Process and system for separation and recovery of perfluorocompound gases

A process to recover at least one perfluorocompound gas or gas mixture from a gas mixture flowing from a semiconductor manufacturing process, comprising the steps of:

• a) providing a gas mixture comprising at least one perfluorocompound gas, at least one species harmful to a glassy polymer membrane, and at least one carrier gas, the perfluorocompound gas devoid of components including chlorine;
• b) providing a glassy polymer membrane having a feed side and a permeate side;
• c) pretreating said gas mixture in order to remove substantially all of said species harmful to said glassy polymer membrane or reduce the concentration of said species harmful to said glassy polymer membrane to an acceptable level and obtaining a treated gas mixture;
• d) contacting the feed side of said membrane with said treated gas mixture at a first pressure;
• e) withdrawing a concentrated gas mixture comprising a higher concentration of the at least one perfluorocompound gas devoid of components including chlorine than in the treated gas mixture, from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to said first pressure;
• and
• f) withdrawing a gas or gas mixture from the permeate side of said membrane permeate stream which is enriched in carrier gas.

A process to recover at least one perfluorocompound gas from a gas mixture, comprising the steps of:

• a) providing a plurality of semiconductor tools arranged in parallel, each tool emitting a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, said gas mixture being at a first pressure and a first temperature;
• b) providing a glassy polymer membrane separation unit for each tool, each glassy polymer membrane separation unit having a feed side and a permeate side;
• c) contacting the feed side of each of said membrane units with gas mixture from its corresponding tool;
• d) withdrawing from the feed side of each membrane separation unit as a first non-permeate stream at a pressure which is substantially equal to said first pressure, a concentrated gas mixture comprising essentially the at least one perfluorocompound gas;
• and
• e) withdrawing from the permeate side of each membrane separation unit as a first permeate stream a depleted gas mixture consisting essentially of the at least one carrier gas.

A process to recover at least one perfluorocompound gas from a gas mixture, comprising the steps of:

• a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, said gas mixture being at a first pressure and a first temperature;
• b) providing a first glassy polymer membrane separation unit having a feed side and a permeate side;
• c) contacting the feed side of said first glassy polymer membrane separation unit with said gas mixture;
• d) withdrawing from the feed side of the first glassy polymer membrane separation unit as a first non-permeate stream at a pressure which is substantially equal to said first pressure, a concentrated gas mixture comprising essentially the at least one perfluorocompound gas;
• e) withdrawing from the permeate side of said first glassy polymer membrane separation unit as a first permeate stream a depleted gas mixture consisting essentially of the at least one carrier gas;
• and
• f) wherein there exists one or more spare membranes, which allow the first glassy polymer membrane separation unit to be serviced or otherwise by-passed.

A process to recover at least one perfluorocompound gas from a gas mixture, comprising the steps of:

• a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, said gas mixture being at a first pressure and a first temperature;
• b) providing a first glassy polymer membrane having a feed side and a permeate side;
• c) pretreating said gas mixture by a pretreatment process prior to entry to the feed side of the first membrane to substantially remove most of species harmful for the first membrane prior to feeding said gas mixture to the feed side of the first membrane;
• d) contacting the feed side of said first membrane with said gas mixture;
• e) withdrawing from the feed side of the first membrane as a first non-permeate stream at a pressure which is substantially equal to said first pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas;
• and
• f) withdrawing from the permeate side of said first membrane as a first permeate stream a depleted gas mixture consisting essentially of the at least one carrier gas.

A semiconductor manufacturing system comprising:

• a) at least one reactor chamber adapted to receive perfluorocompound gases, carrier gases, and the like, the reactor chamber having a reactor effluent gas conduit attached thereto, said perfluorocompound gases devoid of components including chlorine;
• b) at least one glassy polymer membrane separation unit having a feed side and a permeate side, said membrane being permeable to at least one carrier gas and being substantially non-permeable to at least one perfluorocompound gas devoid of components including chlorine, said membrane unit connected to said reactor chamber via the reactor effluent conduit, said membrane unit having a permeate vent conduit and a non-permeate conduit;
• and
• c) means to recycle at least a portion of said non-permeate stream from said membrane unit back to the at least one reactor chamber;
• d) wherein said at least one glassy polymer membrane separation unit is a plurality of glassy polymer membrane separation units arranged in series.

A semiconductor manufacturing system comprising:

• a) at least one reactor chamber adapted to receive perfluorocompound gases, carrier gases, and the like, the reactor chamber having a reactor effluent gas conduit attached thereto, said perfluorocompound gases devoid of components including chlorine;
• b) at least one glassy polymer membrane separation unit having a feed side and a permeate side, said membrane being permeable to at least one carrier gas and being substantially non-permeable to at least one of said perfluorocompound gases devoid of components including chlorine, said membrane unit connected to said reactor chamber via the reactor effluent conduit, said membrane unit having a permeate vent conduit and a non-permeate conduit;
• and
• c) means to recycle at least a portion of said non-permeate stream from said membrane unit back to the at least one reactor chamber;
• d) wherein said at least one glassy polymer membrane separation unit is a plurality of glassy polymer membrane separation units arranged in parallel.

A system for recycling or recovering a perfluorocompound gas from a gas mixture, the system comprising:

• a) an optional treatment means for creating a treated gas mixture suitable for compression;
• b) a compressor for compressing the treated gas mixture to form a compressed gas mixture;
• and
• c) at least one glassy polymer membrane separation unit having a feed side and a permeate side, said membrane being permeable to at least one carrier gas and being substantially non-permeable to at least one perfluorocompound gas, said membrane unit connected to said compressor via a conduit, said membrane unit having a permeate vent conduit and a non-permeate conduit, said at least one perfluorocompound gas devoid of components including chlorine.

A system for recovering or recycling a perfluorocompound gas, the system comprising:

• a) compression means adapted to compress a gas mixture containing a carrier gas and a perfluorocompound gas, said perfluorocompound gas devoid of components including chlorine;
• b) at least one glassy polymer membrane separation unit having a feed side and a permeate side, said membrane being permeable to at least one carrier gas and being substantially non-permeable to at least one of said perfluorocompound gases devoid of components including chlorine, said membrane unit connected to said compression means via a conduit, said membrane unit having a permeate vent conduit and a non-permeate conduit;
• c) means to recycle at least a portion of a non-permeate stream flowing through said non-permeate conduit from said membrane unit back to a source of said gas mixture;
• d) gas treatment means positioned prior to the gas mixture entering the membrane unit, said gas treatment means selected from the group consisting of plasma decomposition, thermal decomposition, catalytic removal, scrubbing, and adsorption;
• e) the membrane unit comprising a sweep gas conduit connecting the non-permeate conduit and the permeate side of the membrane;
• f) a damper or surge tank positioned in the non-permeate conduit;
• and
• g) a compressor, heat exchanger, cryogenic pump or vacuum pump positioned in the non-permeate conduit upstream of the surge tank, allowing an enriched stream of perfluorocompounds devoid of components including chlorine to be stored in condensed form for future use if so desired.