-PSA adsorption tower group; 8-membrane separation unit; 9-stripping tower; 10-deaerator. Detailed Implementation

[0036] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present utility model in a schematic manner. Therefore, they only show the components related to the present utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0037] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0038] Example 1

[0039] See appendix Figure 1 This embodiment provides an apparatus for recovering and purifying hydrogen to produce ultrapure hydrogen, comprising:

[0040] The inlet of the hydrogen buffer tank (1) is connected to the hydrogen tail gas source through the raw material gas pipeline, and the outlet is connected to the inlet of the hydrogen compressor (2) through the first pipeline.

[0041] The outlet of the hydrogen compressor (2) is connected to the top inlet of the desulfurization tower (3) via a second pipeline, and the nitrogen inlet for replacement is connected to the second pipeline.

[0042] The outlet of the desulfurization tower (3) is connected to the shell-side inlet of the bottom heat exchanger (4) of the desulfurization tower through a third pipeline, and the shell-side outlet of the bottom heat exchanger (4) of the desulfurization tower is connected to the inlet of the horizontal adsorption tower (5) through a fourth pipeline.

[0043] The outlet of the horizontal adsorption tower (5) is connected to the main inlet pipe of the PSA adsorption tower group (7) through the fifth pipeline;

[0044] The PSA adsorption tower group (7) includes 6 adsorption towers in parallel (tower 1 to tower 6). The inlet and outlet of each adsorption tower are connected to the main gas inlet pipe and the main product gas pipe through a programmable valve group. The main product gas pipe is connected to the hydrogen product tank (6) through the sixth pipeline.

[0045] The outlet of the hydrogen product tank (6) is divided into two paths. One path transports product hydrogen through the seventh pipeline, and the other path is connected to the flushing gas inlet of the PSA adsorption tower group through the eighth pipeline.

[0046] The inlet of the membrane separation unit (8) is connected to the product gas main pipe of the PSA adsorption tower group through the ninth pipeline, the permeate outlet is connected to the hydrogen product tank (6) through the tenth pipeline, and the interception outlet is divided into two paths through the eleventh pipeline. One path returns to the inlet of the hydrogen compressor (2), and the other path is connected to the thermal oil boiler combustion system.

[0047] The thermal oil boiler combustion system has its exhaust port connected to the tail gas treatment unit.

[0048] The inlet of the stripping tower (9) is connected to the process condensate drain pipe, and the outlet is connected to the deaerator (10) through the twelfth pipe.

[0049] The outlet of the deaerator (10) is connected to the boiler feedwater pipeline.

[0050] Furthermore, each adsorption tower of the PSA adsorption tower group (7) is equipped with an integrated heat exchanger, the shell side of which is connected to the inside of the adsorption tower, and the tube side is connected to the temperature control medium system through an independent circulation pipeline to control the adsorption temperature at 45°C.

[0051] Furthermore, the sixth pipeline is equipped with an online hydrogen analyzer for real-time monitoring of the hydrogen purity of the product and for linkage control with the programmable valve group to control the switching sequence of the PSA adsorption tower group.

[0052] Furthermore, the eighth pipeline is equipped with a flow regulating valve and a temperature sensor to control the flushing hydrogen flow rate to 13 Nm. 3 / min, temperature is 40℃;

[0053] Furthermore, a three-way regulating valve is provided on the eleventh pipeline to control the proportion of intercepted gas returning to the hydrogen compressor (2) to be 70%;

[0054] Furthermore, the main intake pipe of the thermal oil boiler combustion system is equipped with an online hydrogen concentration monitor and a flame detector, which are interlocked with the emergency shut-off valve and the nitrogen purging pipeline.

[0055] Furthermore, the desulfurization tower (3) is equipped with a sewage discharge pipe at the bottom and a vent pipe at the top. The internal packing layer is divided into two layers: the upper layer is zinc oxide desulfurizing agent and the lower layer is activated carbon adsorption layer.

[0056] Furthermore, the horizontal adsorption tower (5) is provided with an activated alumina layer, a 13X molecular sieve layer and a carbon molecular sieve layer in sequence along the airflow direction, and the layers are separated by sieve plates;

[0057] Furthermore, the programmable valve group of the PSA adsorption tower group (7) includes a pressure equalization control valve, a forward discharge valve and a reverse discharge valve. The pressure equalization control valve achieves three-level pressure equalization through cross pipelines, and the reverse discharge valve is connected to the desorption waste gas main pipe.

[0058] Furthermore, the steam inlet of the stripping tower (9) is connected to a low-pressure steam pipeline, and its exhaust port is directly connected to the top air inlet of the deaerator (10) through the twelfth pipeline.

[0059] In summary, this invention employs a dual purification process of "PSA adsorption + membrane separation." The PSA stage first purifies the hydrogen to 99.99%, then refines it using a palladium alloy membrane separation, ultimately achieving a stable hydrogen purity of ≥99.999%, meeting the stringent requirements for ultrapure hydrogen in industries such as semiconductors and photovoltaics. The horizontal adsorption tower pretreatment (activated alumina + molecular sieve) effectively removes impurities such as sulfides and moisture, protecting the subsequent PSA adsorbent and membrane modules, and extending their service life. This invention also features a three-stage pressure equalization energy recovery design (recovery rate ≥85%). This invention significantly reduces compression energy consumption during the PSA regeneration stage; 70% of the membrane separation retentate gas is returned to the compressor for recycling, reducing hydrogen loss and increasing the overall recovery rate by more than 15%; the integrated heat exchanger provides precise temperature control (40-55℃), avoiding increased energy consumption due to temperature fluctuations during adsorption / desorption; the nitrogen replacement system (oxygen content <0.5%) and online hydrogen concentration monitoring eliminate the risk of explosion; the thermal oil boiler combustion system is equipped with a flame detector and automatic nitrogen purging to ensure safe treatment of exhaust gas (CO2≤50ppm, NO...). x ≤10ppm); The programmable valve group with interlock control prevents pressure or temperature exceedances due to misoperation, significantly improving safety performance; This utility model features a modular design, integrating pretreatment, PSA, membrane separation, combustion, and condensation recovery into one unit, reducing the floor space by 30%; The fully automatic control system adjusts the equalization rate (0.8MPa / min) and flushing flow rate (12~15Nm³) in real time. 3 The system reduces the need for manual intervention by adjusting parameters such as per minute, achieving high system integration and convenient operation. This invention utilizes hydrogen-rich tail gas combustion for heating, achieving a thermal efficiency of ≥95% and realizing cascaded energy utilization. Process condensate is recovered via a stripping tower and used as boiler feedwater, achieving zero wastewater discharge and realizing environmental protection and resource recycling. This invention can treat various industrial tail gases with hydrogen concentrations ranging from 30% to 50%, making it widely applicable. The desulfurization tower and horizontal adsorption tower adopt a layered packing structure, facilitating the replacement of failed adsorbents, ensuring convenient maintenance, strong adaptability, and low maintenance costs.

[0060] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to the above embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for recovering and purifying hydrogen to produce ultrapure hydrogen, characterized in that, include: The inlet of the hydrogen buffer tank (1) is connected to the hydrogen tail gas source through the raw material gas pipeline, and the outlet is connected to the inlet of the hydrogen compressor (2) through the first pipeline. The outlet of the hydrogen compressor (2) is connected to the top inlet of the desulfurization tower (3) via a second pipeline, and the nitrogen inlet for replacement is connected to the second pipeline. The outlet of the desulfurization tower (3) is connected to the shell-side inlet of the bottom heat exchanger (4) of the desulfurization tower through a third pipeline, and the shell-side outlet of the bottom heat exchanger (4) of the desulfurization tower is connected to the inlet of the horizontal adsorption tower (5) through a fourth pipeline. The outlet of the horizontal adsorption tower (5) is connected to the main inlet pipe of the PSA adsorption tower group (7) through the fifth pipeline; The PSA adsorption tower group (7) includes 6 adsorption towers in parallel. The inlet and outlet of each adsorption tower are connected to the main gas inlet pipe and the main product gas pipe through a programmable valve group. The main product gas pipe is connected to the hydrogen product tank (6) through the sixth pipeline. The outlet of the hydrogen product tank (6) is divided into two paths. One path transports product hydrogen through the seventh pipeline, and the other path is connected to the flushing gas inlet of the PSA adsorption tower group through the eighth pipeline. The inlet of the membrane separation unit (8) is connected to the product gas main pipe of the PSA adsorption tower group through the ninth pipeline, the permeate outlet is connected to the hydrogen product tank (6) through the tenth pipeline, and the interception outlet is divided into two paths through the eleventh pipeline. One path returns to the inlet of the hydrogen compressor (2), and the other path is connected to the thermal oil boiler combustion system. The thermal oil boiler combustion system has its exhaust port connected to the tail gas treatment unit. The inlet of the stripping tower (9) is connected to the process condensate drain pipe, and the outlet is connected to the deaerator (10) through the twelfth pipe. The outlet of the deaerator (10) is connected to the boiler feedwater pipeline.

2. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, Each adsorption tower in the PSA adsorption tower group (7) is equipped with an integrated heat exchanger. Its shell side is connected to the inside of the adsorption tower, and its tube side is connected to the temperature control medium system through an independent circulation pipeline to control the adsorption temperature at 40-55℃.

3. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The sixth pipeline is equipped with an online hydrogen analyzer, which is used to monitor the hydrogen purity of the product in real time and to control the switching sequence of the PSA adsorption tower group in conjunction with the programmable valve group.

4. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The eighth pipeline is equipped with a flow regulating valve and a temperature sensor to control the flushing hydrogen flow rate to 12–15 Nm³. 3 / min, temperature is 38~42℃.

5. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The eleventh pipeline is equipped with a three-way regulating valve to control the proportion of intercepted gas returning to the hydrogen compressor (2) to be 30% to 70%.

6. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The thermal oil boiler combustion system is equipped with an online hydrogen concentration monitor and a flame detector on the main air intake pipe, which are interlocked with the emergency shut-off valve and nitrogen purging pipeline.

7. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The desulfurization tower (3) is equipped with a sewage discharge pipe at the bottom and a vent pipe at the top. The internal packing layer is divided into two layers: the upper layer is zinc oxide desulfurizing agent and the lower layer is activated carbon adsorption layer.

8. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The horizontal adsorption tower (5) is arranged with an active alumina layer, a 13X molecular sieve layer and a carbon molecular sieve layer in sequence along the airflow direction, and the layers are separated by sieve plates.

9. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The programmable valve group of the PSA adsorption tower group (7) includes a pressure equalization control valve, a forward discharge valve and a reverse discharge valve. The pressure equalization control valve achieves three-level pressure equalization through cross pipelines, and the reverse discharge valve is connected to the desorption waste gas main pipe.

10. The apparatus for hydrogen recovery, purification, and production of ultrapure hydrogen as described in claim 1, characterized in that, The steam inlet of the stripping tower (9) is connected to a low-pressure steam pipeline, and its exhaust port is directly connected to the top air inlet of the deaerator (10) through the twelfth pipeline.

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