Energetic characterization and flash pyrolysis of different elephant grass cultivars (Pennisetum purpureum Schum.)

Abstract

AbstractLimited fossil fuel reserves combined with greenhouse gas intensification due to CO2 emissions has encouraged research in renewable fuels. In this work, a flash pyrolysis study of elephant grass cultivars—Pennisetum purpureum Schum cultivar Mott (MEG), P. purpureum Schum cultivar Roxo (REG), and P. purpureum Schum cultivar Capiaçu (CEG)—was carried out. The biomasses were evaluated in terms of energy characterization by proximate and ultimate analysis, thermogravimetric analyses (TG/DTG), X‐ray diffraction (XRD), Fourier transform infrared (FTIR), and analytical pyrolysis (Py‐GC/MS) at 600°C. The characterization results showed that these biomasses have potential for energy applications and to produce valuable chemicals. The pyrolysis products produced were mainly oxygenated, including short‐chain organic acids (C1‐C4), furans, esters, aldehydes, ketone, and phenols. Although the obtained results were similar for the three biomasses with small variations in the yields of the pyrolysis products, the study reveals an important difference in terms of energy density. CEG was proven as the most promising elephant grass cultivar to be applied for fast pyrolysis to obtain bio‐oil due to its higher dry matter production (2115 t km−2), power generated (9529 MWh km−2), HHV (16.22 MJ kg−1), lower ash content (6.75%), higher volatile content (74.84%), and higher carbon content (42.57%).