A hydrogen purifier is a device to purify
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-to ...
if
hydrogen production
Hydrogen production is the family of industrial methods for generating hydrogen gas. As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming of natural gas and other light hydrocarbons, partial oxidation of ...
is done from hydrocarbon sources, the ultra-high purified hydrogen is needed for applications like
PEM fuel cell
A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen fuel, hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most bat ...
s .
Palladium membrane hydrogen purifiers
The palladium membrane is typically a metallic tube of a
palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself ...
and
silver
Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
alloy material possessing the unique property of allowing only monatomic hydrogen to pass through its crystal lattice when it is heated above 300°C.
Dense thin-metal membrane purifier
Dense thin-metal membrane purifiers are compact, relatively inexpensive and simple to use.
Pressure swing adsorption
Pressure swing adsorption is used for the removal of
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...
(CO
2) as the final step in the large-scale commercial synthesis of
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-to ...
. It can also remove
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane ...
,
carbon monoxide
Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simpl ...
,
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
, moisture and in some cases,
argon
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice a ...
, from hydrogen.
Catalytic recombination or deoxygenation purifier
Catalytic recombination or deoxygenation is used to remove
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...
(O
2) 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.
Electrochemical purifier
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 simultaneously compress the hydrogen.
Applications
Hydrogen purifiers are used in
metalorganic vapour phase epitaxy
Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. ...
reactors for
LED production.
Hydrogen purifiers proving vital to LED production
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See also
* Gas separation
* Hydrogen pinch
Hydrogen pinch analysis (HPA) is a hydrogen management method that originates from the concept of heat pinch analysis. HPA is a systematic technique for reducing hydrogen consumption and hydrogen generation through integration of hydrogen-using act ...
* Membrane gas separation
Gas mixtures can be effectively separated by synthetic membranes made from polymers such as polyamide or cellulose acetate, or from ceramic materials.
While polymeric membranes are economical and technologically useful, they are bounded by thei ...
* Membrane reactor
References
External links
3 industrial hydrogen purifier systems
Power and Energy, Inc.
Setting a new benchmark for hydrogen delivery
{{DEFAULTSORT:Hydrogen Purifier
Hydrogen technologies
Chemical equipment
Industrial gases
Gas technologies