Ash analysis
Three pre-weighed, desiccated crucibles with known mass of dried OPF bagasse sample were burnt using bunsen burner until there was no flame and smoke. The crucibles were put into muffle furnace at 575 °C for 24 h. Later, the samples were cooled in a desiccator for an hour before the weight was recorded. Ash percentage was calculated from the weight of the remain of burnt biomass (ash) over the weight of the original dry sample [27] by the following equation.