Comparative biochemical analysis during the anaerobic digestion of lignocellulosic biomass from six morphological parts of Williams Cavendish banana (Triploid Musa AAA group) plants

Abstract

We studied banana lignocellulosic biomass (BALICEBIOM) that is abandoned after fruit harvesting, and assessed its biochemical methane potential, because of its potential as an energy source. We monitored biogas production from six morphological parts (MPs) of the “Williams Cavendish” banana cultivar using a modified operating procedure (KOP) using KOH. Volatile fatty acid (VFA) production was measured using high performance liquid chromatography. The bulbs, leaf sheaths, petioles–midribs, leaf blades, rachis stems, and floral stalks gave total biogas production of 256, 205, 198, 126, 253, and 221 ml g⁻¹ dry matter, respectively, and total biomethane production of 150, 141, 127, 98, 162, and 144 ml g⁻¹, respectively. The biogas production rates and yields depended on the biochemical composition of the BALICEBIOM and the ability of anaerobic microbes to access fermentable substrates. There were no significant differences between the biogas analysis results produced using KOP and gas chromatography. Acetate was the major VFA in all the MP sample culture media. The bioconversion yields for each MP were below 50 %, showing that these substrates were not fully biodegraded after 188 days. The estimated electricity that could be produced from biogas combustion after fermenting all of the BALICEBIOM produced annually by the Cameroon Development Corporation–Del Monte plantations for 188 days is approximately 10.5 × 10⁶ kW h (which would be worth 0.80–1.58 million euros in the current market). This bioenergy could serve the requirements of about 42,000 people in the region, although CH₄ productivity could be improved.