Fast pyrolysis of Amazon tucumã (Astrocaryum aculeatum) seeds in a bubbling fluidized bed reactor

Biofuels are often presented as a contribution toward the solution of the problems related to the world's strong dependency on fossil fuels, such as greenhouse gas effects and urban pollution, in addition to being a way to support rural development. Biomass is the most important renewable energy source and the state of Amazon in Brazil, which is completely covered by the Amazon rainforest, has great potential as a source of biomass. The aim of this research was to study the conversion process of the seed residue of Amazon-tucumã (Astrocaryum aculeatum) into bio-oil by fast pyrolysis. The seed residue was ground and samples with a diameter smaller than 2 mm were pyrolyzed in a bubbling fluidized bed of inert silica sand. The residence time of gases was maintained at 1.4 s with the reactor temperatures ranging from 400 to 600 °C. All liquid and solid products generated during the process were weighed, analyzed, and characterized (HHV, GC–MS, ultimate analysis and ash mineral analysis). The produced bio-oil was a homogeneous fuel, with a maximum liquid yield of 60 wt% at 500 °C, with a water-free high heating value (HHV) of 20.2 MJ/kg. The highest water-free HHV (30.5 MJ/kg) was found at 550 °C, for which the liquid yield was around 55 wt%. The results demonstrated that there is a great potential for using the bio-oil from Amazon-tucumã for bio-fuel production in addition to the production of some high-value compounds, such as levoglucosan and guaiacol.

► First study of tucumã seed pyrolysis in a lab-scale bubbling fluidized bed reactor.
► The bio-oil produced from tucumã seed could be an attractive fuel with a water-free higher heating value (HHV) of 30.5 MJ/kg at 550 °C.
► The bio-oil average liquid yield at 550 °C was of 55 wt%.
► The optimized pyrolysis temperature for practical process energy yield (90%) and product quality is 550 °C.
► High-value compounds, including levoglucosan and guaiacol, are contained in the bio-oil at 550 °C.