Proximate and compositional assessment of pretreatment methods on selected lignocellulose biomass for biogas production

Abstract

 The efficient conversion of lignocellulosic biomass into biogas is a critical avenue in sustainable bioenergy production. Pretreatment enhances the accessibility of lignocellulose components for subsequent enzymatic hydrolysis and biogas production. This study evaluated the proximate and compositional changes induced by various pretreatment techniques on lemon grass and fluted pumpkin stalk, with a focus on optimizing biogas yield. Alkaline, hydrothermal, and combined hydrothermal pretreatment processes were applied on the feedstocks. The biomass surface characteristics were determined through proximate and compositional analysis.The characterization of the untreated biomass showed that lemon grass and fluted pumpkin stalk recorded; dry matter, moisture content, fixed carbon, total kjeldahl nitrogen and ash content in the ranges of 94.49%-94.56%, 5.44%-5.51%, 26.35%-28.95%, 1.33%-1.932% and 6.00%-12.00% respectively. The cellulose values of the untreated biomass ranged from 34.04% for fluted pumpkin stalk to 38.66% for lemon grass. However, the content of the cellulose increased with pretreatment to values ranging from 44.20% to 51.06%. The results of this analysis showed that the selected lignocellulose biomass has properties that are consistent with past literature stating them as suitable substrates for biogas production. Nonetheless, the potential for increased biogas yield from anaerobic digestion is greater when combined hydrothermal and alkaline pretreatment is used.