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  2. Electrochemical reduction of carbon dioxide - Wikipedia

    en.wikipedia.org/wiki/Electrochemical_reduction...

    In the laboratory, carbon dioxide is sometimes used to prepare carboxylic acids in a process known as carboxylation. An electrochemical CO 2 electrolyzer that operates at room temperature has not yet been commercialized. Elevated temperature solid oxide electrolyzer cells (SOECs) for CO 2 reduction to CO are

  3. Sublimation (phase transition) - Wikipedia

    en.wikipedia.org/wiki/Sublimation_(phase_transition)

    Solid carbon dioxide sublimes rapidly along the solid-gas boundary (sublimation point) below the triple point (e.g., at the temperature of −78.5 °C, at atmospheric pressure), whereas its melting into liquid CO 2 can occur along the solid-liquid boundary (melting point) at pressures and temperatures above the triple point (i.e., 5.1 atm, − ...

  4. Hydrothermal carbonization - Wikipedia

    en.wikipedia.org/wiki/Hydrothermal_carbonization

    A problem in the production of synthesis gas from biomass is the formation of tar, [10] which can be avoided during hydrothermal process management. Biomass is usually processed at a temperature range of (180-350 °C) the biomass is then submerged in water and heated under the pressure of (2-6 MPa) for (5–240 minutes). And the temperature and ...

  5. Sabatier reaction - Wikipedia

    en.wikipedia.org/wiki/Sabatier_reaction

    Paul Sabatier (1854-1941) winner of the Nobel Prize in Chemistry in 1912 and discoverer of the reaction in 1897. The Sabatier reaction or Sabatier process produces methane and water from a reaction of hydrogen with carbon dioxide at elevated temperatures (optimally 300–400 °C) and pressures (perhaps 3 MPa [1]) in the presence of a nickel catalyst.

  6. Carbothermic reaction - Wikipedia

    en.wikipedia.org/wiki/Carbothermic_reaction

    The chemical equation for this process when starting with fluoroapatite, a common phosphate mineral, is: 4 Ca 5 (PO 4) 3 F + 18 SiO 2 + 30 C → 3 P 4 + 30 CO + 18 CaSiO 3 + 2 CaF 2. Of historic interest is the Leblanc process. A key step in this process is the reduction of sodium sulfate with coal: [3] Na 2 SO 4 + 2 C → Na 2 S + 2 CO 2

  7. Carbon dioxide - Wikipedia

    en.wikipedia.org/wiki/Carbon_dioxide

    Plants, algae and cyanobacteria use energy from sunlight to synthesize carbohydrates from carbon dioxide and water in a process called photosynthesis, which produces oxygen as a waste product. [13] In turn, oxygen is consumed and CO 2 is released as waste by all aerobic organisms when they metabolize organic compounds to produce energy by ...

  8. Smelting - Wikipedia

    en.wikipedia.org/wiki/Smelting

    This calcination reaction emits carbon dioxide. The required temperature varies both in absolute terms and in terms of the melting point of the base metal. Examples: Iron oxide becomes metallic iron at roughly 1250 °C (2282 °F or 1523 K), almost 300 degrees below iron's melting point of 1538 °C (2800 °F or 1811 K). [5]

  9. Phase transition - Wikipedia

    en.wikipedia.org/wiki/Phase_transition

    The dependence of the adsorption geometry on coverage and temperature, such as for hydrogen on iron (110). The emergence of superconductivity in certain metals and ceramics when cooled below a critical temperature. The emergence of metamaterial properties in artificial photonic media as their parameters are varied. [2] [3]