Cover improves biomass drying
By Walki Group
By Walki Group
|Residue covered with the
Walki Biomass Cover becomes drier than piles that are left uncovered.
Apr. 15, 2011, Finland – Logging residue is an inexpensive
and easily accessible source of biofuel, but to improve the energy content, it
is left on the ground to dry and then stored in piles for several months. To
shelter the piles from rain, snow, and ice, Finnish company Walki has developed
a paper-based, waterproof cover that can be chipped and burned together with
At first glance, Walki’s biomass cover doesn’t look very
high-tech, but it efficiently improves the energy content in logging residue.
The cover is a 4 metre wide laminate, mainly produced from renewable fibrous
materials. It shelters the top of the pile but leaves the sides open, allowing
moisture to evaporate.
A very thin plastic layer within the cover makes it both waterproof and very
strong. Thanks to the characteristics of the plastic, the cover can be chipped
along with the residue and used as fuel as well.
“The biomass cover is already the widest of its kind on the market, and production
is constantly growing. Now, we are also developing a 6 metre wide version that
can cover even bigger piles of logging residue and other wood-based biofuels,”
says Hannu Nieminen, product line manager at Walki.
In addition to shielding biomass residues from water and snow, the biomass
cover also protects residue from freezing, which can transform the pile into an
icy heap that’s almost impossible to handle and has low energy content.
Finland and Sweden are pioneers in harvesting energy wood, but interest in the
technology is increasing in other parts of the world as well. “Measurements
have shown that the solids content of wood can be raised by as much as 15% by
using the cover,” says Nieminen.
In Finland, the main re-seller of Walki’s biomass cover is Uittokalusto Oy, a
Finnish company owned by Grube KG Forstgerätestelle of Germany. The company has
been selling the cover for about five years now and is very pleased with the
feedback from customers. The biomass cover will be available for sale in North America
shortly, according to Tuomo Wall, vice-president of sales and marketing for
Walki Technical Products.