GB456547A - Improvements relating to the conversion of ethers to alcohols - Google Patents

Abstract

Ethers are converted to alcohols by hydration with a dilute aqueous acid catalyst such as sulphuric, phosphoric, hydrochloric or, less advantageously an organic acid such as acetic acid, or alternatively an acidic salt such as zinc or aluminium chloride at elevated temperature and pressure such that the bulk of the alcohol formed is retained in the liquid phase and preventing substantial increase in the concentration of the acid. The activity of the catalyst may be increased by adding other substances such as silver salts, or oily substances such as fatty or mineral oils or turkey red oil. Ether entering at 1, Fig. 1, is forced by a pump <PICT:0456547/IV/1> <PICT:0456547/IV/2> 2 through a heater 3 and steam may be added at 4. The vapour enters a packed tower 6 having a heating-jacket 9 and acid liquor is introduced at 7. Any olefine formed is withdrawn by a pipe 10 and passed through a condenser 11 to recover ether which separates from the water in a vessel 13. Acid liquor containing alcohol is withdrawn by a pipe 17 through a pressure-reducing valve 18 to a distilling column 19 having a cooling-coil 21 at the top, alcohol vapour containing some ether being drawn off at 22 to a column 23 for separation. In a modification, Fig. 2, the ether vapour meets sprayed acid liquor in an unpacked reaction vessel 106 having spraying nozzles 107. The temperature may be 200--300 DEG C. Some production of olefine may occur at 250 DEG C. and increases at higher temperatures; this may be checked by adding steam. The pressure may be 225--3000 lb. In the examples, sulphuric acid of 10 per cent and 5 per cent strength is used. The Specification as open to inspection under Sect. 91 states that the reaction temperature may be as low as 20 DEG C. This subject-matter does not appear in the Specification as accepted.