Abstract

SANTIAGO-ORTEGA, Mario A. et al. Biomass of Urochloa brizantha cv. Toledo as raw material for bioethanol production. Agrociencia [online]. 2016, vol.50, n.6, pp.711-726. ISSN 2521-9766.

Evaluation of fast-growing and high biomass-yieldinggrasses has increased worldwide because they are potential energy crops for the production of second-generation bioethanol. In Mexico, studies on high biomass-producing grasses have begun with the aim of using them for biofuel production. The objective of this study was to evaluate the biomass of Urochloa brizantha cv. Toledo as raw material for bioethanol production. Yearly biomass production, calorific power, chemical composition, immediate analysis and theoretical bioethanol yield were determined for six cutting frequencies (30, 60, 90, 120, 150 and 180 d after regrowth). The data were analyzed with GLM (SAS) and treatments means were compared with the Tukey test (p≤0.05). The highest content of hemicellulose and cellulose (p≤0.05) was 30.1 and 44.1 % at the frequencies of 60 and 150 d. The lowest content of lignin (p≤0.05) was 16.2 % at 60 d. The highest contents of ash and protein (p≤0.05) was 9 and 8 % at 30-d. Calorific power did not differ (p≤0.05) between cuttings. With 180 days cutting frequency, the highest quantity (p≤0.05) of biomass (27.95 Mg ha-1 year-1), the largest percentage of holocellulose (73.6 %) and the highest yield of bioethanol (281.3 L Mg dry matter) accumulated. The chemical characteristics and yield of biomass underline the potential of U. brizantha for production of bioethanol in tropical areas.

Keywords : Urochloa brizantha; bioethanol; chemical composition; immediate analysis; calorific power.