Can nitrogen sealing reduce the evaporation of substances inside the tank?

Nitrogen sealing merely replaces air with nitrogen to prevent the formation of explosive mixtures; it does not reduce the saturated vapor pressure of the substances inside the tank, meaning that the partial pressure of these substances remains the same at normal pressure； However, by installing a breathing valve, the discharge pressure increases, which can slightly reduce the partial pressure of the substances inside the tank and thus decrease volatilization. The main function of a breather valve is to reduce breathing losses caused by the temperature differences between day and night, and its effect is quite significant.

It’s strange why a breathing valve is always the preferred choice – doesn’t that mean the exhaust gases emitted become uncontrolled gases? Isn’t it more environmentally friendly to include him in the exhaust gas treatment system?

The idea is good, but do you know how high the costs of such recycling are? Unrealistic.

It’s just my personal opinion – the cost of nitrogen sealing is relatively high; if it’s not a toxic or harmful gas, I don’t recommend using nitrogen sealing. Especially for those commercial oil tanks that don’t have a nitrogen supply source, it may be included in the design, but the owners may not opt to use it in actual operation. For substances with high vapor pressure, an internal floating roof is sufficient; although a nitrogen seal is an effective solution, its cost is too high. Moreover, the self-acting control valves must be reliable, otherwise problems can arise, and in many cases the gases emitted need to be sent to incinerators

The nitrogen seal creates a buffer isolation zone with a certain pressure at the top of the tank, thereby effectively isolating the contents inside the tank from oxygen and reducing their volatilization.

Some substances undergo chemical reactions with oxygen; therefore, by using nitrogen to isolate them from oxygen, evaporation does not decrease (under the same conditions).

Nitrogen sealing can reduce minor breathing (evaporation losses) by removing the air from the sealed container, thereby isolating the material from the outside environment and minimizing volatilization; it also helps prevent safety accidents. However, in the case of storage tanks, it is advisable to use an internal floating disk as well, with the surface of this disk filled with nitrogen. This increases the pressure above the floating disk, keeping it in close contact with the liquid surface and thus preventing the volatilization of light components. When used together, the nitrogen seal and the internal floating disk can more effectively reduce evaporation; this is actually the principle by which the nitrogen seal reduces evaporation (nitrogen seal + internal floating disk). Here are a few reference URLs: “http://bbs.hcbbs.com/viewthread.php?tid=603710”, “http://bbs.hcbbs.com/thread-302710-1-1.html”, “http://bbs.hcbbs.com/thread-493577-1-1.html”. You might want to take a look if you’re interested! It can help with a better understanding!

Nitrogen sealing cannot reduce the volatilization of substances; it merely serves to prevent contact between those substances and air. It is generally used to protect substances that are prone to oxidation or hazardous materials with high volatility, thereby reducing their concentration and minimizing the risk of explosion

It can reduce evaporation. Moreover, nitrogen sealing can effectively increase the NPSHa of the pipeline system, which is very helpful for subsequent transportation.