Utilization of pequi Residual Biomass from the Brazilian cerrado for obtaining raw and activated biochars and bio-oil

Abstract

The pequi (Caryocar brasiliense Camb) is a fruit native to the Cerrado, with a production of 765 tons per year. However, their peels (76% of the fruit) are generally discarded. In this study, the physical-chemical characterization of the biomass of the pequi was carried out and physical activation processes were developed through slow pyrolysis and physical chemical activation with zinc chloride (ZnCl2) to produce bio-based products, including bio-oil (30.5%) and biochar (34%). Analytical techniques, such as mid-infrared spectroscopy, gas chromatography coupled with mass spectrometry, surface area, pore size, approximate and elementary analysis, helped to elucidate, identify and quantify such compounds. The biochars produced showed a low surface area of 30,30 m²/g (BET) and 39.11 m²/g (Langmuir), however the superior calorific power of activated carbon (29.59 kJ.g-1) and raw coal (26,92 kJ.g-1) highlight the potential of biochar for use as a solid fuel. Bio-oil, on the other hand, presented valuable chemicals in its fraction, such as vaccenic acid (21.23%), palmitic acid (19.73%) and furfural acid (7.04%).