High efficient co-production of Fischer-Tropsch (FT) transportation fuels and Substitute Natural Gas (SNG) from biomass

The technical, economic, and ecological feasibility was studied of the co-production of 50 PJ of Fischer-Tropsch (FT) transportation liquids and 150 PJ of substitute natural gas (SNG) per year (i.e. 10% of the 2001 Dutch consumption). In the co-production concepts part of the SNG is produced by methanation of the FT off-gas, which already contains significant amounts of C1C4 SNG compounds. The additional required SNG is produced by dedicated methanation of part of the gasification product gas. Co-production results in higher biomass-to-fuel efficiencies, lower biomass input requirements, and less negative net present values (NPVs) compared to the case of complete separate production of both fuels. Co-production concepts based on pressurised oxygen-blown and indirect gasification result in the lowest CO2 emission reduction costs of about 100 €/tonne. Co-production of “green” Fischer-Tropsch transportation fuels and “green” SNG will be an economic feasible process in the Netherlands, when both energy carriers receive the same tax exemptions as currently is given to green electricity or at crude mineral oil prices above 56 $/bbl.