Techno-economic Analysis of Biomass Conversion to Hard Carbon Materials

Abstract: Hard carbon is an important material for future fossil-free transport systems, as it is a popular choice for the production of anodes for sodium-ion batteries. Biomass is a popular carbonaceous raw material for making hard carbon. It was only noticed at first because it is a renewable energy source, but with the wide application of carbon materials in several fields, industrial manufacturing using biomass as raw material has also been studied a lot. Process simulation of biomass pyrolysis and carbonization to produce hard carbon, pyrolysis gas, and bio-oil are investigated in this thesis work. The model simulation is assumed based on the current operating data and previous literature review, where the first two models use heat exchangers, and the last case uses by-products to generate heat. Economic analysis based on operating expenses and total capital investment is given based on simulated results. The results show that the yield of hard carbon is about 17% under 1000kg/h biomass feedstock, and the economic performance of using heat exchangers is better than that of pyrolysis gas combustion to supply energy. The economic results and break-even point are used to calculate the minimum selling price, payback period, and sensitivity analysis. The calculated minimum selling price for hard carbon is about SEK 20/kg, which is within the range of the current market price, and the payback period is about 16 years. From the sensitivity analysis results, if electricity prices continue to rise, the economics of using cracked gas may become more significant.