Gas separations utilizing glassy polymer membranes at sub-ambient temperatures
First Claim
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1. A method of separating component gases in a gas mixture, which method comprises:
- A. contacting a first side of a gas separation membrane, the membrane comprising a discriminating layer or region of a glassy polymer, with the gas mixture while maintaining a difference in chemical potential from the first side of the membrane to a second side of the membrane, such that at least one first component gas of the gas mixture selectively permeates relative to at least one second component gas in the gas mixture from the first side of the membrane through the membrane to the second side of the membrane, wherein said contacting occurs at a temperature of -5°
C. or lower, with the proviso that said permeation of gas occurs at or above the freezing point of any liquid present in the gas mixture, wherein said membrane is selected so that, when using a mixture of 80 mole percent nitrogen and 20 mole percent oxygen as a feed at 30°
C. with a pressure of 30 psia on the first side of the membrane and a vacuum of less than 1 mm Hg on the second side of the membrane, the permeability of oxygen in barrers is less than 2000 and has the following relationship to oxygen/nitrogen selectivity;
##EQU6## B. recovering at least one of the permeate gas or rejected non-permeate gas, with the proviso that cellulose triacetate polymer membranes are excluded.
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Abstract
This invention relates to a method of an apparatus and method for separating component gases in a gas mixture employing a glassy polymer membrane at temperatures at or slightly above the freezing point of any liquid present so as to achieve superior separator of gas components. The composition of certain monomers and polymers are claimed.
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Citations
57 Claims
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1. A method of separating component gases in a gas mixture, which method comprises:
A. contacting a first side of a gas separation membrane, the membrane comprising a discriminating layer or region of a glassy polymer, with the gas mixture while maintaining a difference in chemical potential from the first side of the membrane to a second side of the membrane, such that at least one first component gas of the gas mixture selectively permeates relative to at least one second component gas in the gas mixture from the first side of the membrane through the membrane to the second side of the membrane, wherein said contacting occurs at a temperature of -5°
C. or lower, with the proviso that said permeation of gas occurs at or above the freezing point of any liquid present in the gas mixture, wherein said membrane is selected so that, when using a mixture of 80 mole percent nitrogen and 20 mole percent oxygen as a feed at 30°
C. with a pressure of 30 psia on the first side of the membrane and a vacuum of less than 1 mm Hg on the second side of the membrane, the permeability of oxygen in barrers is less than 2000 and has the following relationship to oxygen/nitrogen selectivity;
##EQU6## B. recovering at least one of the permeate gas or rejected non-permeate gas, with the proviso that cellulose triacetate polymer membranes are excluded.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
- 17. The method as described in claim wherein the membrane is an asymmetric. anisotropic, or composite, or surface treated membrane.
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37. A method of separating component gases in a mixture which optionally contains a liquid component comprising:
A. contacting a first side of a gas separation membrane, the membrane comprising a discriminating layer or region of a glassy polymer, with the gas mixture while maintaining a difference in chemical potential from the first side of the membrane to a second side of the membrane, such that at least one first component gas of the gas mixture selectively permeates relative to at least one second component gas in the gas mixture from the first side of the membrane through the membrane to the second side of the membrane, said contact and separation occurring in the temperature range from about -150°
to about -5°
, with the proviso that the permeation occurs at or above the freezing point of any liquid present, the membrane is selected so that, when using a mixture of 80 mole percent nitrogen and 20 mole percent oxygen as a feed at 30°
C. with a pressure of 30 psia on the first side of the membrane and a vacuum of less than 1 mm Hg on the second side of the membrane, the permeability of oxygen in barrers is less than 2000 and has the following relationship to oxygen/nitrogen selectivity;
##EQU7## B. recovering at least one of the permeate gas or rejected non-permeate gas, wherein at least one of the first component gas and at least one of the second component gas is selected from the group consisting of hydrogen, helium, oxygen, nitrogen, argon, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen oxides, sulfur oxides, ammonia, water vapor, and light hydrocarbons.- View Dependent Claims (38)
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39. A process for separating component gases in a mixture optionally containing a liquid comprising:
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A. contacting a first side of a gas separation membrane comprising a discriminating layer or region of a glassy polymer with the gas mixture under pressure and at a temperature of 5°
C. or lower and above the freezing point of any liquid present;B. maintaining a difference in pressure from the first side of the membrane to a second side of the membrane, under conditions such that at least one first component gas of the gas mixture selectively permeates relative to at least one second component gas through the membrane from the higher pressure first side of the membrane to the lower pressure second side of the membrane; and C. recovering at least one of the rejected non-permeate gas from the first side of the membrane or the permeate gas from the second side of the membrane; wherein the membrane is selected so that, when using a mixture of 80 mole percent nitrogen and 20 mole percent oxygen as a feed at 30°
C. with a pressure of 30 psia on the first side of the membrane and a vacuum of less than 1 mm Hg on the second side of the membrane, the permeability of oxygen barrers is less than 2000 and has the following relationship to oxygen/nitrogen selectivity;
##EQU8## - View Dependent Claims (40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55)
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56. A composition of matter which is a monomer of the structure:
- ##STR12## wherein U is independently selected from the group consisting of chloro and bromo.
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57. A composition of matter which is a glassy polymer having a repeating unit of the formula:
- ##STR13## wherein U is independently selected from the group consisting of bromo and chloro.
Specification