How to prevent concentrated sulfuric acid storage tanks from absorbing water

Generally, no treatment is required; it does not emit smoke during normal storage. However, smoke is produced when the material is being loaded. To address this, we connect a vent pipe to a water seal tank so that the smoke can be absorbed by the water. After the material in the tank truck has been unloaded, we remove the pipe connected to the water seal. This is somewhat troublesome, but it is done for environmental reasons. Concentrated sulfuric acid absorbs water, but usually there are no problems and its functionality is not affected. Yet if the level at the interface of the storage tank remains constant, absorption of water at the gas-liquid interface can result in the formation of dilute acid, which can cause corrosion of the tank. We have a storage tank; for this reason, during a shutdown that lasted half a year, the acid in the tank did not move, and acid began to leak from that area at a consistent rate. During maintenance, people tried to repair it by using welding, which almost led to serious problems – as soon as welding was started, there was an explosion sound inside the tank, and everyone ran away immediately. Fortunately, the impact was not severe; the tank was not damaged and no one was injured. Later analysis showed that the corrosion at the liquid level was caused by a displacement reaction between carbon steel and dilute sulfuric acid, with hydrogen gas accumulating in the upper part of the tank. This incident taught us a valuable lesson. Preventing water absorption in sulfuric acid tanks is a challenging task in industry. For example, installing a nitrogen seal is costly, and the strength of the sulfuric acid tanks must also be increased. When it comes to using adsorption drying devices, it is difficult to select the appropriate desiccant, and it is necessary to ensure that the storage tanks can breathe properly. Therefore, if the requirements are not high, there is no need to install any devices to prevent water absorption.

If possible, a respirator should be added. It can prevent sulfuric acid in the storage tank from coming into contact with air and absorbing moisture from the air.

Add a respirator, and fill the respirator with silica gel.

Consider adding a check valve to prevent moisture in the air from entering the acid tank

In practice, no special components are required; simply using a pipe with a diameter of ≥DN15 and ≤DN50 to connect to the atmosphere is sufficient. Our concentrated acid storage tanks have been in use for 30 years with no problems at all ； Because the liquid level in the storage tank keeps changing, such a small opening cannot draw in much moisture ； Of course, this pipe opening must be sealed for long-term parking.

Reply to 2# chinazwr: Your comments have been very inspiring to me; thank you! We are considering launching a project for the storage of 98% acid, and we would appreciate your professional insights. We are engaged in public warehousing in Dongguan, Guangdong. As a public warehouse, the liquid level in the storage tanks changes frequently, and we pay close attention to the impact of moisture on the quality of the goods. Similar goods include dichloroethane, and corrosion often occurs at the gas-liquid interface; we hope to receive more suggestions from everyone.

We are using 98% concentrated sulfuric acid respirators.

What does a \"98% concentrated sulfuric acid respirator\" look like?

We supply nitrogen to the exhaust pipe at the top of the sulfuric acid storage tank to purge it and prevent air from entering