As the granulation of manure into a premium fertilizer or soil amendment product becomes more popular, testing is needed to confirm feasibility and develop a process around the unique manure sample to be processed. This presentation goes over why testing is important, and details the testing process that occurs in the FEECO Innovation Center, including the phases of testing, how testing works, and what particle characteristics can be targeted.

1. Manure Granulation
Testing
Experts in process design and material
processing for over 65 years.

2. As the granulation of manure into a fertilizer or
soil amendment product becomes
increasingly popular, so too does research
and development around manure
granulation systems.

3. With significant variation between manure
types and even amongst the same type,
testing is a key component to the success of
a manure granulation process. The following is
an overview on testing in the FEECO
Innovation Center.

4. Why Testing is
Important

5. In addition to the significant variation
among manure types, many on-farm
practices will also influence the
consistency and make-up of manure.
This might include the type of feed, the
separation system used, handling
practices, farm location, and even
barn type.

6. With so many variables, the unending matrix of
manure outcome possibilities makes testing an
absolute necessity to the success of the overall
process and the end product.

7. There are a few different approaches to
granulation, and it may not be clear at
the onset of testing which method will
suit the unique manure source best and
be able to produce the desired end
product characteristics.

8. Mixer-dryer granulation works by first
mixing the pre-treated manure in an
industrial mixer, typically either a pin
mixer or pug mill.
FEECO Pug Mill

9. Once a homogenous mixture of the
material and any additional inputs has
been created, the newly-formed pellets
are discharged and carried to a rotary
dryer, where they are dried into their
final form. A cooling step after drying is
also common.
FEECO Rotary Dryer

10. The pelletizing approach is similar, but
with the addition of a disc pelletizer
after the mixer. This approach increases
process efficiency, overall throughput,
and also adds an element of fine-
tuning, ultimately improving the quality
of the end product.
FEECO Disc
Pelletizer

11. Drum granulation is similar to the
pelletizing method, but with a rotary
drum replacing the disc. This approach
allows for higher capacities, and offers a
closed system, unlike the disc pelletizer,
which is considered an open system.
FEECO
Granulation
Drum

12. Extrusion, a pressure agglomeration
approach in which materials are forced
through a die to create a cylindrical
pellet, is also an option and is often
chosen for smaller operations that do
not have the volume to support the
capacities required by a non-pressure
granulation system.
Pellets created via extrusion are
considered a lower-grade product.
FEECO does not offer this approach.

13. How Testing Works

14. Testing in the FEECO Innovation Center
typically happens in four stages:
• Feasibility/Proof of Concept
• Proof of Product
• Proof of Process
• Process/Product Optimization

15. Feasibility/Proof of Concept
In this initial phase of testing, process
experts run batch scale tests to
determine if the specific source of
manure will agglomerate.
Small sample sizes can be produced for
use in lab or grow room trials.

16. Proof of Product
This next phase is a more in-depth batch
testing phase, where more time is spent
determining if the specific manure
sample can be made to exact
specifications.
Additional binders and formulations
may also be tested.

17. Proof of Process
Building off of step two, this phase uses
a continuous setup to determine if the
process is viable on a continuous scale,
as well as what process variables will
need to be for continuous production.

18. Process/Product Optimization
This stage works on fine-tuning the end
product and the process itself, providing
a recipe for scale-up. Samples
produced can be used in field trials.

19. As with any testing, it is critical that the
manure sample be as representative as
possible, to ensure testing simulates
on-farm conditions.

20. The first step in testing manure is to
determine if a pre-conditioning step is
needed to optimize the feedstock for
granulation.
This centers around ensuring ideal
particle size distribution, moisture
content, and material composition for
granulation.

21. It may be obvious from the start whether
a material will require pre-conditioning,
or this conclusion may be reached
through the testing process itself.

22. The type of mixer chosen for the process is
commonly dictated by the consistency of the
manure, with pin mixers favoring more dry,
finely divided solids such as chicken litter, and
pug mills favoring cakes such as separated
dairy manure.

23. If the mixer alone produces suitable
results, process experts can move on to
fine-tuning the process and testing it as
a continuous process loop.

24. If the end product requires more
refinement, or if the process is struggling
to produce on-size product, process
experts will likely try a different
approach, possibly adding a disc
pelletizer to the process, or utilizing a
different mixer.

25. Product
Customization

26. Producers are most often looking to
target a specific set of particle
characteristics. This might include any of
the following:
• Bulk Density
• Crush Strength
• Solubility
• Attrition
• Compression
• Particle Size Distribution
• Flowability
• Moisture Content
• Physical/Surface Quality
• Green/Wet Strength

27. Throughout testing, process experts work with a
number of variables to produce these
targeted parameters. Depending on the
setup, this might include any of the following…

28. • Material Feed Rate
• Amount of Recycle
• Binder Feed Rate
• Type of Binder
• Mixer Speed
• Type of Mixer
• Mixer Pin/Paddle Arrangement
• Disc Speed
• Disc Angle
• Dryer Temperature
• Dryer Air Flow
• Dryer Flight Design and/or Pattern

29. Additionally, while the product can be 100%
manure-based, granulation can also
accommodate the addition of other
beneficial materials such as macro or
micronutrients to improve the quality of the
product or create a fortified nutrient blend
customized to a specific application.

30. Automation

31. Throughout testing in the Innovation
Center, FEECO process experts utilize our
state-of-the-art automation system from
Rockwell Automation to gather, trend,
and report on data, even adjusting
variables in real-time.
This provides customers with complete
process transparency and data
visualization and analysis.
In addition, FEECO can provide Rockwell
Automation systems as part of a system
purchase.

32. Conclusion
Testing is a critical component in the success of
a manure granulation process.
The FEECO Innovation Center offers
comprehensive testing services at both batch
and pilot scale and can help to develop a
process around your unique manure sample
and process goals.

33. has been a leader in transforming wastes into
value-added products since 1951. In addition to
feasibility testing, process design, and custom
equipment, we offer complete systems for the
granulation of manure into a premium product.

34. Want to learn more?
Download our
Organics Granulation
Handbook
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The Organics Granulation Handbook
Granulation as a Solution
Systems and Equipment
Considerations
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