Using molecular sieve adsorption purification process why do most of them use refrigeration precooling system?

Because of the use of molecular sieve adsorption purification process, the water, carbon dioxide and part of the hydrocarbon in the compressed air can be adsorbed in the purifier, in this way, liquid-air adsorber and liquid-oxygen adsorber can be canceled in the design, which simplifies the technological process of air separation production, prolongs the operation cycle of the equipment and improves the utilization rate of the equipment.
However, in order to make the molecular sieve work normally, the requirements on the temperature of the adsorption medium are relatively strict. Because the higher the temperature is, the higher the moisture content in the air will increase the cleaning load of the purifier. However, the adsorptive property of the molecular sieve decreases with the increase of temperature. Therefore, the inlet temperature of the molecular sieve purifier must be controlled below 15℃ to work normally, which generally needs to be 8 ~ Between 15℃. However, it is very difficult for ordinary cooling water to cool the air to such a temperature condition, so it is generally necessary to add the precooling system of the refrigerator to reduce the air temperature to 8 ~ Within 15℃, to ensure the smooth production.