Potential for biogas generation from sweet potato genotypes

Abstract

Biogas is a technology that enables the generation of energy through the process of anaerobic biodigestion, and sweet potato is an option as an energy production source. This research evaluated biogas production in anaerobic biodigesters and characterized the physico-chemical composition of two commercial sweet potato cultivars, BRS Cuia and BRS Rubissol, and two genotypes, Bela Vista and Laranjeiras. Variance analysis, the Tukey test and the physical-chemical characterization were completed, and the results were correlated using principal component analysis (PCA). In the analyses of tuberous root composition, significant differences between the genotypes were observed because of the influence of the absorption of moisture, decomposition, and variations in the yield and quality of roots. For the biochemical methane potential (BMP) test, the estimate of biogas production was 2,906.5 liters ha-1 for the cultivar BRS Cuia, 2,712.4 liters ha-1 for Laranjeiras, 2,906.5 liters ha-1 for BRS Rubissol, and 398,2 liters ha-1 for Bela Vista. The PCA analysis of sweet potato genotypes, physical-chemical and agronomic parameters showed all genotypes have a direct correlation with the amount of reducing sugars and humidity, with 97.77% of the data variability explained. The Laranjeiras genotype has the most significant potential to produce biogas, followed by the BRS Cuia cultivar. The results emphasize that the sweet potato crop is a good source of biomass for energy generation.