In addition to fuels, bio-oil can also be a source of renewable chemical products and materials. The separation of components as products has been considered an important potential use , but actual commercial application has not been achieved. Separation of bio-oil fractions has been investigated widely and a number of leading opportunities are discussed here. The single chemical product commercially recovered from bio-oil is smoke flavourings, which have been produced and recovered since the 1990s by the Red Arrow Products Company LLC in Wisconsin, USA using the fast pyrolysis technology of Ensyn .
 Radlein, D. The Production of Chemicals from Fast Pyrolysis Bio-oils in Fast Pyrolysis of Biomass: A Handbook, pp. 164-188. CPL Press, Newbury, UK, 1999.