Butanol (also butyl alcohol) refers to a four-carbon alcohol with a formula of C4H9OH. There are four possible isomeric structures for butanol, from a straight-chain primary alcohol to a branched-chain tertiary alcohol. APPLICATIONS FOR N-BUTANOL ARE AS FOLLOWS: olvent for dyes, e. g. in printing inks. Extractant in the production of drugs and natural substances such as antibiotics, hormones, vitamines, alkaloids and camphor. Additive in polishes and cleaners, e. g. floor cleaners and stain removers. Solubilizer in the textile industry, e. g. additive in spinning baths or carrier for colouring plastics. -Additive in de-icing fluids. Additive in gasoline for spark-ignition engines (prevents carburetter icing). Mobile phase in paper and thin-layer chromatography. Humectant for cellulose nitrate. Drugs and antibiotics, hormones, and vitamins Gasoline (as an additive) and brake fluid (formulation component) MANUFACTURING PROCESS The main production methods of butanol and octanol are acetaldehyde condensation, fermentation, the Ziegler process andoxo synthesis of propylene. INDIAN PRODUCER At present, n-butanol is produced by The Andhra Petrochemicals Ltd, based on petrochemical feedstock. The company produces butanol along with the octanol at its oxo alcohol plant in Vishakapatnam with the combined installed capacity of 73000 metric tonne per annum. The company expanded the capacity from 39000 metric tonne per annum to 73,000 metric tonne per annum by May 2010. GLOBAL DEMAND There is an increasing interest in use of biobutanol as a transport fuel. 85% Butanol/gasoline blends can be used in unmodified petrol engines. It can be transported in existing gasoline pipelines and produces more power per litre than ethanol. Biobutanol can be produced from cereal crops, sugar cane and sugar beet, etc, but can also be produced from cellulosic raw materials. Biofuels are receiving increasing public and scientific attention, driven by factors such as uncertainties related to oil price, greenhouse gas emission, and the need for increased energy security and diversity. Biofuels are a wide range of fuels which are in some way derived from biomass. It is reported that fossil fuels – oil, coal, and natural gas – dominated the world energy economy, covering more than 80% of the total primary energy supply Global demand 4.5 million metric tonne per annum Growth rate in demand through 2025 3.2% per annum Global demand is split between the U.S., Europe and Asia (driven largely by China).