Valorization of Banana Bunch Waste as a Feedstock via Hydrothermal Carbonization for Energy Purposes

In this article, the potential use of banana bunch waste (BBW) as a source of bioenergy through hydrothermal carbonization (HTC) is investigated. BBW, a byproduct of banana production, is difficult to use as a fuel due to its low density and carbon ratio. However, its high lignocellulose content indicates its potential as a bioenergy source. To determine the optimal HTC conditions, an experiment was conducted using temperature, water to feedstock ratio, and processing time, with the RSM Box-Behnken method used to produce 15 trial formulations. Energy value and mass yield data were collected to determine the optimal values for both. The main parameter affecting energy yield was found to be the water to feedstock ratio, and the optimal conditions were determined to be a temperature of 180oC, a water to feedstock ratio of 1.5:1, and a processing time of 15 minutes. The highest energy yield of 99.7% was observed at these conditions, while the lowest mass yield of 25.30% was observed at a temperature of 200oC with a water ratio of 2 and a time of 15 minutes. The heating value of the HTC solid product ranges from 17-27 MJ/kg, which is comparable to low-grade sub-bituminous coal, indicating potential for co-firing with coal and other hydrothermal products as a fuel.