Two stage process for production of diisopropyl ether

In the process for the production of diisopropyl ether comprising contacting a C.sub.3 hydrocarbon feedstock containing propene and fresh water with shape selective metallosilicate catalyst particles in at least one fixed bed reactor under olefin hydration and etherification conditions, the improvement comprising;

• contacting said propene sequentially in a first reactor containing said metallosilicate catalyst under olefin hydration and etherification conditions with a recycle stream comprising isopropanol;
• separating said first reactor effluent and contacting unconverted propene from said first reactor with excess water in a second reactor containing acidic olefin hydration and/or etherification catalyst under olefin hydration and/or etherification conditions;
• and
• separating effluent from said first and second reactor to recover diisopropyl ether and provide said recycle stream.

A process for the production of high octane value diisopropyl ether, comprising;

• a) contacting C.sub.3 hydrocarbon feedstock containing propene and a recycle stream comprising isopropanol with acidic shape selective metallosilicate catalyst particles in a first fixed bed reactor under olefin etherification conditions whereby a first reactor effluent stream is produced comprising diisopropyl ether, isopropanol, unconverted propene and water;
• b) separating step (a) effluent stream and recovering a first fraction comprising said unconverted propene and a second fraction comprising said diisopropyl ether and isopropanol;
• c) introducing step (b) first fraction and excess water into a second fixed bed reactor under olefin hydration and/or etherification conditions in contact with acidic sulfonated resin etherification and hydration catalyst particles whereby a second reactor effluent stream is produced comprising diisopropyl ether, isopropanol, unconverted C.sub.3 hydrocarbons and water;
• (d) passing step (c) effluent stream and step (b) second fraction to a splitter or fractionator whereby an overhead stream comprising C.sub.3 hydrocarbons and a bottom stream comprising diisopropyl ether, isopropanol and water are produced;
• (e) extracting step (d) bottom stream with water and recovering an organic phase comprising diisopropyl ether and an aqueous phase comprising isopropanol;
• (f) fractionating or splitting step (e) aqueous phase and recovering an overhead stream comprising step (a) recycle stream and a bottom stream comprising water.