Carbon DIoxide, CO2, or Super-Gas?

Criogas is a trusted supplier of carbon dioxide to Mexico and surrounding areas.

Many people not affiliated with the industrial gas industry know carbon dioxide, CO2, as the bubbles in soft drinks and as the chemical in fire extinguishers. But CO2 is utilized in so many different forms that it is actually one of the most versatile gases available

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 an English chemist named Joseph Priestly, found that mixing water and CO2 being expended from a fermentation process created sparkling water which altered the water’s taste and was the driving force behind the start of the soft drink industry.

One of the attributes of the gas that was found was how easily it could be liquefied. The result was that CO2 became the first commercial industrial gas to be supplied as a packaged gas. As more was understood, CO2 became the only gas offered and utlizied in all three of its phases – gas, liquid and solid.

Gas

For those involved in the gas industry, CO2 is most commonly associated 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 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 can be used to regulate the pH in certain applications where the pH is an important system parameter. This is evident in certain 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 form 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. The outcome of this is that any application using liquid CO2 has be under pressure. Workers 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 blanket term to describe different applications but the most prominent is fracking. In fracking man made fissures are used to pump the propant into rocks that are rich in oil. This leads to the fracture of the rock and the subsequent release of the oil inside of it. When using CO2 as an alternative to water, its natural expansion of volume from liquid to gas increases the size of the fissure and leads to the recovery of more oil.

Many people are not aware that liquid CO2 is also used in the dry cleaning industry. In a certain high pressure washer, liquid CO2 is combined with a stain remover. The laundry is then cleaned in a normal fashion 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 used again and the laundry is removed clean and dry since no water was used.

Every chemical (element or compound) has a state in which the three phases (gas, liquid and solid) have the same attributes and is reached through modification of temperature and pressure; this is called the supercritical state. The supercritical state of CO2 can be created in a specifically designed processor. When in its fluid phase, CO2 is a great solvent and is utilized in the extracting of fragrances and color from flowers and plants. The process is, of course, performed under high pressure and requires highly specialized equipment.

Solid

Solid CO2 or dry ice is used as a coolant in several ways and forms. When liquid CO2 is sent 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 can be used in plae of regular ice in bins that hold perishables for long over-the-road transport.

Extremely small pieces of dry ice are (about the size of a grain of rice) used as an abrasive to rid surfaces of coatings without damaging the surface itself by blasting the rice size pellets through a blasting lance. This is prevalent 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. Another advantage is that there is no need to separate the removed coating from the abrasive as the pellets sublimate to CO2 gas leaving the residue particles for easy cleanup.

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

To find out more about how you can get carbon dioxide in Mexico for any of your specialty gas operations, call Criogas at 01-800-400-CRIO or at informes@criogas.com.

John Segura, PE

About the Author

John Segura is a licensed Professional Engineer and an experienced executive in the industrial gas trade. He has worked for over 30 years with both domestic and international experience handling operations, marketing, and sales. 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 lead him to running 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.