A method for contacting a liquid with a gas in which the gas is introduced into a vessel containing at least one hollow fiber membrane having a plurality of porous hollow fibers. The liquid is introduced into a lumen of at least a portion of the plurality of porous hollow fibers at a liquid pressure sufficient to overcome a resistance to wetting of the porous hollow fibers, thereby covering at least a portion of an outer surface of the plurality of porous hollow fibers with the liquid and providing intimate contact between the gas and the liquid.