An apparatus for accurate hydrogen permeability characterization

Jason U Stair, Purdue University

Abstract

This study investigates the construction and validation of a hydrogen permeability test apparatus. Three systems where built to measure the rate of hydrogen flux through a fixed sample. The first apparatus used fixed volumes of gas, held constant on either side of the sample. This apparatus was abandoned for one that allowed fixed streams of gas to flow on either side of the membrane. A hydrogen stream was used on the retentate side of the membrane and a nitrogen stream was used on the permeate side of the membrane. Any hydrogen diffusing through the membrane was swept away by the nitrogen stream and tested using an Agilent 3000 micro gas chromatograph. The system accurately measured the gas mixture; however the hydrogen permeate pressure was difficult to measure. In order to eliminate the permeate pressure as an unknown variable, a third system was built that had a fixed hydrogen flow on the retentate side of the sample and a bubble flow meter on the permeate half. The permeate pressure was fixed at the barometric pressure and the diffusing hydrogen could be simultaneously measured using the bubble flow meter. This apparatus was validated using a 100 micron palladium foil and proved to be a simple and accurate method for measuring hydrogen permeability.

Degree

M.S.

Advisors

Fisher, Purdue University.

Subject Area

Engineering|Mechanical engineering

COinS