A hydrogen compressor is a device that increases the pressure of

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

by reducing its volume resulting in compressed hydrogen or

liquid hydrogen Liquid hydrogen () is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecule, molecular H2 form. To exist as a liquid, H2 must be cooled below its critical point (thermodynamics), critical point of 33 Kelvins, ...

. Traditionally, applications for hydrogen compressors included Chlorine electrolyser and many chemical applications like the production of hydrogen peroxide (HPPO). The newer applications related to green and environmentally friendly technologies include fuel cells and electrolysis for

hydrogen production Hydrogen gas is produced by several industrial methods. Nearly all of the world's current supply of hydrogen is created from fossil fuels. Article in press. Most hydrogen is ''gray hydrogen'' made through steam methane reforming. In this process, ...

Compressor vs pump

Hydrogen compressors are closely related to hydrogen pumps and

gas compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Many compressors can be staged, that is, the gas is compressed several times in steps or ...

s: both increase the pressure on a

fluid In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...

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 Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

is to allow the

to be transported elsewhere.

Types

Reciprocating piston compressors

A proven method to compress hydrogen is to apply reciprocating piston compressors. Widely used in refineries, they are the backbone of refining crude oil. Reciprocating piston compressors are commonly available as either oil-lubricated or non-lubricated; for high pressure (350 - 700 bar), non-lubricated compressors are preferred to avoid oil contamination of the hydrogen. Typical drive power is in the order of magnitude of Megawatts (300kW-15MW). Expert know-how on piston sealing and packing rings can ensure that reciprocating compressors outperform the competing technologies in terms of MTBO (Mean Time Between Overhaul).

Ionic liquid piston compressor

An ionic liquid piston compressor is a hydrogen compressor based on an

ionic liquid An ionic liquid (IL) is a salt (chemistry), salt in the liquid state at ambient conditions. In some contexts, the term has been restricted to salts whose melting point is below a specific temperature, such as . While ordinary liquids such as wate ...

piston instead of a metal piston as in a piston-metal diaphragm compressor.

Electrochemical hydrogen compressor

A multi-stage

electrochemical hydrogen compressor An electrochemical hydrogen compressor is a hydrogen compressor where hydrogen is supplied to the anode, and compressed hydrogen is collected at the cathode with an exergy efficiency up to and even beyond 80% for pressures up to 10,000 psi or 700 b ...

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. The electrochemical compressor works similar to a fuel cell, a voltage is applied to the membrane and the resulting electric current pulls hydrogen through the membrane. With electrochemical compression of hydrogen, a pressure of 14500 psi (1000bar or 100MPa) is achieved. A patent is pending claiming an

exergy efficiency In thermal engineering, exergy efficiency (also known as the second-law efficiency or rational efficiency) computes the effectiveness of a system relative to its performance in reversible conditions. It is defined as the ratio of the thermal effi ...

of 70 to 80% for pressures up to 10,000 psi or 700 bars. A single stage electrochemical compression to 800 bar was reported in 2011.

Hydride compressor

In a hydride compressor, thermal and pressure properties of a

hydride In chemistry, a hydride is formally the anion of hydrogen (H−), a hydrogen ion with two electrons. In modern usage, this is typically only used for ionic bonds, but it is sometimes (and has been more frequently in the past) applied to all che ...

are used to absorb low-pressure hydrogen gas at ambient temperatures and then release high-pressure hydrogen gas at higher temperatures; the bed of hydride is heated with hot water or an electric coil.

Piston-metal diaphragm compressor

Piston A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder (engine), cylinder a ...

-metal diaphragm compressors are stationary high-pressure compressors, four-staged water-cooled, 11–15 kW, 30–50 Nm3/h 40 MPa for dispensation of hydrogen. Since compression generates heat, the compressed gas is to be cooled between stages making the compression less adiabatic and more

isothermal An isothermal process is a type of thermodynamic process in which the temperature ''T'' of a system remains constant: Δ''T'' = 0. This typically occurs when a system is in contact with an outside thermal reservoir, and a change in the sys ...

. The default assumption on diaphragm hydrogen compressors is an adiabatic efficiency of 70%. Used in

hydrogen station A hydrogen infrastructure is the infrastructure of points of hydrogen production, truck and pipeline transport, and hydrogen stations for the distribution and sale of hydrogen fuel, and thus a crucial prerequisite before a successful commerciali ...

Guided rotor compressor

The guided rotor compressor (GRC) is a positive-displacement rotary

compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Many compressors can be staged, that is, the gas is compressed several times in steps o ...

based upon an envoluted

trochoid In geometry, a trochoid () is a roulette curve formed by a circle rolling along a line. It is the curve traced out by a point fixed to a circle (where the point may be on, inside, or outside the circle) as it rolls along a straight line. If the ...

geometry which utilizes a parallel trochoid curve to define its basic compression volume. It has a typical 80 to 85% adiabatic efficiency.

Linear compressor

The single-piston

linear compressor A linear compressor is a gas compressor where the piston moves along a linear track to minimize friction and reduce energy loss during conversion of motion. This technology has been successfully used in cryogenic applications which must be oil-les ...

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.Valved linear compressor
It is used in

cryogenic In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th International Institute of Refrigeration's (IIR) International Congress of Refrigeration (held in Washington, DC in 1971) endorsed a univers ...

References

External links

2004-Osti Hybrid Compressor-Expander
{{DEFAULTSORT:Hydrogen Compressor Gas compressors Hydrogen technologies Industrial gases