Bioenergy with carbon capture and storage (BECCS) has the potential to produce negative emissions. This study assessed the overall energy efficiency and carbon dioxide (CO2) avoidance costs and emission footprint following the integration of BECCS with a polygeneration system (BECCS-PS) for the co-production of green electricity and methanol. The process was simulated in Aspen Plus and Aspen HYSYS v.11. Oil palm empty fruit bunches were used as the feed in a biomass integrated gasification combined cycle power plant. The flue gas, which contained CO2, was captured for methanol synthesis and carbon storage. Green hydrogen for use in methanol synthesis was produced through proton exchange membrane (PEM) electrolysis powered by solar PV (PV-PEM) and geothermal power with double-flash technology (GEO-PEM). The environmental impacts of the process were investigated by a life cycle assessment and the economic aspects were evaluated using the levelized cost method. The overall system efficiency was higher in the PV-PEM scenario than in the GEO-PEM scenario. For any production capacities, the green electricity generated from the BECCS-PS plant resulted in negative emissions. A biomass power plant with a low production capacity generated higher production and CO2 avoidance costs than that with a larger production capacity. The CO2 − eq emissions and costs for methanol production in the PV-PEM scenario were larger than those in the GEO-PEM scenario, with values of -0.83 to -0.70 kg CO2 − eq/kg MeOH and 1,191–1,237 USD/ton, respectively. The corresponding values were − 1.65 to -1.52 kg CO2 − eq/kg MeOH and 918–961 USD/ton, respectively, for the GEO-PEM scenario.
Graphical Abstract