Other

Chevron U.s.a. Inc.

The University of Texas System

De Q Vu

Stephen Joseph Miller

William John Koros

Alexander E Kuperman

Rajiv Mahajan

David Mark Wallace

Michael Sean Driver

Daniel Chinn

John D Wind

Claudia Staudt-Bickel

Laura C Boudreau

William J Koros

Rajiv Mahajn

A process and method for separating COfrom a gaseous stream such as natural gas. An ionic liquid comprising an anion having a carboxylate function and an effective amount of water is used as an adsorbent to selectively complex the COyielding a gaseous stream with a greatly reduced COcontent. The ionic liquid can then be readily be regenerated and recycled.

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A mixed matrix membrane for separating gas components from a mixture of gas components is disclosed. The membrane comprises a continuous phase polymer with inorganic porous particles, preferably molecular sieves, interspersed in the polymer. The polymer has a CO/CHselectivity of at least 20 and the porous particles have a mesoporosity of at least 0.1 cc STP/g. The mixed matrix membrane exhibits an increase in permeability of least 30% with any decrease in selectivity being no more than 10% relative to a membrane made of the neat polymer. The porous particles may include, but are not limited to, molecular sieves such as CVX-7 and SSZ-13, and/or other molecular sieves having the required mesoporosity. A method for making the mixed matrix membrane is also described. Further, a method is disclosed for separating gas components from a mixture of gas components using the mixed matrix membrane with mesoporous particles.

Mixed matrix membrane with mesoporous particles and methods for making and using the same

A mixed matrix membrane is provided which comprises a continuous phase organic polymer and small pore molecular sieves dispersed therein. The molecular sieves have a largest minor crystallographic free diameter of 3.6 Angstroms or less. When these molecular sieves are properly interspersed with a continuous phase polymer, the membrane will exhibit a mixed matrix membrane effect, i.e., a selectivity increase of at least 10% relative to a neat membrane containing no molecular sieves. Finally, methods for making and using such mixed matrix membranes to separate gases from a mixture containing two or more gases are also disclosed.

Mixed matrix membranes with small pore molecular sieves and methods for making and using the membranes

A mixed matrix membrane is provided which comprises a continuous phase organic polymer and small pore alumina containing molecular sieves dispersed therein. The molecular sieves have a silica-to-alumina molar ratio of less than 1.0, more preferably, less than 0.3, and most preferably less than 0.1. In some cases, the molecular sieves have no appreciable amounts of silica. Exemplary compositions include aluminophosphates (AlPO) and silicoaluminophosphates (SAPO). When these molecular sieves are properly interspersed with a continuous phase polymer, the membrane will exhibit a mixed matrix membrane effect, i.e., a selectivity increase of at least 10% relative to a neat membrane containing no molecular sieves. The molecular sieves have pores with a largest minor crystallographic free diameter of 4.0 Angstroms or less. Finally, methods for making and using such mixed matrix membranes to separate gases from a mixture containing two or more gases are also disclosed.

Mixed matrix membranes with low silica-to-alumina ratio molecular sieves and methods for making and using the membranes

A composition of and a method of making high performance mixed matrix hollow fiber membranes is described. The membranes have a high resistance to plasticization by use of a predetermined amount of crosslinking. The preferred polymer material for the membrane is a polyimide polymer continuous phase comprising ester crosslinks and a molecular sieve material dispersed within the polymer continuous phase. The resultant mixed matrix hollow fiber membrane exhibits a high permeance of CO in combination with a high CO /CH selectivity. Another embodiment provides a method of making the mixed matrix hollow fiber membrane from a monesterified polymer followed by final crosslinking after hollow fiber formation.

Crosslinked and crosslinkable hollow fiber mixed matrix membrane and method of making same

Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are preferably polymer membranes that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or &ldquo;sizing agent&rdquo; to &ldquo;size&rdquo; or &ldquo;prime&rdquo; the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film. The mixed matrix membrane film permits passage of carbon dioxide and methane, but at different permeation rates, such that the ratio of the relative permeation rates of carbon dioxide to methane is larger through the mixed matrix membrane film than through the original polymer. The mixed matrix membrane is preferably in the form of a dense film or a hollow fiber. A mixture containing carbon dioxide and methane can be enriched in methane by selective passage of carbon dioxide over methane in a gas-phase process through the membrane.

Mixed matrix membranes and methods for making the same

A high carbon content membrane and method for making the same are disclosed. The carbon membrane includes an asymmetric hollow filamentary carbon membrane, including a partial carbonization product of an asymmetric hollow filament including an aromatic imide polymer material. The carbon membrane is at least 95 weight percent carbon, and has a dense layer located in the outside surface portion of the hollow filamentary membrane and a porous base layer continued from the dense layer and located in the inside portion of the hollow filamentary membrane. A process for separating CO from natural gas is described including: contacting a mixture of CO and natural gas with a first side of a carbon membrane in a manner to cause a portion of the mixture to pass through the carbon membrane to a permeate side. The resulting mixture on the permeate side becomes enriched in CO over that of the mixture on the first side. The contacting step occurs at a pressure of at least about 200 psia.

High carbon content filamentary membrane and method of making the same

Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are preferably polymer membranes, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The particles are formed by pyrolyzing a precursor polymer in the form of a powder or film. The pyrolyzed polymer is then ideally milled to desired small size particles. The preferred ratio of particles to polymer is about 0.25 to about 1.0 by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or &ldquo;sizing agent&rdquo; to &ldquo;size&rdquo; or &ldquo;prime&rdquo; the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film. The mixed matrix membrane film permits passage of carbon dioxide and methane, but at different permeation rates, such that the ratio of the relative permeation rates of carbon dioxide to methane is larger through the mixed matrix membrane film than through the original polymer. The mixed matrix membrane is preferably in the form of a dense film or a hollow fiber. A mixture containing carbon dioxide and methane can be enriched in methane by selective passage of carbon dioxide over methane in a gas-phase process through the membrane.

Carbon molecular sieves and methods for making the same

Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are polymer membranes with a selective layer thickness of between about 1000 Angstroms to about 0.005 inch, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The preferred ratio of particles to polymer is about 20% to about 50% by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or &ldquo;sizing agent&rdquo; to &ldquo;size&rdquo; or &ldquo;prime&rdquo; the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film. The mixed matrix membrane film permits passage of carbon dioxide and methane, but at different permeation rates, such that the ratio of the relative permeation rates of carbon dioxide to methane is larger through the mixed matrix membrane film than through the original polymer. The polymer is preferably a rigid, glassy polymer, more preferably, with a glass transition temperature above about 150&deg; C. The mixed matrix membrane is preferably in the form of a dense film or a hollow fiber. A mixture containing carbon dioxide and methane can be enriched in methane by selective passage of carbon dioxide over methane in a gas-phase process through the membrane.

Gas separations using mixed matrix membranes

The invention includes a process for separating CO,from natural gas including: contacting a mixture of CO,and natural gas with a first side of a carbon membrane in a manner to cause a portion of the mixture to pass through the carbon membrane to a permeate side. The resulting mixture on the permeate side becomes enriched in CO,over that of the mixture on the first side. The carbon membrane includes an asymmetric hollow filamentary carbon membrane, including a partial carbonization product of an asymmetric hollow filament including an aromatic imide polymer material. The carbon membrane is at least 95 weight percent carbon, and has a dense layer located in the outside surface portion of the hollow filamentary membrane and a porous base layer continued from the dense layer and located in the inside portion of the hollow filamentary membrane. The contacting step occurs at a pressure of at least about 200 psia.

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Bakersfield, CA, United States of America

De Q Vu