Improvements in the recovery of alcohols

摘要

Alcohols are recovered from gaseous products under high pressure and temperature containing alcohol vapour, in particular the gaseous products of the hydration of olefines, by scrubbing the gases with liquid water which is substantially under the same conditions of temperature and pressure. Water replaces the alcohol in the gas and is used for hydrating further quantities of olefine, while the aqueous alcohol is run off and distilled. The pressures specified are atmospheric to 3,000 pounds per square inch or more, and the temperatures 175 to 375 DEG C. The usual catalysts are used for hydrating the olefines. The ratio of steam to olefine can vary within wide limits and the olefine may contain ethane, propane or other gases inert to the reaction. In the apparatus shown the olefine-containing gas enters at 10, is mixed with gases from the converter 19, and passes to the scrubber 13, where it is treated with preheated water from 14. The gases, free from alcohol and saturated with water vapour, pass through the superheater 17, and hence to the converter where hydration of the olefine takes place, the products being returned to the scrubber by a gas circulator 21. The aqueous alcohol passes from the scrubber to the still 25, via a heat exchanger 22, where it is cooled by heat exchange with water for the scrubber. The still may be heated by live steam and the water remaining in the still passed by means of pump 32, through the heat exchanger and a water heater 34, into the scrubber. Only aliphatic alcohols, which are stable and at least partially miscible with water at the high temperatures and pressures used, can be treated by the process. Ethylene and propylene are specified olefines.ALSO:Alcohols are recovered from gaseous products under high pressure and temperature, containing alcohol vapour, in particular the gaseous products of the hydration of olefines, by scrubbing the gases with liquid water which is substantially under the same conditions of temperature and pressure. Water replaces the alcohol in the gas and is used for hydrating further quantities of olefine, while the aqueous alcohol is run off and distilled. The pressures specified are atmospheric to 3,000 pounds per square inch or more, and the temperatures 175 to 375 DEG C. The usual catalysts are used for hydrating the olefines. The ratio of steam to olefine can vary within wide limits, and the olefine may contain ethane, propane or other gases inert to the reaction. In the apparatus shown the olefine-containing gas enters at 10, is mixed with gases from the converter 19, and passes to the scrubber 13, where it is treated with preheated water from 14. The gases, free from alcohol and saturated with water vapour, pass through the superheater 17, and hence to the converter where hydration of the olefine takes place, the products being returned to the scrubber by a gas circulator 21. The aqueous alcohol passes from the scrubber to the still 25, via a heat exchanger 22, where it is cooled by heat exchange with water for the scrubber. The still may be heated by live steam and the water remaining in the still passed by means of a pump 32, through the heat exchanger and a water heater 34, into the scrubber. Only aliphatic alcohols, which are stable and at least partially miscible with water at the high temperatures and pressures used, can be treated by the process. Ethylene and propylene are specified olefines.