(175b) Wet Biogenic Waste to Methanol: A Techno-Economic Assessment through Hydrothermal Carbonization-Based Approaches with Negative Carbon Emissions

Methanol has received increased attention for direct use as fuel for shipping, in pure form and in combination with gasoline, in conventional engines with minor modifications. However, due to high manufacturing costs, renewable sources provide only 0.2% of total global methanol supply.

This study investigates the technical and economic aspects of carbon-negative methanol synthesis (CN-MeOH) using sorption-enhanced techniques and hydrothermal wet waste transformation, enabling partial CO₂ capture to maintain an ideal H₂/CO ratio for maximized methanol production efficiency. An alternative scenario backing hydrogen supply using water electrolysis (CN-MeOH Plus) was also evaluated. The CN-MeOH model is the most efficient and environmentally benign methanol production system, with a yield of 67.05%, a 9.88% electric power deficit, and a negative carbon footprint of -2.21 t-CO₂eq/t-MeOH. The CN-MeOH Plus scenario enhances methanol output but at the expense of lower global efficiency (38.99%) and reduced carbon negative potential (-0.275 t-CO₂eq/t-MeOH).