Bio-oil and char obtained from cassava rhizomes with soil conditioners by fast pyrolysis

Abstract

We studied the properties of the bio-oil and char from fast pyrolysis of cassava rhizomes in a free-fall reactor, catalyzed by adding various soil conditioners (or improvers) as catalysts to the reactor at 500 °C and 200 g/h feed rate. Four conditioners were evaluated - granular TPI pH11 soil conditioner, volcanic rock, TPI pelletized organic fertilizer and super dolomite - and added at 50% (w/w) of the rhizomes. Bio-oil and gas yields decreased, whereas char yields increased, yielding bio-oil 57-59%, gas 14-20% and char 23-28%. With the catalysts, the bio-oil higher heating value increased, while that of char decreased: for cassava rhizomes with volcanic rock the bio-oil high heating value increased from 19.4 to 23.6 MJ/kg, whereas rhizomes with dolomite led to an increased viscosity from 27 to 34 × 10-3 mm2/s.