Production, prospects and potential application of pyroligneous acid in agriculture

Pyrolysis of plant biomass is a promising way to produce charcoal (solid), tar and pyroligneous acid, and other gaseous products. These products are of great import as they are alternative to traditional fuels and inorganic chemicals. In this review, main emphasis has been given to properties of pyroligneous acid and its potential benefits in agriculture. Pyroligneous acid is a crude condensed, highly oxygenated organic liquid which is a by product of pyrolysis of plant biomass. It mainly consisted of aliphatic, aromatic, and naphthenic hydrocarbons and other oxygenated compounds such as alcohols, aldehydes, ketones, furans, acids, phenols and ethers. Pyroligneous acid exhibits antioxidant and scavenger properties and has been used in agriculture as antimicrobial agent, insecticide, and for the promotion of seed germination and plant growth. This review takes a critical look at some of the production principles, roles of pyroligneous acid in plant growth, development and defense, and the prospects and broader application of pyroligneous acid in agriculture. It is envisaged that this review will generate global discussion and create awareness for the numerous opportunities in pyroligneous acid research and global use.