329. Raschig Process F. Raschig, FR 698341 (1930), C.A. F. Raschig, FR 698341 (1930), C.A. Contents[show] Divisibility Can Raschig phenol process exhibit divisibility? A. Kent, Riegel's Industrial Chemistry (New York, 1962) p 339; W. L. Faith, D. B. Keyes, R. L. Clark, Industrial Chemistry (New York, 3rd ed., 1965) p 586; R. N. Shreve, Chemical Process Industries (New York, 3rd ed., 1967) p 105; Kirk-Othmer Encyclopedia of Chemical Technology vol. Very good heat resistance, dimensional stability and mechanical properties. Reduced mould shrinkage and post-shrinkage, good chemical resistance. What Fruits Are the Most Suitable in Autumn? Based on thc nct equation for Dow and Bayer process: 25, 3012 (1931). The main steps in this process are the production of chlorobenzene from benzene, hydrochloric acid and oxygen, and the subsequent hydrolysis of chlorobenzene to phenol. Home Raschig phenol process exhibits the following properties. In the first step, the reaction is only run to 10% to 15% conversion to prevent the second addition of a chlorine atom to the desired chlorobenzene. The first step uses either a copper or iron chloride catalyst and exposes the materials to air at 250℃. The reaction, however, takes place at very high temperatures in a very acidic environment with hydrogen chloride vapor and therefore the industrial setting must use highly corrosion resistant equipment for the reaction. Yes. In the Kaschig-Hooker process, hydrolysis takes place catalytically over Ca3(PO4)2/SiO2 with H2O at 400-450°C. and for the Raschig-Hooker process, in which HCl from the hydrolysis of chlorobenzene can be used for the oxychlorination of benzene, one would expect a large economic advantage for the latter: Only about 0.02 tomes of HCl are consumed per tonne of phenol. Raschig Process [7], Ullmann's Encyclopedia of Industrial Chemistry, https://en.wikipedia.org/w/index.php?title=Raschig–Hooker_process&oldid=983788425, Articles with unsourced statements from September 2018, Creative Commons Attribution-ShareAlike License, This page was last edited on 16 October 2020, at 07:27. Due to carbon deposition, the catalyst must be regenerated frequently. The harsh chemical environment, use of catalysts, and large energy consumption has made it a target for green chemistry alternatives. Chlorobenzene is not only a suitable starting matcrial for phenol, but is also used in thc manufacture of aniline and as a raw material for numerous other aromatic intermediates. The second step shares the low conversion rate and high selectivity of the first step. In the more economical Raschig-Hooker process - first operated in 1932 by Kh6ne-Poulenc in a 3000 tonne-per-year plant - hlorobenzene is obtained by oxychlorination of benzene with HCl/air mixtures at about 240°C and atmospheric pressure: CuCl2 FeCl3/Al2O3 is used as the catalyst. About 5% higher chlorinated benzenes are obtained as byproducts. In the USA, all plants using this technology have been shut down; however, this classical chlorobcnzene/phenol route is still used to some extent in several countries, including Argentina, India, Italy, and Poland. Commercial process for the production of phenol by the hydrolysis of chlorobenzene, produced by the chlorination of benzene with hydrochloric acid and air: Furthermore, due to the rcquired vaporization of dilutc hydrochloric acid, the Raschig-Hooker process uses large amounts of energy. The ability to recycle the hydrogen chloride made the Raschig–Hooker process preferable to the Dow and Bayer process. The Raschig–Hooker process is a chemical process for the production of phenol. HCl from the benzene chlorinalion is used to release the phenol from its sodium salt. The classical chlorination of benzene, as was still run, for example, by Dow and Bayer until 1975 and 1977, respectively, was done at 25-50°C in the liquid phase with FeCl3 catalyst. The main steps in this process are the production of chlorobenzene from benzene, hydrochloric acid and oxygen, and the subsequent hydrolysis of chlorobenzene to phenol.