Case Study: DDG Processing

Technology and Material Conditioning Processes

The Story

In 2022, IEC Thermo received an inquiry from a Joint Venture Partner in the Midwest about the material conditioning and moisture reduction of dried distillery grains (DDG), a hi-protein ethanol processing by-product from a yet to be commercialized technology (R&D).

The Requirement

We were tasked with developing a drying technology that would reduce the DDG moisture content while preserving/protecting the hi-level protein of the product and conform to The Hunter scale for color (a universal and objective unit of measurement relative to the color of a particular product, post-processing which is used to gauge or measure “quality” for the Buyer.)  

The Goals

  • Reduce moisture content from 79% to 10% (baseline feedstock moisture content)
  • Maintain a minimum nutritional profile of at least 50% protein
  • Meet the Hunter Color Scale L* at greater than 50 for the end product
  • Meet preset input and output capacity in tons per hour

The Solution

IEC Thermo’s engineering team utilized a patented two-stage low-temperature drying technology and material conditioning to enhance the processing throughput.

Combined with low temperature drying, material conditioning would allow for increased drying capacity and an ability to meet the output levels without introducing excess heat (degrading the protein level).

The Outcome

Outcomes and measurements for the final product were:

  • The protein profile retention report aligned with the Joint Venture Partner’s specifications 
    • Nutritional profile analysis performed by an independent 3rd party laboratory
  • Achieved a Hunter Color Scale L* of 53
  • Achieved the client’s output objectives at 13 TPH input and 3 TPH output (based on their results)

Beyond Meeting the Specifications

IEC Thermo:

  • Demonstrated a dryer design customized to achieve the client’s output objectives 
  • Demonstrated flexibility in dryer designs based on moisture content and tons per hour capacity.

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