The present work aims to evaluate the potential of producing bio-oils and chars from biomass residues through fast pyrolysis. Pinewood and agro-biomasses – olive bagasse, wheat straw and rice husk – were pyrolysed in a bench scale screw...
moreThe present work aims to evaluate the potential of producing bio-oils and chars from biomass residues through fast pyrolysis. Pinewood and agro-biomasses – olive bagasse, wheat straw and rice husk – were pyrolysed in a bench scale screw reactor at 580 ºC using a carrier gas flow rate of 526 mL/min in order to maximize the resultant bio-oil fraction. The yields of bio-oil, bio-char and gas obtained were
quantified. Bio-liquid yields varied between 51 wt.% for pinewood and 31 wt.% for olive bagasse and the bio-char yields between 38 wt.% for wheat straw and 24 wt.% for pinewood. Subsequently, the bio-oils and chars obtained were analyzed in terms of moisture content, elemental analysis, ash content and heating value. The main conclusions are as follows:
1) pinewood showed the highest potential to pyrolyse; the resultant bio-oil and char have potential to be used as fuels without further treatments.
2) The substantial ash content in the feedstock of the agro-biomasses decreased drastically their bio-oil quality and yield. Furthermore, the low conversion yields related to such biomasses observed in the present work may not justify their valorisation through pyrolysis.
3) The non-homogeneity of the bio-oils from agro-biomasses is a higher challenge to their use as fuel, however, is an opportunity for recovering added-valued by-products. 4) The chars obtained from agrobiomasses with higher ash content and lower energy densities may have potential to be used in the preparation of active carbon when its pore structure and surface are appropriate.
