Carbon dioxide separation membranes and process
AssigneeCompact Membrane Systems, Inc.
InventorsNing SHANGGUAN, Stuart Marshall NEMSER, Sudipto MAJUMDAR, Andrew Edward FEIRING
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Abstract
This invention discloses a thin-film composite membrane and process for the separation of carbon dioxide from non-hydrophilic gases such as methane, hydrogen, and nitrogen. The thin-film composite membrane has a gas-separation layer and a nonporous high-diffusion-rate layer, and has carbon dioxide to non-hydrophilic gas selectivity that is greater than the intrinsic selectivity of the gas-separation layer alone.
Claims25
A thin-film composite membrane, comprising:
- a) a porous-layer support;
- b) a nonporous high-diffusion rate layer that is in direct contact with said porous-layer support;
- and
- c) a gas-separation layer that is nonporous and in direct contact with said nonporous high-diffusion rate layer,
- wherein:
- the gas separation layer comprises an ionomer comprising covalently bound ionic groups, and the ionomer is fluoropolymer comprising repeat units A and B in which A is a polymerized derivative of a fluorinated monomer and B comprises hydrophilic ionic groups;
- and
- the hydrophilic ionic groups are sulfonate groups having a lithium cation.
(canceled)
A process for separating a gaseous composition comprising carbon dioxide and a non-hydrophilic gas using a thin-film composite membrane, the process comprising:
- a) providing a thin-film composite membrane having a feed side and a permeate side and comprising:
- i) a porous-layer support,
- ii) a nonporous high-diffusion rate layer that is in direct contact with said porous-layer support, and;
- iii) a gas-separation layer that is nonporous and in direct contact with said nonporous high-diffusion rate layer;
- and;
- b) exposing the feed-side of the thin-film composite membrane to a flowing feed-side composition comprising carbon dioxide, water vapor and a non-hydrophilic gas;
- and
- c) providing a driving force and producing a permeate-side composition at the permeate side of the thin-film composite membrane having a higher ratio of carbon dioxide to non-hydrophilic gas than the feed-side composition,
- wherein:
- the gas separation layer comprises an ionomer comprising covalently bound ionic groups, and the ionomer is fluoropolymer comprising repeat units A and B in which A is a polymerized derivative of a fluorinated monomer and B comprises hydrophilic ionic groups;
- and
- the hydrophilic ionic groups are sulfonate groups having a lithium cation.
(canceled)
Dependencies are inferred from the claim text.