An on-board fuel separation system includes a supply fuel tank configured to store an input fuel stream; a fuel separator fluidly coupled to the supply fuel tank and configured to separate the input fuel stream into a first fractional fuel stream and a second fractional fuel stream. The fuel separator includes a membrane that includes a plurality of pores sized based on a molecular size of one or more components of the first fractional fuel stream. The system includes a first fractional fuel tank fluidly coupled to the fuel separator to receive the first fractional fuel stream passed through the membrane and defined by a first auto-ignition characteristic value. The system includes a second fractional fuel stream coupled to the fuel separator to receive the second fractional fuel stream from the fuel separator that is defined by a second auto-ignition characteristic value that is different than the first auto-ignition characteristic value.

Provided herein are in situ methods for fabricating a mixed-matrix membrane or a mixed-matrix hollow fiber membrane for increasing formation of zeolitic imidazolate framework nanoparticles inside the mixed-matrix membrane. Generally, in the method a polyimide polymer coated onto at least one support is hydrolzed with a base and the poly(amic acid)-salt film formed thereby undergoes ion exchange with a metal ion, treatment of the formed poly(amic acid)-metal salt film with an organic linker to produce metal-organic framework nanoparticles in situ, and imidization of the treated poly(amic acid)-metal salt film produces a polyimide/metal-organic framework mixed-matrix membrane or a mixed-matrix hollow fiber membrane module. Also provided is the mixed-matrix membrane and the polymer mixed-matrix hollow fiber membrane module fabricated by the methods and methods for separating a binary gas mixture via the fabricated mixed-matrix membrane.

Provided herein are in situ methods for fabricating a mixed-matrix membrane or a mixed-matrix hollow fiber membrane for increasing formation of zeolitic imidazolate framework nanoparticles inside the mixed-matrix membrane. Generally, in the method a polyimide polymer coated onto at least one support is hydrolzed with a base and the poly(amic acid)-salt film formed thereby undergoes ion exchange with a metal ion, treatment of the formed poly(amic acid)-metal salt film with an organic linker to produce metal-organic framework nanoparticles in situ, and imidization of the treated poly(amic acid)-metal salt film produces a polyimide/metal-organic framework mixed-matrix membrane or a mixed-matrix hollow fiber membrane module. Also provided is the mixed-matrix membrane and the polymer mixed-matrix hollow fiber membrane module fabricated by the methods and methods for separating a binary gas mixture via the fabricated mixed-matrix membrane.

This invention provides a new facilitated transport membrane comprising a relatively hydrophilic, very small pore, nanoporous support membrane, a hydrophilic polymer inside the very small nanopores on the skin layer surface of the support membrane, a thin, nonporous, hydrophilic polymer layer coated on the surface of the support membrane, and metal salts incorporated in the hydrophilic polymer layer coated on the surface of the support membrane and the hydrophilic polymer inside the very small nanopores, a method of making this membrane, and the use of this membrane for olefin/paraffin separations, particularly for C3=/C3 and C2=/C2 separations.

This invention provides a new facilitated transport membrane comprising a relatively hydrophilic, very small pore, nanoporous support membrane, a hydrophilic polymer inside the very small nanopores on the skin layer surface of the support membrane, a thin, nonporous, hydrophilic polymer layer coated on the surface of the support membrane, and metal salts incorporated in the hydrophilic polymer layer coated on the surface of the support membrane and the hydrophilic polymer inside the very small nanopores, a method of making this membrane, and the use of this membrane for olefin/paraffin separations, particularly for C3=/C3 and C2=/C2 separations.

The present invention provides a method for selectively separating a straight-chain conjugated diene with high purity from a mixture containing the straight-chain conjugated diene and at least one type of straight-chain olefin. The method involves separating the straight-chain conjugated diene from the mixture containing the straight-chain conjugated diene and the straight-chain olefin using a zeolite membrane composite. The composite contains a porous support and a zeolite layer formed on the surface and in the fine pores of the support, and the zeolite contains an alkali metal cation.

The present invention provides a method for selectively separating a straight-chain conjugated diene with high purity from a mixture containing the straight-chain conjugated diene and at least one type of straight-chain olefin. The method involves separating the straight-chain conjugated diene from the mixture containing the straight-chain conjugated diene and the straight-chain olefin using a zeolite membrane composite. The composite contains a porous support and a zeolite layer formed on the surface and in the fine pores of the support, and the zeolite contains an alkali metal cation.

The present invention provides a method for selectively separating a straight-chain conjugated diene with high purity from a mixture containing the straight-chain conjugated diene and at least one type of straight-chain olefin. The method involves separating the straight-chain conjugated diene from the mixture containing the straight-chain conjugated diene and the straight-chain olefin using a zeolite membrane composite. The composite contains a porous support and a zeolite layer formed on the surface and in the fine pores of the support, and the zeolite contains an alkali metal cation.

A process and system for separating paraxylene from a mixture of paraxylene, metaxylene, orthoxylene, and ethylbenzene in a simulated moving bed apparatus using a membrane to separate non-aromatics from a desorbent stream. The lower nonaromatics content in the desorbent improves paraxylene product purity, increases paraxylene production at the same desorbent rate, reduces the desorbent rate, and/or reduces energy consumption in the product tower.

A process and system for separating paraxylene from a mixture of paraxylene, metaxylene, orthoxylene, and ethylbenzene in a simulated moving bed apparatus using a membrane to separate non-aromatics from a desorbent stream. The lower nonaromatics content in the desorbent improves paraxylene product purity, increases paraxylene production at the same desorbent rate, reduces the desorbent rate, and/or reduces energy consumption in the product tower.