Carbon DIoxide, CO2, or Super-Gas?

Delille Oxygen Company is a trusted supplier of carbon dioxide to Columbus and surrounding areas.

The majority of people not affiliated with the industrial gas industry recognize carbon dioxide, CO2, as the bubbles in soft drinks 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

CO2 was discovered in the early 1600’s as the off gas of burning wood by Jan Baptista von Helmont, a scientist in Finland. In the mid 1700’s an English chemist named Joseph Priestly, discovered sparkling water through the process of combining water and CO2 dissipated from a fermentation process which altered the water’s taste and was the driving force behind the start of 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 knowledge about CO2 was discovered the only gas sold and used in all three of its phases – gas, liquid and solid.

Gas

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

The most fitting 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 has the ability to regulate the pH in certain applications where the pH is an important system parameter. This is prominent in some industries such as paper production, textiles, and water treatment processes. An additional benefit is that carbonic acid is not stored as an acid (such as sulfuric or hydrochloric acids). As mentioned, the CO2 requires water to create 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 usually around 800 psig depending on the atmospheric temperature. This means that any application using liquid CO2 has be under pressure. Employees in the oil industry are aware can compensate for water in enhanced oil recovery (EOR) where the liquid is combined with sand or sand like substance (proppant) and propelled through an oil well to recover oil that has been trapped between layers of rock. EOR is a wide-ranging term that can refer to several different processes but the most common 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 CO2 is used instead of water, its natural expansion of volume from liquid to gas increases the size of the fissure and leads to the recovery of more oil.

It is not commonly known that liquid CO2 is also applied in dry cleaning. In a specific high pressure washer, liquid CO2 is introduced with a stain remover. The laundry is treated as in a regular washing machine employing turbulence to clean the wash. When the cycle is finished, the dirt, grime and stain remover are separated from the liquid CO2. The liquid CO2 is then removed for reuse and when the clothing is taken out and is clean and not wet since there was no water applied.

Every chemical (element or compound) has a state in which the three phases (gas, liquid and solid) have the same qualities and is achieved through proper adjustment of temperature and pressure; this is referred to as the supercritical state. The supercritical state of CO2 can be created in a specifically 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 utilized applied in many different ways as a coolant. When liquid CO2 is transported through a high pressure line and passed through special nozzles, it instantly turns to CO2 snow and is used in the refrigeration or freezing of food. Dry ice pellets can be used in plae of regular ice in cases that hold perishables for long road transportation.

Extremely small pieces of dry ice are (about the size of a grain of rice) applied 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 popular in the aircraft industry where the airplane’s bodies need to remain unharmed and not be damaged from sand blasting. An additional benefit is that the removed coating does not have to be separated from the abrasive as the pellets sublimate to CO2 gas resulting in a simple cleanup.

Referring to CO2 as a super-gas may be debatable, but it is without a doubt the most versatile gas available in the industrial gas market.

For more information on how you can be supplied with carbon dioxide in Columbus for any of your specialty gas operations, call Delille Oxygen Company at (614) 444-1177 or at scotta@delille.com.

John Segura, PE

About the Author

John Segura is a licensed Professional Engineer and an experienced executive in the industrial gas business. He has been in the industry for over 30 years and is experienced in marketing, sales, and operations at both domestic and international levels. Segura has led teams of engineers and technicians as an R & D manager for major gas companies. His work lead him to running the marketing efforts of technology worldwide industrial gas suppliers. Now, he acts as an industry consultant on the business specializing in operations, applications and marketing.