Techno-economic Optimization of a Flexible Biomass-integrated Power-to-X System for District Heating Electrification and E-methanol Production

Biomass integration with power-to-X (PtX) and power-to-heat (PtH) systems supports the transition to sustainable energy systems by providing a stable heat supply and a biogenic source for carbon recycling. This study presents a techno-economic optimization of a polygeneration system integrating biomass, wind, and solar energy for district heating (DH) electrification and e-methanol production. A biomass-fueled combined heat and power (CHP) unit, heat pump, and electric boiler meet city-scale heating demand, while 50 kton/year of e-methanol is produced from green hydrogen and captured biogenic . Optimization is performed in the Calliope framework using mixed-integer linear programming (MILP). The results show a levelized cost of heat (LCOH) of 41.7 €/MWh, about 55% below Finland's current average DH price. The LCOH is nearly identical to the DH-only scenario, showing that PtX integration does not penalize heat supply economics and even reduces biomass input by 8%. About 70 kton of biogenic is captured and recycled annually into e-methanol, supporting negative emissions objectives. The levelized cost of e-methanol (LCOM) is 980 €/ton, positioning the system at the lower end of current reported production costs. The findings highlight the strong potential of biomass integration to enhance flexibility, support sector coupling, and displace fossil-based methanol production.