Hydrogen chloride purification

Erroneous use of aluminium instead of alumina pellets in a hydrogen chloride purification reactor caused a vigorous exothermic reaction which distorted the steel reactor shell. 

F020 - Wastes (except wastewater and spent carbon from hydrogen chloride purification) from the production or manufacturing use (as a reactant, chemical intermediate, or component in a formulating process) of tri- or tetrachlorophenol, or of intermediates used to produce then-pesticide derivatives. (This hsting does not include wastes from the production of hexachlorophene from highly purified 2,4,5-trichlorophenol.)... 

F023 - Wastes (except wastewater and spent carbon from hydrogen chloride purification)... 

The gases from the reactor are then cooled and subjected to a caustic wash to remove unreacted hydrogen chloride. This is then followed by a methanol wash to remove water introduced during the caustic wash. A final purification to remove aldehydes and ethylidene dichloride, formed during side reactions, is then carried out by low-temperature fractionation. The resulting pure vinyl chloride is then stored under nitrogen in a stainless steel tank. 

An alternative purification can be effected by dissolving the reaction product in water. The ester base is liberated by rendering the clarified aqueous solution alkaline. Removal of the base from the alkaline solution is achieved by extraction with a Suitable solvent such as benzene or ether. The pure hydrochloride of diethylaminoethyl 2-chloro-4-aminobenzoate Is then precipitated from the dried extract by the addition of dry hydrogen chloride. After removal by filtration and recrystallization from ethanol it is found to have a melting point of 173° to 174°C. 

Since hydrogen chloride is evolved in the early stages of this distillation, no effort is made to control the pressure. The vacuum pump is protected from the hydrogen chloride by insertion of a 1.5 X 15-in. glass tube packed with sodium hydroxide pellets in the vacuum line. The purpose of this distillation is to remove dissolved hydrogen chloride and the zinc chloride catalyst it should be completed as rapidly as possible, under the best vacuum attainable, with no attempt at fractionation. The distillate may be fractionally distilled for further purification if... 

Anhydrous copper(II) sulfate, 7 773 Anhydrous ethanol, production by azeotropic extraction, 8 809, 817 Anhydrous gaseous hydrogen sulfide, 23 633 Anhydrous hydrazine, 13 562, 585 acid-base reactions of, 13 567-568 explosive limits of, 13 566t formation of, 13 579 vapor pressures of, 13 564 Anhydrous hydrogen chloride, 13 809-813 physical and thermodynamic properties of, 13 809-813 purification of, 13 824-825 reactions of, 13 818-821 uses for, 13 833-834... 

Though the PECH decomposes to indefinite fragments with n-butyl lithium or sodium hydride in THF at room temperature, it reacts with sodium methoxide with liberation of Cl in which the -elimination of hydrogen chloride predominates instead of nucleophilic substitution. For instance, PECH in DMSO was reacted with double the molar quantity of sodium methoxide at room temperature for 24 h to give the unsaturated polyether (DS 92.3%,v(C=C) 1630,5 (=CH2) 795 cm" ) after purification by dissolution(DMF)-precipitation (H20) technique. A similar unsaturated polyther was obtained by the pyrolysis of the sulfilimine 13 (110-130°C) but not of sulfoxide 12 (100-150°C). When the polymer 26, was heated to 90°C, the absorption of C=C and =CH2 decreased and a new absorption at 1720 cm appeared and increased. This is explained as a result of [3.3] sigmatropic rearrangement of to afford including C=CH2 and C=0 structure as shown in equation 7. 

Acetylation of the stericaUy hindered amine in 40 required treatment with acetic anhydride and sodium acetate at 116°C. The resulting r-butyl acetamide was treated with one equivalent of hydrogen chloride in ethanol followed by filtration of the precipitate to give clean hydrochloride salt 41 in 87% yield. This was the only purification step in the entire... 

In the second step, trichlorosilane is formed by the reaction of the silicon with anhydrous hydrogen chloride, HCl. The reaction of the sohd silicon and gaseous HCl occurs at 300°C in the presence of a catalyst. This step is important to purification, since chlorides of the aluminum and boron impurities also are formed. The resulting... 

Hydrogen, purification of, 186 Hydrogenation, catalytic, 471 high pressure, 866-874 Hydrogen bromide, 180-182 Hydrogen chloride, 179, 180 Hydrogen cyanide, 182 Hydrofluoric acid, 611... 

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