Method 1: Nitrogen production by molecular sieve air separation

Molecular sieve air separation of nitrogen is a method of separating nitrogen and oxygen by using air as raw material and carbon molecular sieve as adsorbent， applying the principle of pressure change adsorption， and making use of the selective adsorption of carbon molecular sieve on oxygen and nitrogen， which is commonly known as PSA (Pressure Swing Adsorption) to make nitrogen. This method is a new technology of nitrogen production developed rapidly in the 1970s. Compared with the traditional nitrogen production method， it has the features of simple process， high degree of automation， fast gas production (15-30 minutes)， low energy consumption， product purity can be adjusted according to the user's needs within a wide range， convenient operation and maintenance， low operating cost， strong adaptability of equipment， etc. Therefore， it is quite competitive in the nitrogen production equipment below 1000m3/h， which is more and more welcome by the users of medium-sized and small-sized high-purity nitrogen gas. PSA has become a better method for medium and small-sized nitrogen users.

Method 2: Deep cooling air separation nitrogen production

Deep-cooling air separation nitrogen is a traditional method of nitrogen (nitrogen) production， which has a history of nearly ninety years. It takes air as raw material， after compression and purification， and then uses heat exchange to make the air liquefied into liquid air. Liquid air is mainly a mixture of liquid oxygen and liquid nitrogen， the use of liquid oxygen and liquid nitrogen with different boiling points (at 1 atmospheric pressure， the former boiling point of -183 ℃， the latter for -196 ℃)， through the distillation of liquid air， so that they are separated to obtain high-purity nitrogen. Deep cooling air separation nitrogen equipment is complex， covers a large area， higher infrastructure costs， more one-time investment in equipment， higher operating costs， slow gas production (12-24h)， high installation requirements， long cycle. Comprehensive equipment， installation and infrastructure factors， 3500m3/h below the equipment， the same specifications of the PSA equipment investment scale than the deep-cooling air separation equipment is 20% to 50% lower. Deep-cooling air separation nitrogen equipment is suitable for large-scale industrial nitrogen production， while medium and small-scale nitrogen production is not economical.

Method 3: Membrane air separation nitrogen production

Membrane air separation of nitrogen is a new type of nitrogen technology developed rapidly in foreign countries in the 1980s， and its popularisation and application in China is a matter of nearly three or four years. The basic principle of membrane air separation nitrogen production is to use air as raw material， and under the specified pressure conditions， use the different properties of oxygen and nitrogen and other gases in the membrane with different permeation rates to separate oxygen and nitrogen. Compared with other nitrogen equipment， it has the advantages of simpler structure， smaller volume， no switching valve， less maintenance， faster gas production (≤3 minutes)， easy to increase the capacity， etc. It is especially suitable for medium and small-sized nitrogen users with the purity of nitrogen ≤98%， and it has a better function-price ratio. When the purity of nitrogen is more than 98%， the price of PSA nitrogen generator with the same specification is more than 15% higher than that of PSA nitrogen generator. As can be seen from the above， MnZn ferrite production enterprises， the use of what gas supply and what gas supply technology， need to be based on the enterprise situation for technical and economic demonstration， choose a better high-purity nitrogen generator home and gas supply programme.