Abstract: Disclosed is a humidifier for fuel cell including a membrane housing including a first end, a second end positioned at an opposite side of the first end, and plural holes provided along the outer circumferential surface of the second end; hollow fiber membranes having both ends respectively potted into the first and second ends of the membrane housing, wherein the hollow fiber membranes are positioned inside the membrane housing; and a cap including an inlet for moisture-containing unreacted gas, wherein the cap is installed at the second end of the membrane housing, and an inner surface of the cap is provided with plural projections enabling the moisture-containing unreacted gas supplied through the inlet to be uniformly distributed to the plural holes.

Abstract: Method for supplying a high purity gas product comprising providing a first gas stream including a major component and at least one impurity component, determining the concentration of the at least one impurity component, and comparing the concentration so determined with a reference concentration for that component. When the value of the concentration so determined is less than or equal to the reference concentration, the first gas stream is utilized to provide the high purity gas product. When the value of the concentration so determined is greater than the reference concentration, a second gas stream comprising the major component is provided and the first and second gas streams are mixed to yield a mixed gas stream having a concentration of the at least one impurity component that is less than the reference concentration.