Hydrogen purification system with tower cutting function

Abstract

The utility model relates to the field of hydrogen purification, in particular to a hydrogen purification system with a tower cutting function. Comprising a plurality of adsorption towers including at least one standby adsorption tower; a plurality of interfaces of the heavy valve are respectively connected with the bottoms of the adsorption towers through branch pipelines at the bottoms of the adsorption towers; a plurality of interfaces of the light valve are respectively connected with the tops of the adsorption towers through partial branch pipelines at the tops of the adsorption towers; the tower bottom and the tower top of the standby adsorption tower are consistent with the adsorption towers respectively, valves are additionally arranged on the tower bottom and the tower top of the standby adsorption tower, the standby adsorption tower is connected with the adsorption towers through corresponding tower cutting pipelines, and the standby adsorption tower is connected through a subline pipeline and is controlled by the top valve and the bottom valve. When the efficiency of an adsorbent in the adsorption tower is reduced, the standby tower can be directly switched, purification production operation can be continuously completed, and the faulted adsorption tower is cut out to complete disposal, so that the situation of system production halt caused by the reduction of the efficiency of a single adsorption tower is effectively avoided, non-stop disposal is realized, and uninterrupted production of the hydrogen purification device is ensured.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen purification, and in particular to a hydrogen purification system with tower cutting function. Background Technology

[0002] Pressure swing adsorption (PSA) purification methods are highly adaptable and can be widely applied in the field of gas purification. Traditional PSA units are controlled by multiple programmable valves, which, due to frequent operation, can cause problems such as internal leakage or valve malfunction. r-PSA, however, perfectly solves these problems. r-PSA uses dual rotary valve control, with periodic rotation completing the desorption, regeneration, and gas production processes of each adsorption tower. The r-PSA process can only operate in a 6-tower mode; if one tower fails, production cannot proceed and a shutdown is necessary.

[0003] like Figure 1 As shown: The feed gas is connected to the heavy valve inlet of the rotary valve of the r-PSA unit through a pipeline. The heavy valve has 6 outlets, which are connected to the inlets of the 6 adsorption towers respectively. The generated desorbed gas is sent from the outlet of the heavy valve, the fuel gas is sent to the fuel gas pipeline network, the adsorption tower outlet is connected to the 6 inlets of the light valve, and the light valve outlet is connected to the product hydrogen pipeline.

[0004] In normal production, pressure swing adsorption (PSA) units can regenerate the adsorbent to a acceptable level through processes such as pressure reduction and purging. However, sometimes the adsorption efficiency of one adsorption tower decreases, or impurities penetrate or heavy components, or polar substances enter the pores of the adsorbent, making them difficult to remove. This reduces the adsorption capacity of one adsorption tower, significantly decreasing the overall PSA product recovery rate and increasing production costs. Furthermore, r-PSA production units experience long downtime, high costs, and high labor costs.

[0005] A typical pressure swing adsorption (PSA) unit, taking a 6-adsorption tower purification process as an example, can achieve a 6-3-1 mode (6 adsorption towers, 3 towers for regeneration, and 1 tower for gas production), and can also achieve a 5-2-1 mode (5 adsorption towers, 2 towers for regeneration, and 1 tower for gas production), and can disconnect a faulty adsorption tower. Utility Model Content

[0006] The purpose of this utility model patent is to overcome the shortcomings of the prior art and provide a hydrogen purification system with tower-cutting function, which uses a backup adsorption tower for continuous production, effectively avoiding system shutdown and speeding up the commissioning time.

[0007] The technical solution of this utility model patent is:

[0008] This utility model patent provides a hydrogen purification system with tower cutting function, including:

[0009] Multiple adsorption towers, including at least one standby adsorption tower;

[0010] The heavy valve has multiple interfaces that are connected to the bottom of each adsorption tower through the branch pipeline at the bottom of the adsorption tower. Each adsorption tower bottom branch valve is installed on the branch pipeline at the bottom of the adsorption tower. A tee and a bottom cutting tower branch pipeline are connected between the bottom branch valves of each adsorption tower and the heavy valve, and a bottom cutting tower pipeline valve is added.

[0011] The light valve has multiple ports that are connected to the top of each adsorption tower via branch pipelines at the top of the adsorption tower. A branch valve at the top of each adsorption tower is installed on the branch pipelines at the top of the adsorption tower. A tee and a top-cut-off branch pipeline are connected between the branch valves at the top of each adsorption tower and the light valve, and a valve is added to the top-cut-off pipeline.

[0012] The bottom and top of the backup adsorption tower are the same as those of each adsorption tower, and valves are added to each tower. The backup tower is connected to each adsorption tower through corresponding tower-cutting pipelines.

[0013] Furthermore, the bottom of the standby adsorption tower is equipped with a drain valve for discharging gas from the tower during the tower-cutting operation.

[0014] Furthermore, the backup adsorption tower is connected via a secondary pipeline and controlled by top and bottom valves.

[0015] Furthermore, the system also includes an online analyzer installed on the product pipeline to monitor the adsorption effect of each adsorption tower and the product hydrogen index in real time, so as to promptly detect adsorption towers with declining adsorption efficiency and trigger tower-switching operations.

[0016] Furthermore, the valve is a manual valve.

[0017] The raw gas is connected to the first port of the heavy valve via the raw gas pipeline. The six ports of the heavy valve are connected to the bottom of the adsorption tower via branch pipelines at the bottom of the adsorption tower. Bottom branch valves of the adsorption tower are installed on the bottom pipelines of the adsorption tower. A tee is connected to the bottom branch pipeline between each bottom branch valve and the heavy valve, and a bottom cut-off branch pipeline is connected to it. A bottom cut-off pipeline valve is added. The bottom and top of the standby adsorption tower are the same as the adsorption tower, and valves are added to both. The top of the adsorption tower is connected to the six ports of the light valve via branch pipelines at the top of the adsorption tower. A top branch valve of the adsorption tower is installed on the top branch pipeline. The seventh port of the light valve is connected to the main product gas pipeline. A tee is connected to the top branch pipeline between each top branch valve and the light valve, and a top cut-off branch pipeline is connected to it. A top cut-off pipeline valve is added.

[0018] When the adsorption efficiency of an adsorption tower decreases, manifested as a decrease in recovery rate, excessive hydrogen content in the product of a single adsorption tower, or a decrease in production load, the adsorption tower with the decreased absorption efficiency is switched off and a backup adsorption tower is started. At the same time, the adsorption tower with low absorption efficiency is treated by closing the top and bottom branch valves of the low-efficiency adsorption tower and opening the top and bottom branch valves of the backup adsorption tower, as well as the valves on the corresponding disconnected tower pipeline.

[0019] This utility model patented switching tower purification system is applicable to all pressure swing adsorption purification processes, as well as traditional pressure swing adsorption devices.

[0020] The advantages and positive effects of this invention are:

[0021] 1. This utility model can complete the treatment of low-efficiency adsorption towers without stopping the purification system, effectively avoiding losses caused by production stoppage and speeding up the commissioning time.

[0022] 2. This utility model can sequentially cut out multiple adsorption towers, gradually completing the treatment of each adsorption tower. The operation is simple and reduces the adverse impact on downstream customers caused by product supply disruptions.

[0023] 3. The backup adsorption tower in this utility model can store a portion of high-purity gas and complete the pressurization and protection of other towers one by one. Attached Figure Description

[0024] Figure 1 : The original r-PSA flowchart;

[0025] Figure 2 Flowchart of r-PSA switching tower;

[0026] Among them: 1-Q adsorption tower (standby tower) bottom valve, 2-Q adsorption tower (standby tower) bottom drain valve, 3-Q adsorption tower (standby tower) top valve, 4-Q adsorption tower (standby tower) and ABCDEF adsorption tower top valve, 5-Q adsorption tower (standby tower) and ABCDEF adsorption tower bottom valve, 6-ABCDEF adsorption tower bottom valve, 7-ABCDEF adsorption tower bottom drain valve, 8-ABCDEF adsorption tower top valve, 9-Q adsorption tower (standby tower) top and bottom valves, 10-analyzer, LV1-light valve, HV1-heavy valve. Detailed Implementation

[0027] In this invention, the adsorption towers are A, B, C, D, E, F, and Q (as a backup adsorption tower). For ease of description, only A, B, C, and Q will be used in the explanation. The point is that A, B, C, D, E, and F are all connected to Q (as a backup adsorption tower), and Q has the ability to replace A and B adsorption towers.

[0028] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0029] like Figure 2 The purification system with a tower cutter shown, taking the purification of hydrogen by r-PSA as an example, has the following process flow: the raw gas enters the first port of the heavy valve HV1 through the raw gas pipeline. The six ports of the heavy valve HV1 are connected to the bottom valve 6 of the ABCDEF adsorption tower through the branch pipeline at the bottom of the adsorption tower. The bottom valve 5 of the Q adsorption tower (standby tower) is connected to the bottom valve 1 of the Q adsorption tower (standby tower). The top pipeline of the Q adsorption tower (standby tower) is connected to the port of the light valve LV1 of the top valve 8 of the ABCDEF adsorption tower. Finally, the product gas enters the chromatogram for testing and analysis to determine whether the components are qualified. The top valve 4 of the Q adsorption tower (standby tower) is connected to the top valve 3 of the Q adsorption tower (standby tower); the bottom pipeline of the Q adsorption tower (standby tower) is connected to the bottom valve 6 of the ABCDEF adsorption tower; the bottom drain valve 2 of the Q adsorption tower (standby tower) and the bottom drain valve 7 of the ABCDEF adsorption tower are for external discharge, generally discharged to the flare; the top and bottom valves 9 of the Q adsorption tower (standby tower) can realize the system series connection, connecting the top gas of the ABCDEF adsorption tower or the Q adsorption tower (standby tower) to the bottom of the adsorption tower to be replaced.

[0030] A method for a purification system with a switching tower includes the following steps:

[0031] When the adsorbent is normal and the unit is in normal production, close the bottom valve 1, bottom drain valve 2, top valve 3, top valve 4 of the Q adsorption tower (standby tower) and the ABCDEF adsorption towers, bottom valve 5 of the Q adsorption tower (standby tower) and the ABCDEF adsorption towers, and bottom drain valve 7 of the ABCDEF adsorption tower; open the bottom valve 6 of the ABCDEF adsorption tower and the top valve 8 of the ABCDEF adsorption tower; This achieves the following functions and... Figure 1 Consistent.

[0032] When the adsorption efficiency of the adsorbent decreases, resulting in a decrease in the overall recovery rate, the system analyzer 10 detects the adsorption tower with low recovery and purification efficiency. If the hydrogen index of the product from a single adsorption tower exceeds the standard, the tower switching purification system can be activated to address the adsorption tower failure without interrupting the PSA unit. Taking the low efficiency of adsorption tower A in the ABCDEF adsorption tower as an example, adsorption tower A needs to be switched out, and adsorption tower Q (the backup tower) should be put into operation to replace adsorption tower A and complete the purification work.

[0033] The working steps of the tower cutter purification system are as follows:

[0034] 1) Pressure replenishment of Q adsorption tower (standby tower)

[0035] The purification system actively reduces its load to replenish the pressure of the standby adsorption tower. It opens the top valve 3 of the Q adsorption tower (standby tower), and the valves connected to the top valves of the A adsorption tower (standby tower) and the A adsorption tower (ABCDEF adsorption tower) (4) are slowly opened. This allows qualified product hydrogen to slowly enter the Q adsorption tower (standby tower) from the top valve 3. After the pressure stabilizes, the valves connected to the A adsorption tower (standby tower) and the top valves of the A adsorption tower (4) are fully opened.

[0036] 2) Cut out adsorption tower A

[0037] When the A adsorption tower completes the purification process and the internal pressure begins to drop, open the bottom valve 1 of the Q adsorption tower (standby tower) and the valve connecting the Q adsorption tower (standby tower) to the bottom valve 5 of the ABCDEF adsorption tower, which connects to the A adsorption tower. Close the A adsorption tower valve in the bottom valve 5 of the ABCDEF adsorption tower and the A adsorption tower valve in the top valve 8 of the ABCDEF adsorption tower. Discharge the hydrogen inside the A adsorption tower to the flare system through the A adsorption tower drain valve 7 of the ABCDEF adsorption tower, and then replace it with nitrogen.

[0038] 3) Recovery after treatment of adsorption tower A

[0039] Nitrogen gas is introduced from the A adsorption tower drain valve 7 of the ABCDEF adsorption tower to pressurize and replace the A adsorption tower. After the oxygen is qualified, the load of the overall PSA is reduced. The A adsorption tower top valve 8 of the ABCDEF adsorption tower is opened, and the A adsorption tower valve of the Q adsorption tower (standby tower) and the A adsorption tower top valve 4 of the ABCDEF adsorption tower are slowly opened. After slowly increasing the pressure, the Q adsorption tower (standby tower) and the A adsorption tower top valve 4 of the ABCDEF adsorption tower are closed. The gas is discharged to the flare from the A adsorption tower drain valve 7 of the ABCDEF adsorption tower bottom. After the sample in the adsorption tower is qualified, it is pressurized to the maximum pressure. While waiting for the Q adsorption tower (standby tower) to complete the purification process and start depressurization, the gas is connected to the A adsorption tower. At the same time, the Q adsorption tower (standby tower) top valve 3 is closed.

[0040] 4) Q Adsorption Tower (Standby Tower) Protection

[0041] After the system stabilizes, open valve 1 at the bottom of the Q adsorption tower (standby tower). Once the pressure drops to its lowest level, slowly open either valve 4 at the top of the Q adsorption tower (standby tower) or the ABCDEF adsorption tower. After pressurizing and protecting the Q adsorption tower (standby tower), close either valve 4 at the top of the Q adsorption tower (standby tower) or the ABCDEF adsorption tower. At the same time, close valve 1 at the bottom of the Q adsorption tower (standby tower) and valve 3 at the top of the Q adsorption tower (standby tower).

[0042] To monitor the adsorption efficiency and product hydrogen index of each adsorption tower in real time, and to promptly identify adsorption towers with declining adsorption efficiency and trigger tower-switching operations, the system also includes an online analyzer installed on the product pipeline.

[0043] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model, and these all fall within the protection scope of this patent.

Claims

1. A hydrogen purification system with a chopper function, characterized by, The system comprises: a plurality of adsorption towers, including at least one standby adsorption tower; a heavy valve, a plurality of interfaces of which are connected to the bottoms of the adsorption towers respectively through adsorption tower bottom branch pipelines, adsorption tower bottom branch valves are installed on the adsorption tower bottom branch pipelines respectively, and three-way pipes and bottom tower cutting branch pipelines are connected between the adsorption tower bottom branch valves and the heavy valve, and bottom tower cutting pipeline valves are added; a light valve, a plurality of interfaces of which are connected to the tops of the adsorption towers respectively through adsorption tower top branch pipelines, adsorption tower top branch valves are installed on the adsorption tower top branch pipelines, and three-way pipes and top tower cutting branch pipelines are connected between the adsorption tower top branch valves and the light valve, and top tower cutting pipeline valves are added; the bottoms and the tops of the standby adsorption tower are consistent with those of each adsorption tower, valves are added, and the standby adsorption tower is connected to each adsorption tower through corresponding tower cutting pipelines.

2. The hydrogen purification system of claim 1, wherein, The bottom of the standby adsorption tower is provided with a guide valve for discharging gas in the tower during tower cutting operation.

3. The hydrogen purification system of claim 1, wherein, The standby adsorption tower is connected through a secondary pipeline and is controlled by top and bottom valves.

4. The hydrogen purification system of claim 1, wherein, The system further comprises an online analyzer installed on a product pipeline for real-time monitoring of the adsorption effect of each adsorption tower and the product hydrogen index, so as to timely find an adsorption tower with decreased adsorption efficiency and trigger tower cutting operation.

5. The hydrogen purification system of claim 1, wherein, The valves are hand valves.

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