Exploring the economic and environmental implications of integrating carbon capture in biorefinery systems

Identifier:  TDX:4495

Handle: https://hdl.handle.net/20.500.11797/TDX4495

Authors:  Fanourakis, Stylianos

Abstract:
This thesis examines the integration of bioenergy with carbon capture and storage (BECCS) within a biorefinery that processes olive tree prunings, obtaining bioethanol and antioxidants. The biorefinery, capable of processing 1,500 tons of prunings daily, produces approximately 12,000 tons of antioxidants (with over 60% purity) and 78,000 tons of bioethanol annually. Employing a comprehensive approach that includes process simulations and life cycle assessment, the thesis evaluates the technical, economic, and environmental aspects across two scenarios: one using natural gas and the other using a BECCS system fuelled by olive prunings. The findings indicate that BECCS can significantly reduce the carbon footprint, potentially achieving net-negative emissions (-84.37 kg CO2eq per 1.00 kg of bioethanol and 0.15 kg of antioxidants produced). However, these environmental benefits are tempered by economic and environmental challenges, as investment and operating costs nearly double those of conventional biorefineries. On the other hand, there are notable trade-offs in the environmental perspective, such as increased eutrophication (+75%), water consumption (+45%), and land use (+80%). Despite these challenges, the high added-value of carbon-negative processes, along with increasing awareness and supportive policy frameworks, could help overcome these economic hurdles. This study underscores the importance of a holistic evaluation when integrating carbon capture and sequestration into biorefineries, enabling informed decision-making to mitigate unintended negative impacts and promote sustainability.