Carbon DIoxide, CO2, or Super-Gas?

Elite Air is a trusted supplier of carbon dioxide to Riverside and surrounding areas.

Many people not involved the industrial gas industry are familiar with carbon dioxide, CO2, as the carbonation in soda and as the chemical in fire extinguishers. However, so many different forms of CO2 are employed in the industrial gas industry that it is one of the most versatile gases on the market

Brief History

At the start of the 1600’s, CO2 was discovered as the product of wood burning by a Finnish scientist named Jan Baptista von Helmont. In the mid 1700’s Joseph Priestly, an English chemist, discovered that the combination of water and CO2 being dispensed from a fermentation process generated sparkling water which gave the water a different taste and became the basis for the soft drink industry.

One of the properties of the gas that was unconvered was it’s simple liquefaction process. This led to CO2 being the first commercial industrial gas to be supplied as a packaged gas. As more was understood, CO2 became the only gas supplied and employed in all three of its phases – gas, liquid and solid.

Gas

Most of us in the industry associate CO2 with the food and beverage industry for its use as a refrigerant or as a shielding gas in welding. There are also additional unique properties of CO2 that contribute to its versatility .

The prime example is when CO2 creates carbonic acid after coming into contact with water. Although it is not a very powerful acid, it is an acid nonetheless and can be used to adjust the pH in some cases where the pH is a relevant system parameter. This is the case in certain industries such as paper production, textiles, and water treatment processes. Another advantage is that carbonic acid is not stored as an acid (such as sulfuric or hydrochloric acids). As mentioned, the CO2 needs water to generate the acid so it remains CO2 until needed and is not considered hazardous like other acids.

Liquid

CO2 is stored as a liquid regardless of the container. The pressure in an uninsulated CO2 cylinder is approximately around 800 psig depending on the surrounding temperature. The result is that any method using liquid CO2 must be under pressure. Employees in the oil industry are aware that CO2 takes the place of water in enhanced oil recovery (EOR) where the liquid is put in a blend with sand or sand like substance (proppant) and sent down an oil well to recover oil that is stuck between rock layers. EOR is a general term that can apply to a variety of procedures but the most frequent is fracking. In this case man made fissures are used to pump the propant into rocks that are rich in oil. As a result, the rock fractures and the trapped oil is released. When using CO2 as an alternative to water, its natural expansion of volume from liquid to gas helps enlarge the fissure and recover an additional amount of oil.

It’s not common knowledge that liquid CO2 is also used to dry clean clothing. In a special high pressure washer, liquid CO2 is introduced with a stain remover. The clothes are then washed regularly employing turbulence to clean the wash. When the cycle is done, the dirt, grime and stain remover are separated from the liquid CO2. The liquid CO2 is then taken out to be recycled and the clean clothes are removed and has remained dry since there was no water utilized in the process.

Every chemical (element or compound) has a state in which the three phases (gas, liquid and solid) have the same qualities and is reached through modification of temperature and pressure; this is known as the supercritical state. The supercritical state of CO2 can be produced in a specially designed processor. The fluid phase of supercritical CO2 is an exceptional solvent and is used to extract fragrances and color from flowers and plants. This process requires specific equipment and is carried out under high pressure.

Solid

Solid CO2 or dry ice is applied in a wide variety of methods as a coolant. When liquid CO2 is moved through a high pressure line and passed through special nozzles, it right away transforms into CO2 snow and utilized to refrigerate and freeze food. Dry ice pellets act as a replacement for regular ice in bins that hold perishables on long trips via roadways.

Extremely small pieces of dry ice are (about the size of a grain of rice) employed as an abrasive to remove coatings from surfaces without harming the surface itself by blasting the rice size pellets through a blasting lance. This is prominent in the aircraft industry where an airplane’s body has to maintain its integrity and cannot tolerate any damage that would occur with sand blasting. An additional benefit is that there is no need to separate the removed coating from the abrasive as the pellets sublimate to CO2 gas leading to a cleanup that is quite easy.

Referring to CO2 as a super-gas may be overstepping the bounds of the definition, but it is certainly the most versatile product available in the industrial gas market.

To learn more about how you can get carbon dioxide in Riverside for any of your specialty gas operations, call Elite Air at (951) 686-7822 or at info@cal-tool.com.

John Segura, PE

About the Author

John Segura is a licensed Professional Engineer and a well-rounded executive in the industrial gas industry. He has over 30 years of experience covering sales, marketing and operations both domestic and international. Segura has been a leader to several teams of technicians and engineers through his work as an R&D manager for dominant gas companies. His work directed him to lead the marketing efforts of technology worldwide industrial gas suppliers. He still remains in the industry but now as a consultant on the business specializing in operations, applications and marketing.