The bulk of acetone production around the world as of 2011 is done through what is known as the cumene process, a hydrolysis reaction of cumene hydroperoxide. Over 90% of acetone production is generated in this manner, and involves a reaction between the plastic propylene and the aromatic compound benzene. The output of the two chemical compounds is phenol and acetone, and, for every pound (0.45 kilograms) of phenol that is produced by the reaction, approximately 0.62 pounds (0.28 kilograms) of acetone is created. Some acetone is also generated from a deyhdrogenation reaction process involving isopropyl alcohol or through the direct hydrogenation of various hydrocarbons.
The cumene process for acetone production was first discovered by Rudolf Yur'evich Uldris in Russia in 1942, and production of acetone using it began in 1949 in Russia and Canada. By 1953, 8,000 metric tons per year were being generated in Canada and, by the year 2002, the US alone was producing 1,839,000 metric tons of the chemical. Commercially, 75% of acetone produced in the US is used to make other chemicals, 12% is used as a universal solvent, and the remaining 13% has a variety of purposes, from the manufacture of adhesives to pharmaceuticals.
The cumene chemical reaction is a fairly straightforward process. Cumene, which itself is a solvent, C9H12, is derived from benzene propylation and then oxidized to produce cumene hydroperoxide. The reaction takes place in a water-based emulsion containing sodium carbonate, Na2CO3, at a temperature of 194° to 266° Fahrenheit (90° to 130° Celsius), and a pressure of 72 to 145 pounds per square inch (5 to 10 bar). The oxidized state of cumene as cumene hydroperoxide is then concentrated in vacuum columns where a cleaving process or splitting of covalent molecular bonds is used to separate it into phenol and acetone.
Acetone production that involves the use of isopropyl alcohol requires combining i-propyl alcohol with water and steam in a vaporizing chamber that is heated to a temperature where the chemicals all react with each other. The reaction is facilitated by circulating the compounds in a turbulent flow, and the useful products of the reaction are acetone and hydrogen. Waste generated in the reaction includes water and some i-propyl alcohol. The acetone is then separated from the hydrogen gas in a scrubber and acetone production in this manner results in a 99% purity by volume.
Though acetone can also be generated using bacterial fermentation processes or through the dry distillation of acetates, the cumene process has come to dominate as of 2011. This is due to the fact that the input chemicals for the process of benzene and propylene are considered to be rather inexpensive, abundant compounds. By contrast, phenol and acetone are valuable industrial chemicals used in the millions of tons around the world in the 21st century.
