Techno-economic and life-cycle assessment of integrated Fischer-Tropsch process in ethanol industry for bio-diesel and bio-gasoline production

Abstract

The Fischer-Tropsch process is less complex and more environmentally friendly alternative to petroleum-based fuels. With growing interest in biomass-to-fuel conversion like the production of bioethanol, there is a steady supply of unfermentable biomass from bioethanol industries, which can be gasified and converted to Fischer-Tropsch syncrude. In this work, the economic and ecological feasibility of integrating a Fischer-Tropsch process using syngas obtained from the gasification of dry distillers’ grain is explored. Data from a lab-scale experiment using pelletized promoted iron supported on Carbon Nano Tubes (Fe/CNT) is used to simulate a plant for the production of 1000 kg of syncrude/h. The techno-economic feasibility of setting up a Fischer-Tropsch process is explored based on chemical engineering plant cost index of 628.2. An internal rate of return of 107.9% was obtained with a net annual profit of 5.2 MUSD/year which is higher than those reported for other Fischer-Tropsch plants due to the readily availability of the feedstock without any associated transportation costs. The potential environmental impact of the Fischer-Tropsch fuels was evaluated by the WAste Reduction (WAR) algorithm and suggested that the integration of the Fischer-Tropsch process into the bio-ethanol production plant is environmentally benign.