Butanol

Butanol is an organic chemical alcohol with four carbon atoms (C4H10O) that refers to four structural isomers: 1-butanol (n-butanol), 2-butanol (sec-butanol), 2-methyl-1-propanol (isobutanol), and 2-methyl-2-propanol (tert-butanol). It is used as a solvent and chemical intermediate, and as a potential biofuel or gasoline blending component.

Industrial production combines petrochemical and biological routes. The predominant petrochemical route converts propylene to butyraldehyde by hydroformylation, followed by hydrogenation to give n-butanol. Isobutanol and other isomers can be prepared from corresponding aldehydes or via hydration of isobutylene and related olefins. Biobased production includes acetone–butanol–ethanol (ABE) fermentation, historically using Clostridium species, with ongoing research to increase yields and tolerance.

Common uses include as a versatile solvent for coatings, inks, adhesives, cleaners, and as a building block for plastics, lubricants, and other chemicals. Butanol is also evaluated as a platform chemical and as a fuel component, offering advantages such as higher energy density and lower water absorption compared with ethanol.

Safety and environmental notes: Butanol is flammable and can form explosive mixtures with air. Exposure can irritate the eyes, skin, and respiratory system; higher concentrations may affect the nervous system. It is typically biodegradable and has moderate aquatic toxicity; spills should be contained and ventilated.