Abstract
Biogas is a promising source of renewable energy, particularly when produced from agro-industrial residues such as sugarcane waste. However, its utilization requires efficient H2S removal to reduce equipment corrosion, toxicity, and catalyst deactivation. This study provides a comprehensive simulation and economic optimization of the THIOPAQ® process for desulfurization of biogas from sugarcane residues. The process was simulated in Aspen Plus v.15 with the ENRTL-RK thermodynamic model. Three biogas compositions derived from sugarcane straw, bagasse, and filter cake were evaluated using data obtained from a local biogas plant. The process was optimized using a particle swarm optimization algorithm. In all optimization cases, the resulting biogas had an H2S concentration of 5.00 mg/Nm3, corresponding to the upper limit imposed by the optimization model constraints. Bagasse-derived biogas had the lowest process cost (621.66 × 103 USD/yr), followed by filter cake-derived biogas (651.85 × 103 USD/yr) and straw-derived biogas (680.83 × 103 USD/yr). The optimization results indicated that higher CO2 and H2S concentrations in the biogas and NaOH flow rates in the desulfurization process are associated with increased operating costs. Overall, the combined simulation and optimization strategy provides an effective approach to evaluate and improve the THIOPAQ® process for biogas desulfurization from different sugarcane residues.