| 摘要 |
PROBLEM TO BE SOLVED: To provide high purity nitrogen gas by recovering gases except a gas having high oxygen concentration in an adsorption tower finishing a desorption step in a pressure equalization step.SOLUTION: In a nitrogen gas separation method, a raw material gas containing nitrogen gas and oxygen gas is supplied to two or more adsorption towers 1A, 1B filled with molecular sieve carbon under pressure, each adsorption tower 1A, 1B repeats an adsorption step, a pressure equalization step, a desorption step and the pressure equalization step and then nitrogen gas is separated as a product gas. In the pressure equalization step at the adsorption tower 1A finished with the adsorption step, a gas is derived from the intermediate part of the adsorption tower 1A, the gas is moved to the adsorption tower 1B operating the pressure equalization step after finishing the desorption step and a part of the gas is released from around the raw material gas inlet of the adsorption tower 1A after finishing the adsorption step. |
