Advantages of producing liquid nitrogen using a liquid nitrogen generator

What supply method should be used for liquid nitrogen production? Did you know that most of the air we breathe is nitrogen? Everyone needs oxygen to survive, but air contains 78% nitrogen, only 21% oxygen and a small amount of other gases. Although the human body does not need nitrogen, it is used in various industrial applications. In short, because air is an unlimited source of nitrogen, you can produce nitrogen of the required purity at a cost that is only a small fraction of the annual nitrogen cost.

When using nitrogen and oxygen industrial gases in factory production, a solution that might come to mind is to purchase bottled nitrogen or oxygen. However, there are actually good alternatives. In this article, we will discuss three nitrogen supply methods: bottled nitrogen, liquid nitrogen, PSA orliquid nitrogen generator equipment。

The first option is to purchase bottled nitrogen from a nitrogen producer. This process is very simple: order the required amount of nitrogen according to the production needs, and the supplier will ship it in large and heavy cylinders. Liquid nitrogen and liquid oxygen produced by cryogenic nitrogen plants are bottled under very high pressure (300 bar) and then depressurized to gaseous nitrogen and oxygen at the customer's site, meaning that a large amount of nitrogen can be stored in a relatively small cylinder. However, due to the high pressure, the walls of the bottle are very thick. The bottles are placed on racks and transported to their destination by truck, and empty bottles are collected by the gas company after use.

The second option is to install liquid nitrogen generator equipment at the factory and have it filled regularly by a gas company. This liquid nitrogen generator equipment can be rented (e.g., from a natural gas company) or purchased, and must be equipped with an evaporator to obtain nitrogen. The evaporator converts liquid nitrogen into usable gaseous nitrogen. Just as liquid nitrogen generator equipment needs to be transported to the factory by truck, liquid nitrogen is produced by cryogenicliquid nitrogen generator equipmentplants, transported by large insulated tank trucks, and then pumped from the truck into the storage tanks of the liquid nitrogen generator equipment on site. If the gas demand is small, small liquid nitrogen tanks can also be ordered.

Advantages and disadvantages of the third option, liquid nitrogen, evaporation loss: The insulation of liquid nitrogen generator equipment cannot guarantee perfect insulation. This means that the liquid gas will heat up, and the evaporation pressure inside the liquid nitrogen generator equipment will increase until the safety valve opens and releases some gas, which is called evaporation loss. Evaporation loss is waste. When the nitrogen consumption is less than the original calculated value, the pressure in the tank will increase, and evaporation loss will occur.

If there is no gas demand, the daily evaporation loss will be as high as 1% of the remaining gas in the tank. In order to offset these losses, it is necessary to replenish liquid nitrogen regularly (usually once a week). Liquid nitrogen generator equipment.

When nitrogen consumption is very high,liquid nitrogen generator equipmenta (small) cryogenic liquid nitrogen generator may be installed at your production site. This is the same type of production as bottled nitrogen and liquid nitrogen. So how is on-site nitrogen production achieved? Unlike the methods of obtaining nitrogen discussed earlier, liquid nitrogen generators do not require a cryogenic process. Harsh temperatures do not occur when using membrane nitrogen or pressure swing adsorption (PSA) for nitrogen production. The nitrogen generator draws air into its internal components to separate the air in different ways.

PSA nitrogen generation and membrane nitrogen generation are two different technologies, both of which require compressed air to produce nitrogen. Because these two technologies are different from cryogenic nitrogen generation, the purity of the produced nitrogen will also be different. Cryogenic nitrogen production can produce nitrogen with fixed and very high purity. The advantage of on-site nitrogen generation is that it can be adjusted according to nitrogen purity requirements, but to obtain nitrogen with the same purity as cryogenic nitrogen generation, the efficiency is very low. Using these two nitrogen generation methods, obtaining higher purity nitrogen requires more compressed air, which in turn requires more electricity, resulting in higher operating costs. That being said, for most applications and companies, the purity of cryogenic liquid nitrogen significantly exceeds the Specification.