Method for deep hydrogen removal and water removal

Abstract

The application provides a hydrogen deep removal and moisture removal method. High-concentration raw gas is dynamically mixed with dry low-concentration reflux gas in a mixer to form mixed gas, so as to reduce the hydrogen content and reduce the reaction risk. After pressurized heating, oxygen with a precisely matched hydrogen concentration is injected into a reactor for reaction. The reactor is provided with an alternating fixed and rotatable cylinder, and the inner wall of the flow channel is coated with a catalyst; the corresponding cylinder speed is automatically adjusted based on real-time hydrogen concentration detection downstream, and the speed is accelerated when the concentration exceeds the standard to strengthen turbulent contact and prolong the reaction time, combined with the concentration threshold setting decreasing along the flow direction, so that the hydrogen is deeply removed to an ultralow level. The reaction generates moisture, most of which is separated by two-stage water cooling, and then is deeply adsorbed and dried to be completely removed to an ultralow content. Finally, the gas is divided into two parts, one part is output as product gas, and the other part is completely dried reflux gas which is recycled to the initial mixing step to reduce the reaction risk of high hydrogen content.

Description

Technical Field

[0001] This invention relates to the field of hydrogen removal in mixers, and more particularly to a method for deep hydrogen removal and moisture removal. Background Technology

[0002] In traditional hydrogen removal processes, direct treatment of high-concentration hydrogen poses a risk of combustion and explosion, often requiring the introduction of external inert gases for dilution. However, this introduces impurities and incurs high energy consumption. Existing catalytic dehydrogenation reactors have poor adaptability to fluctuations in hydrogen concentration, easily leading to insufficient removal depth due to incomplete local reactions, with residual hydrogen threatening downstream safety. Moisture removal stages often rely on single cooling or adsorption methods, making it difficult to balance deep dehydration with energy consumption control. Furthermore, residual moisture in the circulating gas can easily cause equipment emulsification, freezing, and blockage. In addition, static reactor structures cannot dynamically respond to concentration changes, resulting in excessive or insufficient oxygen injection, affecting dehydrogenation efficiency and safety. There is an urgent need for an intrinsically safe, deep-removal, and self-adaptive integrated process. Summary of the Invention

[0003] This invention proposes a method for deep hydrogen removal and moisture removal, comprising:

[0004] S1. The feed gas with hydrogen concentration M1 and the return gas with hydrogen concentration M2 are introduced into a mixer and mixed to form a first mixed gas with hydrogen concentration M3, wherein the following relationship is satisfied: M2 <M3<M1;

[0005] S2. Pressurize the first mixture to a predetermined pressure to obtain a pressurized mixture;

[0006] S3. Heat the pressurized mixture and inject oxygen into it. Under the action of a catalyst, the hydrogen in the pressurized mixture containing oxygen reacts with the oxygen in the reactor to generate water, thus obtaining a second mixture containing water, dehydrogenated and deoxygenated.

[0007] S4. The second mixture is dried to obtain a dehydrated third mixture.

[0008] S5. The third mixed gas is split, with one part being output as product gas and the other part being circulated back to S1 as return gas.

[0009] The heating operation described in S3 includes:

[0010] The pressurized mixture is preheated by the second mixture through a heat exchanger;

[0011] The preheated pressurized mixture is then reheated.

[0012] In step S4, before the drying process, the second mixture is pre-cooled using the dehydrated third mixture to obtain the pre-cooled second mixture.

[0013] Specifically, S4 includes:

[0014] S41. The pre-cooled second mixed gas is passed into a primary water cooler for primary cooling and condensate separation.

[0015] S42. The gas after primary cooling is passed into a secondary water cooler for secondary cooling and condensate separation to obtain a dehydrated third mixed gas.

[0016] The reactor includes a shell, multiple first cylindrical assemblies, multiple second cylindrical assemblies, multiple drive components, and a main shaft. The main shaft is coaxially mounted inside the shell. The first and second cylindrical assemblies are also coaxially mounted on the main shaft. The multiple first and second cylindrical assemblies are arranged alternately along the axial direction of the main shaft. Multiple independent flow channels run through all the first and second cylindrical assemblies. The inner walls of the flow channels are coated with a catalyst. The first cylindrical assemblies are all fixedly mounted on the main shaft, and the second cylindrical assemblies are all rotatably mounted on the main shaft. Multiple drive components are connected one-to-one with multiple second cylindrical assemblies and can drive the corresponding second cylindrical assemblies to rotate. The mating surfaces of adjacent first and second cylindrical assemblies are dynamically sealed and abutted.

[0017] In S3, hydrogen and oxygen in the pressurized mixture containing oxygen react in multiple channels of the reactor to produce water.

[0018] Specifically, injecting oxygen into the pressurized mixture in S3 includes: real-time detection of the hydrogen concentration in the pressurized mixture, and dynamic adjustment of the oxygen injection amount based on the detected hydrogen concentration value.

[0019] Downstream of the gas flow within the second cylindrical assembly is a receiving space parallel to the cross-section of the second cylindrical assembly. This receiving space connects all flow channels, and a hydrogen concentration detection unit is arranged within this receiving space.

[0020] S3 further includes: when the real-time hydrogen concentration value detected by the hydrogen concentration detection unit in any of the multiple storage spaces is greater than the first preset concentration value set for that storage space, the driving component corresponding to the second cylinder assembly to which that storage space belongs will drive the second cylinder assembly to rotate. The greater the difference between the real-time hydrogen concentration value and the first preset concentration value, the faster the rotation speed of the second cylinder assembly will be controlled.

[0021] The first cylindrical assembly is arranged at both the beginning and end of the main shaft.

[0022] Among them, the multiple first preset concentration values ​​corresponding to the multiple storage spaces arranged in the direction from the head end of the main shaft to the tail end of the main shaft gradually decrease.

[0023] This method dynamically dilutes the feed gas through the internal circulation reflux gas, avoiding the introduction of external impurities and achieving intrinsic safety. The rotatable cylinder assembly innovatively designed in the reactor automatically adjusts the rotation speed according to the real-time hydrogen concentration, strengthens the turbulent contact and extends the reaction time, and combines the concentration gradient preset mechanism to ensure the deep removal of hydrogen to an ultra-low level. The moisture removal adopts two-stage water cooling pre-cooling and deep adsorption drying, significantly reducing the energy consumption and completely eliminating the moisture residue, avoiding the equipment freezing and blocking failures. The oxygen is dynamically injected to match the hydrogen concentration, precisely controlling the reaction process and eliminating the oxygen residue. The overall process integrates the internal circulation dilution, self-adaptive catalytic reaction and high-efficiency dehydration modules, improving the dehydrogenation efficiency and system stability while ensuring safety, and reducing the operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic flow chart of the method for deep hydrogen removal and moisture removal of the present invention;

[0025] Figure 2 It is a schematic flow chart of the method for deep hydrogen removal and moisture removal of the present invention;

[0026] Figure 3 It is a schematic structural diagram of the reactor in the present invention;

[0027] Figure 4 It is a schematic structural diagram of the reactor in the present invention;

[0028] Figure 5 It is a schematic layout diagram of the entire system corresponding to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] REFERENCE Figures 1-5 , the present invention provides a method for deep hydrogen removal and moisture removal, including:

[0030] S1. Feed the feed gas with a hydrogen concentration of M1 and the reflux gas with a hydrogen concentration of M2 into the mixer 11 for mixing to form a first mixed gas with a hydrogen concentration of M3, where the relationship: M2 < M3 < M1 is satisfied. Specifically, M1 ∈ (20%, 40%), M3 < 2%, M2 < 1 ppm, ensuring that the hydrogen is removed outside the explosion range for reaction removal, thereby ensuring the process safety.

[0031] A feed gas with a hydrogen concentration of M1 and a reflux gas with a hydrogen concentration of M2 are simultaneously introduced into mixer 11 for thorough mixing. The reflux gas originates from the dehydrogenated gas separated in subsequent steps, and its concentration M2 is significantly lower than that of the feed gas M1. During mixing, the input amounts of reflux gas and feed gas are dynamically adjusted by monitoring the flow ratio of the two gases in real time. Dynamically diluting the feed gas with reflux gas prevents the risk of combustion or explosion caused by high-concentration hydrogen in subsequent heating or reactions, and also avoids the introduction of impurities due to dilution by external inert gases. Precise control of concentration M3 ensures process safety and provides the optimal hydrogen concentration window for subsequent catalytic reactions: excessively high concentrations lead to violent exothermic reactions and potential loss of control, while excessively low concentrations reduce dehydrogenation efficiency. This dynamic dilution mechanism based on internal circulation solves the safety hazards and external dilution contamination problems associated with traditional direct treatment of high-hydrogen feed gas, enabling the system to achieve efficient dehydrogenation under inherently safe conditions. Finally, the first mixed gas enters the pressurization stage with a stable concentration and flow rate, supporting the continuous operation of subsequent multi-stage reactions.

[0032] S2. The first mixed gas is pressurized to a predetermined pressure to obtain a pressurized mixed gas. The pressurization operation is achieved by a pressurization device 12, such as a circulating hydrogen compressor or a circulating hydrogen pump, to increase the pressure to a medium pressure of 1.6 MPa, so as to improve the efficiency of the subsequent dehydrogenation reaction.

[0033] S3. Heating the pressurized mixture and injecting oxygen into it. Specifically, the heating operation involves preheating the pressurized mixture using the second mixture obtained later through heat exchanger 14, and then reheating the preheated pressurized mixture to 100℃~120℃ via heater 15. Injecting oxygen into the pressurized mixture specifically includes: real-time monitoring of the hydrogen concentration in the pressurized mixture and dynamically adjusting the oxygen injection amount based on the detected hydrogen concentration; under the action of a catalyst, the hydrogen and oxygen in the oxygen-injected pressurized mixture react in reactor 13 to generate water, resulting in a second mixture containing water, dehydrogenated, and deoxygenated. Hydrogen removal is carried out in reactor 13, under conditions of temperature not exceeding 200℃ and pressure 1.6MPa, through an oxygen-added catalytic reaction to deeply remove hydrogen to below 10ppb, to prevent safety risks caused by hydrogen enrichment in downstream processes.

[0034] The reactor 13 includes: a shell 1, multiple first cylindrical assemblies 2, multiple second cylindrical assemblies 3, multiple drive components 4, and a main shaft 5. The main shaft 5 is coaxially mounted inside the shell 1. The first cylindrical assemblies 2 and the second cylindrical assemblies 3 are coaxially mounted on the main shaft 5. The multiple first cylindrical assemblies 2 and the multiple second cylindrical assemblies 3 are arranged alternately along the axial direction of the main shaft 5. Multiple independent flow channels 6 pass through all the first cylindrical assemblies 2 and the second cylindrical assemblies 3. The inner wall of the flow channel 6 has a catalyst coating 7. The first cylindrical assemblies 2 are all fixedly mounted on the main shaft 5, and the second cylindrical assemblies 3 are all rotatably mounted on the main shaft 5. The multiple drive components 4 are connected one-to-one with the multiple second cylindrical assemblies 3 and can drive the corresponding second cylindrical assemblies 3 to rotate. The mating surfaces of adjacent first cylindrical assemblies 2 and second cylindrical assemblies 3 are dynamically sealed and abutted. The first cylindrical assemblies 2 are arranged at both the beginning and end positions of the main shaft 5. The hydrogen and oxygen in the pressurized mixture injected with oxygen react in the multiple flow channels 6 of the reactor 13 to generate water. Downstream of the gas flow within the second cylindrical assembly 3, there is a receiving space 8 parallel to the cross-section of the second cylindrical assembly 3. The receiving space 8 connects to all flow channels 6, and a hydrogen concentration detection unit is arranged within this receiving space 8. When the real-time hydrogen concentration value detected by the hydrogen concentration detection unit in any of the multiple receiving spaces 8 is greater than a first preset concentration value set for that receiving space 8, the driving component 4 corresponding to the second cylindrical assembly 3 to which that receiving space 8 belongs will drive the second cylindrical assembly 3 to rotate. The greater the difference between the real-time hydrogen concentration value and the first preset concentration value, the faster the rotation speed of the second cylindrical assembly 3 will be controlled. The multiple first preset concentration values ​​corresponding to the multiple receiving spaces arranged in the direction from the head end of the main shaft 5 to the tail end of the main shaft 5 gradually decrease.

[0035] First, the second mixed gas generated in subsequent steps is used to preheat the pressurized mixed gas through heat exchanger 14 to recover heat energy and reduce energy consumption. Next, the preheated pressurized mixed gas is reheated to reach the reaction temperature. Oxygen is dynamically injected into the heated pressurized mixed gas. Specifically, the hydrogen concentration in the pressurized mixed gas is monitored in real time, and the oxygen injection rate is dynamically adjusted based on this concentration value to ensure precise matching of oxygen and hydrogen and prevent residual oxygen after dehydrogenation. Subsequently, the pressurized mixed gas with injected oxygen enters a specially constructed reactor 13. The reactor 13 includes a shell 1, a main shaft 5, and multiple first cylindrical assemblies 2 alternately arranged and fixed on the main shaft 5, and multiple second cylindrical assemblies 3 rotatably mounted on the main shaft 5. Both ends of the main shaft 5 are first cylindrical assemblies 2. Multiple independent flow channels 6 run through the interior of all assemblies, and the inner walls of the flow channels 6 are coated with catalyst. The mating surfaces of adjacent assemblies maintain a dynamic seal. Within the second cylindrical assembly 3, the gas flows through the flow channels 6 and enters a downstream receiving space 8 parallel to the cross-section. This receiving space 8 connects all the flow channels 6 of the component and houses a hydrogen concentration detection unit. Hydrogen and oxygen react in the catalyst-filled flow channels 6 to produce water, resulting in a second water-containing mixed gas. The receiving space 8 of each second cylinder component 3 continuously monitors the real-time hydrogen concentration flowing out. When the real-time hydrogen concentration in a certain space exceeds the first preset concentration value set for that space, the corresponding drive component 4 of the second cylinder component 3 is immediately triggered to rotate. The greater the difference between the real-time concentration and the preset value, the faster the drive component 4 controls the second cylinder component 3 to rotate. Along the direction of gas flow from the beginning to the end of the main shaft 5, the first preset concentration value set in the receiving space 8 of subsequent second cylinder components 3 gradually decreases. By detecting and driving the rotation of local cylinders in real time, the flow channel 6 is actively blocked at the location where the concentration exceeds the standard, which can prolong the gas residence reaction time. At the same time, the rotation enhances the turbulent contact between the gas and the catalyst wall, which can improve the reaction efficiency. Combining a preset concentration gradient decrease along the flow direction, a slightly higher residual concentration is allowed in the initial stage to avoid premature hindrance, while a forced deep reaction is implemented in the later stage, and the fixed cylinder at the end ensures complete dehydrogenation. The 8-channel collection space gathers and detects gas mixing across multiple channels, making the results closer to the actual overall concentration. Finally, the second mixed gas undergoes deep dehydrogenation with controllable oxygen residue, which is used to preheat subsequent gases and proceed to the drying step.

[0036] S4. The second mixture is dried to obtain a dehydrated third mixture. Specifically, this includes:

[0037] S41. The pre-cooled second mixed gas is introduced into the primary water cooler 16 for primary cooling and condensate separation. Specifically, the pre-cooled second mixed gas is introduced into the primary water cooler 16 for primary cooling and condensate separation. The primary water cooler 16 uses circulating water at 28℃~32℃ in the circulating water system 18 for heat exchange and cooling, resulting in the precipitation of a large amount of condensate. The condensate is automatically discharged through an automatic drain valve logic control.

[0038] S42. The gas after primary cooling is passed into a secondary water cooler 17 for secondary cooling and condensate separation to obtain a dehydrated third mixed gas. Specifically, the gas after primary cooling is passed into a secondary water cooler 17 for secondary cooling and condensate separation to obtain a dehydrated third mixed gas. The secondary water cooler 17 uses chilled water at 5℃~8℃ in the chilled water system 19 for three heat exchange coolings, precipitating a small amount of condensate, which is automatically discharged through an automatic drain valve. Subsequently, the gas enters a drying device 20 for deep dehydration to remove water content to below 1ppm (minimum 0.02ppm). The drying device 20 includes 2~3 adsorption towers, with one tower operating while the others are regenerated. Before drying, the second mixed gas is pre-cooled using the dehydrated third mixed gas to obtain a pre-cooled second mixed gas.

[0039] S5. The third mixed gas is split, with one part output as product gas and the other part circulated back to S1 as return gas. Specifically, after splitting, the return gas passes through a drying system 100% to ensure that the moisture content is below 1 ppm, preventing problems such as emulsification of lubricating oil or freezing and blockage in winter in the downstream circulating hydrogen compressor or pump.

[0040] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for deep hydrogen removal and water removal, characterized by, The method comprises the following steps: S1, mixing raw gas with a hydrogen concentration of M1 and reflux gas with a hydrogen concentration of M2 in a mixer (11) to form first mixed gas with a hydrogen concentration of M3, wherein the relationship M2 < M3 < M1 is satisfied; S2, pressurizing the first mixed gas to a predetermined pressure to obtain pressurized mixed gas; S3, heating the pressurized mixed gas and injecting oxygen into the pressurized mixed gas, and under the action of a catalyst, hydrogen and oxygen in the pressurized mixed gas into which oxygen is injected react in a reactor (13) to generate water, thereby obtaining second mixed gas containing water, dehydrogenated and deoxygenated; S4, drying the second mixed gas to obtain third mixed gas after dehydration; S5, dividing the third mixed gas into two parts, one part is output as product gas, and the other part is circulated to S1 as reflux gas; The reactor (13) comprises a shell (1), a plurality of first cylinder assemblies (2), a plurality of second cylinder assemblies (3), a plurality of driving members (4), and a main shaft (5). The main shaft (5) is coaxially installed in the shell (1). The first cylinder assemblies (2) and the second cylinder assemblies (3) are coaxially installed on the main shaft (5). The plurality of first cylinder assemblies (2) and the plurality of second cylinder assemblies (3) are alternately arranged along the main shaft (5) in the axial direction. A plurality of independent flow channels (6) penetrate through all the first cylinder assemblies (2) and the second cylinder assemblies (3). The inner wall of the flow channel (6) is provided with a catalyst coating (7). The first cylinder assemblies (2) are fixedly installed on the main shaft (5). The second cylinder assemblies (3) are rotatably installed on the main shaft (5). The plurality of driving members (4) are connected to the plurality of second cylinder assemblies (3) one by one and can drive the corresponding second cylinder assemblies (3) to rotate. Adjacent first cylinder assemblies (2) and second cylinder assemblies (3) are dynamically sealed against each other at the abutting surface.

2. The method of claim 1, wherein the hydrogen deep removal and water removal is performed at a temperature of 200 to 400°C. The heating operation in S3 comprises: Preheating the pressurized mixed gas by using the second mixed gas through a heat exchanger (14); Secondary heating the preheated pressurized mixed gas.

3. The method of claim 1, wherein the hydrogen deep removal and water removal is performed at a temperature of 200-400°C. In S4, before the drying treatment, the second mixed gas is pre-cooled using the third mixed gas after dehydration to obtain pre-cooled second mixed gas.

4. The method for deep hydrogen removal and water removal according to claim 3, wherein S4 specifically comprises: S41, passing the pre-cooled second mixed gas into a first water cooler (16) for primary cooling and condensing water separation; S42, passing the once-cooled gas into a second water cooler (17) for secondary cooling and condensing water separation to obtain the third mixed gas after dehydration.

5. The method of claim 1, wherein the hydrogen deep removal and water removal is performed at a temperature of 200-400°C. In S3, hydrogen and oxygen in the pressurized mixed gas into which oxygen is injected react in the plurality of flow channels (6) of the reactor (13) to generate water.

6. The method for deep hydrogen removal and water removal according to claim 5, wherein, In S3, the injection of oxygen into the pressurized mixed gas specifically comprises: real-time detection of the hydrogen concentration in the pressurized mixed gas, and dynamic adjustment of the oxygen injection amount according to the detected hydrogen concentration value.

7. The method of claim 5, wherein the hydrogen deep removal and water removal is performed at a temperature of 200 to 400°C. Downstream of the gas flow in the second cylinder assembly (3) has a receiving space (8) parallel to the cross section of the second cylinder assembly (3), the receiving space (8) communicates all the flow channels (6), and a hydrogen concentration detection unit is arranged in the receiving space (8); S3 further comprises: when the real-time hydrogen concentration value detected by the hydrogen concentration detection unit in any storage space (8) of the plurality of storage spaces (8) is greater than the first preset concentration value set for the storage space (8), the second cylinder assembly (3) to which the storage space (8) belongs is driven to rotate by the driving member (4) corresponding to the second cylinder assembly (3), and the greater the difference between the real-time hydrogen concentration value and the first preset concentration value, the faster the rotation speed of the second cylinder assembly (3) is controlled.

8. The method for deep hydrogen removal and water removal according to claim 7, wherein, The first end position and the last end position of the main shaft (5) are arranged as the first cylinder assembly (2).

9. The method of claim 8, wherein the hydrogen is removed to a level of less than 1 ppm. The plurality of first preset concentration values corresponding to the plurality of storage spaces (8) arranged in the direction in which the first end of the main shaft (5) points to the last end of the main shaft (5) gradually decrease.

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