Effect of Aqueous Pre-treatment on Biomass Pyrolysis to Bio-oil

Biomass contains several minerals collectively called ash. Some of these minerals enhances bio-oil yield during pyrolysis processes while the others such as sodium, potassium, calcium, zinc, magnesium and silicon reduce the bio-oil yield and promote char formation. The present study focusses on the selective extraction of ash from locally grown biomass via aqueous acidic and basic pretreatments. The pretreatment parameters were optimized (20:1 of liquid-solid ratios, 4.5% of H2SO2 concentrations, 70oC of reaction temperatures and 1 to 10 hours of retention time depending on the species) for the effective extraction of undesired minerals. The pretreated and untreated samples were fast pyrolyzed in a semi-batch tubular furnace in an inert atmosphere (10-50 ml/min of nitrogen flow). The maximum yield of bio-oil, char and non-condensable were 33.2, 45.5 and 44.5wt% observed when pyrolysis temperatures varied from 450 to 800˚C.