Techno-Economic Evaluation of the Thermochemical Energy Valorization of Construction Waste and Algae Biomass: A Case Study for a Biomass Treatment Plant in Northern Greece

Biomass treatment for energy production is a promising way for achieving fossil fuel replacement and environmental relief. Thermochemical processes are a common way of processing biomass, but their potential economic benefits are not always clear to investors. In this work, three basic thermochemical processes (combustion, gasification, and pyrolysis) are examined in terms of their theoretical yields and their products, as well as their economic viability. The goal of this analysis was to look into the total amount of available biomass streams and compare business plans in terms of sustainability from a technical and economic perspective. The estimation of the fixed capital investment was based on ready-made solutions that are already available on the market. The analysis showed that the gasification unit has the optimum sustainability results since the total amount of gross income was EUR 0.13/kg of biomass while the treatment cost was estimated at EUR 0.09/kg of biomass. The internal rate of return of the investment was calculated at 9%, establishing a promising alternative solution to sustainable "green" energy production.