Willows as a Source of Renewable Fuels and Diverse Products

Abstract

Willows ( Salix ) have a long history of diverse uses which refl ect the large variation in growth form, physiology and biochemistry that can be found within the genus. Perhaps the three most commonly known uses of willows are basket-making, cricket bats and aspirin, all of which rely on specifi c attributes of willow wood. Other traditional uses include hurdles, windbreaks, river-bank stabilisers, and riparian fi lters. Whilst of key importance to the industries they support, these applications of willow have not resulted in extensive and wide-scale plantings. However, since the 1980s, willows have become recognised as a biomass crop, providing renewable feedstock for the energy industry. This includes co-fi ring with coal in electricity plants as well as using willow feedstock in dedicated biomass boilers of all scales to provide heat and/or power. More recently willow is also being investigated as pos- sible biomass source for biofuels and industrial chemicals. These latter applications have already resulted in increased acreage of willow and could in the near future result in very large scale plantations in many countries world-wide. This chapter reviews the diversity of willow in growth form, wood structure and biomass composition and then relates this to the potential of this diverse genus for different end-uses, starting with the more traditional but focusing especially on the more recent.