Liquid gas – not to be confused with liquid fuel – is any gas species or compound that has been liquefied by cooling, pressurization, or a combination of the two. There are numerous benefits to this method, namely the ability to consolidate the space required for storage. The volumetric difference between a gas in its natural state and when it has been liquefied can be extraordinary, increasing gas storage and transportation capabilities by a factor of thousands of liters (L). For example, 1,000 L of gaseous carbon dioxide (CO2) can be reduced to approximately 2.567 L through liquefaction. Liquid gas storage is consequently more cost-effective and efficient than storing it in its natural state.
In this post, Masteel explores some of the principles of CO2 liquid gas storage in more detail.
Carbon Dioxide: Liquid Gas Storage Parameters
Liquefied CO2 cannot form under normal atmospheric pressures, even in cryogenic conditions. The gas transitions directly to a solid phase, also known as dry ice, via desorption when temperatures drop below -78.5°C (-109.3°F). To put that into context, the only place on earth that approaches within ten degrees of the sublimation point of CO2 is in Antarctica. As a result, liquefied CO2 can only be acquired through industrial methods.
Liquid gas storage conditions typically involve pressures of more than five times that of atmospheric conditions. The gas reduces to a liquefied state at ambient temperatures under a pressure range of approximately 45 – 65 bar. This pressure range can be reduced as low as 12 bar provided the storage tanks are refrigerated to temperatures as low as -35°C (-31°F).
Although liquid CO2 is largely safe to transport and store, care must be taken to remove all but trace levels of water and water vapor from the liquid gas storage container, as liquid CO2 can react with H2O molecules to form the volatile compound carbonic acid. This can inhibit optimal liquid gas storage conditions and reduce the yield for end-users.
Liquid Gas Storage with Masteel
Masteel is one of the UK’s leading suppliers of cryogenic steels for liquid gas storage applications. We provide an industry-tested range of alloys with the appropriate chemistries and mechanical properties for safe and reliable storage of liquefied substances such as liquid CO2.
Although a comparatively niche liquid gas storage application compared to the juggernaut of the liquid natural gas (LNG) market, liquid CO2 storage is still supporting an enormous global industry reported to grow to US $9.16 billion by 2026. This falls in-line with new, industrially-lucrative applications of the gas in its liquid state, from chemical wholesaling to oil recovery operations.
If you are interested in cryogenic steels for liquid gas storage, you might like to read our previous blog post detailing the challenges of liquid gas storage. Otherwise, if you have any questions for the Masteel team, simply contact us today.