Cattail Pellets/Biomass Magazine

[MHC]

Manitoba researchers convert cattails into pellets
By Anna Austin | March 08, 2011



Researchers at the University of Manitoba have discovered a way to use
cattails to improve the health of Lake Winnipeg and produce a
renewable fuel.
PHOTO: UNIVERSITY OF MANITOBA...University of Manitoba researchers,
while working on a project to restore health to Canada’s Lake
Winnipeg, discovered that turning the lake’s massive quantity of
cattails into fuel pellets is an efficient way to keep unwanted
nutrients out of the lake and produce a renewable, clean-burning,
energy-dense fuel.

Lead researcher Richard Grosshans said the project was initiated to
determine the impact that harvesting sedge, a plant found in marshes,
from Lake Winnipeg’s Netley Marsh would have on excessive nutrient
levels in the lake. The Netley Marsh filters the water that flows into
the lake from the Red River, which is its primary source of nutrients.

In particular, the researchers wanted to find out how much phosphorous
could be permanently removed from Lake Winnipeg by harvesting marsh
grasses. “We ended up mostly focusing on cattails, because it is
pretty effective as a wastewater treatment plant,” Grosshans said.
“Our cattails were loaded with phosphorous, which is one of the things
we’re interested in taking out of the marsh, and they have a really
high energy value.”

Some nutrients, such as nitrogen, are cycled in a wetland; they are
stored and naturally broken down over time, Grosshans pointed out.
“That’s not the case with phosphorus, as it’s all stored in
sediments,” he said. “Over time it can accumulate to the point where
the wetland is completely saturated and can’t store any more
phosphorous.”

When the project began four years ago, the researchers were focusing
on turning the cattails into bales to be used in a gasifier, Grosshans
said. About halfway through the project, power utility Manitoba Hydro
expressed interest in using densified fuel made from the material, and
provided the researchers with funding to investigate that possibility.

Cattail cubes were tried initially, but pellets turned out to be the
best option. “We had trials with and without binders and found that
the pellets with no binder had the exact same durability,” Grosshans
said. “It compresses and binds really nice in standard pellet
equipment.” The cattail pellets also have about the same calorific
value as standard wood pellets, according to tests done by the Alberta
Research Council.

Because of the pellets’ high ash content, however, Grosshans said the
material would work best when made into mixed fuel pellets. The
researchers are currently working with a mixed fuel pellet
manufacturer to test results on a commercial scale.

Sustainability of cattails shouldn’t be a problem when harvested
correctly, according to Grosshan. “They are extremely competitive and
resilient and as long as you leave stubble above the water so the
plant can breathe, it’ll grow back,” he said. “We’re getting about 14
to 19 tons of biomass per hectare (2.47 acres), with 90 days to plant
maturity.”

[Jock Gill]

I wonder if cattail biochar would retain all of the phosphorus which could then be returned to the land!  Pyrolysis would also deal very nicely with the high ash content.

Jock