A hydrogen compressor is a device that increases the pressure of hydrogen by reducing its volume. Compression of hydrogen gas naturally increases its temperature, due to Charles' Law.

Hydrogen compressors are closely related to hydrogen pumps and gas compressors: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of hydrogen gas, whereas the main result of a pump raising the pressure of a liquid is to allow the liquid hydrogen to be transported elsewhere.

Contents 1 Types of hydrogen compressors 1.1 Piston-Metal Diaphragm compressor 1.2 Ionic liquid piston compressor 1.3 Guided rotor compressor 1.4 Linear compressor 1.5 Hydride compressor 1.6 Electrochemical hydrogen compressor 2 See also 3 References 4 External links

[edit] Types of hydrogen compressors

[edit] Piston-Metal Diaphragm compressor

Piston-metal diaphragm compressors are stationary high pressure compressors, 4 staged water cooled, 11~15kW 30~50Nm3/h 40MPa for dispensation of hydrogen.^[1] Since compression generates heat, the compressed gas is to be cooled between stages making the compression less adiabatic and more isothermal. The default assumption on diaphragm hydrogen compressors is an adiabatic efficiency of 70%^[2]. Used in hydrogen stations.

[edit] Ionic liquid piston compressor

A ionic liquid piston compressor, is a hydrogen compressor based on a ionic liquid piston instead of a metal piston as in a piston-metal diaphragm compressor^[3].

[edit] Guided rotor compressor

The guided rotor compressor (GRC) is a positive displacement rotary compressor based upon an envoluted trochoid geometry which utilizes a parallel trochoid curve to define its basic compression volume^[4][5]. It has a typical 80 to 85% adiabatic efficiency^[6].

[edit] Linear compressor

The single piston linear compressor uses dynamic counterbalancing, where an auxiliary movable mass is flexibly attached to a movable piston assembly and to the stationary compressor casing using auxiliary mechanical springs with zero vibration export at minimum electrical power and current consumed by the motor^[7]. It is used in cryogenics

[edit] Hydride compressor

In a hydride compressor the use of the thermal and pressure properties of a hydride are used to absorb low pressure hydrogen gas on ambient temperatures and release high pressure hydrogen gas on higher temperatures, on release the bed is heated with hot water or an electric coil^[8].

[edit] Electrochemical hydrogen compressor

A multi-stage electrochemical hydrogen compressor incorporates a series of membrane-electrode-assemblies (MEAs), similar to those used in proton exchange membrane fuel cells, this type of compressor has no moving parts and is compact. With electrochemical compression of hydrogen a pressure of 5000 psi is achieved. Pressure is believed to go beyond 10,000 psi to the structural limits of the design ^[9]. A patent is pending for an exergy efficiency of 70 to 80% for pressures up to 10,000 psi or 700 bars^[10]

[edit] See also

• Compressed hydrogen
• Hydrogen turboexpander-generator
• High pressure electrolysis
• Hydrogen embrittlement
• Hydrogen tank
• Hydrogen leak testing

[edit] References

1. ^ Piston-metal diaphragm compressor
2. ^ Efficiency and performance measurement of a pdc single stage diaphragm hydrogen compressor-Pag.32
3. ^ New developments in pumps and compressors using Ionic Liquids
4. ^ GRC - Detailed description and defining geometry
5. ^ Hydrogen delivery liquefaction & compression
6. ^ Mechanical properties
7. ^ Valved linear compressor
8. ^ Hydride compressor
9. ^ Electrochemical hydrogen compressor
10. ^ Electrochemical hydrogen compressor

[edit] External links

• 2004-Osti Hybrid Compressor-Expander