Researchers have synthesized a membrane that may purify hydrogen more efficiently than conventional chemical methods do.
The chemical reactions that produce hydrogen, used widely by the chemical industry, leave the gas contaminated with carbon dioxide, water, and hydrogen sulfide. Depending on the application, these impurities must be partially or completely removed, says Benny D. Freeman of the University of Texas at Austin.
Using membranes for hydrogen purification could require less energy than conventional methods do, Freeman says. Available membranes pass hydrogen into low-pressure chambers, leaving behind the contaminants. However, industry typically needs the gas at high pressures. The cost to recompress the gas has kept membranes from competing with conventional methods, he says.