The Deacon process, invented by Henry Deacon, is a process used during the

manufacture Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of the secondary sector of the economy. The term may refer to a r ...

alkali In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The a ...

s (the initial end product was

sodium carbonate Sodium carbonate (also known as washing soda, soda ash, sal soda, and soda crystals) is the inorganic compound with the formula and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water ...

) by the

Leblanc process The Leblanc process was an early industrial process for making ''soda ash'' ( sodium carbonate) used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: making sodium sulfate from sodium chloride, fol ...

Hydrogen chloride The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...

gas was converted to

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

gas, which was then used to manufacture a commercially valuable bleaching powder, and at the same time the emission of waste

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

was curtailed. To some extent this technically sophisticated process superseded the earlier

manganese dioxide Manganese dioxide is the inorganic compound with the formula . This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for is for dry-cel ...

process.

Process

The process was based on the oxidation of hydrogen chloride: :4 HCl + O₂ → 2 Cl₂ + 2 H₂O The reaction takes place at about 400 to 450 °C in the presence of a variety of catalysts, including copper chloride (CuCl₂). Three companies developed commercial processes for producing

based on the Deacon reaction:Peter Schmittinger et al. "Chlorine," Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co, 2006, *The Kel-Chlor process developed by the M. W. Kellogg Company, which utilizes nitrosylsulfuric acid. *The Shell-Chlor process developed by the

Shell Oil Company Shell USA, Inc. (formerly Shell Oil Company, Inc.) is the United States–based wholly owned subsidiary of Shell plc, a UK-based transnational corporation " oil major" which is among the largest oil companies in the world. Approximately 18,000 ...

, which utilizes copper catalysts. *The MT-Chlor process developed by the Mitsui Toatsu Company, which utilizes chromium-based catalysts. The Deacon process is now outdated technology. Most chlorine today is produced by using electrolytic processes. New catalysts based on

ruthenium(IV) oxide Ruthenium(IV) oxide is the inorganic compound with the formula Ruthenium, RuOxygen, O2. This black solid is the most common oxide of ruthenium. It is widely used as an electrocatalyst for producing chlorine, chlorine oxides, and O2. Like many dio ...

have been developed by Sumitomo.K. Seki, Catal. Surv. Asia 14, 168 (2010) .

Leblanc-Deacon process

The Leblanc-Deacon process is a modification of the Leblanc process. The Leblanc process was notoriously environmentally unfriendly, and resulted in some of the first Air and Water pollution acts. In 1874, Henry Deacon had derived a process to reduce HCl emissions as mandated by the Alkali Act. In this process,

hydrogen chloride The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...

is oxidized by oxygen over a copper chloride

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

, resulting in the production of

. This was widely used in the paper and textile industries as a bleaching agent, and as a result

was no longer the primary product of these plants, and henceforth sold at a loss.

References

External links

* http://www.che.lsu.edu/COURSES/4205/2000/Lim/paper.htm * http://www.electrochem.org/dl/interface/fal/fal98/IF8-98-Pages32-36.pdf * Deacon chemistry revisited: new catalysts for chlorine recycling. ETH (2013). {{doi, 10.3929/ethz-a-010055281; https://dx.doi.org/10.3929/ethz-a-010055281 Chemical processes Inorganic reactions Chlorine

Process

Leblanc-Deacon process

See also

References

External links