Liquid and Compressed Carbon Dioxide (CO2)

A number of people know carbon dioxide (CO2) as something produced from combustion, as an integral part of photosynthesis, a plant’s ability to convert carbon dioxide and water to glucose and oxygen in the presence of light, and the stuff that provides “carbonation” to soft drinks, beer and sparkling wines.

But where does purified carbon dioxide start? With all the focus around climate change and the part that carbon dioxide plays in that process, you might think that atmospheric extraction would make the most sense. Surprisingly, atmospheric levels of carbon dioxide average less than 450 parts per million, making that process not very cost-effective and highly inefficient Similarly, natural fermentation may work in a wine bottle and brewing tank, but that process is difficult to replicate on a large-scale basis, is not very efficient and costs too much on a larger scale. No, almost all the purified carbon dioxide that is on the market today is a byproduct of chemical manufacturing, oil refining and natural gas purification.

Carbon dioxide is a slightly acidic, nonflammable gas that is colorless and odorless and, because it is available on such a large scale, has many uses in a wide range of industries. The food industry uses CO2 in food freezing, carbonated beverage manufacturing and modified atmosphere packaging. Carbon dioxide is regarded as an “active gas” in shielding the arc in gas metal arc welding (GMAW / MIG welding) either by itself or in mixtures of argon and helium. Its acidic properties mixed with water make it a good water treatment additive for pH control. Liquid Carbon Dioxide is also expanded in specialized equipment to produce “dry ice” blocks and nuggets used for temporary refrigeration.

Higher purities of carbon dioxide, from Dry to Ultra High Purity and Research Grades are used in laser cutting and marking operations, spanning everything from medical devices to steel fabrication. Growers apply controlled amounts of CO2 to improve fertilizers in greenhouse operations. High purity CO2 is commonly used as an oxygen-free atmosphere for anaerobic incubation, and in the preparation of special application mixtures for blood gas monitoring.

With all these applications, having local Auburn experts on hand to answer questions about carbon dioxide can be really helpful. Give them a call today at Spec Air Specialty Gases at or contact us online.