초록 ▼

A process for separating a gas from a gas mixture containing the gas and a C3+ hydrocarbon vapor, using gas-separation membranes selective for the gas over the C3+ hydrocarbon vapor. The membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstr

A process for separating a gas from a gas mixture containing the gas and a C3+ hydrocarbon vapor, using gas-separation membranes selective for the gas over the C3+ hydrocarbon vapor. The membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons.

대표청구항 ▼

1. A process for separating a desired gas from a gas mixture comprising the desired gas and a C3+ hydrocarbon vapor, the process comprising the steps of:(a) passing the gas mixture across the feed side of a separation membrane having a feed side and a permeate side, the separation membrane having a

1. A process for separating a desired gas from a gas mixture comprising the desired gas and a C3+ hydrocarbon vapor, the process comprising the steps of:(a) passing the gas mixture across the feed side of a separation membrane having a feed side and a permeate side, the separation membrane having a selective layer comprising a polymer having: (i) a ratio of fluorine to carbon atoms in the polymer greater than 1:1; (ii) a fractional free volume no greater than about 0.3; and (iii) a glass transition temperature of at least about 100.degree. C.; and the separation membrane being characterized by a post-exposure selectivity for the desired gas over the C3+ hydrocarbon vapor, after exposure of the separation membrane to liquid toluene and subsequent drying, that is at least about 65% of a pre-exposure selectivity for the desired gas over the C3+ hydrocarbon vapor, as measured pre- and post-exposure with a test gas mixture of the same composition and under like conditions; (b) providing a driving force for transmembrane permeation; (c) withdrawing from the permeate side a permeate stream enriched in the desired gas compared to the gas mixture; (d) withdrawing from the feed side a residue stream depleted in the desired gas compared to the gas mixture.