Biocarbon production from biomass based energy plant forapplication in high-value materials

Abstract: Natural graphite, a type of carbon, is used in most battery driven electronic devices around the world as it serves as the anode in Li-ion batteries. Since 67\% of global production of graphite originates from a single country the EU has classified it as a critical raw material with a high supply risk. If graphite can be produced locally from biomass not only would it potentially make batteries cheaper it could be a huge boon to the Swedish bio industry. In this thesis carbonization of pure lignin is done through hydrothermal carbonization and slow pyrolysis with peak temperature of 900\degree C. The type of carbon needed for these applications involves a high degree of crystallization and large surface areas and pore volumes. Analysis of the samples was done through X-Ray Diffraction, Raman spectroscopy, CHNO- and specific surface analysis. Results show a D/G ratio of 0.85, full width half maximum (FWHM) values of 7.7, which points toward a hard carbon with nano crystalline graphite present in the samples. SSA results show a Brunauer–Emmett–Teller (BET) surface area of around 350 $m^2/g$ and CHNO show a carbon content of about 90\%. The results are promising for use as an anode in hard carbon sodium-ion batteries or for $CO_2$ separation. Techno-economical analysis show that integrated biocarbon production in a bio-ethanol plant is a much more profitable solution than selling the lignin as biofuel or burning it for electricity production.