Thermodynamic, financial and resource assessments of a large-scale sugarcane-biorefinery: Prelude of full bioenergy carbon capture and storage scenario

A large-scale sugarcane-based ethanol biorefinery is assessed and analyzed as a conceivable integration of plantation-biorefinery for large-scale carbon dioxide drainage by coupling production of bioenergy to carbon capture and storage (BECCS) vis-a-vis the conventional biorefinery. The plantation-biorefinery integration is simulated to assess ethanol production, power production through bagasse-fired cogeneration, heat demand, water demand, carbon dioxide intake, profitability and resource utilization. Results are compared with several metrics of maximum possible outcomes without violating the Second Law of Thermodynamics. Typical results for a conventional biorefinery processing 1,000 t/h of sugarcane comprises 284 MW of net electricity exportation, emissions of approximate to 0.7 tCO(2) per ton of sugarcane, 3,616.4 t/h of water consumption accounting for blowdown and evaporation in the cooling-tower, 550.2 MMUSD of fixed capital investment and 709.6 MMUSD of net value from ethanol/electricity revenues at 10% annual interest rate. On the other hand, the proposed BECCS reconfiguration stands as a large-scale atmospheric carbon dioxide drainage system with potentially impressive negative emissions, power exportation of 88.5 MW, BECCS potential of 5.72 MtCO(2)/y, resource utilization and profitability analyzed via Sankey diagrams. Profitability of the BECCS biorefinery is warranted provided the captured carbon dioxide is traded for enhanced oil recovery. The limiting power production for the sugarcane intake is estimated via two thermodynamic approaches: maximum Carnot equivalent power and maximum power at 25 degrees C and 1 atm via the Second Law of Thermodynamics. The assessment reveals the thermodynamic inefficiency of the actual biorefineries in terms of power production. Future studies should investigate exergy efficiencies and expand the study beyond the biorefinery boundary to include carbon emissions in the sugarcane supply-chain.