Many yeasts are unable to tolerate temperatures above 94°F without making changes to your process, such as reducing solids. The reduction in solids and increased byproducts produced by the yeast steal sugars from ethanol production and sacrifice yield.
Here are 8 things you can do about it!
Be proactive with your cooling capacity
Do you know the limit to your cooling capacity? Calculate or evaluate what is the maximum outside (ambient) temperature that your cooling towers can handle. Check the weather to prepare your operations when heat waves come.
Review backset ratio
The impact from organic acid stress in fermentation can be lessened by decreasing backset ratio and/or increasing fresh water to the slurry. This in turn can help alleviate temperature stress.
Monitor supplemental nitrogen
Pay close attention to how nitrogen is being dosed. Too much at the beginning will accelerate kinetics and produce more energy than your cooling process can handle.
Monitor gluco-amylase addition
Higher temperatures will make the gluco-amylase work faster. Pay close attention and change addition strategy when necessary.
Prepare to have chillers operating correctly
Even though this will increase your operating expenditures, it may be necessary to maintain yields. Here’s how you can T prepare chiller operations:
Avoid repeatedly turning chiller on and o¬ff
Standardize chiller water allocation procedure
Allocate chilled water resources
Prepare for increased copper levels
Pay attention to heat exchangers
Heat exchangers may be at their limit! It may be necessary to increase CIP frequency and include the addition of phytase to help decrease the deposition rates.
Review dry solids loading
Though reducing dry solids might reduce fermentation peak temperatures and osmotic stress, you will be losing throughput and spending more energy in the backend. Make sure to check the above-mentioned adjustments strategies before resorting to this approach.
Choose your yeast wisely
Choose a robust yeast that is tolerant of heat excursions and fermentation stressors to reliably maintain performance. Innova yeast strains have demonstrated tolerance to temperature excursions as high as 98°F with minimal reduction in solids. With certain Innova yeast strains the tolerated temperature excursion can be as high as 104°F. By using an advanced yeast specially built for this purpose, you’ll eliminate downtime, cut cooling costs, and maximize your plant’s efficiency. For more information on Novozymes’ yeasts please reach out to your Novozymes Account Manager.
For more information on the guidelines above please reach out to a Novozymes Specialist to make the most of your strategy.