A process is provided to separate a hydrocarbon stream comprising a mixture of light olefins and light paraffins, the process comprising sending the hydrocarbon stream through a pretreatment unit to remove impurities selected from the group consisting of sulfur compounds, arsine, phosphine, methyl acetylene, propadiene, and acetylene to produce a treated hydrocarbon stream; vaporizing the treated hydrocarbon stream to produce a gaseous treated hydrocarbon stream; adding liquid or vapor water to the gaseous treated hydrocarbon stream; then contacting the gaseous treated hydrocarbon stream to a membrane in a membrane system comprising one or more membrane units to produce a permeate stream comprising about 96 to 99.9 wt % light olefins and a retentate stream comprising light paraffins.

The present invention provides a composition for a CO.sub.2 gas separation membrane containing: at least one compound selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate, and an alkali metal hydroxide; a crosslinked polymer in which a polymer having a carboxyl group has been crosslinked; and a non-crosslinked polymer obtained by polymerization of one or more monomers selected from the group consisting of vinyl acetate, acrylic acid, methacrylic acid, and a derivative thereof.

Process for separating a highly pure propylene product from a liquefied petroleum gas stream is disclosed, which eliminates a C3 splitter having over 120 trays and the additional equipment that a C3 splitter requires. The process includes passing a feed stream to a dividing wall column to produce an overhead stream, a first side draw stream, a second side draw stream, and a product stream. The first side draw stream is passed to a treatment unit to produce a treated stream. The treated stream is passed to a membrane unit and a permeate stream is passed from the membrane unit to produce a polymer grade propylene stream.

A process is provided to separate a hydrocarbon stream comprising a mixture of light olefins and light paraffins, the process comprising sending the hydrocarbon stream through a pretreatment unit to remove impurities selected from the group consisting of sulfur compounds, arsine, phosphine, methyl acetylene, propadiene, and acetylene to produce a treated hydrocarbon stream; vaporizing the treated hydrocarbon stream to produce a gaseous treated hydrocarbon stream; adding liquid or vapor water to the gaseous treated hydrocarbon stream; then contacting the gaseous treated hydrocarbon stream to a membrane in a membrane system comprising one or more membrane units to produce a permeate stream comprising about 96 to 99.9 wt % light olefins and a retentate stream comprising light paraffins.

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 relates to a combined C3/C4 splitter with a membrane system. More specifically, the present invention relates to a combined C3/C4 splitter column to separate highly pure propylene product from a liquefied petroleum gas stream, which eliminates a C3 splitter having over 120 trays and the additional equipment that a C3 splitter requires.

The present invention relates to a combined C3/C4 splitter with a membrane system. More specifically, the present invention relates to a combined C3/C4 splitter column to separate highly pure propylene product from a liquefied petroleum gas stream, which eliminates a C3 splitter having over 120 trays and the additional equipment that a C3 splitter requires.

Provided is a method for separating, from a raw gas containing a specific gas, the specific gas using a gas separation membrane module. The gas separation membrane module includes a housing and a gas separation membrane element enclosed in the housing. The gas separation membrane element includes a gas separation membrane including a hydrophilic resin composition layer for selectively allowing for permeation of the specific gas. The method includes the steps of: increasing pressure in an interior of the gas separation membrane module; increasing a temperature in the interior of the gas separation membrane module; and feeding a raw gas to the interior of the gas separation membrane module in that order.

A membrane process is provided for separating light olefins from light paraffins to produce a polymer grade light olefin product stream that is about 99.5 mol % ethylene or propylene. The process involves multiple stages to achieve the high purity product and provides for processing hydrocarbon streams that have differing concentrations of light olefins.

Disclosed are selectively-permeable membranes and components configured for selective permeation of a specified gas, such as oxygen, therethrough, methods for making the same and methods for using the same, for example, to implement fuel cells and electrochemical cells.