Process simulation and techno-economic assessment of vinasse-to-biogas in Cuba: Deterministic and uncertainty analysis

This paper presents a process simulation model in Aspen Plus (R) and a techno-economic assessment for the anaerobic digestion of Cuban sugarcane vinasses considering three scenarios for biogas application: electricity production (S_1), biomethane as vehicle fuel (S_2), and biomethane for gas grid injection (S_3). From the simulation model, non-significant differences (p value >= 0.1779) between experimental and simulation results were found. S_1 showed the best economic performance among the assessed biogas applications. From the sensitivity analysis, the mean electricity price leading to a net present value of zero for S_1 was 90 USD/MWh, while for S_2 and S_3 the mean incentive required was 0.33 USD/m(biomethane)(3) and 0.67 USD/m(biomethane)(3), respectively. The uncertainty analysis showed a chance for investment failure in S_1 less than 10%, whereas for S_2 and S_3 it ranged between 31-37%. The minimum scale required (milling and distillery capacities, ethanol yield) for getting profits from biomethane projects was targeted at 10,800 t(cane)/day, 108 m(ethanol)(3)/d at 10 L-ethanol/t(cane), respectively. To this end, Cuban plants should significantly increase their average capacities; otherwise, a centralized biomethane production by limiting the number of biomethane plants to one or two per province could be implemented. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study presents a process simulation model in Aspen Plus (R) and a techno-economic assessment for the anaerobic digestion of Cuban sugarcane vinasses. It found that the electricity production biogas application (S_1) showed the best economic performance, with the mean electricity price leading to a net present value of zero being 90 USD/MWh. The recommendation is for Cuban plants to increase their capacities significantly or implement centralized biomethane production to ensure project profits.