How can two alcohol molecules form an ether through acid-catalyzed dehydration?

Through a process known as bimolecular dehydration, two molecules of an alcohol can react in the presence of an acid to form an ether and water.12

In this reaction, the acid acts as a catalyst to facilitate the loss of a water molecule from the two alcohol reactants. This method is most effective when using simple, primary alcohols, such as methanol or ethanol, and is the primary industrial process for producing diethyl ether.12

It is important to note that this bimolecular pathway competes with unimolecular dehydration, which instead leads to the formation of an alkene. Because these two reactions compete, the formation of ethers via this method requires carefully controlled conditions to ensure a useful yield.12