Provided is a method for separating a specific gas from a raw gas using a gas separation membrane module that includes a gas separation membrane element enclosed in a housing. The element includes a gas separation membrane including a hydrophilic resin composition layer. The method includes: preparing the module; increasing pressure in an interior of the module; increasing a temperature in the interior; and feeding a raw gas to the interior. The layer of the module prepared is adjusted to contain moisture, and a moisture content thereof is an amount that allows an equilibrium relative humidity at a temperature of 23 C. of a gas phase portion in the housing to be 10% RH or more. The raw gas feeding step is performed after the preparation step. The pressure increase step and the temperature increase step are performed after the preparation step and before the raw gas feeding step.

The present invention relates to a separation membrane element including: a separation membrane; and a permeate-side channel material disposed on a permeate side of the separation membrane, wherein the permeate-side channel material is a rugged sheet object having a recess and a protrusion on at least one face thereof, the rugged sheet object is composed of a porous region formed of a through-hole in a thickness direction of the rugged sheet and a non-porous region other than the porous region, and a rate of a number of the through-hole in the recess of the rugged sheet object to a total number of the through-hole present in the rugged sheet object is 80% or more.

The present disclosure provides a composite filter assembly and a water purification system, the composite filter assembly includes a housing, and a composite filter, the housing defines a raw water inlet, an initial filtered water outlet, a pressurized water inlet, a pure water outlet, and a waste water outlet, the composite filter includes a pre-posed filter, a membrane filter, and a post-posed filter, the pre-posed filter and the membrane filter are defined in a manner from outside to inside, the post-posed filter is connected with the membrane filter; the initial filtered water outlet is communicated with an outlet end of the pre-posed filter, the pressurized water inlet is communicated with an inlet end of the membrane filter; the outlet end of the pre-posed filter is adjacent to the inlet end of the membrane filter, the initial filtered water outlet is an annular opening which surrounds the pressurized water inlet.

Provided is a membrane module which has a simple and easy structure to restrain its vessel from being increased in costs, and which allows to fabricate the vessel by a simple and easy work, and further to locate an inlet for a fluid, and others at respective predetermined positions of the membrane module.

Provided is an acid gas separation membrane that includes an acid gas separation layer containing a hydrophilic resin and an acid gas carrier, a hydrophobic porous membrane layer supporting the acid gas separation layer, a porous membrane protective layer protecting the acid gas separation layer, and a first layer having a Gurley number of less than or equal to 0.5 times a Gurley number of the hydrophobic porous membrane layer and the porous membrane protective layer, the Gurley number of the first layer being greater than or equal to 0.1 s and less than or equal to 30 s. Also provided is an acid gas separation method using the acid gas separation membrane, as well as an acid gas separation module and an acid gas separation apparatus that each include the acid gas separation membrane.

Provided is a compression bar apparatus for applying pressure to desired areas of a thin film composite (TFC) membrane, such as spiral wound TFC membranes and elements, including membranes and elements used for nanofiltration, reverse osmosis or forward osmosis to purify water, such as tap water, seawater, and brackish water. Application of pressure to a spiral wound element by the apparatus produces a membrane with increased sealant penetration, reduced osmotic blistering, and minimal damage to the active area of the membrane. Also provided are methods of using the apparatus.

A carbon dioxide separation method including the steps of: feeding a mixed gas that contains at least carbon dioxide and water vapor to a carbon dioxide separation membrane that contains a hydrophilic resin and a carbon dioxide carrier; separating, from the mixed gas, a permeation gas that contains the carbon dioxide by use of the carbon dioxide separation membrane; adjusting temperature of gas which contacts the carbon dioxide separation membrane so that a temperature difference between the mixed gas and the permeation gas is not lower than 0? C. and not higher than 20? C.; and adjusting pressure of the permeation gas, the pressure of the permeation gas and water vapor partial pressure in the mixed gas satisfying the following formula (1): 2.5 kPaA<(pressure of permeation gas)<(water vapor partial pressure in mixed gas) . . . (1).

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.

Provided is a method for separating a specific gas from a raw gas using a gas separation membrane module that includes a gas separation membrane element enclosed in a housing. The element includes a gas separation membrane including a hydrophilic resin composition layer. The method includes: preparing the module; increasing pressure in an interior of the module; increasing a temperature in the interior; and feeding a raw gas to the interior. The layer of the module prepared is adjusted to contain moisture, and a moisture content thereof is an amount that allows an equilibrium relative humidity at a temperature of 23? C. of a gas phase portion in the housing to be 10% RH or more. The raw gas feeding step is performed after the preparation step. The pressure increase step and the temperature increase step are performed after the preparation step and before the raw gas feeding step.

A novel positive traction permeate tube and fittings therefor are described for use in spirally wound membrane filtration elements for filtration and separation applications. Membrane filtration elements incorporate the novel permeate tube. Methods of making the novel positive traction permeate tube are also disclosed, as are the preferred sanitary stainless steel materials used for the sanitary tube and fittings. The novel permeate tube involves a sanitary tubing having two open ends, each with an end fitting. The end fittings engage a positive traction drive for high tension spiral winding of a membrane element spirally around the novel permeate tube. Membrane filtration elements made with the novel permeate tube are less subject to slippage and breakage during manufacture and can withstand higher pressure drops and flow rates during use without failure of the spirally wound membrane element. The positive traction permeate tube facilitates membrane replacements.