A safe absorption and purification utilization hydrogen recovery system and method

Abstract

The present application relates to a kind of safe absorption and purification hydrogen recovery system and method for utilization, solve the problem that the tail gas generated by existing aluminum sol device reaction cannot be well recovered, causes environmental pollution and causes resource waste simultaneously.Problems include aluminum sol reaction unit, nitrogen replacement unit, buffer unit, tail gas impurity absorption unit, nitrogen pressurizing system and gas separation unit, mixed gas is buffered and stored by buffer unit, then enters into primary absorption tower and is preliminarily absorbed, then flows into secondary absorption tower and is further absorbed, acid liquor formed by absorption condensation is discharged through discharge port, if oxygen content monitored by oxygen analyzer is unqualified, nitrogen pressurizing system is connected to secondary absorption tower and nitrogen is introduced, while gas is backflowed to buffer tank until oxygen content is qualified and backflowing stops;If oxygen content is qualified, mixed gas is introduced into gas separation unit for separation, so that hydrogen is safely recovered and utilized, and hydrogen chloride is absorbed and recovered to prevent environmental pollution.

Description

Technical Field

[0001] This invention relates to a hydrogen recovery system and method for safe absorption, purification, and utilization. Background Technology

[0002] Current aluminum sol devices mostly involve the chemical reaction of diluted hydrochloric acid with aluminum sheets (or blocks). Due to the instability of the reaction, the influence of impurities, and the difficulty in controlling the exothermic reaction, the hydrogen produced as a byproduct is simply treated along with water vapor and hydrogen chloride before being directly released into the atmosphere. Because of its simple processing flow rate and incomplete absorption of impurities such as hydrogen chloride, it causes environmental pollution. Furthermore, the direct release of hydrogen wastes energy. Given the current state of these devices and the development of similar hydrogen production processes, as well as environmental protection requirements, a safe absorption, purification, and utilization hydrogen recovery system has been researched and developed. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that the exhaust gas generated by the reaction in existing aluminum sol devices cannot be effectively recovered, causing environmental pollution and resource waste.

[0004] The technical solution adopted to solve the technical problem proposed in this invention is as follows: The hydrogen recovery system for safe absorption and purification of this invention includes an aluminum sol reaction unit and a nitrogen replacement unit for removing oxygen from the reaction unit before the reaction. The hydrogen recovery system also includes a buffer unit, a tail gas impurity absorption unit, a nitrogen pressurization system, and a gas separation unit. The buffer unit includes a buffer tank connected to the outlet of the reaction unit. The tail gas impurity absorption unit includes a primary absorption tower connected to the buffer tank and a secondary absorption tower connected to the primary absorption tower. The primary absorption tower has a first nozzle at the top, which is connected to a first demineralized water pipe. The secondary absorption tower has a drain port at the bottom and a second nozzle at the top. An oxygen analyzer is located at the top of the secondary absorption tower and connected to it. The nitrogen pressurization system is connected to the secondary absorption tower. The top of the secondary absorption tower is connected to both the buffer unit and the gas separation unit.

[0005] The method for safe absorption and purification of hydrogen using any of the above-described safe absorption and purification hydrogen recovery systems includes the following steps:

[0006] Step A: Before the reaction in the aluminum sol reaction unit, nitrogen gas is introduced into the system through the nitrogen replacement unit to remove the oxygen in the system;

[0007] Step B: The mixed gases of hydrogen chloride, hydrogen and water vapor produced by the aluminum sol reaction unit are passed into a buffer tank for buffer storage;

[0008] Step C: The mixed gas in the buffer tank then enters the primary absorption tower, where the first nozzle sprays demineralized water to cool the mixed gas and preliminarily absorb the hydrogen chloride and water vapor in it.

[0009] Step D: The mixed gas and acid flowing out of the primary absorption tower flow into the secondary absorption tower. The second nozzle sprays demineralized water to further cool the mixed gas and absorb the hydrogen chloride and water vapor in the mixed gas. The acid formed by absorption and condensation is discharged through the drain port. The oxygen analyzer at the top of the secondary absorption tower monitors the oxygen content of the mixed gas. If the oxygen content is not up to standard, the nitrogen pressurization system introduces nitrogen into the secondary absorption tower, and at the same time, the mixed gas in the secondary absorption tower is returned to the buffer tank until the oxygen content is up to standard and the return stops. If the oxygen content is up to standard, the mixed gas is introduced into the gas separation unit for separation.

[0010] The technical solutions that further define the present invention include:

[0011] The second nozzle is connected to the second desalination pipe.

[0012] The bottom of the secondary absorption tower is equipped with a pH analyzer, and a bottom circulation pump is provided between the drain outlet and the secondary absorption tower. The bottom circulation pump is connected to a circulation condenser, one end of which is connected to a second nozzle, and the other end of which is connected to a second demineralized water pipe.

[0013] The buffer unit also includes a first pressure gauge and a safety valve device located inside the buffer tank.

[0014] The nitrogen pressurization system includes a second pressure gauge and an automatic nitrogen replenishment valve assembly.

[0015] The nitrogen booster system also includes a hydrogen booster compressor.

[0016] In step D, a pH analyzer is installed at the bottom of the secondary absorption tower to monitor the pH value of the acid solution. A bottom circulation pump is installed between the drain port and the secondary absorption tower. The bottom circulation pump is connected to a circulating condenser. One end of the circulating condenser is connected to a second nozzle, and the other end is connected to a second demineralized water pipe. When the drain port is closed, the bottom circulation pump sends the acid solution into the circulating condenser. At the same time, the second demineralized water pipe introduces demineralized water into the circulating condenser. After the diluted acid solution enters the circulating condenser and is cooled, it is sprayed out through the second nozzle to completely absorb the hydrogen chloride and water vapor in the secondary absorption tower. Then, the drain port is opened to drain the solution.

[0017] In step D, the nitrogen pressurization system also includes a hydrogen pressurization compressor. When the pressure in the system is lower than a certain value, the hydrogen pressurization compressor is turned on to increase the pressure in the system.

[0018] Through the above technical solution, the beneficial effects of the present invention are as follows: In the hydrogen recovery system for safe absorption and purification of the present invention, the mixed gas generated by the aluminum sol reaction unit is buffered and stored in a buffer unit during recovery. The mixed gas in the buffer tank then enters the primary absorption tower for preliminary absorption. The mixed gas and acid flowing out of the primary absorption tower flow into the secondary absorption tower for further absorption. The acid formed by absorption and condensation is discharged through the drain port. An oxygen analyzer at the top of the secondary absorption tower monitors the oxygen content of the mixed gas. If the oxygen content is unqualified, a nitrogen pressurization system introduces nitrogen into the secondary absorption tower, while simultaneously recirculating the mixed gas in the secondary absorption tower back into the buffer tank until the oxygen content is qualified and the recirculation stops. If the oxygen content is qualified, the mixed gas is introduced into the gas separation unit for separation, thereby separating hydrogen and achieving safe recovery and utilization of hydrogen. Simultaneously, hydrogen chloride is absorbed and recovered to prevent environmental pollution. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a hydrogen recovery system for safe absorption, purification and utilization according to the present invention. Detailed Implementation

[0020] The structure of the present invention will be further described below with reference to the accompanying drawings.

[0021] Reference Figure 1 A safe absorption and purification hydrogen recovery system includes an aluminum sol reaction unit 1 and a nitrogen replacement unit 2 for removing oxygen from the reaction unit before the reaction. The hydrogen recovery system also includes a buffer unit 3, a tail gas impurity absorption unit 4, a nitrogen pressurization system 5, and a gas separation unit 6. The buffer unit 3 includes a buffer tank 31 connected to the outlet of the reaction unit. The tail gas impurity absorption unit 4 includes a primary absorption tower 41 connected to the buffer tank and a secondary absorption tower 42 connected to the primary absorption tower. The top of the primary absorption tower is provided with a first nozzle 411, which is connected to a first demineralized water pipe 412. The bottom of the secondary absorption tower 42 is provided with a drain port 421. The top of the secondary absorption tower is provided with a second nozzle 422. The top of the secondary absorption tower is provided with an oxygen analyzer 423 connected to the secondary absorption tower. The nitrogen pressurization system 5 is connected to the secondary absorption tower 42. The top of the secondary absorption tower is connected to both the buffer unit and the gas separation unit.

[0022] In this embodiment, the second nozzle is connected to the second demineralized water pipe 424 (422). The second demineralized water is sprayed out through the second nozzle to form a spray that reabsorbs water vapor and hydrogen chloride gas in the secondary absorption tower.

[0023] In this embodiment, a pH analyzer 425 is installed at the bottom of the secondary absorption tower 42. A bottom circulation pump 7 is installed between the drain port and the secondary absorption tower. The bottom circulation pump is connected to a circulating condenser 8. One end of the circulating condenser is connected to a second nozzle, and the other end is connected to a second demineralized water pipe. The pH analyzer 425 is used to analyze the concentration of the acid solution at the bottom of the secondary absorption tower. If the concentration is too low, the drain port is closed, the circulating condenser is turned on, and the acid solution at the bottom of the secondary absorption tower is pumped to the circulating condenser by the bottom circulation pump. At the same time, demineralized water is introduced into the circulating condenser through the second demineralized water pipe. After the diluted acid solution enters the circulating condenser and is cooled, it is sprayed out through the second nozzle to completely absorb the hydrogen chloride and water vapor in the secondary absorption tower. Then, the drain port is opened to drain the solution.

[0024] In this embodiment, the buffer unit further includes a first pressure gauge and a safety valve device located inside the buffer tank. The first pressure gauge is used to detect the pressure inside the buffer tank, and the safety valve device is mainly used for system safety to prevent overpressure.

[0025] In this embodiment, the nitrogen pressurization system includes a second pressure gauge and an automatic nitrogen replenishment valve assembly. When the oxygen analyzer detects that the oxygen concentration in the secondary absorption tower exceeds the standard, the automatic nitrogen replenishment valve assembly is used to replenish nitrogen into the secondary absorption tower. In addition, when the second pressure gauge detects that the pressure in the system is lower than a certain value, nitrogen can be replenished to increase the pressure in the system and prevent negative pressure from occurring in the system.

[0026] In this embodiment, the nitrogen pressurization system also includes a hydrogen pressurization compressor. When the second pressure gauge detects that the pressure inside the system is lower than a certain value, the pressure inside the system can be increased by the hydrogen pressurization compressor without adding nitrogen.

[0027] The method for safe absorption and purification of hydrogen using any of the above-described safe absorption and purification hydrogen recovery systems includes the following steps:

[0028] Step A: Before the aluminum sol reaction unit reacts, nitrogen gas is introduced into the system through the nitrogen replacement unit to remove the oxygen in the system; this prevents the oxygen generated in the reaction unit from reacting with hydrogen and causing an explosion.

[0029] Step B: The mixed gases of hydrogen chloride, hydrogen, and water vapor generated by the aluminum sol reaction unit are passed into a buffer tank for buffer storage. In this embodiment, the buffer unit also includes a first pressure gauge and a safety valve device located inside the buffer tank. The first pressure gauge is used to detect the pressure inside the buffer tank, and the safety valve device is mainly used for system safety to prevent overpressure.

[0030] Step C: The mixed gas in the buffer tank then enters the primary absorption tower, where the first nozzle sprays demineralized water to cool the mixed gas and preliminarily absorb the hydrogen chloride and water vapor in it.

[0031] Step D: The mixed gas and acid flowing out of the primary absorption tower flow into the secondary absorption tower. A second nozzle sprays demineralized water to further cool the mixed gas and absorb hydrogen chloride and water vapor. The acid formed by absorption and condensation is discharged through the drain port. An oxygen analyzer at the top of the secondary absorption tower monitors the oxygen content of the mixed gas. If the oxygen content is unqualified, a nitrogen pressurization system introduces nitrogen into the secondary absorption tower, while simultaneously recirculating the mixed gas back into the buffer tank until the oxygen content is within acceptable limits. If the oxygen content is acceptable, the mixed gas is then introduced into the gas separation unit for separation. This achieves the safe recovery and utilization of hydrogen while simultaneously absorbing and recovering hydrogen chloride to prevent environmental pollution.

[0032] In this embodiment, in step D, a pH analyzer can be installed at the bottom of the secondary absorption tower to monitor the pH value of the acid solution. A bottom circulation pump is installed between the drain port and the secondary absorption tower. The bottom circulation pump is connected to the circulation condenser. One end of the circulation condenser is connected to the second nozzle, and the other end is connected to the second demineralized water pipe. When the drain port is closed, the bottom circulation pump sends the acid solution into the circulation condenser. At the same time, the second demineralized water pipe introduces demineralized water into the circulation condenser. After the diluted acid solution enters the circulation condenser and is cooled, it is sprayed out through the second nozzle to circulate and thoroughly absorb the hydrogen chloride and water vapor in the secondary absorption tower. Then, the drain port is opened to drain the solution.

[0033] In this embodiment, in step D, the nitrogen pressurization system also includes a hydrogen pressurization compressor. When the pressure in the system is lower than a certain value, the hydrogen pressurization compressor is turned on to increase the pressure in the system and prevent negative pressure from occurring in the system.

[0034] Although specific embodiments of the present invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of the present invention. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of the present invention.

Claims

1. A safe absorption, purification, and utilization hydrogen recovery system, comprising an aluminum sol reaction unit and a nitrogen replacement unit for removing oxygen from the reaction unit before the reaction, characterized in that: The hydrogen recovery system further includes a buffer unit, a tail gas impurity absorption unit, a nitrogen pressurization system, and a gas separation unit. The buffer unit includes a buffer tank connected to the outlet of the reaction unit. The tail gas impurity absorption unit includes a primary absorption tower connected to the buffer tank and a secondary absorption tower connected to the primary absorption tower. The primary absorption tower has a first nozzle at its top, connected to a first demineralized water pipe. The secondary absorption tower has a drain outlet at its bottom and a second nozzle at its top. An oxygen analyzer connected to the secondary absorption tower is located at the top of the secondary absorption tower. The nitrogen pressurization system is connected to the secondary absorption tower. The top of the secondary absorption tower is connected to both the buffer unit and the gas separation unit. The second nozzle is connected to a second demineralized water pipe. A pH analyzer is located at the bottom of the secondary absorption tower. A bottom circulation pump is located between the drain outlet and the secondary absorption tower, connected to a circulating condenser. One end of the circulating condenser is connected to the second nozzle, and the other end is connected to the second demineralized water pipe. The gas separation unit includes a drying unit and a reverse osmosis membrane separation unit connected to the drying unit.

2. The hydrogen recovery system for safe absorption and purification as described in claim 1, characterized in that: The buffer unit also includes a first pressure gauge and a safety valve device located inside the buffer tank.

3. The hydrogen recovery system for safe absorption and purification as described in claim 1, characterized in that: The nitrogen pressurization system includes a second pressure gauge and an automatic nitrogen replenishment valve assembly.

4. The hydrogen recovery system for safe absorption, purification, and utilization as described in claim 3, characterized in that: The nitrogen booster system also includes a hydrogen booster compressor.

5. A method for safely absorbing and purifying hydrogen using a hydrogen recovery system employing any one of the methods described in 1-4, characterized in that: The method for safe absorption, purification, and utilization of hydrogen includes the following steps: Step A: Before the reaction in the aluminum sol reaction unit, nitrogen gas is introduced into the system through the nitrogen replacement unit to remove the oxygen in the system; Step B: The mixed gases of hydrogen chloride, hydrogen and water vapor produced by the aluminum sol reaction unit are passed into a buffer tank for buffer storage; Step C: The mixed gas in the buffer tank then enters the primary absorption tower, where the first nozzle sprays demineralized water to cool the mixed gas and preliminarily absorb the hydrogen chloride and water vapor in it. Step D: The mixed gas and acid flowing out of the primary absorption tower flow into the secondary absorption tower. The second nozzle sprays demineralized water to further cool the mixed gas and absorb the hydrogen chloride and water vapor in the mixed gas. The acid formed by absorption and condensation is discharged through the drain port. The oxygen analyzer at the top of the secondary absorption tower monitors the oxygen content of the mixed gas. If the oxygen content is not up to standard, the nitrogen pressurization system introduces nitrogen into the secondary absorption tower, and at the same time, the mixed gas in the secondary absorption tower is returned to the buffer tank until the oxygen content is up to standard and the return stops. If the oxygen content is up to standard, the mixed gas is introduced into the gas separation unit for separation.

6. The method for safe absorption, purification, and utilization of hydrogen as described in claim 5, characterized in that: In step D, a pH analyzer is installed at the bottom of the secondary absorption tower to monitor the pH value of the acid solution. A bottom circulation pump is installed between the drain port and the secondary absorption tower. The bottom circulation pump is connected to a circulating condenser. One end of the circulating condenser is connected to a second nozzle, and the other end is connected to a second demineralized water pipe. When the drain port is closed, the bottom circulation pump sends the acid solution into the circulating condenser. At the same time, the second demineralized water pipe introduces demineralized water into the circulating condenser. After the diluted acid solution enters the circulating condenser and is cooled, it is sprayed out through the second nozzle to completely absorb the hydrogen chloride and water vapor in the secondary absorption tower. Then, the drain port is opened to drain the solution.

7. The method for safe absorption, purification, and utilization of hydrogen as described in claim 5, characterized in that: In step D, the nitrogen pressurization system also includes a hydrogen pressurization compressor. When the pressure in the system is lower than a certain value, the hydrogen pressurization compressor is turned on to increase the pressure in the system.

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