Fast pyrolysis of biomass of different type and origin: Effect on bio-oil and char

Pyrolysis is considered the most promising approach to convert biomass and to generate valuablebio-oils and biochars. This study aimed to investigate fast pyrolysis of different types of wastesfrom Mediterranean biomasses (Opuntia Ficus Indica, Pomegranate, Aleppo Pine Cones, and PinusPinea Cones) and compare the quality of bio-oils and chars.Biomasses were characterized by proximate and ultimate analyses, FTIR spectroscopy, X-ray diffraction,thermogravimetric and calorimetric analysis. Fast pyrolysis experiments were carried outin a heated strip reactor with a heating rate of 103 K/s and holding time of 3 s at 1000 K. Tar productswere readily quenched and collected on a cold pyrex bridge, positioned above the sampleholder at near ambient temperature, so as to minimize secondary reactions. Tar samples were characterizedby GC-MS analysis and the quality in terms of chemical families was discussed. Charsamples were recovered from the strip and analysed by SEM, elemental analysis, and XRD.The results show that the bio-oils and char composition vary sensibly:- Aleppo pine cones and pinus pinea cones, the hardest of the examined biomasses, upon fastpyrolysis produce a bio-oil that is made of oxygenated aromatic compounds and a bio-charwith high carbon content (>60 %), which could be envisaged for soil amendment and carbonsequestration.- Pyrolysis of Opuntia Ficus Indica wastes (peels and cladodes) generates chars with comparablylower carbon content, but particularly rich in potassium (K) and calcium (Ca).The bio-oil from the peels is still rich in aromatic compounds, similar to APC and PPC,while the bio-oil from the cladodes is almost exclusively made of anhydrosugars.- Pyrolysis of pomegranate peels generates a carbon-rich char, as APC and PPC, but the biooilis rich in anhydrosugars and also furfural.From the morphological point of view, all bio-chars seem to be made up of agglomerates of irregularelongated or semi-spherical shaped particles with large macropores.