The present invention relates method for purifying antibodies, said method comprising a limited number of steps while still allowing obtaining high yields of purified antibodies with an appropriate degree of purity. Briefly, this method comprises only filtration and precipitation steps, omitting the need for chromatography steps.

The present invention relates to a thin-film composite (TFC) membrane composition comprising macrocycles. The invention also relates in part to a method of fabricating a TFC membrane and to a method of using the TFC membrane to separate a desired liquid or gas from a liquid or gas mixture.

The present invention relates to a thin-film composite (TFC) membrane composition comprising macrocycles. The invention also relates in part to a method of fabricating a TFC membrane and to a method of using the TFC membrane to separate a desired liquid or gas from a liquid or gas mixture.

Separation of a gas mixture comprising first and second gases may be improved using three stages of gas separation membrane modules that includes the additional techniques of cooling the feed gas stream that is fed to the feed stage and using a portion of the permeate stage retentate as a sweep gas on the permeate stage.

Separation of a gas mixture comprising first and second gases may be improved using three stages of gas separation membrane modules that includes the additional techniques of cooling the feed gas stream that is fed to the feed stage and using a portion of the permeate stage retentate as a sweep gas on the permeate stage.

Separation of a gas mixture comprising first and second gases may be improved using two cascaded stages of gas separation membrane modules that includes the additional techniques of cooling the feed gas stream that is fed to the feed stage and using a portion of the feed stage retentate as a sweep gas on the feed stage.

Separation of a gas mixture comprising first and second gases may be improved using two cascaded stages of gas separation membrane modules that includes the additional techniques of cooling the feed gas stream that is fed to the feed stage and using a portion of the feed stage retentate as a sweep gas on the feed stage.

A gas separation system includes: a first gas separation membrane unit; a second gas separation membrane unit; a material gas feed line connected to a gas inlet port of the unit; a first compressor interposed to the line; a first connection line connecting a permeated gas discharge port of the unit and a gas inlet port of the unit; and a second connection line connecting a non-permeated gas discharge port of the unit and the line. The unit and unit each have a gas separation selectivity of 30 or greater. The CH.sub.4 recovery rate is 98% or higher. The CO.sub.2 content in non-permeated gas of the unit is 5 mol % or less. The flow rate of gas fed to the unit is 60% or less of the flow rate of material gas fed to the unit.

A gas separation system includes: a first gas separation membrane unit; a second gas separation membrane unit; a material gas feed line connected to a gas inlet port of the unit; a first compressor interposed to the line; a first connection line connecting a permeated gas discharge port of the unit and a gas inlet port of the unit; and a second connection line connecting a non-permeated gas discharge port of the unit and the line. The unit and unit each have a gas separation selectivity of 30 or greater. The CH.sub.4 recovery rate is 98% or higher. The CO.sub.2 content in non-permeated gas of the unit is 5 mol % or less. The flow rate of gas fed to the unit is 60% or less of the flow rate of material gas fed to the unit.

A raw material solution concentration system that has: a first unit for obtaining a concentrated raw material solution and a diluted induction solution by bringing a raw material solution containing a solvent and a solute into contact with an induction solution containing an induction solute through a forward osmosis membrane and transferring the solvent in the raw material solution into the induction solution and the induction solute in the induction solution into the raw material solution; and a second unit for performing a freeze-dry treatment on the concentrated raw material solution and obtaining a further-concentrated product.