 | Carbon dioxide: Encyclopedia II - Carbon dioxide - Uses
Carbon dioxide - Uses
Liquid and solid carbon dioxide are important refrigerants, especially in the food industry, where they are employed during the transportation and storage of ice cream and other frozen foods. Solid carbon dioxide is called "dry ice" and is used for small shipments where refrigeration equipment is not practical.
Carbon dioxide is used to produce carbonated soft drinks and soda water. Candy called Pop Rocks is pressurized with carbon dioxide gas at about 600 PSI. When you put the candy in your mouth, it melts (just like other hard candy) and releases the gas bubbles with an audible "pop". Traditionally, the carbonation in beer and sparkling wine comes about through natural fermentation, but some manufacturers carbonate these beverages artificially.
The leavening agents used in baking produce carbon dioxide to cause dough to rise. Baker's yeast produces carbon dioxide by fermentation within the dough, while chemical leaveners such as baking powder and baking soda release carbon dioxide when heated or exposed to acids.
Carbon dioxide is often used as an inexpensive, nonflammable pressurized gas. Life jackets often contain canisters of pressured carbon dioxide for quick inflation. Steel capsules are also sold as supplies of compressed gas for airguns, paintball markers, for inflating bicycle tires, and for making seltzer. Rapid vaporization of liquid CO2 is used for blasting in coal mines.
Carbon dioxide extinguishes flames, and some fire extinguishers, especially those designed for electrical fires, contain liquid carbon dioxide under pressure. Carbon dioxide also finds use as an atmosphere for welding, although in the welding arc, it reacts to oxidize most metals. Use in the automotive industry is common despite significant evidence that welds made in carbon dioxide are brittler than those made in more inert atmospheres, and that such weld joints deteriorate over time because of the formation of carbonic acid. It is used as a welding gas primarily because it is much less expensive than more inert gases such as argon or helium.
Liquid carbon dioxide is a good solvent for many organic compounds, and is used to remove caffeine from coffee. It has begun to attract attention in the pharmaceutical and other chemical processing industries as a less toxic alternative to more traditional solvents such as organochlorides. It's used by some dry cleaners for this reason. (See green chemistry.)
Plants require carbon dioxide to conduct photosynthesis, and greenhouses may enrich their atmospheres with additional CO2 to boost plant growth. It has been proposed that carbon dioxide from power generation be bubbled into ponds to grow algae that could then be converted into biodiesel fuel. High levels of carbon dioxide in the atmosphere effectively exterminate many pests. Greenhouses will raise the level of CO2 to 10,000 ppm (1%) for several hours to eliminate pests such as whitefly, spider mites, and others.
In medicine, up to 5% carbon dioxide is added to pure oxygen for stimulation of breathing after apnea and to stabilize the O2/CO2 balance in blood.
A common type of industrial gas laser, the carbon dioxide laser, uses carbon dioxide as a medium.
Carbon dioxide is commonly injected into or adjacent to producing oil wells. It will act as both a pressurizing agent and, when dissolved into the underground crude oil, will significantly reduce its viscosity, enabling the oil to flow more rapidly through the earth to the removal well. In mature oil fields, extensive pipe networks are used to carry the carbon dioxide to the injection points.
Other related archives1750s, 1772, 17th century, 1823, 1834, 1925, 1945, 1958, 2003, Antarctic, Arterial blood gas, As of 2004, B-47, Baker's yeast, Bohr Effect, C4, Callendar effect, Cameroon, Carbon audit regime, Carbon dioxide (data page), Cellular respiration, Charles' law, Earth's atmosphere, Flemish, Greenland, Hemoglobin, Humphrey Davy, Industrial Revolution, Jan Baptist van Helmont, Joseph Black, Joseph Priestley, Lake Nyos, Life jackets, Liquid, Mauna Loa, Michael Faraday, Natural gas, OSHA, Plants, Pop Rocks, Scottish, Water, acids, air, airguns, algae, allosteric, animals, apnea, argon, artificially, asphyxiation, atm, bacteria, baking powder, baking soda, beer, bicarbonate, bicycle, biodiesel, biomass, blood, boron, brittler, bushings, caffeine, calcium carbonate, calcium hydroxide, capillaries, carbohydrates, carbon, carbon cycle, carbon dioxide laser, carbon dioxide sinks, carbonate, carbonated, carbonic acid, carbonic anhydrase, cellular respiration, central processing unit, charcoal, chemical compound, cloud seeding, coal, coal mines, coffee, colorless, combustion, condensation, crude oil, cycle, deforestation, dipole, double bonds, dry cleaners, dry ice, earth's atmosphere, fats, fermentation, fire extinguishers, flammable, fluid or gas inclusions, fog, fog machine, food industry, fossil fuels, frozen foods, fungi, gas, genericized trademark, global warming, graphics processing unit, green chemistry, greenhouse effect, greenhouse gas, greenhouses, hard, helium, heterotrophic, hypercapnia, hyperventilation, ice, ice ages, ice core, ice cream, immediately dangerous to life and health, inerting system, infrared, interglacials, ions, isotope, laser, leavening agents, limestone, lungs, metabolism, microorganisms, mucous membranes, oceans, oil wells, organic compounds, organic matter, organochlorides, overclocking, oxidize, oxygen, paintball, peat, petroleum, pharmaceutical, photosynthesis, ppmv, precipitation, pressures, red blood cells, refrigerants, respiration, respiratory acidosis, respiratory alkalosis, saliva, seltzer, short tons, shot, soda water, soft drinks, solid, solvent, sparkling wine, special effects, stomata, sublimates, sublimation, suffocation, sugars, temperature, teragrams, tonnes, toxic, transmuted, volcanic, volcanic activity, volume, water, weathering, welding, °C, °F
 Adapted from the Wikipedia article "Uses", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki |
