Techno-economic assessment of biogas to liquid fuels conversion technology via Fischer-Tropsch synthesis.

Biogas derived from anaerobic digestion of organic wastes, and lignocellulosic biomass can be used to produce drop-in diesel fuel via Fischer-Tropsch ( FT) synthesis. In this study, we developed a process-based simulation model for the biogas to liquid fuel ( BgTL) plant to conduct mass and energy balances and to evaluate techno-economic assessment of producing drop-in FT fuels. The BgTL plant operations consisted of biogas cleaning, biomethane reforming, FT synthesis of syngas and hydrocracking and final distillation to produce drop-in liquid fuels. The unconverted syngas and syncrude were utilized to generate steam and electricity to meet internal plant demand, while the excess power was sold to the grid. The base case BgTL plant (2 000 Nm3/h) produced about 4.6 million gallons per annum of total FT fuels which consisted of 62% diesel, 32% gasoline, 6% LPG with an overall biogas conversion of 54%. A discounted cash flow rate of return ( DCFOROR) approach for the Nth plant was used to estimate the capital and operating costs with the minimum selling price for the FT drop-in fuels of about $5.67/gal ($5.29/ GGE). The increase in plant feed capacity to 20 000 Nm3/h decreased the minimum selling price to $2.06/gal ($1.92/ GGE). The sensitivity analysis conducted on the base case plant demonstrated that the internal rate of return ( IRR), FT conversion rate, plant operating hours, and biogas cost were the most sensitivity parameters to the minimum selling price. Overall, the BgTL technology is deemed to be economically feasible to meet US biofuels demand. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]