| 摘要 |
PCT No. PCT/FI96/00677 Sec. 371 Date Jun. 22, 1998 Sec. 102(e) Date Jun. 22, 1998 PCT Filed Dec. 19, 1996 PCT Pub. No. WO97/23437 PCT Pub. Date Jul. 3, 1997A process for preparing tertiary alkyl ethers comprises the steps of reacting C4-7 isoolefins of an olefinic hydrocarbon feedstock with an alkanol in the presence of a first catalyst in a reaction zone to form a reaction mixture containing a tertiary alkyl ether or a mixture of tertiary alkyl ethers, feeding the reaction mixture to a distillation column, distilling the reaction mixture and recovering the alkyl ether(s) with the bottoms product of the distillation. An azeotrope formed by unreacted C4 hydrocarbons and the alkanol is withdrawn as an overhead product of the distillation. According to the invention, a part of the liquid flow of the column is withdrawn to form a side drawoff, and the side drawoff is recirculated to the reaction zone. As a result, the conversion of the reactive C6 hydrocarbons is increased and the operating cost of the ethers process is reduced. |
