Hydrogen purifier
A hydrogen purifier is a device to purify hydrogen if hydrogen production is done from hydrocarbon sources, the ultra-high purified hydrogen is needed for applications like PEM fuel cells .
Contents
Palladium membrane hydrogen purifiers[edit]
The palladium membrane is typically a metallic tube of a palladium and silver alloy material possessing the unique property of allowing only monatomic hydrogen to pass through its crystal lattice when it is heated above 300°C.[1]
Dense thin-metal membrane purifier[edit]
Dense thin-metal membrane purifiers are compact, relatively inexpensive and simple to use.[2][3][4]
Pressure swing adsorption[edit]
Pressure swing adsorption is used for the removal of carbon dioxide (CO2) as the final step in the large-scale commercial synthesis of hydrogen. It can also remove methane, carbon monoxide, nitrogen, moisture and in some cases, argon, from hydrogen.
Catalytic recombination or deoxygenation purifier[edit]
Catalytic recombination or deoxygenation is used to remove oxygen (O2) impurities. The process is also known as a 'deoxo' process. The oxygen reacts with the hydrogen to form water vapor, which can then be removed by a dryer if necessary. The catalysts that are used are based on platinum group metals (PGM). A typical system could handle up to 3% O2 in H2 in the feed, and reduce the O2 content to less than 1ppm.[5]
Electrochemical purifier[edit]
The electrochemical purifier works similar to a fuel cell, a voltage is applied to the membrane and the resulting electric current pulls hydrogen through the membrane. A well designed system can simulanously compress the hydrogen.
Applications[edit]
Hydrogen purifiers are used in metalorganic vapour phase epitaxy reactors for LED production.[6]
See also[edit]
References[edit]
- ^ Advanced palladium membrane scale-up for hydrogen separation
- ^ Hydrogen purification membranes
- ^ Dense metal membranes for hydrogen purifying
- ^ Development of Pd Alloy hydrogen separation membranes with dense-porous hybrid structure for high hydrogen perm-selectivity
- ^ 45 Home Power #67 • October / November 1998
- ^ Hydrogen purifiers proving vital to LED production
