Reassessment of the energetic value of lignocellulosic biomass in closed carbon cycles

Related to its energetic value, lignocellulosic biomass is typically characterized by its gross and net calorific value. However, while aiming for closed carbon cycles, this characterization does not reflect that organic matter is a carbon carrier providing “green” carbon urgently needed within a defossilized world, where material utilization of carbon for synthesizing carbon-rich materials is pursued. To address this, the assessment of biomass is expanded to include the work required to separate CO 2 from the atmosphere, which is vital for reducing carbon into biopolymers through photosynthesis. A biogenic and a technical pathway are compared to highlight the advantages of biomass utilization. The analysis reveals that relying solely on the calorific value underestimates the true energetic value of biomass in closed carbon cycles. Organic matter is predestined to be used as a carbon source to provide carbon-based materials to maximize the utilization of nature's inherent separation and reduction capabilities. Consequently, a reassessment of the energetic value of biomass is necessary within the context of a non-fossil economy. • Evaluation of lignocellulose biomass via natural and technical synthesis methods. • Minimum CO 2 separation work from air (426 ppm) equals 21.72 kJ/mol. • Lignocellulose's value totals 488.19 kJ/mol from CO 2 capture and chemical reduction. • Technical synthesis effort includes CO 2 separation, H 2 O splitting, and heat release. • Sustainable economies must recognize biomass potential beyond its energy content.