Pyrolysis: a promising technology for agricultural waste conversion into value-added products

Agricultural waste management poses a significant challenge due to increasing generation rate of this residue, necessitating the development of solutions to minimize various problems in this context. Among the potential possibilities, pyrolysis stands out as a promising technology due to its low operational costs, simplicity of operation, and the production of several value-added products, including solids (biochar), liquids (pyroligneous extracts: pyroligneous acid and bio-oil), and gaseous (non-condensable gases). This work aimed to synthesize the recent advances and potential uses for the products obtained from the pyrolysis of agricultural wastes, with a particular focus on the emerging applications of the liquid fraction. To achieve the purpose of this review, a bibliographic portfolio was created using a state-of-the-art approach, utilizing Scopus as the database. The yields and uses of pyrolysis products vary according to operational parameters, such as temperature, heating rate, residence time, reactor, agro-waste characteristics, and others. These products have diverse potential applications, including environmental uses (soil remediation, wastewater treatment, and bioenergy), pharmaceutical purposes (antimicrobials, antioxidants, anti-inflammatories), food industry uses (preservatives and smoke flavor), and applications in agriculture and livestock (plant growth promotion, pest and disease control, feed additive, and soil conditioner). Therefore, pyrolysis is a promising technology for the valorization of agricultural wastes, promoting various aspects of the circular economy and providing a sustainable solution to obtain several value-added products with diverse applications from this thermochemical conversion process.