Process for continuously producing diisopropyl ether

Claim 1

In a process for continuously producing diisopropyl ether of high purity from isopropyl alcohol and propylene at a high yield, the improvements comprising the steps of: passing continuously isopropyl alcohol and propylene at a molar ratio of 1:0.5 to 1:3, of isopropyl alcohol to propylene, through a first fixed bed filled with particles of strongly acidic cation-exchange resin having a mean grain diameter of 0.5 to 10 mm at a liquid space velocity of 0.2 to 2 (1/hr) at a temperature from over 100° C. to 130° C. at a pressure ranging from 20 to 50 atmospheres to react with each other; dividing the resultant reaction mixture emerging from said first fixed bed into first and second streams; passing said first stream through a second fixed bed filled with a water-insoluble, solid, particulate, acid-neutralizing agent having a mean grain diameter of 0.1 to 10 mm, at a temperature ranging from 20° to 130° C., said acid-neutralizing agent being selected from the group consisting of MgO, MgO.mH 2 O (m=0 to 0.5), Al 2 O 3 , hydrotalcite (6MgO.Al 2 O 3 .CO 2 .12H 2 O), Al 2 O 3 .mSiO 2 .nH 2 O (m=0.5 to 3, n=1 to 6), Al 2 O 3 .nH 2 O (n=1 to 6), 2.5MgO.Al 2 O 3 .nH 2 O (n=1 to 6), Na 2 O.Al 2 O 3 .nH 2 O (n=1 to 6), and 2MgO.6SiO 2 .nH 2 O (n=1 to 6); recycling said second stream to said first fixed bed filled with said cation-exchange resin; introducing the resultant neutralized mixture from said second fixed bed into a flashing tower and flashing the mixture to remove unreacted propylene from said mixture; distilling the flashed mixture in a multi-stage distillation tower to recover unreacted isopropyl alcohol from the bottom of said distillation tower and obtain an azeotropic mixture comprising isopropyl alcohol and diisopropyl ether from an upper portion of said distillation tower; bringing said azeotropic mixture comprising isopropyl alcohol and diisopropyl ether into contact with a solvent selected from the group consisting of hydrocarbons, water and lower alcohols having from 1 to 4 carbon atoms, thereby separating said azeotropic mixture into a layer of isopropyl alcohol and a layer of diisopropyl ether, said layer of isopropyl alcohol containing said solvent when said solvent is water or the lower alcohol, and said layer of diisopropyl ether containing said solvent when said solvent is hydrocarbons; separating said layers; and distilling said layer of diisopropyl ether, whereby diisopropyl ether of high purity is obtained.