CoRyFee

Cost effective fermentation

First-generation ethanol production has in the past exhibited stable compounded annual growth rate over the last two decades, exemplified by the 10-fold growth in production and 4-fold expansion of production plants in the US.

The European Union, which was the main financier for the project, has set ambitious environmental goals, including the goal to make the Union carbon neutral by 2050. Ethanol has an important role in such a change and the project’s goal was to reduce the total production costs of ethanol from residual products such as straw and sawdust and to make ethanol production from these raw materials more cost effective. This was achieved during the project by developing a new and more efficient fermentation process that reduces investment and operating costs for the process by at least 50 percent.

Conclusion of the results

The CoRyFee fermentation technology which takes advantage of a newly developed fermentation monitoring and control strategy. By monitoring the sugar concentration and consumption rate of sugar and ethanol productivity in real-time allows the technology to keep fermentation conditions at a “sweet spot”, thus allowing for optimal ethanol productivity and increased yields. Additionally and importantly, the fermentation can be performed in continues operation without fresh addition of yeast after the initial inoculum has been to start the fermentation process.

Jointly developed, the CoRyFee platform was the subject of a joint patent application filed by SEKAB E-Technology AB and Terranol A/S in 2018. The platform has at this point in time been demonstrated at fermentation scale of 10.000L fermentation volume with 50,000 L of hydrolysate being fermented at 95 percent ethanol yield at the Biorefinery Demo Plant in Örnsköldsvik, Sweden. Continuous fermentation operations of 21 days without interruption and without addition of yeast after the initial fermentation have been demonstrated. The technology is suitable for any type of fermentation process regardless of fermenting organism and fermentation product.

The main improvements of the CoRyFee platform compared to standard fermentation technologies can be summarized as follows:

• Significantly improved yeast economy due to a 20-fold lower yeast utilization compared to batch fermentations with similar throughput.
• 6-fold increase in volumetric ethanol productivity compared to batch fermentations.
• Stable and continuous 95 percent yields form sugar to ethanol.
• 50 percent lower investment cost due to reduced need for tank volume, cleaning, and sterilization.
• Increased tolerance towards an array of inhibitors released by the pre-treatment process from sugar and lignin degradation.

The Coryfee technology is currently being optimized and implemented with producers of second generation bioethanol in Europe. Promising to improve production capacities, production yields and productivities in existing production plants as well as future.