Economic and environmental implications of carbon capture in an olive pruning tree biomass biorefinery

Abstract

This study explores the integration of bioenergy with carbon capture and storage (BECCS) in a biorefinery system that converts olive tree prunings into bioethanol and antioxidants. With a capacity to process 1,500 tons of prunings daily, the biorefinery yields an annual production of around 12,000 tons of antioxidants (purity >60 %) and 78,000 tons of bioethanol. Utilizing a holistic approach involving process simulations and life cycle assessment, our analysis covers technical, economic, and environmental dimensions across two scenarios differing in design and heating source: natural gas or a BECCS system using olive prunings. Our findings reveal the potential for BECCS to drastically reduce the carbon footprint, potentially achieving net-negative emissions (−84.37 kg CO2eq per 1.00 kg of bioethanol and 0.15 kg antioxidants produced). However, these environmental gains are counterbalanced by economic and environmental challenges, with investment and operating costs nearly doubling and leading to complex environmental trade-offs related to eutrophication (+75 %), increased water consumption (+45 %), and expanded land use (+80 %). Nevertheless, the premium nature of carbon-negative products, coupled with growing awareness and supportive policy frameworks, may overcome these economic barriers. This study highlights the importance of holistic evaluation when integrating CCS into biorefineries facilitating informed decision-making to address unintended adverse effects and promoting sustainability.