1. Gas Liquefaction
Nick Kretschmar

2. Background Most gases were able to be liquefied in the 1800's
First done with a beaker in ice water to compress and cool the gas
All gases have a critical temperature which means the gas cannot liquify at any pressure unless it is less than this temperature

3. Uses Transportation and storage because the density increases greatly
Oxygen in space for burning fuels
Nitrogen in Cryogenics
Helium for near 0 K temperatures and low viscosity

4. Methods Cascade process- Using liquefied gas to liquify another
Compression- apply pressure to the gas at a temperature below the critical temperature
External work by the gas- the gas is cooled and run through a turbine which causes it to loose energy and cool
Joule-Thomson effect- compressing and then rapidly expanding the gas

5. Joule-Thomson effect First a gas is compressed at room temperature
The gas is then released through a small valve
This causes the gas to expand quickly and therefore the temperature to drop
Any gas not turned into liquid is run through the cycle again
The liquid collects and is removed

6. References

7. Any questions? Nick Kretschmar Gas Liquefaction