At present, the demand areas of nitrogen products mainly include oil field nitrogen injection, petrochemical industry, synthetic fiber, synthetic ammonia, glass, steel rolling, high-tech materials and electronic industry. Generally, large-scale high-purity nitrogen plant is mainly used for nitrogen injection in oil field; large and medium-sized high-purity nitrogen plant is mainly used in petrochemical industry, float glass, synthetic fiber, synthetic ammonia, steel rolling and other industries; small-scale nitrogen plant is mainly used in electronic industry. The demand of high purity nitrogen air separation plant is also increasing.