A pre-purification system and process for hydrogen production

Abstract

The application relates to the field of hydrogen production by pressure swing adsorption of raw coal gas, in particular to a pre-purification system and process for hydrogen production, which comprises a pre-purification tower, the pre-purification tower comprises a shell, the shell is provided with a gas inlet and a gas outlet, the shell is internally provided with a reagent storage box for placing an adsorbent, one end of the reagent storage box is provided with a discharge port, the inside of the reagent storage box is provided with a pushing assembly, the pushing assembly is used for pushing the adsorbent in the reagent storage box out of the discharge port, a feeding port is formed in the side wall of the reagent storage box, a flow guide plate is arranged between the outer side wall of the reagent storage box and the inner wall of the shell, the flow guide plate is used for guiding the adsorbent falling out of the discharge port to the feeding port, and the flow guide plate is made of polypropylene. The application can improve the adsorption effect of the adsorption layer, thereby improving the removal effect of the impurities in the raw coal gas by the purification tower.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hydrogen production from raw coal gas by pressure swing adsorption, and in particular to a pre-purification system and process for hydrogen production. BACKGROUND

[0002] Raw coal gas is a coal gasification product, usually composed of carbon monoxide, carbon dioxide, methane, ethane, etc., and contains a large amount of hydrogen. The extracted pure hydrogen can be used as an energy source for various equipment, such as being added to the engine to react with oxygen in the air to generate energy to drive the car to run, and can also be used as a raw material in various industrial production processes, such as manufacturing batteries, synthesizing chemicals, etc. The hydrogen extracted from raw coal gas can be used for various purposes in industrial production, such as synthesizing ammonia, synthesizing methanol, preparing organic chemicals, etc.

[0003] Currently, the industry usually uses vacuum pressure swing adsorption method to produce high-purity hydrogen from raw coal gas. Vacuum pressure swing adsorption method is a technology that uses pressure changes to realize gas adsorption and regeneration, thereby achieving gas separation. It generally sets an adsorption layer in the purification tower, and then makes the raw coal gas pass through the adsorption layer, thereby achieving the effect of removing impurities in the raw coal gas.

[0004] However, in the above technology, the adsorption layer near the inlet end of the purification tower first adsorbs the impurities in the raw coal gas, so the adsorption layer near the inlet end of the purification tower will reach adsorption saturation earlier than the adsorption layer near the outlet end of the purification tower, thereby reducing the adsorption effect of the entire adsorption layer. The regeneration process of the purification tower is to blow hot gas against the adsorption layer in the opposite direction of the movement of the raw coal gas, so that the impurities on the adsorption layer fall off, thereby restoring the adsorption capacity of the adsorption layer. However, the amount of impurities falling off from the adsorption layer near the inlet end is relatively small, so the adsorption effect of the entire adsorption layer is still reduced. SUMMARY

[0005] In order to improve the adsorption effect of the adsorption layer and thereby improve the removal effect of impurities in the raw coal gas by the purification tower, the present application provides a pre-purification system and process for hydrogen production.

[0006] The pre-purification system for hydrogen production provided by the present application adopts the following technical solution:

[0007] The utility model provides a kind of pre-purification system for hydrogen production, including pre-purification tower, the pre-purification tower includes shell, gas inlet and gas outlet are provided on the shell, the inside of shell is provided with the storage agent box for placing adsorbent, one end of the storage agent box is provided with discharge port, the inside of the storage agent box is provided pusher assembly, the pusher assembly is used to push adsorbent in storage agent box from discharge port, inlet is opened on the lateral wall of the storage agent box, guide vane is arranged between the outside wall of storage agent box and the inner wall of shell, the guide vane is used to guide adsorbent that falls from discharge port to inlet, the guide vane is made of polypropylene.

[0008] By adopting the above technical scheme, when the raw coal gas enters the inside of the shell from the gas inlet on the shell, the pusher assembly is started, the adsorbent in the storage agent box is pushed out from the discharge port on the storage agent box, the adsorbent pushed out from the discharge port of the storage agent box falls to the guide vane, and then the guide vane guides the adsorbent falling out from the storage agent box to the inside of the storage agent box from the inlet on the storage agent box. Thus, the adsorbent in the storage agent box is in a flowing state all the time, so that the raw coal gas entering the inside of the shell can be in full contact with all the adsorbent as much as possible, thereby making the saturation of the adsorbent at different places relatively average and maximizing the adsorption effect of the adsorbent, so as to improve the adsorption effect of the adsorption layer and the removal effect of the pre-purification tower on impurities in the raw coal gas. In addition, the guide vane is made of polypropylene, which can pass through gas but not solid particles, so that the raw coal gas can pass through but the adsorbent cannot, thereby not affecting the normal flow of the gas. In addition, the distribution of impurities on the adsorbent is also relatively uniform, so that when the pre-purification tower is in a regeneration state, the amount of impurities falling off all the adsorbent is also relatively average, and the falling-off effect of the impurities is better, so as to ensure that the adsorbent also has a good adsorption effect in the next adsorption process, thereby prolonging the service life of the adsorbent.

[0009] Optionally, the pusher assembly includes a screw rod and a driving device, the screw rod is rotationally connected to the inner wall of the shell, and the driving device is connected with the screw rod and used to drive the screw rod to rotate along its axis.

[0010] By adopting the above technical scheme, when it is needed to push the adsorbent in the storage agent box out of the storage agent box, the driving device is started, the screw rod is driven to rotate by the driving device, and the adsorbent at the bottom of the storage agent box is pushed upward by the screw rod when it rotates, so that the adsorbent at the upper part falls off from the discharge port, thereby realizing the pushing effect of the pusher assembly.

[0011] Optionally, the gas inlet is located below the shell, and the gas outlet is located above the shell.

[0012] By adopting the technical scheme, since the mass of hydrogen is smaller than that of air, after the raw coal gas is adsorbed by the adsorbent, the gas with a high hydrogen content can be discharged from the gas outlet on the shell, so as to improve the flow rate of the raw coal gas, thereby improving the efficiency of the pre-purification tower in removing impurities from the raw coal gas.

[0013] Optionally, the gas inlet is located above the shell and opposite to the discharge outlet, and the gas outlet is located below the shell.

[0014] By adopting the technical scheme, when the raw coal gas enters the shell from the gas inlet, the raw coal gas first contacts the adsorbent at the discharge outlet of the storage box, and then the adsorbent after contacting the raw coal gas is immediately pushed out by the pushing assembly, and then the relatively clean adsorbent in the storage box is pushed to the discharge outlet, and the cycle is repeated, and each time the relatively clean adsorbent contacts the raw coal gas, so that the impurities in the raw coal gas are removed more completely, thereby improving the adsorption effect of the adsorbent; in addition, since the raw coal gas after being adsorbed by the adsorbent is relatively light in mass, the raw coal gas after being adsorbed by the adsorbent is pushed by the following raw coal gas to move downward, at this time, the flow rate of the raw coal gas is relatively slow, so the contact time with the adsorbent is longer, the adsorption effect of the adsorbent on the raw coal gas is better, and the moving direction of the adsorbent in the storage box is opposite to the flow direction of the gas, so the adsorbent can form resistance to the flow of the raw coal gas, thereby further slowing down the flow rate of the raw coal gas, so the contact time with the adsorbent is further lengthened, thereby further improving the adsorption effect of the adsorbent.

[0015] Optionally, a plurality of inclined plates are arranged between the storage box and the shell, and the plurality of inclined plates are located above the guide plates, and a gap is left between the plurality of inclined plates and the side wall of the storage box or the shell.

[0016] By adopting the technical scheme, on the one hand, the arrangement of the inclined plates causes the adsorbent to be layered in the space inside the shell, thereby increasing the contact area between the adsorbent and the raw coal gas, thereby improving the adsorption effect of the adsorbent; on the other hand, the arrangement of the inclined plates prolongs the time for the adsorbent to fall from the discharge outlet to the inlet, thereby lengthening the contact time between the adsorbent and the raw coal gas, and further improving the adsorption effect of the adsorbent as a whole.

[0017] Optionally, the length of the gap is 1 / 3-1 / 4 of the shortest distance between the shell and the storage box.

[0018] By adopting the technical scheme, on one hand, the adsorbent on the last layer of the inclined plate stays on the inclined plate for a longer time, thereby prolonging the time for the adsorbent to drop from the discharge port to the feeding port, and further improving the adsorption effect of the adsorbent; on the other hand, the notch length is set to make the adsorbent on the last layer drop on the highest position of the next layer of the inclined plate, so that the adsorbent can cover the upper surface of the inclined plate as much as possible, and the situation that the adsorbent is accumulated at a certain position of the inclined plate is prevented as much as possible, thereby ensuring the smoothness of the flow of the adsorbent.

[0019] Optionally, the plurality of inclined plates are uniformly and crossly arranged along the vertical direction.

[0020] By adopting the technical scheme, due to the uniform and cross arrangement of the plurality of inclined plates, the speed of the adsorbent in the flow process is relatively average, thereby further ensuring the smoothness and stability of the flow of the adsorbent.

[0021] Optionally, the tail end of the inclined plate extends a straight plate, and the straight plate is arranged along the horizontal direction.

[0022] By adopting the technical scheme, due to the influence of the gravitational acceleration, the speed of the adsorbent in the flow process on the inclined plate is faster and faster, and the speed of the adsorbent in the flow process is slowed down by the arrangement of the straight plate, thereby prolonging the time for the adsorbent to drop from the discharge port to the feeding port, and further improving the adsorption effect of the adsorbent.

[0023] A pre-purification system for hydrogen production further comprises:

[0024] An air inlet pipe;

[0025] An air outlet pipe;

[0026] Pre-purification towers, the pre-purification towers are the pre-purification towers described above, and at least three pre-purification towers are provided, and the at least three pre-purification towers are connected in parallel and are in communication with the air inlet pipe and the air outlet pipe;

[0027] Coolers, at least two coolers are provided, the at least two coolers are connected in parallel and are in communication with the pre-purification towers;

[0028] A desorption gas separation tank, one end of the desorption gas separation tank is in communication with the at least two coolers, and the other end of the desorption gas separation tank is in communication with an out-of-boundary pipe network;

[0029] A desorption gas pipe, one end of the desorption gas pipe is in communication with the pre-purification tower, and a gas source is connected to one end of the desorption gas pipe;

[0030] A heater, the heater is in communication with the pre-purification tower through the desorption gas pipe.

[0031] By adopting the above technical scheme, the setting of the pre-purification tower greatly improves the adsorption effect of the adsorbent on the impurities in the raw coal gas, and also prolongs the service life of the adsorbent, on the one hand, thereby improving the removal effect of the system on the ammonia, tar, benzene, naphthalene and sulfides and other impurities in the raw coal gas as a whole, thereby minimizing the probability of corrosion and blockage of the subsequent pipelines and equipment; on the other hand, the service life of the adsorbent is increased, the frequency of replacing the adsorbent is reduced, and the cost of operating the device is reduced.

[0032] A pre-purification process for hydrogen production, comprising the following steps:

[0033] S1: open the gas inlet pipe, and start the driving device in the pre-purification tower,

[0034] S2: when the adsorbent in the pre-purification tower is in a saturated state, close the gas inlet pipe, and open the desorption gas pipe and the heater,

[0035] S3: after the adsorbent is desorbed, stop the heater, and keep the desorption gas pipe open,

[0036] S4: after the adsorbent is cooled to the adsorption temperature, open the cooler and the desorption gas separation tank.

[0037] By adopting the above technical scheme, first, the gas inlet pipe is opened, so that the raw coal gas enters the pre-purification tower, and the driving device is started, and the adsorbent in the storage box is driven to be in a flowing state by the screw rod, thereby improving the contact area and contact time of the adsorbent and the raw coal gas, and improving the adsorption effect of the adsorbent on the impurities in the raw coal gas;

[0038] When the adsorbent is in a saturated state, the heater is started and the desorption gas of the desorption gas pipe is heated to about 150℃, and then the adsorption layer is swept against the adsorption direction, so that a large amount of tar, HCN, ammonia, benzene, naphthalene and other aromatic compounds are completely desorbed under heating. At this time, the adsorbent is still in a flowing state, which improves the contact area and contact time of the adsorbent and the desorption gas, and improves the effect of the desorption gas on removing the impurities on the adsorbent;

[0039] After desorption, stop heating the desorption gas, and continue to use normal temperature desorption gas to sweep the adsorption bed against the gas inlet direction, so that it is cooled to the adsorption temperature for the next use of the adsorbent.

[0040] In summary, the present application has at least one of the following beneficial technical effects:

[0041] 1. The arrangement of the pushing assembly makes the adsorbent in the storage box always in a flowing state, thus the raw coal gas entering the shell can be in full contact with all the adsorbent as much as possible, so that the saturation of the adsorbent everywhere is relatively average, and the adsorption effect of the adsorbent is maximized, thereby improving the adsorption effect of the adsorption layer, and thus improving the removal effect of the impurities in the raw coal gas by the purification tower; in addition, when the pre-purification tower is in a regeneration state, the amount of impurities falling off all the adsorbent is also relatively average, and the falling-off effect of the impurities is also better, so as to ensure that the adsorbent also has a good adsorption effect in the next adsorption process, thereby prolonging the service life of the adsorbent.

[0042] 2. On the one hand, the arrangement of the inclined plate makes the adsorbent layered in the space inside the shell, thereby increasing the contact area of the adsorbent with the raw coal gas, and thus improving the adsorption effect of the adsorbent; on the other hand, the arrangement of the inclined plate prolongs the time of the adsorbent falling from the discharge port to the feeding port, thereby prolonging the contact time of the adsorbent with the raw coal gas, and further improving the adsorption effect of the adsorbent as a whole.

[0043] 3. The gas inlet is arranged above the shell and opposite to the discharge port, so that the raw coal gas is in contact with the relatively clean adsorbent each time, so that the impurities in the raw coal gas are removed more thoroughly, thereby improving the adsorption effect of the adsorbent; the moving direction of the adsorbent in the storage box is opposite to the flow direction of the gas, so that the adsorbent can form resistance to the flow of the raw coal gas, thereby further slowing down the flow speed of the raw coal gas, and thus further prolonging the contact time with the adsorbent, thereby further improving the adsorption effect of the adsorbent. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is the overall structure schematic diagram of embodiment 1 of the present application.

[0045] Figure 2 is the overall structure schematic diagram of embodiment 1 of the present application.

[0046] Figure 3 is the structure schematic diagram of the storage box in embodiment 1 of the present application.

[0047] Figure 4 is the overall structure schematic diagram of embodiment 2 of the present application.

[0048] BRIEF DESCRIPTION OF DRAWINGS

[0049] 1, inlet pipe; 2, outlet pipe; 3, pre-purification tower; 31, shell; 32, inlet; 33, outlet; 34, reagent storage box; 341, outlet; 342, inlet; 343, deflector; 35, pushing assembly; 351, screw rod; 352, driving device; 36, inclined plate; 361, straight plate; 37, filter screen; 4, cooler; 5, desorption gas separation tank; 6, desorption gas pipe; 7, heater. DETAILED DESCRIPTION

[0050] The following will be described in detail with reference to the accompanying drawings Figures 1-4 The application is further described in detail.

[0051] Example 1

[0052] The embodiments of the application disclose a pre-purification system for hydrogen production. Figure 1 The pre-purification system for hydrogen production comprises an inlet pipe 1, an outlet pipe 2, pre-purification towers 3, a cooler 4, a desorption gas separation tank 5, a desorption gas pipe 6 and a heater 7.

[0053] The pre-purification towers 3 are provided in at least three, and only three are shown in the embodiments, and four or five can be provided according to actual conditions; the three pre-purification towers 3 are connected in parallel and communicate with the inlet pipe 1 and the outlet pipe 2. In normal operation, two pre-purification towers 3 are in an adsorption state, and one pre-purification tower 3 is in a regeneration state; when the load is low, one pre-purification tower 3 can be in an adsorption state, one pre-purification tower 3 can be in a regeneration state, and the remaining one can be in a maintenance or online adsorbent replacement state, so that the reliability and stability of the device operation can be greatly improved.

[0054] The cooler 4 is provided in at least two, and only two are shown in the embodiments; the two coolers 4 are connected in parallel and communicate with the pre-purification towers 3 through the outlet pipe 2. One is in operation and the other is in standby in normal production, but when the heat exchange effect of the cooler 4 is found to be reduced, the cooler 4 can be cut out of the system, and after the pre-purification cooler 4 is purged with steam, the two coolers 4 are used alternately.

[0055] One end of the desorption gas separation tank 5 communicates with the two coolers 4, and the other end of the desorption gas separation tank 5 communicates with an external pipe network.

[0056] One end of the desorption gas pipe 6 communicates with the pre-purification tower 3, one end of the desorption gas pipe 6 is connected with a gas source, and the heater 7 communicates with the pre-purification tower 3 through the desorption gas pipe 6.

[0057] When the pre-purification tower 3 is in the adsorption state, the raw coal gas enters the pre-purification tower 3 from the gas inlet pipe 1, and after the pre-purification treatment, the purified raw coal gas is discharged from the gas outlet pipe 2; when the pre-purification tower 3 is in the regeneration state, the heater 7 heats the desorption gas in the desorption gas pipe 6, and the heated desorption gas enters the pre-purification tower 3 from the desorption gas pipe 6, and removes the impurities on the surface of the adsorbent in the pre-purification tower 3, after the impurities are desorbed, the heating of the desorption gas is stopped, and the adsorption bed is swept in the opposite direction of the gas inlet with the normal temperature desorption gas to cool to the adsorption temperature, then the desorption gas mixed with impurities is cooled by the cooler 4, as the temperature of the desorption gas decreases, the tar, benzene, naphthalene and other impurities desorbed will be precipitated, and then the impurities are separated by the desorption gas liquid separator 5, and the regenerated desorption gas flows to the external pipe network.

[0058] With reference to Figure 2 The pre-purification tower 3 described above comprises a shell 31, and the shell 31 in the embodiment is a closed column as a whole, and in other alternative embodiments, the shell 31 can be square or the like.

[0059] The upper end surface of the shell 31 is provided with a gas outlet 33, and the gas outlet 33 on the shell 31 is also fixedly installed with a gas outlet pipe 2, and the lower end surface of the shell 31 is provided with a gas inlet 32, and the gas inlet 32 on the lower end surface of the shell 31 is provided with a gas inlet pipe 1. The gas inlet 32 in the embodiment is annular, and for the same reason, the gas inlet pipe 1 in the embodiment is also provided in the form of an annular pipe, and the annular pipe-shaped gas inlet pipe 1 can divide the raw coal gas into a certain amount, so that the raw coal gas can be relatively uniformly distributed in the shell 31, thereby facilitating the adsorption device to fully adsorb the impurities in the raw coal gas. Of course, in other alternative embodiments, the gas inlet 32 can also be provided in the form of a circle or a square, and the gas inlet pipe 1 can also be provided in the form of a circle or a square corresponding thereto.

[0060] With reference to Figure 3 The shell 31 is internally provided with a storage box 34 for placing adsorbent, in order to adapt to the shape of the shell 31, the storage box 34 in the embodiment is also provided in the form of a column, and the storage box 34 is coaxially arranged with the shell 31 and fixedly installed on the lower end of the shell 31, the upper end of the storage box 34 is provided with a discharge port 341, and a plurality of feeding ports 342 are formed on the side wall of the lower part of the storage box 34, the plurality of feeding ports 342 are uniformly and spacedly arranged around the axis of the storage box 34, and the feeding port 342 in the embodiment is provided in the form of a circle, and in other embodiments, it can be provided in the form of a square according to actual conditions. In addition, the adsorbent in the storage box 34 is in the form of a large number of granular blocks.

[0061] The inside of the storage box 34 is provided with a pushing assembly 35, and the pushing assembly 35 comprises a screw rod 351 and a driving device 352.

[0062] The screw rod 351 is rotationally connected to the lower end of the shell 31, and the screw rod 351 is coaxially arranged with the reagent box 34. The driving device 352 in the embodiment is a driving motor, which is fixedly installed on the lower end face of the shell 31, and the output shaft of the driving motor penetrates the shell 31 and is fixedly connected with the screw rod 351 coaxially. Of course, in other alternative embodiments, the driving device 352 can also be a combination of a cylinder and a gear, and other components capable of driving the screw rod 351 to rotate along its own axis.

[0063] A flow guide plate 343 is arranged between the outer side wall of the reagent box 34 and the inner wall of the shell 31. One end of the flow guide plate 343 is fixedly connected with the outer side wall of the reagent box 34, and the other end of the flow guide plate 343 is fixedly connected with the inner wall of the shell 31. The flow guide plate 343 is arranged obliquely along the direction close to the reagent box 34, and the end of the flow guide plate 343 close to the reagent box 34 is flush with the port wall of the lower part of the feed port 342, so that the flow guide plate 343 guides the adsorbent into the feed port 342.

[0064] Meanwhile, the flow guide plate 343 in the embodiment is made of polypropylene, and can also be made of ultra-thin film molecules and other materials. Such materials can allow gas to pass through, but cannot allow granular solids such as adsorbents to pass through.

[0065] In addition, in order to prevent the adsorbent from falling into the gas inlet pipe 1 through the joint gap between the flow guide plate 343 and the shell 31 or the reagent box 34 as much as possible, a filter screen 37 matching the shape of the gas inlet 32 is arranged at the gas inlet 32 of the shell 31. The filter screen 37 can allow raw gas to pass through, but cannot allow adsorbent to pass through.

[0066] When the raw gas passes through the gas inlet pipe 1 and enters the inside of the shell 31, the driving motor is started, and the driving motor drives the screw rod 351 to rotate, so that the screw rod 351 pushes the adsorbent in the reagent box 34 out of the discharge port 341 of the reagent box 34. The adsorbent pushed out of the discharge port 341 of the reagent box 34 falls onto the flow guide plate 343, and then the flow guide plate 343 guides the adsorbent falling out of the reagent box 34 into the reagent box 34 through the feed port 342 of the reagent box 34. In this way, the adsorbent in the reagent box 34 is always in a flowing state. The raw gas after being adsorbed is discharged from the gas outlet 33 and flows to the next device through the gas outlet pipe 2. Therefore, the raw gas entering the shell 31 can be in contact with all the adsorbents as much as possible, so that the saturation of the adsorbents at different positions is relatively average and the adsorption effect of the adsorbents is maximized, thereby improving the adsorption effect of the adsorption layer and the removal effect of the impurities in the raw gas by the pre-purification tower 3.

[0067] Furthermore, the guide plate 343 is made of polypropylene, which allows gas to pass through but not solid particles. Therefore, raw coal gas can pass through, but the adsorbent cannot, thus not affecting the normal flow of gas. In addition, the impurities on the adsorbent are relatively evenly distributed. Thus, when the pre-purification tower 3 is in the regeneration state, the amount of impurities detached from all the adsorbents is relatively even, and the detachment effect of impurities is also better, so as to ensure that the adsorbent has a good adsorption effect in the next adsorption process, thereby extending the service life of the adsorbent.

[0068] Continue to refer to Figure 3 To improve the removal effect of impurities in raw coal gas by the pre-purification tower 3, multiple inclined plates 36 are provided between the storage box 34 and the outer shell 31. In this embodiment, three inclined plates 36 are provided. In other optional embodiments, the number of inclined plates 36 can be set according to the actual situation. The three inclined plates 36 are all located above the guide plate 343, and the three inclined plates 36 are evenly and crosswise arranged in the vertical direction to ensure the smoothness and stability of the adsorbent during flow. The three inclined plates 36 are fixedly connected to the storage box 34, the outer shell 31, and the storage box 34 in sequence, and the three inclined plates 36 are all arranged at a downward inclination. There are gaps between the first layer of inclined plates 36 and the outer shell 31, between the second layer of inclined plates 36 and the storage box 34, and between the first layer of inclined plates 36 and the outer shell 31.

[0069] When the adsorbent falls from the outlet 341 of the storage box 34, it slides down the three inclined plates 36 onto the guide plate 343. On the one hand, the inclined plates 36 cause the adsorbent to be layered in the space inside the outer shell 31, thereby increasing the contact area between the adsorbent and the raw coal gas, thus improving the adsorption effect. On the other hand, the inclined plates 36 prolong the time it takes for the adsorbent to fall from the outlet 341 to the inlet 342, thereby lengthening the contact time between the adsorbent and the raw coal gas, and further improving the overall adsorption effect.

[0070] Secondly, the inclined plate 36 can also be made of materials such as polypropylene and ultra-thin film molecules to ensure that the raw coal gas can fully contact the adsorbent on the inclined plate 36, thereby enhancing the adsorption effect of the adsorbent.

[0071] The length of the gap is 1 / 3-1 / 4 of the shortest distance between the shell 31 and the agent storage box 34, so that the adsorbent on the upper inclined plate 36 can stay on the inclined plate 36 for a longer time, thereby prolonging the time for the adsorbent to fall from the discharge port 341 to the feeding port 342, and further improving the adsorption effect of the adsorbent. On the other hand, the length of the gap makes the adsorbent on the upper layer fall on the highest point of the lower inclined plate 36, so that the adsorbent can cover the upper surface of the inclined plate 36 as much as possible, preventing the adsorbent from accumulating on a certain position of the inclined plate 36, and ensuring the smooth flow of the adsorbent.

[0072] In addition, the tail end of the inclined plate 36 extends a straight plate 361, which is arranged in the horizontal direction.

[0073] Due to the influence of gravitational acceleration, the speed of the adsorbent flowing on the inclined plate 36 will become faster and faster. By arranging the straight plate 361, the speed of the adsorbent flowing can be slowed down, thereby prolonging the time for the adsorbent to fall from the discharge port 341 to the feeding port 342, and further improving the adsorption effect of the adsorbent.

[0074] Finally, it should be noted that since different impurities in the raw coal gas need to be specifically removed, the adsorption in the agent storage box 34 can be a mixture of multiple adsorbents, or multiple pre-purification towers 3 as described above can be arranged, and the adsorbents in each pre-purification tower 3 are different. Then, the multiple pre-purification towers 3 are connected in series or stacked from bottom to top to form a total pre-purification tower 3, so that different impurities in the raw coal gas can be fully absorbed.

[0075] Example 2

[0076] Referring to Figure 4 The difference between the embodiment of the present application and example 1 is that the gas outlet 33 above the shell 31 is arranged as a gas inlet 32, the gas inlet pipe 1 is arranged as a gas outlet pipe 2, the gas inlet 32 below the shell 31 is arranged as a gas outlet 33, the gas inlet pipe 1 is arranged as a gas outlet pipe 2, and the gas inlet 32 is directly opposite the discharge port 341 of the agent storage box 34. Therefore, the raw coal gas enters from the upper part of the shell 31, is adsorbed by the adsorbent, and is then discharged from the lower part of the shell 31.

[0077] When the raw coal gas enters the shell 31 from the gas inlet 32, the raw coal gas first contacts the adsorbent at the discharge port 341 of the agent storage box 34, and then the adsorbent after contacting the raw coal gas is immediately pushed out by the pushing assembly 35. Then, the relatively clean adsorbent in the agent storage box 34 is pushed to the discharge port 341, and the cycle is repeated. Each time, the relatively clean adsorbent contacts the raw coal gas, so that the impurities in the raw coal gas are removed more thoroughly, thereby improving the adsorption effect of the adsorbent.

[0078] In addition, since the raw coal gas that has passed through the adsorbent is relatively light in quality, the raw coal gas after being adsorbed by the adsorbent is pushed by the raw coal gas behind to move downward, at this time, the flow speed of the raw coal gas is relatively slow, and therefore, the contact time with the adsorbent is longer, and the adsorption effect of the adsorbent on the raw coal gas is better. In addition, the moving direction of the adsorbent in the storage box 34 is opposite to the flow direction of the gas, and therefore, the adsorbent can form resistance to the flow of the raw coal gas, so that the flow speed of the raw coal gas is further slowed down, and therefore, the contact time with the adsorbent is further lengthened, and therefore, the adsorption effect of the adsorbent is further improved.

[0079] Example 3

[0080] A pre-purification process for hydrogen production based on the above-mentioned pre-purification system, comprising the following steps:

[0081] S1: open the gas inlet pipe 1, and start the driving device 352 in the pre-purification tower 3.

[0082] S2: when the adsorbent in the pre-purification tower 3 is in a saturated state, close the gas inlet pipe 1, and open the desorption gas pipe 6 and the heater 7.

[0083] S3: after the desorption of the adsorbent is completed, stop the heater 7, and keep the desorption gas pipe 6 open.

[0084] S4: after the adsorbent is cooled to the adsorption temperature, open the cooler 4 and the desorption gas separation tank 5.

[0085] First, open the gas inlet pipe 1, so that the raw coal gas enters the pre-purification tower 3, and drive the driving device 352 to drive the adsorbent in the storage box 34 to be in a flowing state, thereby improving the contact area and contact time of the adsorbent with the raw coal gas, and thereby improving the adsorption effect of the adsorbent on the impurities in the raw coal gas.

[0086] When the adsorbent is in a saturated state, start the heater 7 and open the desorption gas pipe 6, and the desorption gas is heated to about 150°C and then blown against the adsorption direction to sweep the adsorption layer, so that a large amount of tar, HCN, ammonia, benzene, naphthalene and other aromatic compounds are completely desorbed under heating. At this time, the adsorbent is still in a flowing state, thereby improving the contact area and contact time of the adsorbent with the desorption gas, and thereby improving the effect of the desorption gas on the impurities on the adsorbent.

[0087] After the desorption is completed, stop heating the desorption gas, and continue to use normal temperature desorption gas to blow against the gas inlet direction to sweep the adsorption bed, so that it is cooled to the adsorption temperature for the next use of the adsorbent.

[0088] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: all equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. A pre-purification system for hydrogen production, characterized in that, include: Intake pipe (1); Air outlet (2); A pre-purification tower (3) is provided, at least three of which are connected in parallel and are all connected to the inlet pipe (1) and the outlet pipe (2); the pre-purification tower (3) includes a shell (31), an inlet (32) and an outlet (33) are provided on the shell (31), and a storage box (34) for placing adsorbent is provided inside the shell (31), and a discharge port (341) is provided at one end of the storage box (34). An internal pusher assembly (35) is provided, which is used to push the adsorbent in the storage box (34) out from the outlet (341). An inlet (342) is provided on the side wall of the storage box (34). A guide plate (343) is provided between the outer wall of the storage box (34) and the inner wall of the outer shell (31). The guide plate (343) is used to guide the adsorbent falling from the outlet (341) to the inlet (342). The guide plate (343) is made of polypropylene, and the guide plate (343) is made of polypropylene. One end of the guide plate (343) is fixedly connected to the outer wall of the storage box (34), and the other end of the guide plate (343) is fixedly connected to the inner wall of the outer shell (31). The guide plate (343) is arranged obliquely along the direction close to the storage box (34), and the end of the guide plate (343) close to the storage box (34) is flush with the lower part of the inlet wall of the feed port (342). A plurality of inclined plates (36) are provided between the storage box (34) and the outer shell (31), and the plurality of inclined plates (36) are all located above the guide plate (343). 36) A gap is left between the storage box (34) and the side wall or the outer shell (31); the length of the gap is 1 / 3 to 1 / 4 of the shortest distance between the outer shell (31) and the storage box (34); multiple inclined plates (36) are evenly and crosswise arranged in the vertical direction; the tail end of the inclined plate (36) extends into a straight plate (361), and the straight plate (361) is arranged in the horizontal direction; the air inlet (32) is located on the upper end face of the outer shell (31); the air outlet (33) is located on the lower end face of the outer shell (31); Cooler (4), at least two coolers (4) are provided, at least two coolers (4) are connected in parallel and are all connected to the pre-purification tower (3); Desorption gas separator (5); one end of the desorption gas separator (5) is connected to at least two of the coolers (4), and the other end of the desorption gas separator (5) is connected to the external pipeline network; Desorption pipe (6), one end of which is connected to the pre-purification tower (3), and the other end of which is connected to a gas source; the desorption pipe (6) is used to guide the desorption gas to purge the adsorbent in the opposite direction of the movement of the raw coal gas. The heater (7) is connected to the pre-purification tower (3) through the desorption pipe (6).

2. The pre-purification system for hydrogen production according to claim 1, characterized in that, The feeding assembly (35) includes a screw rod (351) and a driving device (352). The screw rod (351) is rotatably connected to the inner wall of the outer shell (31). The driving device (352) is connected to the screw rod (351) and is used to drive the screw rod (351) to rotate along its own axis.

3. The pre-purification system for hydrogen production according to claim 1, characterized in that, The air inlet (32) is directly opposite the discharge outlet (341).

4. A pre-purification process for hydrogen production, characterized in that, A pre-purification system for hydrogen production as described in any one of claims 1-3 is provided, comprising the following steps: S1: Open the air inlet pipe (1) and start the drive device (352) in the pre-purification tower (3) at the same time. S2: When the adsorbent in the pre-purification tower (3) is saturated, close the inlet pipe (1) and open the desorption pipe (6) and heater (7). S3: After the adsorbent has completely desorbed, stop the heater (7) and keep the desorption tube (6) open. S4: After the adsorbent has cooled to the adsorption temperature, turn on the cooler (4) and the desorption gas separator (5).

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