Hydrous bioethanol production from sugarcane bagasse via energy self-sufficient gasification-fermentation hybrid route

Abstract

Production of second generation ethanol can be accomplished with biomass gasification followed by syngas fermentation using acetogenic bacteria in a hybrid process. Using process simulation and financial analysis, this study evaluated the feasibility of producing hydrous ethanol from sugarcane bagasse in a conceptual hybrid plant designed to be energetically self-sufficient. The process was found to be competitive with other second generation routes, achieving an ethanol yield of 330 L per metric ton of dry biomass and an overall carbon conversion of 30%. The minimum ethanol selling price to achieve Net Present Value break-even with 10% Internal Rate of Return was estimated to be 706 US$/m³ after taxes in the base model. When accounting for uncertainties in the fixed capital investment and the cost of raw materials, the Net Present Value was found to be non-negative in 80% of the cases for a selling price of 783 US$/m³.