Carbon DIoxide, CO2, or Super-Gas?

Mississippi Welders Supply Co., Inc. is a trusted supplier of carbon dioxide to Winona and surrounding areas.

The majority of people not involved the industrial gas industry are familiar with carbon dioxide, CO2, as the bubbles in certain beverages and as the chemical in fire extinguishers. CO2 is used in more forms than any other gas in the industrial gas market making it one of the most versatile products sold

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 a chemist in England, Joseph Priestly, discovered sparkling water through the process of combining water and CO2 dissipated from a fermentation process which changed the taste of water and initiated the start of the soft drink industry.

One of the properties of the gas that was found was how easily it could be liquefied. This led to CO2 being the first commercial industrial gas to be sold as a packaged gas. Eventually, after learning more about the gas, CO2 became the only gas sold and used in all three of its phases – gas, liquid and solid.

Gas

CO2 is most often associated by those in the gas industry with welding as a shielding gas and as a refrigerant in the food industry. CO2 also has other attributes that contribute to its uniqueness .

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 is employed to modify the pH in some processes where the pH is a relevant system parameter. This is prominent in some industries such as paper production, textiles, and water treatment processes. One more plus is that carbonic acid is not stored as an acid (such as sulfuric or hydrochloric acids). As mentioned, the CO2 calls for water to generate the acid so it remains CO2 until needed and unlike many other acids, is not considered harmful.

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 ambient temperature. This means that any application using liquid CO2 must be under pressure. Workers in the oil industry are aware can compensate for water in enhanced oil recovery (EOR) where the liquid is mixed with sand or sand like substance (proppant) and propelled through an oil well to recover oil that is trapped inside the rock layers. EOR is a general term that can apply to a variety of procedures but the most common is fracking. In this case the proppant is forced into the oil rich rock through man made fissures. 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 combined with a stain remover. The laundry is then cleaned in a normal fashion using turbulence to clean the wash. When the cycle is completed, the dirt, grime and stain remover are separated from the liquid CO2. The liquid CO2 is then taken out to be recycled 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 properties and is attained adjusting the pressure and temperature; this is known 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 method calls for unique tools and equipment and is executed under high pressure.

Solid

Solid CO2 or dry ice is used as a coolant in several ways and forms. 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 tubs that hold perishables on long trips via roadways.

Extremely small pieces of dry ice are (about the size of a grain of rice) applied as an abrasive to eliminate coating on surfaces without hurting the surface itself by shooting the rice size pellets through a blasting lance. This is prevalent in the aircraft industry in which the body of an airplane must remain intact and not suffer from the harm that sand blasting would cause. This is also advantageous because is that the removed coating does not require separating from the abrasive as the pellets sublimate to CO2 gas leaving the residue particles for easy cleanup.

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

To find out more about how you can get carbon dioxide in Winona for any of your specialty gas operations, call Mississippi Welders Supply Co., Inc. at (507) 454-5231 or at winona@mwsco.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 well-rounded experience leading teams of engineers and technicians from his years as an R&D manager for large gas companies. His work directed him to lead the marketing efforts of technology worldwide industrial gas suppliers. He now consults to the industry on the business specializing in operations, applications and marketing.