Assessing Biomass-Based Methanol Production via Electrified Gasification and Solar-Assisted CO₂ Utilization

This study investigates an electrified biomass-to-methanol synthesis pathway integrated with carbon utilization and renewable energy technologies. Two representative feedstock categories are assessed, namely, lignocellulosic biomass (pine) and agri-food wastes (spent coffee grounds, SCG). Process simulations are conducted in Aspen Plus for four configurations: a fully electrified base case powered by grid electricity, a solar-assisted variant of base case, a methanation-enhanced configuration of base case, and a hybrid system combining both solar electricity and methanation. An advanced process optimization framework is applied to enhance waste heat recovery, power generation, and utility integration, while identifying the minimum energy requirements (MER) of each configuration. Electrification of gasification and reforming processes enhances carbon utilization, achieving carbon efficiencies of 61.6% for lignocellulose and 52.6% for agri-food waste. Methanation further improves carbon recovery to 82.9 and 68.4%, while solar integration increases efficiencies to 87.3 and 73.6%, respectively. Feedstock cost remains the dominant driver of the minimum selling price (MSP), whereas solar integration significantly reduces external utility dependence. Carbon credits for captured biogenic CO₂ (assumed at 65 €/t) solar-assisted configurations yield methanol MSP of 0.683 €/kg (lignocellulosic biomass) and 0.785 €/kg (agri-food waste), compared with 0.707 and 0.791 €/kg for the corresponding grid-powered cases. Overall, solar-assisted biomass-to-methanol systems show strong potential for techno-economic viability and renewable electricity integration in the Spanish biomass context.