Grantee Research Project Results
Final Report: Rapid freeze drying system
EPA Contract Number: 68HERC21C0024Title: Rapid freeze drying system
Investigators: Dunn, Kyle
Small Business: Dunn Infinite Designs
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2021 through August 31, 2021
Project Amount: $99,750
RFA: Small Business Innovation Research (SBIR) - Phase I (2021) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Sustainability
Description:
The project research included determining the viability of various designs and batch run times while measuring emissions, power output, and product quality. Secondary data sources include existing research on water content and resulting quality during runtime as a function of venturi chamber designs, power system performance, and under differing operating configurations.
The research is applicable to a variety of industries: food processing, biomedical, pharmaceutical, and industrial feedstock processing. Specifically, the Phase I research focused on food processing and the applicability for reducing post harvest food waste. Dehydrated food is also an important part of future manned space travel due to the beneficial nutrient density characteristics.
Summary/Accomplishments (Outputs/Outcomes):
The project objective was to build and evaluate a prototype system for rapid food dehydration. In order to evaluate system viability, the following hypothesis were to be tested:
- A venturi tube can meet freeze drying performance requirements
- A steam-driven electrical generation system can sustain a microwave heating unit for the duration of a drying batch
- Microwave radiation heating is more energy-efficient per ton of product compared to infrared and/or conduction
- The end product meets regulatory requirements and consumer quality expectations.
Conclusions:
The project identified a viable design during Phase I: an enclosed stainless steel pipe with auxiliary systems for trapping water vapor. The Phase I system run time was determined to be 0.83 hours per pound per kilowatt of heating input for sliced peaches. Emissions for field testing were not quantified during Phase I due to procurement delays and an initial design flaw. Equivalent CO2 emissions during facility testing are estimated at 2.6 pounds per pound of product - a theoretical net reduction of 1.2 pounds of CO2 equivalent per pound of avoided food waste. Power consumption during operation was approximately 2 kilowatts. Subjective product quality measures were promising; the processed product retained considerable flavor and was recognizable in shape. An FDA nutrition panel was conducted and demonstrated a comparable nutritional composition to existing freeze dried equivalents and a water content of approximately 8%. Following each system test, water content was estimated by comparing pre/post processing mass; empirically determined run times consistently produced results with <5% water content. Several vacuum system design revisions were undertaken, though power system performance was only tested under a facility "umbilical", rather than in the field due to the aforementioned procurement delays and initial design flaws.
The end product was submitted to an external laboratory for an FDA nutrition panel evaluation to validate the nutrient density and moisture content. Results related to system design, run times, emissions, and power were not independently validated during Phase I.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.