Evaluation of the economic and energy performance of advanced biofuels from OFMSW in a demonstration-scale biorefinery

Abstract

This study presents a comprehensive economic and energy performance assessment of a demonstration scale, energy driven biorefinery plant, highlighting the innovative valorization of the organic fraction of municipal solid waste as a feedstock for advanced liquid biofuel production. A gate-to-gate mass and energy balance were conducted, leading to both a cost assessment and an Energy Return on Investment (EROI) analysis. The results for this specific plant underline the drying process as the most energy intensive stage, contributing 80 % and 49 % to the total energy demand for bio-oils and bioethanol production, respectively. By employing a high-efficiency dryer, characterized by specific energy consumption equal to 0.25 kWh per kilogram of water evaporated, bio-oils and bioethanol production costs decreased significantly, reaching 0.44 and 0.86 €/kg. For the best-case scenario, EROI values of 1.76 for bio-oil and 0.8 for bioethanol were estimated, with biogas contribution leading to a final biorefinery EROI of 1.36, indicating energy viability (as total EROI >1). The integration of a high efficiency distillation process could further increase the plant EROI to almost 2. This study reveals the significant dual role of the system as both an energy production plant and a waste treatment solution. The integration of such biorefinery plants with existing industries where waste heat is available is suggested as a critical strategy to secure both economic and energy viability. As a real data driven assessment, this study provides reliable and useful insights that can enforce the current literature about the feasibility of advanced liquid biofuel production.