Carbon dioxide is an odorless (at very low concentrations), colorless gas that is stable at room temperature. Living creatures produce carbon dioxide as a waste product of respiration, which is then utilized by plants to form food by photosynthesis. Carbon dioxide also has numerous industrial and commercial uses—ranging from firefighting to electronic equipment manufacture.
Carbon Dioxide is used in diverse applications covering many industries, including:
- Food and Beverage…Carbon dioxide is used in beverage carbonation. A natural anti-microbial, carbon dioxide is also used to increase the shelf life of juice and dairy products, protecting taste and texture, and reducing the need for preservatives, natural and artificial. Other applications include: food freezing and chilling, packaging, mixer and blender cooling, ingredient cooling and conveying, and in-transit refrigeration. In its solid form, it is known as dry ice. Many people know carbon dioxide is used in food freezing, carbonated beverages and dry ice. But most don’t realize it also helps to clear the air, clean the water and save the trees.
- Water/Wastewater Treatment…Industrial and municipal wastewater must be neutralized before being discharged to the environment. Carbon dioxide replaces harsher acids for the alkaline neutralization process. It’s safer and cheaper than sulfuric-acid systems, improves controllability, and there’s less downtime and no labor to handle chemicals. It also is less corrosive, and easier to handle and store.
- Metal Fabrication…Commonly utilized as a shielding gas during welding. This prevents atmospheric contamination of molten weld metal during gas shielded electric arc welding process.
- Plant Growth…Carbon dioxide systems greatly improve growth and quality of plants in the greenhouse. Increasing concentrations of the gas results in larger, healthier and faster-growing plants and lower operating costs, especially during the winter, when it can reduce heating costs by 50%. Carbon dioxide replaces gas generators, saving fuel costs and eliminating harmful emissions.
- Pulp and Paper…Carbon dioxide is being used for several different applications within paper mills, all developed to reduce costs and recover valuable chemicals used within the mill process. A process using carbon dioxide, instead of sulfuric acid, to treat pitch build-up in screen rooms is proving very successful.
- Saving the Forest…Carbon dioxide is used to make precipitated calcium carbonate (PCC), which is used to reduce the use of virgin wood fiber in paper making. Applications include: supply of carbon dioxide for on-site PCC production and in-situ formation of PCC during the paper-making process.
- Energy Source…Storage of carbon dioxide at its triple point (the temperature-pressure combination at which carbon dioxide can exist simultaneously as a solid, liquid or gas) is being tested as a means of providing closed-loop refrigeration in order to shift electrical-energy demand to off-peak consumption hours. Under test in Japan, the process offers the potential to customers to shift electrical load while maintaining temperatures as low as minus 60°F (-51°C).
- Cleaning and Solvent Extraction…In its supercritical state (87.9°F (31.1°C) and 1070.6 psia (7.38MPa)), carbon dioxide becomes a versatile solvent. It can replace chlorinated fluorocarbons to clean equipment components. It also can replace many volatile organic chemicals for operations such as decaffeinating coffee or extracting fat from food products.
- Fire Fighting…Carbon dioxide smothers fires without damaging or contaminating materials and is used for fighting fires when water is ineffective, undesirable or unavailable.