METHOD OF PREPARING ALKYL-TERT-ALKYL ETHERS Russian patent published in 1997 - IPC

FIELD: gasoline production. SUBSTANCE: high-anti-knock components of gasoline, namely alkyl-tert-alkyl ethers are prepared from tert-olefins and alcohols by bringing in contact hydrocarbon streams containing tertiary olefins and alcohols with heterogeneous etherification catalysts in one or several separate reaction zones and tapping off stream enriched in unreacted hydrocarbons from the top of concentrating rectification zone and stream enriched in alkyl-tert-alkyl ether(s) from its bottom. Inside diameter of separate reaction zones is as large as 1.5-5 inside diameter of each rectification zone, and one of reaction zones may be formed within exhausting or concentrating rectification zone and have the same inside diameter as the latter. Contacting of all initial hydrocarbon stream or a part of it with alcohol(s) can be preliminarily effected in one or several straight-run reactors, whereupon reaction mixture and hydrocarbons not subjected to contact with alcohol(s) are fed into lower part of separate reaction zone(s) and inside reaction zone or into top part of exhausting rectification zone, advantageously by separate streams, and a part of initial alcohol(s) is preferably fed either into upper part of indicated separate reactor(s) and inside reaction zone, or into concentrating rectification zone. When process scheme is run including at least two reaction zones having cutoff connection with one common concentrating and one common exhausting rectification zones, reactors can be switched such that one of them functions as reaction zone with separate withdrawal of streams into rectification zones and return of streams therefrom, whereas the other plays part of straight-run preliminary reactor. As catalyst activity in reaction zone connected with concentrating and exhausting rectification zones lowers down, this reaction zone is switched to be used as straight-run preliminary reactor and, in place of it, second reaction zone is switched on. EFFECT: enhanced efficiency of process. 3 cl, 4 dwg