Recovery of SF/sub 6/ from N/sub 2//SF/sub 6/ gas mixtures by using a polymer membrane

The investigation of gas recovery from N/sub 2//SF/sub 6/ gas mixtures using a polymer membrane has been reported. It has been shown that the purity of recovered gas, the recovery loss, and the gas handling speed depend on various parameters such as original gas mixing ratio, gas feeding pressure, gas flow rate, and temperature of the membrane. A gas recovering system with two membrane separators connected in cascade has proved to be very efficient in attaining high purity in a recovered gas, with negligibly small recovery loss and high handling speed for practical use. Furthermore, this system could be applied for CO/sub 2//SF/sub 6/, He/SF/sub 6/ and even for ternary mixtures such as N/sub 2//CO/sub 2//SF/sub 6/ without any modification in the system, where we expect much better performance in comparison with N/sub 2//SF/sub 6/.