Chemical-looping hydrogen production system for semi-coke tail gas

Abstract

The invention discloses a semi-coke tail gas chemical looping hydrogen production system which is characterized in that a first gas inlet chamber and a second gas inlet chamber are arranged in the hydrogen production system, and a reaction tube comprises a first reaction chamber and a second reaction chamber; the gas inlet of the first reaction chamber is communicated with the gas inlet of the second reaction chamber; the air outlet of the first reaction chamber is communicated with the air outlet of the second reaction chamber, so that the first reaction chamber and the second reaction chamber can supply air independently, the air speed in the first air inlet chamber is higher than that in the second reaction chamber, internal airflow circulation is effectively formed in the internal circulating fluidized bed, the reaction process is more sufficient, and the reaction efficiency is improved. The device effectively improves the hydrogen production efficiency, is simple in structure, realizes the independent air supply process through the independent design of the two cavities of the gas inlet pipe and the reaction pipe, realizes the effective circular reaction of tail gas in the reaction pipe through the control of the air speed, and improves the conversion efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of blue coke tail gas and relates to a blue coke tail gas chemical chain hydrogen production system. Background Art

[0002] Semi-coke tail gas is a by-product of the semi-coke production process. The main components of semi-coke tail gas are H2, CH4, CO and a large amount of N2. Due to the high nitrogen content and many impurities, it has always been difficult to process and utilize. Most semi-coke tail gas is only used for combustion power generation, while the resource utilization of semi-coke tail gas (such as methanol production, natural gas production and synthetic ammonia production, etc.) is mostly based on multi-stage separation and purification of components, which has high energy consumption. Semi-coke tail gas chemical chain hydrogen production is an efficient, low-cost, high-purity hydrogen production technology. It can obtain pure hydrogen from carbonaceous fuels and water through oxygen carriers as a medium, and does not require additional separation processes. It can chemically chain the semi-coke tail gas after pressure swing adsorption hydrogen extraction to produce high-purity hydrogen in one step, realizing the high-quality utilization of semi-coke tail gas. The existing semi-coke tail gas chemical chain hydrogen production system includes reduction, steam oxidation, air oxidation and other stages, which increases the complexity and difficulty of process operation, and the conversion rate of process hydrogen production is low, which limits the reprocessing process of semi-coke tail gas. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a semi-coke tail gas chemical chain hydrogen production system, thereby solving the complex technical problems of the process operation of the semi-coke tail gas chemical chain hydrogen production system in the prior art.

[0004] The present invention is achieved through the following technical solutions: A semi-coke tail gas chemical chain hydrogen production system, comprising a preheater, an internal circulating fluidized bed and a gas-solid separator which are sequentially connected; the inlet end of the preheater is connected to the outlet pipeline of the semi-coke tail gas; the internal circulating fluidized bed comprises an inlet pipe, a reaction pipe and a reflux pipe which are sequentially connected; The air inlet pipe includes a first air inlet chamber and a second air inlet chamber; the reaction tube includes a first reaction chamber and a second reaction chamber; The air inlet of the first reaction chamber is connected to the air inlet of the second reaction chamber; the air outlet of the first reaction chamber is connected to the air outlet of the second reaction chamber; When in use, the gas in the first air inlet chamber enters the first reaction chamber, and the gas in the second reaction chamber enters the second reaction chamber; the wind speed in the first air inlet chamber is greater than the wind speed in the second reaction chamber.

[0005] Preferably, a first air distribution plate is provided between the air inlet pipe and the reaction pipe; a second air distribution plate is provided between the reaction pipe and the reflux pipe; and a third air distribution plate is provided at the outlet of the reflux pipe.

[0006] Preferably, a plurality of partitions are provided in the reaction tube; the partitions are arranged along the length direction of the reaction tube; a gap is arranged between the bottom end of the partition close to the first air distribution plate and the first air distribution plate, and a gap is arranged between the top end of the partition close to the second air distribution plate and the second air distribution plate.

[0007] Preferably, the volumes of the first reaction chamber and the second reaction chamber are equal.

[0008] Preferably, a plurality of ribs are provided along the reaction tube; any one of the ribs is extended along the length direction of the reaction tube.

[0009] Preferably, a plurality of the ribs are evenly spaced along the inner wall of the reaction tube.

[0010] Preferably, the number of the ribs arranged in the reaction tube is 3 to 5.

[0011] Preferably, a plurality of the ribs are arranged on one side of the first reaction chamber.

[0012] Preferably, the rib plate includes a first side wall and a second side wall, the first side wall is connected to the inner wall of the reaction tube; and the second side wall is a wave structure.

[0013] Preferably, a plurality of thermocouples are provided in the air inlet pipe, the reaction pipe and the reflux pipe.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: The invention discloses a semi-coke tail gas chemical chain hydrogen production system, in which a first air inlet chamber and a second air inlet chamber are arranged in the hydrogen production system, and a reaction tube comprises a first reaction chamber and a second reaction chamber; and an air inlet of the first reaction chamber is connected with an air inlet of the second reaction chamber; an air outlet of the first reaction chamber is connected with an air outlet of the second reaction chamber, so that the first reaction chamber and the second reaction chamber can be supplied with air separately, and the wind speed in the first air inlet chamber is greater than the wind speed in the second reaction chamber, and an internal air flow circulation is effectively formed in an internal circulating fluidized bed, so that the reaction process is more sufficient, and the efficiency of hydrogen production is effectively improved. The device has a simple structure, and an independent air supply process is realized by independently designing two chambers of the air inlet pipe and the reaction tube, and an effective circulation reaction of the tail gas in the reaction tube is realized by controlling the wind speed, thereby improving the conversion efficiency.

[0015] Furthermore, a first air distribution plate is provided between the air inlet pipe and the reaction tube; a second air distribution plate is provided between the reaction tube and the reflux pipe; and a third air distribution plate is provided at the outlet of the reflux pipe, which can support the bed material, evenly distribute the airflow, maintain the stability of the bed and discharge large particles.

[0016] Furthermore, a plurality of partitions are provided in the reaction tube; the partitions are arranged along the length direction of the reaction tube; a gap is provided between the bottom end of the partition close to the first air distribution plate and the first air distribution plate, and a gap is provided between the top end of the partition close to the second air distribution plate and the second air distribution plate. The partitions can improve the distribution of materials in the bed layer, making the materials more evenly distributed in the bed layer, thereby improving the fluidization effect, and at the same time can optimize the fluidization state in the bed layer, making the contact between the gas and the material more complete, thereby improving the reaction or processing efficiency. In addition, the partitions help to reduce the back-mixing phenomenon of gas and solid particles.

[0017] Furthermore, the volumes of the first reaction chamber and the second reaction chamber are equal, so that the gas distribution and speed can be adjusted and the reaction effect can be enhanced.

[0018] Furthermore, a plurality of ribs are provided along the reaction tube; any one of the ribs is extended along the length direction of the reaction tube, which can optimize gas distribution and enhance heat and mass transfer.

[0019] Furthermore, a plurality of the ribs are evenly spaced along the inner wall of the reaction tube, which can increase the bed stability and extend the service life of the equipment.

[0020] Furthermore, the number of the ribs arranged in the reaction tube is 3 to 5, which can effectively guide the flow of airflow in the bed, avoid the fluid in the local area being too concentrated or too thin, and achieve a more uniform fluid distribution. The ribs serve as a supporting structure, which can enhance the overall stability of the bed and prevent the bed from violently fluctuating or collapsing under the action of the airflow.

[0021] Furthermore, a plurality of the ribs are arranged on one side of the first reaction chamber, which can guide the airflow to form a specific flow pattern in the bed. This design helps to reduce turbulence and eddy currents in the bed, allowing the airflow to pass through the bed more smoothly.

[0022] Furthermore, the rib plate includes a first side wall and a second side wall, which can optimize the gas-solid two-phase flow state in the fluidized bed, improve the mass transfer efficiency and reaction rate, and the first side wall is connected to the inner wall of the reaction tube; the second side wall is a wave structure.

[0023] Furthermore, a plurality of thermocouples are provided in the air inlet pipe, the reaction pipe and the reflux pipe, which can effectively ensure that the temperature of each module is constant and improve the efficiency of hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a structural schematic diagram of an internal circulating fluidized bed in the present invention; Figure 2 It is a schematic diagram of the structure of a rib plate in one embodiment of the present invention; Figure 3 A top view of the reaction tube of the present invention; Figure 4 It is a schematic diagram of the blue char tail gas chemical chain hydrogen production system in the present invention.

[0026] Among them: 1. air inlet pipe, 11. first air inlet chamber, 12. second air inlet chamber, 2. reaction tube, 21. first reaction chamber, 22. second reaction chamber, 23. rib plate, 231. first side wall, 232. second side wall, 24. partition plate, 3. reflux pipe, 4. first air distribution plate, 5. second air distribution plate, 6. third air distribution plate, 7. thermocouple. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings: Example 1 like Figure 1 , 4 As shown, the present invention discloses a semi-coke tail gas chemical chain hydrogen production system, comprising a preheater, an internal circulating fluidized bed and a gas-solid separator connected in sequence; the inlet end of the preheater is connected to the outlet pipeline of the semi-coke tail gas; the internal circulating fluidized bed comprises an air inlet pipe 1, a reaction tube 2 and a reflux pipe 3 connected in sequence; the air inlet pipe 1 comprises a first air inlet chamber 11 and a second air inlet chamber 12; the reaction tube 2 comprises a first reaction chamber 21 and a second reaction chamber 22; the air inlet of the first reaction chamber 21 is connected to the air inlet of the second reaction chamber 22; the air outlet of the first reaction chamber 21 is connected to the air outlet of the second reaction chamber 22; when in use, the gas in the first air inlet chamber 11 enters the first reaction chamber 21, and the gas in the second reaction chamber 22 enters the second reaction chamber 22; the wind speed in the first air inlet chamber 11 is greater than the wind speed in the second reaction chamber 22.

[0034] The air inlet of the first reaction chamber 21 is connected to the air inlet of the second reaction chamber 22; the air outlet of the first reaction chamber 21 is connected to the air outlet of the second reaction chamber 22; when in use, the gas in the first air inlet chamber 11 enters the first reaction chamber 21, and the gas in the second reaction chamber 22 enters the second reaction chamber 22; the wind speed in the first air inlet chamber 11 is greater than the wind speed in the second reaction chamber 22, so that an air flow circulation is formed inside the reaction tube 2, achieving sufficient contact reaction between the lignite tail gas and the oxygen carrier, and effectively improving the hydrogen production efficiency of the lignite tail gas.

[0035] Further preferably, a first air distribution plate 4 is provided between the air inlet pipe 1 and the reaction pipe 2; a second air distribution plate 5 is provided between the reaction pipe 2 and the return pipe 3; and a third air distribution plate 6 is provided at the outlet of the return pipe 3. The first air distribution plate 4 can effectively prevent the oxygen carrier from flowing into the air inlet pipe 1, the second air distribution plate 5 can effectively prevent the oxygen carrier from being brought into the return pipe 3 by the air flow, and the third air distribution plate 6 can fully prevent part of the oxygen carrier from flowing out of the reaction pipe 2.

[0036] A plurality of partitions 24 are provided in the reaction tube 2; the plurality of partitions 24 are arranged along the length direction of the reaction tube 2; the bottom end of the partition 24 close to the first air distribution plate 4 is arranged with a gap with the first air distribution plate 4, and the top end of the partition 24 close to the second air distribution plate 5 is arranged with a gap with the second air distribution plate 5. The plurality of partitions 24 are arranged at even intervals.

[0037] like Figure 3 As shown, in a more preferred embodiment, the volumes of the first reaction chamber 21 and the second reaction chamber 22 are equal, that is, a plurality of partitions 24 are arranged along a symmetric axis in a length direction of the reaction tube 2 to divide the reaction tube 2 into two equal parts.

[0038] In a more preferred embodiment, a plurality of ribs 23 are provided along the reaction tube 2; any one of the ribs 23 is extended along the length direction of the reaction tube 2. The plurality of ribs 23 are evenly spaced along the inner wall of the reaction tube 2. The number of the ribs 23 provided in the reaction tube 2 is 3 to 5. The plurality of ribs 23 are provided on one side of the first reaction chamber 21. The ribs 23 include a first side wall 231 and a second side wall 232, wherein the first side wall 231 is connected to the inner wall of the reaction tube 2; and the second side wall 232 is a wave structure.

[0039] A semi-coke tail gas chemical chain hydrogen production system has the advantages of simple structure and no need for complex separation and purification devices, which effectively solves the problem of many impurities in semi-coke tail gas and avoids high energy consumption caused by multi-stage separation and purification. The use of an internal circulation fluidized bed does not need to worry about the control problem of the return device. The operation is relatively simple and only requires a solid particle oxygen carrier, which reduces the use of catalysts and adsorbents. It does not require a complex hydrogen purification process and can directly condense to obtain pure hydrogen. The fuel does not come into direct contact with oxygen, and the emission of polluted gases is small. It can achieve The capture and production of hydrogen from lignite tail gas is an environmentally friendly and resource-based method that helps reduce industrial emissions and waste generation. The pure hydrogen produced can be used as a supplement to clean energy and help optimize the energy structure.

[0040] Example 2 In order to further explain the blue carbon tail gas chemical chain hydrogen production system of the present invention, this embodiment is used to illustrate: like Figure 4 As shown, a system for producing hydrogen from a chemical chain of semi-coke tail gas includes a purification tank, an air compressor, a flow meter, a gas detector, a pressure sensor, a gas-solid separator, a cooler, a thermocouple, an internal circulating fluidized bed and a preheater. The purification tank is used to remove tar and dust from the semi-coke tail gas, leaving the gas to participate in the chemical chain hydrogen production reaction. The semi-coke tail gas is pressurized by an air compressor to meet the pressure drop of the entire system. The internal circulating fluidized bed is used, and the stability and gas production quality of the internal circulating fluidized bed are better than those of the external circulating fluidized bed. At the same time, there is no need to worry about the control problem of the return device, and the operation is relatively simple. The semi-coke tail gas is input into the preheater in two pipelines, and the two routes are divided into two routes to pass through the preheater to generate a pressure difference through diversion, which promotes its circulation in the fluidized bed. The preheater heats the semi-coke tail gas to 800°C, and then enters the internal circulating fluidized bed, so that the semi-coke tail gas fully reacts with the oxygen carrier in the internal circulating fluidized bed, and only one oxygen carrier is required, reducing the use of catalysts and adsorbents.

[0041] In addition, in the present invention, before the inner circulating fluidized bed is opened, the lignite tail gas purified by the purification tank should be tested and qualified before the valve is opened to enter the preheater to prevent the lignite tail gas impurities from affecting the activity of the oxygen carrier in the inner circulating fluidized bed.

[0042] The internal circulating fluidized bed adopts a wall rib structure. By increasing the heat exchange area and enhancing fluid flow, the wall rib can significantly improve the heat exchange efficiency and reduce energy consumption.

[0043] The internal circulating fluidized bed adopts a partition design, that is, a partition 24 is set in the reaction tube 2. The partition 24 divides the fluidized bed, that is, the reaction tube 2, into two parts. At the same time, there is a gap between the partition 24 and the first air distribution plate 4, so that the bottom of the fluidized bed is connected. When working, air is blown through two high and low air distribution chambers, that is, the first air inlet chamber 11 and the second air inlet chamber 12. The wind speed in the first air inlet chamber 11 is greater than the wind speed in the second reaction chamber 22, so that a high-speed air distribution area is formed in the first reaction chamber 21, forming a bubbling bed, and a low-speed air distribution area is formed in the second reaction chamber 22, forming a moving bed. Above the partition 24, the oxygen carrier flows back from the high-speed area to the low-speed area, and below the partition 24, the oxygen carrier flows from the low-speed area to the high-speed area through the gap at the bottom of the partition 24, thereby forming an internal circulation flow of the material in the bed, effectively increasing the contact time between the semi-coke tail gas and the oxygen carrier.

[0044] In addition, the lignite tail gas enters the cooler for cooling after the reaction, and then passes through the gas-solid separator to remove the solid particles carried by the lignite tail gas, and the lignite tail gas flows back to the main pipeline.

[0045] When using this system, after the first reaction of the lignite tail gas, nitrogen is used to purge the inner circulating fluidized bed and the lignite tail gas in the pipeline. The time can be preferably 5 minutes. Then the nitrogen carries water vapor into the inner circulating fluidized bed. The water vapor reacts with the oxygen carrier to generate high-purity hydrogen, which is then cooled in a cooler and flows back to the lignite tail gas main pipeline.

[0046] The lignite tail gas flowing back from the gas-solid separator to the main pipeline needs to be gas tested.

[0047] Example 3 The present invention adopts As an oxygen carrier, the following are the main chemical reactions for producing hydrogen from the chemical chain of semi-coke tail gas:

[0048]

[0049]

[0050] raw material Entering the inner circulating fluidized bed, oxygen carrier (in oxygen-rich state) oxidation, combustion reaction occurs to produce and The generated products enter the gas-solid separator, where the gas phase products only need to be simply condensed to obtain a higher purity ,accomplish Low-cost capture of Restored to Then water vapor is introduced and reacts with water vapor to generate hydrogen. Oxidation After passing through the gas-solid separator and condensation equipment, high-purity hydrogen can be obtained. Finally, air is introduced. Due to the strong oxidizing ability of air, Completely oxidized to After passing through the gas-solid separator, the air after the reaction is discharged. The whole process is carried out in an internal circulating fluidized bed. The meteorological products will carry trace solid particles when discharged. After passing through the gas-solid separator, the solid particles remain in the separator, and the gas products are discharged. The present invention solves the problem of many impurities in the semi-coke tail gas, avoids the high energy consumption of multi-stage separation and purification of semi-coke tail gas, is conducive to obtaining a cheap hydrogen source that is not polluted by carbon, and realizes the high-quality utilization of semi-coke tail gas.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A blue coke tail gas chemical chain hydrogen production system, characterized in that: It comprises a preheater, an internal circulating fluidized bed and a gas-solid separator which are connected in sequence; the inlet end of the preheater is connected to the outlet pipeline of the blue coke tail gas; the internal circulating fluidized bed comprises an inlet pipe (1), a reaction pipe (2) and a reflux pipe (3) which are connected in sequence; The air inlet pipe (1) comprises a first air inlet chamber (11) and a second air inlet chamber (12); the reaction tube (2) comprises a first reaction chamber (21) and a second reaction chamber (22); The air inlet of the first reaction chamber (21) is connected to the air inlet of the second reaction chamber (22); the air outlet of the first reaction chamber (21) is connected to the air outlet of the second reaction chamber (22); When in use, the gas in the first air inlet chamber (11) enters the first reaction chamber (21), and the gas in the second reaction chamber (22) enters the second reaction chamber (22); the wind speed in the first air inlet chamber (11) is greater than the wind speed in the second reaction chamber (22).

2. A blue coke tail gas chemical chain hydrogen production system according to claim 1, characterized in that: A first air distribution plate (4) is provided between the air inlet pipe (1) and the reaction pipe (2); a second air distribution plate (5) is provided between the reaction pipe (2) and the return pipe (3); and a third air distribution plate (6) is provided at the outlet of the return pipe (3).

3. A blue carbon tail gas chemical chain hydrogen production system according to claim 2, characterized in that: A plurality of partitions (24) are provided in the reaction tube (2); the partitions (24) are arranged along the length direction of the reaction tube (2); a bottom end of the partition (24) close to the first air distribution plate (4) is arranged with a gap to the first air distribution plate (4), and a top end of the partition (24) close to the second air distribution plate (5) is arranged with a gap to the second air distribution plate (5).

4. A blue coke tail gas chemical chain hydrogen production system according to claim 1, characterized in that: The volumes of the first reaction chamber (21) and the second reaction chamber (22) are equal.

5. A blue coke tail gas chemical chain hydrogen production system according to claim 1, characterized in that: A plurality of ribs (23) are arranged along the reaction tube (2); any one of the ribs (23) is extended along the length direction of the reaction tube (2).

6. A blue carbon tail gas chemical chain hydrogen production system according to claim 5, characterized in that: A plurality of the ribs (23) are evenly spaced along the inner wall of the reaction tube (2).

7. A blue coke tail gas chemical chain hydrogen production system according to claim 5, characterized in that: The number of the ribs (23) arranged in the reaction tube (2) is 3 to 5.

8. A blue coke tail gas chemical chain hydrogen production system according to claim 5, characterized in that: A plurality of ribs (23) are arranged on one side of the first reaction chamber (21).

9. A blue coke tail gas chemical chain hydrogen production system according to claim 5, characterized in that: The rib plate (23) comprises a first side wall (231) and a second side wall (232); the first side wall (231) is connected to the inner wall of the reaction tube (2); and the second side wall (232) is a wave structure.

10. A blue coke tail gas chemical chain hydrogen production system according to claim 1, characterized in that: A plurality of thermocouples (7) are provided in the air inlet pipe (1), the reaction pipe (2) and the reflux pipe (3).

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