Types Of Nitrogen Production Devices

There are three kinds in industry, namely cryogenic air separation method, molecular sieve air separation method (PSA) and membrane air separation method.
Cryogenic air separation for nitrogen production
Nitrogen production by cryogenic air separation is a traditional method of nitrogen production, which has a history of recent decades. It takes air as raw material, after compression, purification, and then heat exchange to liquefy the air into liquid air. Liquid-air is mainly a mixture of liquid oxygen and liquid nitrogen, using the boiling point of liquid oxygen and liquid nitrogen is different (at 1 atmospheric pressure, the boiling point of the former is -183 ° C, the latter is -196 ° C), through the distillation of liquid-air, so that they are separated to obtain nitrogen. The cryogenic air separation nitrogen equipment is complex, occupies a large area, has high infrastructure costs, more one-time investment in equipment, higher operating costs, slow gas production (12 ~ 24h), high installation requirements and long cycle. Comprehensive equipment, installation and infrastructure factors, equipment below 3500Nm3/h, PSA equipment of the same specification is 20% to 50% lower than cryogenic air separation equipment. The cryogenic air separation nitrogen device is suitable for large-scale industrial nitrogen production, while the medium and small-scale nitrogen production is uneconomical.
Nitrogen production by air separation of molecular sieve
Compared with the traditional nitrogen production method, it has the characteristics of simple process, high degree of automation, fast gas production (15 ~ 30 minutes), low energy consumption, product purity can be adjusted in a large range according to the needs of users, easy operation and maintenance, low operating cost, and strong adaptability of the device, so it is very competitive in the nitrogen production equipment below 1000Nm3/h. More and more popular with small and medium nitrogen users, PSA nitrogen has become the preferred method for small and medium nitrogen users.
Membrane air separation for nitrogen production
Using air as raw material, under certain pressure conditions, oxygen and nitrogen gas with different properties in the membrane have different penetration rates to separate oxygen and nitrogen. Compared with other nitrogen production equipment, it has the advantages of simpler structure, smaller volume, no switching valve, less maintenance, faster gas production (≤3 minutes), convenient capacity increase, etc. It is especially suitable for medium and small nitrogen users with nitrogen purity ≤98%, and has the best functional price ratio. When the purity of nitrogen is more than 98%, the price is more than 15% higher than that of PSA nitrogen making equipment of the same specification.