Abstract: A process for the production of diisopropyl ether where acid is removed, without extraction, from the reactor effluent before being recycled to the reactor or being passed to downstream processing units has been developed. The process involves (1) reacting propylene and water to produce isopropyl alcohol in a reactor and reacting the isopropyl alcohol with propylene to produce diisopropyl ether in the presence of an acidic ion exchange resin catalyst to afford a reactor effluent stream containing at least water, isopropyl alcohol, diisopropyl ether, propylene, and acid, (2) passing the reactor effluent to an acid removal zone to produce an acid-depleted stream, (3) dividing the acid-depleted stream into two portions, and (4) recycling a portion to the reactor and collecting a portion.