METHOD AND APPARATUS FOR SEPARATING AND RECOVERING PERFLUORO COMPOUND

摘要

A PFC separation recovery method to separate and recover PFC by raising the pressure of diluted mixed gas consisting of PFC gas and diluent gas, and subsequently contacting the gas with a membrane which permeates more diluent gas than PFC gas, and to separate it into a permeable gas flow rich in diluent gas and a non-permeable gas flow rich in PFC gas; and a PFC separation recovery system therefor. Moreover, the method repeatedly separates the non-permeable gas flow into another permeable gas flow and another non-permeable gas flow by contacting the gas flow with another membrane having the same functions as those of the membrane; subsequently detecting the pressure or flow rate of the other permeable gas flow; and controlling the flow rate of the other non-permeable gas flow so as to make the pressure or flow rate constant. Even if there is inconsistency in the concentration of PFC gas in diluted mixed gas to be treated, the concentration of PFC that is recovered after the treatment becomes stable. Also no expensive concentration analyzer is required.