Future prospects of cryogenic air separation technology

I. Preface With the rapid development of industry, nitrogen has been widely used in chemical engineering, electronics, metallurgy, food, machinery and other fields. The demand for nitrogen in our country increases at a speed of more than 8% every year. The chemical property of nitrogen is not active, and it shows great inertia under normal conditions, so it is not easy to react with other substances. Therefore, nitrogen is widely used as protective gas and sealing gas in metallurgical industry, electronic industry and chemical industry. Generally, the purity of protective gas is required to be 99.99%, and some require high purity nitrogen of more than 99.998%. Liquid nitrogen is a relatively convenient cold source, which is more and more widely used in food industry, medical service and the seminal storage of animal husbandry. During the production of synthetic ammonia in the chemical fertilizer industry, if the mixture of hydrogen and nitrogen, the feed gas of synthetic ammonia, is...

After the argon fraction is extracted from the top Tower, it enters into the crude argon tower and conducts the separation of oxygen and argon by the rectification method. Generally, the components of crude argon from the top of the crude argon tower are: argon is more than 98%, nitrogen is less than 0.5%, and oxygen is less than 1.5%. Import Crude argon with purity over 98% into molecular sieve adsorber. There are two adsorbers in each group. One is equipped with 5A Molecular sieve to absorb nitrogen in crude argon; the other is equipped with 4A molecular sieve to absorb oxygen in crude argon. In order to release the adsorbents, two groups of adsorbents need to be set up to switch to use. The adsorber works at the temperature of 90 K. The crude argon enters into 5A Molecular sieve adsorber to remove nitrogen first, and then enters into 4A molecular sieve adsorber to remove oxygen. The process is shown in Figure 18. The gas from a group of molecular sieve adsorbers has a purity of 9...