The Future of Ethanol Cooling

Pinnacle Stainless Ahead of the Curve

Zach Harris - Co-founder and CEO . - March 13, 2020

Let’s talk ethanol chilling solutions.

In our industry today there are three primary methods used to chill ethanol for cannabinoid processing. It is my opinion that only two of those will be used in the future once the FDA releases consumer product regulations along with manufacturing regulations for the facilities creating a “food-grade” product. The FDA does not allow direct refrigeration to be used in the manufacturing of a food-grade product due to potential cross contamination of the chilling loop via heat-exchanger leak.

I want to focus on the two most common chilling options; LN2 (Liquid Nitrogen), and standard refrigeration. I am not focusing on direct injection of LN2 into the product stream. I am simply comparing FDA approved chilling designs.

In fall of 2017, I worked with a Cryogenic Engineering firm who provides thermal calculations and solutions to NASA and Cryogenic companies around the world. Our design was to use LN2 primarily as a cooling source for chilling ethanol from +30c to -40c. The calcs were figured using both the latent heat and sensible heat of the nitrogen at 50% efficiency. The low efficiency covers a collection of things, like cooling down the balance tank, heat-exchanger ineffectiveness, and other miscellaneous heat loads and losses.

Using 600 gallons (per day) as the metric for this comparison, chilling ethanol from +20c (68F) to -40c(-40F) would require roughly 1135 Liters (300 Gallons) of LN2. The current market price for LN2 ranges on delivery method. Dewar’s are roughly $2/3.78 Liters (1 Gallon), while the bulk tank price is roughly $.50/3.78 Liters (1 Gallon).
  • 600 Gallons to chill in total at bulk price would cost $94 per day.
  • 300 Days of Operation Per Year Dewar Price = $180,00
  • 300 Days of Operation Per Year Bulk Price = $45,000
After seeing these numbers, I realized that commercial refrigeration was the way to go from an operating expense point-of-view for the facilities. Pinnacle decided to go with a continuous chilling loop utilizing a large chiller, pump, insulated tank, insulated heat-exchanger, and insulated transfer lines.

Our current system to chill 600 gallons (in 10 hours) uses 28kWH x 10 Hours @ .13c per kwH.
  • 600 Gallons to chill in total cost $36.40 per day
  • 300 Days of Operation Per Year = $10,920 per day.
I would love to hear more about how others are set up, how they are calculating their energy usages, and how that correlates with facility operating expense.  I believe that an industry filled with businesses who can grow and learn from one another is an industry that can positively impact everyone. 

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