US-based biofuel producer Gevo has implemented a side-by-side (SBS) fermentation process to co-produce renewable isobutanol (IBA) along with ethanol at its plant in Luverne, Minnesota, US.
The plant has one fermenter dedicated to IBA and three fermenters dedicated to ethanol using its proprietary GIFT system, which can use corn mash to produce IBA or ethanol, Gevo said.
The project had been announced as a way to fully utilise the plant facilities and increase cash flow as it commercialises IBA production.
“Operating all the assets of the plant has aided us greatly in solving issues that were impeding the ramp-up of isobutanol using one fermenter in isolation, specifically the consistent management of infections and the handling of recycle streams and solids,” Gevo CEO Patrick Gruber said.
The plant has been able to produce initial IBA run rates in the tens of thousands of gal/month in a 1m litre fermenter. Yields have reached 90% of targets based on starch content, up from 70% prior to SBS, and costs are down 25% since using SBS, Gevo said.
“Our yields and costs have improved very quickly. And while we have more work to do, I am pleased with our overall progress and look forward to continuing to increase the production levels of isobutanol at the plant,” Gruber said.
Ethanol has been produced at the plant at 1.5m gal/month, generating about $3m/month.
“By running the SBS we have dramatically reduced our cash burn at the plant and we are targeting breakeven at Luverne by year end,” Gruber said.
Gevo’s IBA can be used as a building block to make jet fuel and chemical products in markets such as plastics and fibres, as well as solvents and coatings.
- Additional reporting by Jeremy Pafford