| abstract |
The method for separation of isobutylene from hydrocarbon fractions containing four carbon atoms consists in processing said hydrocarbon fractions with water at a temperature of 70°-110° C and a pressure of 16 - 23 atmospheres, at a molar ratio of the said hydrocarbon fractions to water of 1:5-20, in the presence of a polar solvent taken in the quantity of 10-70 per cent of the weight of water, and also in the presence of a catalyst. The resultant reaction mixture contains tertiary butyl alcohol and water. Tertiary butyl alcohol is isolated from the reaction mixture as its aqueous solution and is dehydrated at a temperature of 80°-110° C and a pressure not above 3 atm, in the presence of the same catalyst. The catalyst, that is used at the stage of processing the hydrocarbon fractions with water, and also at the step of dehydration of tertiary butyl alcohol, is a moulded ion-exchange catalyst consisting of a sulphonated copolymer of styrene with divinylbenzene or diisopropenylbenzene, and a sulphonated thermoplastic material, for example, sulfonated-polyethylene, -polypropylene and -polyvinyl chloride, taken in the weight ratio of 1-4:1-2, of sulfonated styrene-dialkenylbenzene copolymer:sulfonated thermoplastic material, respectively. |