Hevea brasiliensis seeds: A novel sustainable feedstock for ethanol production

Abstract The rubber tree ( Hevea brasiliensis ) is cultivated on a large scale mainly for the extraction of latex in Brazil and Southeast Asia, also generating large quantities of seeds. These seeds currently do not have large‐scale applications and may thus be considered as a residue. On another note, ethanol is a biofuel produced from renewable feedstocks, whose production benefits from the use of cheap or residual feedstocks. Thus, this study aimed to analyze the potential of the rubber tree seeds (RTS) for ethanol production, thereby enhancing their value and diversifying biofuel feedstocks. Therefore, an analysis of the RTS composition was carried out, followed by an optimization of the RTS sulfuric acid‐catalyzed hydrolysis, which achieved a yield of 238.03 g of reducing sugars per kg of RTS. Then, the fermentation of these reducing sugars was optimized, using thermoresistant and common baker yeasts, for comparison, yielding 129.82 and 153.85 mL of ethanol per kg of RTS, respectively. As such, it can be concluded that it is possible to produce ethanol from RTSs and, to the best of the author's knowledge, this is the first work describing such a finding.