­To what extent is hydrolysis pretreatment effective for biogas yield enhancement

The trend of transitioning to low-carbon and sustainable energy systems is crucial for environmental sustainability. While fossil fuels dominate the energy set-up of the world, the continued use of the same is inimical to the environment. Waste-to-energy is a budding area for renewable energy's role in energy transition, thus offering prospects for research and development. As a waste-to-energy conversion pathway, anaerobic digestion (AD) is a technology gaining traction in the global energy landscape. As such, this study assessed the potential enhancement of anaerobic digestion of fibrous waste material mixtures using a pretreatment agent produced from vegetable waste (hydrolysis water), with easily adaptable approaches for the global south. Emphatically, the effect of such pretreatment methods on co-digested waste materials, and their overall implications for Waste-to-Energy technologies is explored. For fibrous waste mixtures pretreated with hydrolysis water produced from vegetable waste (HM), the biogas yields measured are 554.43 ± 4.48 ml/g oTS and 510.08 ± 4.48. For fibrous waste mixtures pretreated with water (NHMM), the yields are 528.02 ± 5.31 ml/g oTS and 496.34 ± 5.31 ml/g TS. The BMPs are 304.9365 ± 4.48 ml/g oTS and 290.411 ± 5.31 ml/g oTS respectively. The study indicates that the samples produced biogas yields which are 49% and 53% higher respectively than what was obtained by their parent mixture studied by the same authors earlier. While the active contribution yield from the pretreatment agents: ordinary water and hydrolysis water are not accounted for, the comfortable difference seen is an indication of the effectiveness of the pretreatment methods used. The study effectively evaluated the theoretical maximum biogas potentials (TBMP) of the samples, using the Boyle’s model, the modified Boyle’s model and the Buswell & Müller model.