Biomass pre-treatment for bioenergy – Case study 5: Leaching as a biomass pre-treatment method for herbaceous biomass
Herbaceous biomass originates from plants that typically have a non-woody stem and that die back at the end of the growing season, in contrast to trees which build up woody biomass over years. For most applications the high inorganic / ash content (particularly Cl and K) causes problems of corrosion or slagging in thermal conversion processes. Extraction experiments with oil palm empty fruit bunches (EFB) and sugar and cane trash have shown that K and Cl concentrations can be reduced to acceptable levels. The cost of extraction on a scale of 40,000 DM (equivalent to a large oil palm mill) was estimated to be approximately 8 US$/ton (6.5 €/ton), which is 5 to 10% of the delivery cost of biomass pellets to European harbours.