Sweet sorghum (Sorghum bicolor (L.) Moench), an annual C4 plant, is considered as a suitable biomass for biofuel production due to its high biomass yields, rapid growth rate, and low water and nutrient needs. In an integrated biorefinery concept, sweet sorghum has the potential to produce high-value products such as animal feed, renewable fuels, chemicals, and fertilisers, unlike any other annual crop. This integrated biorefinery approach will allow us to utilise the whole crop biomass more efficiently to generate renewable biofuels, high-value by-products such as organic acids, thereby enhancing the economic viability of the project through crop biorefinery concept. The aim of this PhD study is to evaluate the feasibility of utilising sweet sorghum, grown on fallow land of sugarcane farming, as a feedstock to produce biohydrogen (H2), organic acids, and methane (CH4) in an integrated biorefinery concept. To optimise the individual bioprocesses, chemical composition analysis and lab-scale experiments were conducted, followed by a feasibility of farm-scale biogas plant and evaluate the biogas utilisation options. [...]