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Cryostar, manufacturer of cryogenic equipment. Proposes cryogenic pumps, centrifugal compressor for Industrial Gas, Natural Gas (LNG), Hydrocarbons and Clean Energy Cryostar : Pressure let down station
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Home Page > Clean Energy > Clean energy generation > Geopressure




  Natural gas comes out of the ground at a very high pressure, called geopressure. It is this pressure that moves the gas through the pipelines of gas distribution systems. However, the pressure is too high to be used safely by end-users (power stations, and industrial, commercial and domestic users).

The pressure at the production platform is between 100-800 bars. For the gas to be suitable for domestic use, it is expanded to just one bar so that it may be used for cooking, for example.

Pressure let down station

At several points in the system, gas goes through ‘pressure reduction stations’, where the pressure of the gas is lowered by squeezing it through a valve. Reducing the pressure in this way releases energy. In most instances today this energy is not being harnessed, even though it is possible to generate carbon free electricity merely by installing a turbo-expander generator system at some of these stations.

Pressure reducing station = Cryostar Clean Energy electricity generation

The gas expands through the turbine resulting in pressure reduction and electricity generation. No gas is burned or used up in this process. It is similar to hydropower, where it is the flow of the water that turns the turbine or mill, leaving the water itself unchanged by the process.

As it is not the gas but the actual pressure reduction that produces energy, geopressure also applies to other fluids where pressure is reduced such as for example with geosteam.

Geopressure is a travelling companion of natural gas
Geopressure follows the electrical base load demand

The amount of electricity that can be generated from a pressure reduction station depends on the required pressure drop and flow.

Cryostar designs and builds turbines to customer requirements in the geopressure industry. Our radial inflow turbines are suitable for this application, their high reliability and efficiency as high as 92% ensure that customers achieve optimal energy recovery.

Use the Cryostar geopressure calculator to estimate the level of potential electricity generation:

Turbo generator single stage with lube oil bearings
- Power output range: 500 kW to 15 MW
- Speed range: 6 000 rpm to 33 000 rpm

Turbo generator double stages with lube oil bearings
- Power output range: 500 kW to 15 MW
- Speed range: 6 000 rpm to 33 000 rpm

Magnetic bearing turbo generator
- Power output: 300 kW
- Speed: 30 000 rpm

Cryostar is a pioneer in expanders equipped with active magnetic bearings (AMB).It began to develop this technology as early as 1984 and delivered its first AMB expander back in 1988. Now Cryostar has the largest base of AMB expanders in operation in the world. No other manufacturer can match this experience.

But Cryostar has not stopped there: it was the first to develop the principle of the MTG pictured above. This innovative turbine is a compact and hermetic solution comprising a high frequency generator with a permanent magnet rotor suspended by active magnetic bearings. This configuration without shaft seal or oil lubricated turbo-gearbox and shaft bearings is almost maintenance free. The MTG can be employed as a throttling device for any gas processes (air separation, natural gas processing, organic Rankine cycle, etc.) instead of throttling valves.


Germany 7.8 MW
Italy 7.7 MW
Netherlands 5.3 MW
Switzerland 2.6 MW
Canada 1.0 MW

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CRYOSTAR - Manufacturer of cryogenic equipment for Industrial Gas, Natural Gas (LNG), Hydrocarbons and Clean Energy