Carbonic

 

Carbon dioxide (chemical formula CO2) is a chemical compound that is a colorless gas with a density about 53% higher than the density of dry air. Carbon dioxide molecules consist of one carbon atom that is covalently bonded to two oxygen atoms. It occurs naturally in the Earth's atmosphere as a trace gas. The current concentration is about 0.04% (417 ppm) by volume, up from pre-industrial levels of 280 ppm. It forms an acidic solution in water due to the formation of carbonic acid (H2CO3). Natural sources include volcanoes, forest fires, hot springs, geysers, and it is released from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, ice caps, glaciers, and seawater. There are oil and natural gas reserves. Carbon dioxide has a pungent, acidic odor and tastes like soda water in the mouth, but is odorless at normal concentrations.

 As a source of carbon in the carbon cycle, atmospheric carbon dioxide is the main source of carbon for life on earth, and its concentration was in the pre-industrial atmosphere of the earth and has been regulated by photosynthetic organisms and geological phenomena since the end of the Precambrian period. Plants, algae, and cyanobacteria use sunlight energy to synthesize carbohydrates from carbon dioxide and water in a process called photosynthesis, which produces oxygen as a waste product.

In turn, oxygen is consumed and CO2 is released as waste by all aerobic organisms as they metabolize organic compounds to produce energy through respiration. Because plants need CO2 for photosynthesis and humans and animals depend on plants for food, CO2 is essential for life on Earth to survive. It is returned to the water through the gills of fishes and to the air through the lungs of terrestrial animals that breathe air, including humans. Carbon dioxide is produced during the processes of rotting organic matter and fermentation of sugars in bread, beer and winemaking. It is produced from the combustion of wood, peat and other organic materials and fossil fuels such as coal, oil and natural gas. It is an unwanted by-product in many large-scale oxidation processes, for example, it is used in the production of acrylic acid (more than 5 million tons per year).

Carbon dioxide was the first gas to be described as a separate substance. Around 1640, the Flemish chemist Jan-Baptiste van Helmont observed that when charcoal was burned in a sealed container, the mass of the resulting ash was much less than the original charcoal. His interpretation was that the rest of the charcoal had turned into an invisible substance, which he called "gas" or "wild spirit" (spiritus sylvestris). The Scottish physician Joseph Black studied the properties of carbon dioxide in the 1750s. He discovered that limestone (calcium carbonate) could be heated or treated with acids to produce a gas he called "fixed air". He observed that still air is denser than air and has neither flame nor support for animal life. However, he also found that when passed through limewater (an aqueous solution saturated with calcium hydroxide), it precipitates calcium carbonate.

He used this phenomenon to show that carbon dioxide is produced by animal respiration and microbial fermentation. In 1772, the English chemist Joseph Priestley published a paper entitled Saturation of Water with Still Air, in which he described the process of dripping sulfuric acid (or oil of vitriol as Priestley knew it) on plaster to produce carbon dioxide and force the gas to It explained. By stirring a bowl of water, it dissolves in contact with the gas. Carbon dioxide was first liquefied (at high pressure) by Humphrey Davy and Michael Faraday in 1823. The first description of solid carbon dioxide (dry ice) was given by French inventor Adrien-Jean-Pierre Tillorier, who in 1835 opened a pressurized container of liquid carbon dioxide, but found that the cooling caused by the rapid evaporation of the liquid Is. It resulted in a "snow" of solid CO2.

Chemical and physical properties

Structure, bonding and molecular vibrations

Molecular orbital diagram § Carbon dioxide Symmetry of a carbon dioxide molecule in its equilibrium geometry is linear and center of symmetry. The carbon-oxygen bond length in carbon dioxide is 116.3, which is significantly shorter than the approximately 140 pm length of a typical C-O bond and shorter than other functional groups with multiple C-O bonds such as carbonyls. Since the molecule is symmetrical, it has no electric dipole moment.

Carbonic acid is carbon dioxide dissolved in water, where it reversibly forms H. Carbon dioxide (carbonic acid), which is a weak acid because its ionization in water is incomplete.

Chemical reactions of CO2

CO2 is a strong electrophile with an electrophilic reactivity comparable to that of benzaldehyde or strong alpha, β-unsaturated carbonyl compounds. However, unlike similarly reactive electrophiles, nucleophilic reactions with CO2 are thermodynamically less favored and are often highly reversible. Only very strong nucleophiles, such as carbanions provided by Grignard reagents and organolithium compounds, react with CO2 to form carboxylates.

Physical characteristics

"Dry ice" pellets are the common form of solid carbon dioxide, colorless carbon dioxide. At low concentrations, the gas is odorless. However, in high enough concentrations, it has a pungent, acidic odor. At standard temperature and pressure, the density of carbon dioxide is about 1.98 kg/m3, which is about 1.53 times the density of air. Carbon dioxide is not liquid at pressures below 0.51795 MPa. At a pressure of 1 atmosphere (0.101325 MPa), a gas precipitates directly into a solid below 194.6855 (30) K [2] (-78.4645 (30) °C), and a solid sublimes directly into a gas above this temperature. . In its solid state, carbon dioxide is usually called dry ice.

Applications

Carbon dioxide is used by food industry, oil industry and chemical industry. This compound has various commercial uses, but one of its biggest uses is as a chemical in the production of carbonated soft drinks. This application of this compound can be seen in carbonated drinks such as soda water, beer and sparkling wine.

Agriculture

Plants need carbon dioxide to carry out photosynthesis. The atmosphere of greenhouses may (if large) be filled with additional carbon dioxide to maintain and speed up plant growth. At very high concentrations (100 times the atmospheric concentration or more), carbon dioxide can be toxic to animals, so increasing the concentration to 10,000 ppm (1%) or more for several hours kills pests such as whiteflies and spider mites.

Edibles

Carbon dioxide bubbles in a soft drink

Carbon dioxide is a food additive that is used as a propellant and acidity regulator in the food industry.

The candy, called Pop Rocks, is pressurized with carbon dioxide gas to about 4,000 kPa (40 bar; 580 psi). When placed in the mouth, it dissolves (just like other hard candies) and releases gas bubbles with an audible sound.

Yeasts cause the dough to rise by producing carbon dioxide. Baker's yeast produces carbon dioxide by fermenting the sugars in the dough, while chemical yeasts such as baking powder and baking soda release carbon dioxide when heated or exposed to acids.

Drinks

Carbon dioxide is used to produce carbonated soft drinks and soda water. Traditionally, the carbonation of beer and sparkling wine occurred through natural fermentation, but many producers carbonate these beverages with carbon dioxide recovered from the fermentation process. For bottled and cask beer, the most common method used is carbonation with recycled carbon dioxide.

The taste of soda water (and the associated taste sensation in other carbonated beverages) is caused by dissolved carbon dioxide rather than by bursting gas bubbles. Carbonic anhydrase converts to carbonic acid, which results in a sour taste, and dissolved carbon dioxide also causes a somatosensory response.

Winemaking

Dry ice is used to store grapes after harvest. Carbon dioxide in the form of dry ice is often used during the cold maceration step in winemaking to rapidly cool the grape bunches after picking to help prevent spontaneous fermentation by wild yeast. The main advantage of using dry ice over water ice is that it cools the grapes without adding additional water, which may reduce the sugar concentration in the grape pomace and thus the alcohol concentration in the finished wine. Carbon dioxide is also used to create a low-oxygen environment for carbonic maceration, a process used to produce Beaujolais wine.

 Animal anesthesia

Carbon dioxide is often used to "anesthetize" or so-called tranquilize animals for slaughter before slaughter.

Ineffective gas

Carbon dioxide is one of the most common compressed gases for pneumatic systems (gas under pressure) in portable pressure tools. Carbon dioxide is also used as a welding atmosphere, although in the welding arc, it reacts to oxidize most metals. Despite substantial evidence that welds made in carbon dioxide are more brittle than those made in more neutral atmospheres, their use has become common in the automotive industry.

Fire extinguisher

Use of CO2 fire extinguishers

 Carbon dioxide can be used to extinguish flames by flooding the environment around the flame with gas. It does not react to extinguish the flame by itself, but rather destroys the oxygen by displacing the flame. Some fire extinguishers, especially those designed for electrical fires, contain pressurized liquid carbon dioxide. Carbon dioxide extinguishers work well on small flammable liquid and electrical fires, but not on conventional combustible fires because they do not cool the burning material significantly, and when the carbon dioxide disperses, it They can catch fire due to exposure to atmospheric oxygen. They are mainly used in server rooms.

 Supercritical CO2 as solvent

In addition, Supercritical Carbon Dioxide and Green Chemistry Liquid carbon dioxide is a good solvent for many lipophilic organic compounds and is used to remove caffeine from coffee. Carbon dioxide has gained attention in the pharmaceutical and other chemical processing industries as a less toxic alternative to more traditional solvents such as organochlorides. For this reason, it is also used by some dry cleaners. It is used in the preparation of some aerogels due to the properties of supercritical carbon dioxide.

Medical and pharmaceutical

In medicine, up to 5% of carbon dioxide (130 times atmospheric concentration) is added to oxygen to stimulate breathing after apnea and to stabilize the 2/CO2 O balance in the blood. Carbon dioxide can be mixed with up to 50% oxygen to form an inhalable gas. This is known as carbogen and has various medical and research applications. Another medical application is Moffat's dry spas, which use carbon dioxide from volcanic eruptions for therapeutic purposes.

Energy

Supercritical carbon dioxide is used as the working fluid in the Allam power motorcycle.

Recovery of fossil fuels

Carbon dioxide is used to enhance oil recovery where it is injected into or adjacent to producing oil wells, usually in supercritical conditions, when it becomes miscible with oil. This approach can increase original oil recovery by reducing residual oil saturation between 7 and 23% in addition to primary extraction. It acts both as a pressure agent and, when dissolved in crude oil underground, significantly reduces its viscosity, changing the surface chemistry, enabling the oil to move more quickly through the reservoir to the well. to be In mature oil fields, extensive pipe networks are used to transport carbon dioxide to injection points.

In enhanced coalbed methane recovery, carbon dioxide is pumped into the coal seam to displace the methane, as opposed to current methods that rely primarily on water removal (to reduce pressure) to release the coal seam from its trapped methane.

Bio-to-fuel conversion

It has been suggested that carbon dioxide from power generation be pumped into ponds to stimulate algae growth, which can then be converted into biodiesel fuel. A strain of the cyanobacterium Synechococcus elongatus has been genetically engineered to produce the fuel isobutyraldehyde and isobutanol from carbon dioxide using photosynthesis. Researchers have developed a process called electrolysis that uses enzymes isolated from bacteria to power chemical reactions that convert carbon dioxide into fuel.

Refrigerant

Liquid and solid carbon dioxide are important refrigerants, especially in the food industry, where they are used to transport and store 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. Solid carbon dioxide is always below −78.5 °C (−109.3 °F) at normal atmospheric pressure, regardless of air temperature.

Minor

Carbon dioxide laser

Carbon dioxide laser, which is one of the oldest types of lasers.

pH control

Carbon dioxide can be used as a means of controlling the pH of pools, by continuously adding the gas to the water, thereby preventing the pH from rising. One of the advantages of this is avoiding handling acids that are (more dangerous). Similarly, it is also used in reef aquariums, where calcium carbonate is commonly used in calcium reactors to temporarily lower the pH of the passing water to allow the calcium carbonate to dissolve freely in the water. Some corals use it to build their skeletons. It is used as a primary coolant in the British advanced gas-cooled reactor to produce nuclear energy.

Refrence

  1.  "Carbon Dioxide" (PDF). Air Products. Archived from the original (PDF) on 29 July 2020. Retrieved 28 April 2017.
  2. Jump up to:a b c d e f g h i Span R, Wagner W (1 November 1996). "A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple‐Point Temperature to 1100 K at Pressures up to 800 MPa". Journal of Physical and Chemical Reference Data. 25 (6): 1519. Bibcode:1996JPCRD..25.1509S. doi:10.1063/1.555991.
  3.  Touloukian YS, Liley PE, Saxena SC (1970). "Thermophysical properties of matter - the TPRC data series". Thermal Conductivity - Nonmetallic Liquids and Gases. Data book. 3.
  4.  Schäfer M, Richter M, Span R (2015). "Measurements of the viscosity of carbon dioxide at temperatures from (253.15 to 473.15) K with pressures up to 1.2 MPa". The Journal of Chemical Thermodynamics. 89: 7–15. doi:10.1016/j.jct.2015.04.015.
  5. Jump up to:a b c NIOSH Pocket Guide to Chemical Hazards. "#0103". National Institute for Occupational Safety and Health (NIOSH).
  6.  "Carbon dioxide". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  7.  "Safety Data Sheet – Carbon Dioxide Gas – version 0.03 11/11" (PDF). AirGas.com. 12 February 2018. Archived (PDF) from the original on 4 August 2018. Retrieved 4 August 2018.
  8.  "Carbon dioxide, refrigerated liquid" (PDF). Praxair. p. 9. Archived from the original (PDF) on 29 July 2018. Retrieved 26 July 2018.
  9.  Eggleton T (2013). A Short Introduction to Climate Change. Cambridge University Press. p. 52. ISBN 9781107618763. Archived from the original on 23 July 2021. Retrieved 9 November 2020.
  10. "Carbon Dioxide Concentration". Climate Change: Vital Signs of the Planet. NASA. Archived from the original on 23 June 2021. Retrieved 23 June 2021.
  11.  Spritzler F (3 November 2019). "Carbonated (Sparkling) Water: Good or Bad?". healthline.com. Archived from the original on 10 May 2020.
  12.  Kaufman DG, Franz CM (1996). Biosphere 2000: protecting our global environment. Kendall/Hunt Pub. Co. ISBN 978-0-7872-0460-0.
  13.  "Food Factories". www.legacyproject.org. Archived from the original on 12 August 2017. Retrieved 10 October 2011.
  14.  Csepei LI, Muhler M (2011). Kinetic studies of propane oxidation on Mo and V based mixed oxide catalysts (PDF) (PhD thesis). Technical University of Berlin. Archived (PDF) from the original on 30 May 2016. Retrieved 9 July 2017.
  15.  Amakawa K, Kolen'ko YV, Villa A, Schuster ME, Csepei LI, Weinberg G, et al. (2013). "Multifunctionality of Crystalline MoV(TeNb) M1 Oxide Catalysts in Selective Oxidation of Propane and Benzyl Alcohol". ACS Catalysis. 3 (6): 1103–1113. doi:10.1021/cs400010q. Archived from the original on 22 October 2018. Retrieved 9 July 2017.
  16.  d'Alnoncourt RN, Csepei LI, Hävecker M, Girgsdies F, Schuster ME, Schlögl R, Trunschke A (2014). "The reaction network in propane oxidation over phase-pure MoVTeNb M1 oxide catalysts" (PDF). Journal of Catalysis. 311: 369–385. doi:10.1016/j.jcat.2013.12.008. hdl:11858/00-001M-0000-0014-F434-5. Archived from the original (PDF) on 15 February 2016. Retrieved 9 July 2017.
  17. Jump up to:a b Tsotsas E, Mujumdar AS (2011). Modern drying technology. Vol. 3: Product quality and formulation. John Wiley & Sons. ISBN 978-3-527-31558-1. Archived from the original on 21 March 2020. Retrieved 3 December 2019.
  18.  Mikhail M, Wang B, Jalain R, Cavadias S, Tatoulian M, Ognier S, Gálvez ME, Da Costa P (1 April 2019). "Plasma-catalytic hybrid process for CO2 methanation: optimization of operation parameters". Reaction Kinetics, Mechanisms and Catalysis. 126 (2): 629–643. doi:10.1007/s11144-018-1508-8. S2CID 104301429.
  19.  "Catalysts for climate protection". Fraunhofer Institute for Interfacial Engineering and Biotechnology. 19 August 2019. Archived from the original on 1 October 2021. Retrieved 19 October 2019.
  20.  Voiry D, Shin HS, Loh KP, Chhowalla M (2018). "Low-dimensional catalysts for hydrogen evolution and CO2 reduction". Nature Reviews Chemistry. 2 (1): 0105. doi:10.1038/s41570-017-0105.
  21.  Gomez E, Yan B, Kattel S, Chen JG (10 September 2019). "Carbon dioxide reduction in tandem with light-alkane dehydrogenation". Nature Reviews Chemistry. 3 (11): 638–649. doi:10.1038/s41570-019-0128-9. OSTI 1580234. S2CID 202159972. Archived from the original on 15 March 2020. Retrieved 19 October 2019.
  22.  Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean. Washington, DC: National Academies Press. 22 April 2010. doi:10.17226/12904. ISBN 978-0-309-15359-1. Archived from the original on 5 February 2016. Retrieved 29 February 2016.
  23.  Harris D (September 1910). "The Pioneer in the Hygiene of Ventilation". The Lancet. 176 (4542): 906–908. doi:10.1016/S0140-6736(00)52420-9. Archived from the original on 17 March 2020. Retrieved 6 December 2019.
  24.  Almqvist E (2003). History of industrial gases. Springer. p. 93. ISBN 978-0-306-47277-0.
  25.  Priestley J, Hey W (1772). "Observations on Different Kinds of Air". Philosophical Transactions. 62: 147–264. doi:10.1098/rstl.1772.0021. S2CID 186210131. Archived from the original on 7 June 2010. Retrieved 11 October 2007.
  26.  Davy H (1823). "On the Application of Liquids Formed by the Condensation of Gases as Mechanical Agents". Philosophical Transactions. 113: 199–205. doi:10.1098/rstl.1823.0020. JSTOR 107649.
  27.  Thilorier AJ (1835). "Solidification de l'Acide carbonique". Comptes Rendus. 1: 194–196. Archived from the original on 2 September 2017. Retrieved 1 September 2017.
  28.  Thilorier AJ (1836). "Solidification of carbonic acid". The London and Edinburgh Philosophical Magazine. 8 (48): 446–447. doi:10.1080/14786443608648911. Archived from the original on 2 May 2016. Retrieved 15 November 2015.
  29. Jump up to:a b Greenwood NN, Earnshaw A (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  30.  Atkins P, de Paula J (2006). Physical Chemistry (8th ed.). W.H. Freeman. pp. 461, 464. ISBN 978-0-7167-8759-4.