Isopropyl alcohol demand capacity and production technology

It has been reported that isopropyl alcohol (IPA), also known as isopropyl alcohol, is used as a low-cost solvent in many industrial and consumer products and can also be used as an extractant. According to the analysis of European Solvent Industry Group (ESIG), in 2001 in Europe, IPA accounted for 32% of its consumption of intermediates, 14% for anti-icing agents, 13% for coatings and resins, and 9% for pharmaceuticals. 4% for food, 3% for ink and binder. It can also be used as a solvent for petroleum and gums, and for the preparation of fishmeal feed concentrates. Low grade IPA can be used as a vehicle fuel. The use of IPA as a raw material for acetone production is declining. There are several compounds that can be synthesized from IPA, mainly methyl isobutyl ketone and many esters. The general purity of anhydrous IPA is more than 99%, and the special grade (used for making flavor and medicine) has an IPA purity of more than 99.8%.

Demand and capacity

According to statistics, in 2001, the total IPA capacity of BP, Sasol and Shell in Europe was 424,100 tons. In 2001, the sales volume in Western Europe was nearly 366,000 tons and the export volume was 46,000 tons. The annual growth rate of demand in Europe and the United States is 1% to 2%. It is expected that the growth rate in Central and Eastern Europe and Asia will be higher. IPA has great potential for use in the production of derivatives and as a solvent with little or no growth.

The total global production capacity exceeds 2.42 million tons/year. Domo and Mitsui Chemicals will build a combined 80,000-ton/year solvent (including IPA) unit in Luna, Germany, and it is expected to start production in 2004.

Production technology

There are two commercial processes for preparing isopropyl alcohol (IPA), all of which use propylene as a raw material. The older method utilizes the indirect dehydration of refinery-grade propylene using sulfuric acid to produce isopropyl sulfate, which is then hydrolyzed with steam to produce sulfuric acid and IPA. The crude IPA is purified by distillation. Newer routes use chemical grade (90% to 99%) propylene to hydrate directly, avoiding the use of sulfuric acid. Propylene and water are heated and the gas-liquid mixture under pressure enters a trickle bed reactor containing sulfonated polystyrene cation exchange resin. The reaction can also be carried out in the gas phase in a fixed bed with phosphoric acid as a catalyst. There is also a liquid phase route using a soluble tungsten catalyst. IPA is obtained from aqueous solutions by distillation. There is also a small amount of IPA produced by hydrogenation in the liquid phase using acetone, but the process is only applicable where there is excess acetone available.