In February Southwest announced a $30 million investment in LanzaJet SAF (Sustainable Aviation Fuel) technology. In March, Southwest announced acquisition of Saffire Renewable, a company with technology to produce ethanol from corner stover which would then become feedstock for LanzaJet SAF production.
Many question if SAF production can ever be economic without government subsidies (e.g. public tax money). Corn stover may seem like a inexpensive feedstock to produce ethanol with a low enough carbon intensity score to qualify for SAF production. However, corn stover is normally left on the ground and tilled back in to the soil, thereby returning nutrients to the soil. Removing large amounts for SAF production could result in need for additional fertilizer. There is also the cost in collection and transportation of corn stover; not to mention that farmers will be want to get paid a fair price for it.