Argonne National Laboratory’s Systems Assessment Center on Oct. 11 announced the 2021 release of the suite of GREET models, an analytical tool that stimulates the energy use and emissions output of vehicle and fuel combinations.

Major expansions and updates included in GREET 2021 include those related to corn starch ethanol, corn fiber ethanol, biodiesel, renewable diesel, sustainable aviation fuel (SAF) and a variety of other biobased fuels.

For corn starch ethanol, the updated model accounts for data showing that corn grain yields have increased in recent years while fertilizer inputs per acre have remained constant. In addition, the model reflects updated data showing that corn grain ethanol yield and reductions in energy use have reduced the life-cycle greenhouse gas (GHG) emissions per megajoule (MJ) of corn grain ethanol produced and used. The updated GREET model also includes a reconfigured corn fiber ethanol pathway that links grain ethanol with corn fiber ethanol interactively.

Argonne updated and expanded the biodiesel (BD) and renewable diesel (RD) pathways in GREET 2021, and added carinata to BD/RD, palm fatty acid distillate to BD and tallow to RD pathways. Feedstock production data for soy oil and canola oil have also been updated.   

In addition, the updated GREET 2021 model includes eight new SAF production pathways. Argonne also added a new coprocessing module to GREET 2021 that is intended to examine the impact of coprocessing biobased feedstocks in petroleum refineries.

Additional information, including a 58-page summary of 2021 updates to the GREET model, is available on the Argonne website.