How Is Isopropyl Alcohol Made?

Isopropyl alcohol is primarily synthesized using a direct or indirect process of hydrating propene with water. Both methods involve a further purification technique of distilling the isopropyl alcohol from water and other byproducts.

Isopropyl alcohol, otherwise known as 2-propanol, propan-2-ol or its abbreviated form, IPA, is a chemical substance characterized by a lack of color, intense odor and high combustibility. It has the chemical formula C3H8O, where its secondary structure is expressed as (CH3)2CHOH.

IPA is commercially manufactured using the older indirect hydration process, which is widely used in the United States, and the modern direct hydration process, which is more prevalent in Europe. The indirect method involves combining propene, or propylene, with sulfuric acid to create sulfate ester compounds. These organic compounds are then chemically broken down through the addition of steam water to produce IPA and sulfuric acid. The direct hydration technique requires exposing a liquid-gaseous mixture of propene and water to extreme heat and pressure. An ion exchange of sulphonated polystyrene cation consequently occurs inside a flow reactor to form IPA. A completely separate gaseous reaction can be performed using a phosphoric catalyst, while a tungsten catalyst can be utilized in a liquefied reaction. Isopropyl alcohol can also be obtained through the hydrogenation process of acetone, but this method is not economically viable.