A techno-economic comparison of Fischer-Tropsch and fast pyrolysis as ways of utilizing sugar cane bagasse in transportation fuels production.

摘要

Due to limited biomass availability, the establishment of optimal route biofuel value chains (one conversion route for each feedstock) is a key prerequisite for a feasible bioenergy sector. This way, biorefineries can take advantage of the economies of scale and increase their economic potential. Therefore, techno-economic comparison between similar conversion processes for the utilisation of individual feedstocks is essential. To this effect, the present study focuses on the feasibility of two biomass to liquids (BtL) thermochemical conversion routes for the production of hydrocarbon fuels. Aspen plus software was employed to investigate a gasification followed by Fischer-Tropsch synthesis 20 route (G-FT) and fast pyrolysis followed by hydroprocessing (FP-H) by developing process flowsheets and solving the associated mass, and energy balances. Based on the simulations, thermodynamic (energy/exergy analysis) and economic (financial and risk analysis) evaluations were carried out. Sensitivity analyses have been performed in order to define the key parameters of each conversion route. Sugar cane bagasse, the waste solid residue of the sugar cane milling process, was considered as feedstock at a flowrate of 100 t/h. Based on the outcomes of the evaluations, the two alternatives were compared and it was concluded that, both energetically and financially, G-FT synthesis is the more efficient option.