Views: 0 Author: Site Editor Publish Time: 2023-11-06 Origin: Site
Air contains nitrogen, oxygen, argon, water, carbon dioxide and hydrogen sulfide. Oxygen produced by air separation can be used for steel making, pure oxygen and oxygen-enriched body can also be used for non-ferrous metal smelting, biological fermentation, medical industry, etc. Nitrogen obtained by air separation can be used for fertilizer production, metallurgical industry, refrigerant, food industry, etc. However, in the process of direct and indirect application of air, it is necessary to remove the water in the air and carbon dioxide and other substances, because these components often cause serious harm.
Drying air with molecular sieves is very convenient and effective, and can remove water quite completely at room temperature and pressure, and in addition to dehydration, carbon dioxide and acetylene can be removed at the same time under medium and high pressure. And under the same conditions, the molecular sieve drying air, can be lower than with silica gel to get the dew point, and adsorption capacity is 3-4 times higher.
Before making oxygen by molecular sieve air separation, water, carbon dioxide and acetylene must be removed from the air first. Otherwise, water and carbon dioxide can cause freezing in cryogenic fractionation systems, while acetylene can cause explosions.
Water, carbon dioxide, acetylene are highly polar or unsaturated molecules, molecular sieve has a strong affinity for them. The order of this affinity when H2O ≥ C2H2 ≥ CO2, therefore, the degree of air purification is mainly determined by the effect of removing CO2.
The kinetic activity of CO2 adsorption by molecular sieve is related to temperature, pressure and flow rate of air. Practice shows that: in the medium and high pressure with 13X and 5A molecular sieve can simultaneously remove moisture, carbon dioxide and acetylene in the air, through the fractionation tower deep cooling separation into high purity nitrogen and oxygen.