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Best Practices in Wood Waste Recycling PDF File Not Avaialble Wood Waste Feedstock Specification for Densified Fuel
Material: Wood Waste
Issue: Densified fuel products include
pressed
fuel
pellets,
fuel
pucks
(usually
industrial
boiler
fuel),
cubes,
and
pressed
logs.
The
most
widely
manufactured
densified
fuel
product
is
pellet. It is used for fire pellet stoves in residential heating. The majority of wood-based densified fuel manufacturers
rely
on
mill
residuals
for
their
raw
material
which
are
usually
clean
and
uniform
in
composition.
Fuel
manufacturers
expect
these
high
standards.
Therefore,
to
displace
traditional
virgin
wood
fiber
with
wood
waste
feedstock,
wood
waste
processors
need
to
provide
manufacturers
with
specific
product
characteristics
that
meet
their
requirements.
Satisfying
the
manufacturer’s
specifications
and
product
quality
expectations
are
critical
to
sustaining
the
captured
market
share. A lack of understanding or failure to achieve
them
leads
to
price
reductions,
rejection
of
delivered
products,
or
termination
of
the
business
relationship.
Best Practice: This Best Practice recommends that wood waste feedstock suppliers and
end-users
come
to
a
clear,
written
understanding
with
regard
to
product
quality
requirements.
The
development
of
written
specifications
for
acceptable
waste
wood
feedstock
products
are
an
important
means
of
communication
between
wood
waste
processors
and
the
densified
fuel
manufacturing
customers.
Wood
waste
processors
need
to
develop
these
agreements
with
each
individual
customer
since
the
particular
details
of
feedstock
specifications
will
vary
from
manufacturer
to
manufacturer.
The
variations
in
feedstock
specifications
are
due
to
differences
in
the
processing
equipment
and
techniques
between
each
manufacturing
plant
or
the
targeted
end
product.
Wood
Species Species
specifications
will
vary
by
mill
and
region.
In
general,
the
manufacturer
will
rely
on
a
small
number
of
species
or
even
a
single
specie
for
raw
material.
Pellet
fuel
manufacturers
tend
to
require
particular
softwood
species
because
other
species
or
hardwood
species
are
too
abrasive
on
their
equipment.
The
equipment
for
making
pressed
logs
is
more
tolerant
of
hardwood
species
and
abrasive
bark
material.
Size Distribution Pellet fuel manufacturers tend to require fine wood
particles.
Their
raw
material
usually
comes
in
the
form
of
sawdust,
planer
shavings,
or
sander
dust. Pressed log manufacturers will accept larger
wood
particles.
Their
raw
material
usually
comes
in
the
form
of
sawdust,
planer
shavings,
sander
dust,
and
hogged
fuel.
The
largest
acceptable
dimension
is
generally
about
three
inches. Acceptable
Geometry The
geometry
of
acceptable
feedstocks
vary
from
one
manufacturer
to
another.
Maximum
Allowable
Contaminant
Levels Since
densified
fuel
manufacturers
are
generally
accustomed
to
virgin
wood
fiber
supplies,
they
tend
to
be
intolerant
of
any
non-wood
contaminants. This is particularly true of the pellet fuel
manufacturers.
Feedstock
must
be
free
of
dirt,
rock,
metal,
rubber,
plastics,
silicon,
exposure
to
hazardous
wastes,
and
any
other
foreign
material.
Color/Brightness Color
specifications
vary
from
one
manufacturer
to
another. Color uniformity is important for some products (usually fuel pellets)
and
unimportant
for
others
(usually
pressed
logs).
Moisture The
moisture
content
of
the
feedstock
vary
from
one
manufacturer
to
another. Some manufacturers rely on the kiln-dried mill
residuals
from
another
manufacturer.
Others
experience
seasonal
fluctuations
in
the
feedstock
moisture
content
ranging
from
15
percent
in
the
summer
to
60
percent
in
the
winter
months.
Implementation: Wood waste processors should work with each manufacturer’s fiber buyer to develop and adhere to written specifications for their unique production systems and product requirements. A quality control program should be in place to ensure product consistently complies with the manufacturer’s specifications. The goal of the quality control program should be to detect and correct any problems before shipping the processed wood to the manufacturers.
However, if problems are identified, they should be resolved properly, quickly, and objectively. Regardless of whether the supplier (wood waste processor) failed to meet the required specifications or the buyer (the manufacturer) changed the agreed upon specifications and expectations, both parties should work together to resolve the problem. Maintaining an open communication and diplomacy throughout the settlement process would foster a healthy business relationship and avoid future problems.
Benefits: Consistently providing high quality feedstock and adhering to the specifications improves the marketability of the material and potentially increases the price and use of it. Arbitrating problem loads promptly, adjusting specifications mutually, and continuously making equipment and process modifications are practices that could improve the use of the wood waste processor’s material.
Application Site: Manufacturing Site and Processing Facility. Contact: For
more
information
about
this
Best
Practice,
contact CWC (206) 443‑7746, e-mail info@cwc.org. References:
1.
International
Resources
Unlimited,
Inc.
Eugene,
OR.
2.
Leffler,
Bob.
Northwest
Pellet
Mill. Brownsville, OR.
3.
Lyon,
Bob.
Hardwood
Industries. Tualatin, OR.
4.
“Oregon Bioenergy Guidebook.” Oregon Department of Energy; September 1993.
Issue
Date
/
Update: March
1997
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