by Mike Millikin

A team at Argonne National Laboratory’s Systems Assessment Center has evaluated the well-to-wheel (WTW) greenhouse gas (GHG) emissions of Fischer–Tropsch (FT) fuels produced via various electrolytic H₂ pathways and CO₂ sources; using various process designs (i.e., with and without H₂ recycle); and two different system boundaries: a stand-alone plant (with CO₂ from any source) and an integrated plant with corn ethanol production (supplying CO₂).

In a paper in the ACS journal Environmental Science & Technology, they report that using nuclear or solar/wind electricity, the stand-alone FT fuel production (Naphtha, jet, diesel) from various plant designs can reduce WTW GHG emissions by 90–108%, relative to petroleum fuels.

Zang et al.

When integrating the FT fuel production process with corn ethanol production, the WTW GHG emissions of FT fuels are 57–65% lower compared to petroleum counterparts.

The authors modeled the FT fuel synthesis process using Aspen Plus, which showed that 45% of the carbon in CO₂ can be fixed in the FT fuel, with a fuel production energy efficiency of 58%.

This study highlights the sensitivity of the carbon intensity of FT fuels to the system boundary selection (i.e., stand-alone vs integrated), which has different implications under various GHG emission credit frameworks.

—Zang et al.

Resources

• Guiyan Zang, Pingping Sun, Amgad Elgowainy, Adarsh Bafana, and Michael Wang (2021) “Life Cycle Analysis of Electrofuels: Fischer–Tropsch Fuel Production from Hydrogen and Corn Ethanol Byproduct CO₂” Environmental Science & Technology doi: 10.1021/acs.est.0c05893