Production of Functional Raw Materials via Pyrolysis of Agro-Industrial Byproducts

Abstract

The valorization of agro-industrial byproducts through pyrolysis represents a sustainableroute for generating multifunctional raw materials within the framework of a circularbioeconomy. In this study, rice husk (RH) and sugarcane bagasse (SCB) were pyrolyzed ina semi-continuous reactor at 500 ◦C in order to compare product yields and to characterizeresulting gas, aqueous and tar fractions. SCB produced the highest bio-oil yield (44.2 wt%),whereas RH generated the highest char yield (42.9 wt%), consistent with its higher ashand lignin contents. In both cases, tar represented about 12 wt% of the bio-oil. Detailedcharacterization revealed that the liquid products contained oxygenated compounds ofinterest, mainly carboxylic acids, ketones, and phenols. Acetic acid was the predominantcompound in the aqueous phases, while tars were composed mainly of phenols, ketones,furans, and acids. Particularly, phenols accounted for 52.6% and 37.8% of the total chromatographicarea in RH and SCB tars, respectively, whereas ketones represented about 10%in both cases. These results show that pyrolysis of agro-industrial residues not only enablesenergy recovery but also provides liquid fractions enriched in value-added chemicals.