1. Science, Technology and Innovation
Special Edition
WOBAMA – Wood-based materials and fuels
Creating eco-friendly
bioproducts from wood

2. Insight Publishers | Projects2
Wood is one of the materials upon which
human civilisation was built, but recent
history has seen many new materials such
as plastics created from unsustainable
resources. Over the course of three years,
researchers from the WOBAMA project
have been developing techniques that can
diversify the way in which wood is used,
with the long-term goal of creating
sustainable and eco-friendly products
that can replace some of the materials and
fuels commonly used today.
WOBAMA — Wood-based materials and
fuels — took place between January 2012
and December 2014 as part of the
WoodWisdom-Net Research Programme
and ERA-NET Bioenergy. “The aim of the
project was to find new ways of converting
wood-based raw materials into a range of
value added bioproducts — both materials
and fuels — using a range of conversion
technologies,” explains Monica Ek, professor
of wood chemistry at Sweden’s KTH Royal
Institute of Technology. This institution has
worked alongside academic partners from
four other countries, as well as a host of
commercial partners who have brought
specialised industry expertise and facilities
to enhance the group’s effectiveness.
“EU members like Finland, Poland and
Sweden possess extensive wood resources,”
says Ek, “but their lumber industries face
competition from Asia and South America.”
The harvesting lifetime of forests in warmer
regions can be less than ten years, compared
to countries in Europe where growth periods
can be anywhere between seventy and one
hundred years. “It is difficult to compete on
this level, so it is important for us to consider
alternative ways of using the raw materials
provided by trees,” continues Ek. “This is
incredibly important for our economies and
businesses with forestry investments and
assets throughout the EU, and is one of the
main reasons why the work of the WOBAMA
project is so valuable.”
Financial incentives aside, there is also a
compelling environmental case for the
development of new wood-based
bioproducts. “Modern materials like plastics
are everywhere, but are derived from non-
renewable resources which will eventually
run out,” says Ek. “Wood makes for an
excellent alternative – a renewable resource
which comprises part of the planet’s
ecosystem.” Trees use photosynthesis to
convert carbon dioxide from the atmosphere
and build up polysaturates in the wood,
which can be used for creating packaging
and hygiene materials. In turn, these
products can then be recycled or burnt for
fuel. Although quantities of carbon dioxide
are released during these processes, it’s a
controlled aspect of the product’s lifecycle.
The bio-refinery
Once felled, timber needs to undergo
processing in order to obtain useful
bioproducts. This is done in a ‘bio-refinery’,
which extracts, pulps, bleaches and
performs various other treatments to the
wood. “A bio-refinery in the traditional
Biology Biotech
Wood is one of the most abundant resources in the EU, but the lumber industry faces stiff competition
from countries with faster growing wood. One potential means of revitalising the sector is to find different
ways to use wood. The WOBAMA project has been looking at ways to create eco-friendly bioproducts out
of wood, including fuels, adhesives, and plastic-like compounds
New techniques
for biorefining
in the EU
Hydrophobic paper (left corner: original paper).

3. www.projectsmagazine.eu.com 3
sense generates pulp fibres for usage in
paper or packaging,” says Ek. “However,
the models we’re introducing are
comparable to petroleum refineries, which
convert oil into different types of
commodities.” Valuable derivatives can be
separated and isolated by these refineries.
“Our greatest challenge has been
optimising the extraction techniques, and
obtaining efficient fuel compounds,” says
Ek. “It’s also very important that the
methods we champion can be employed in
real world contexts, and use ethically sound
catalysts like water, rather than toxic or
tightly regulated chemicals. These impose
limitations on methodology, so we need to
be very careful about which types of
additives enter our systems, to reduce risk
of contamination.
Scientific outcomes
With the project now complete, a number
of exciting, novel processes for creating
bioproducts have been discovered.
Prehydrolysis kraft pulping (PHK) is one
important way to produce dissolving
pulps with high cellulose content. The
partners at Aalto University have
developed a new prehydrolysis process
involving consecutive recirculation and
percolation modes, which could
selectively remove hemicelluloses with
limited degradation of polysaccharides,
as well as limited recondensation of
lignin. The pulps produced using this new
process followed by kraft pulping had
fairly high cellulose content of up to 95
per cent before bleaching.
The researchers from Aalto University
used sodium borate under alkaline
conditions to extract galactoglucomannan
(GGM, a hemicellulose) after bleaching.
Sodium borate is able to remove GGM
effectively and selectively. However,
cellulose II was formed after this treatment
due to the high alkalinity. To tackle this
problem, they tried to lower the alkalinity
but at the same time keep the effective
extraction of hemicelluloses by using an
enzymatic treatment in the beginning.
Using this combined treatment, the
hemicellulose content in the produced pulp
was fairly low, cellulose content was as
high as 98 per cent, and cellulose II content
was limited due to lowered alkalinity.
In the PHK process, in order to know when
or where to stop the bleaching to save the
yield and viscosity of the produced pulps, it
is important to understand the bleachability
of these pulps. The partners at Grenoble
INP-Pagora compared the bleachability of
PHK pulps and conventional kraft pulps,
focusing on oxygen delignification (due to
the process being environmentally
friendly). They found it was much easier to
bleach the PHK pulps than conventional
kraft pulps. Their findings showed that
modification of the lignin carbohydrate
complex during prehydrolysis might make
bleaching easier.
The partners at IBWCh have developed a
process to prepare high-tenacity films
based on cellulose, which have the potential
to replace conventional synthetics. The
hydrothermally treated dissolving pulp is
dissolved in ionic liquid and then
regenerated in an ethanol-water bath for
film casting. The films are fairly transparent
and homogenous, with tensile strengths of
115-126 MPa and elongations at maximum
stress of 25-60 per cent. The quality is thus
similar to that of commercial cellophane.
At present, bark in pulp mills is burnt to
produce energy, but there are actually
many better uses for the bark. It is an
ideal resource for creating many
interesting polymers. Birch bark, for
instance, has high quantities of suberin
present in it. Researchers from KTH Royal
Institute of Technology isolated a suberin
monomer and polymerised it to prepare
polyesters. These polyesters were then
crosslinked on the surfaces of paper,
making the paper more hydrophobic and
stronger. The hydrophobicity was also
stable against moisture.
In spruce bark, two abundant polymers
are cellulose and non-cellulosic
polysaccharides (NCPs). At KTH, these
NCPs were extracted from the spruce bark,
after which the residue was used to isolate
the cellulose in the form of nanoparticles
“Modern materials like plastics are everywhere,
but are derived from non-renewable resources
which will eventually run out”
AT A GLANCE
Project Title:
WOBAMA: Wood Based Materials
and Fuels
Project Objective:
The aim of the WOBAMA project was
to convert wood based raw materials
to a range of value added biobased
products, both materials and fuels,
using different conversion technologies,
within the biorefinery concept:
Wood Based Material - Conversion
Technologies - Biobased products
The WOBAMA project includes
• Pre- and postextraction of
hemicelluloses and impact on the
subsequent cooking and bleaching
processes
• Production of bioethanol of second
generation
• Cellulose functionalization for high-
tenacity films and biocomposites
• Hemicellulose functionalization for
adhesives
The project has resulted in a series of
demonstrators.
Project Duration and Timing:
January 2012 to December 2014
Project Funding:
WoodWisdom-Net and ERA-NET
Bioenergy
Project Partners:
Sweden: KTH Royal Institute of
Technology, AkzoNobel Casco
Adhesives, OrganoClick AB, SP
Processum AB
Finland: Aalto University, Stora Enso
Oyj, ANDRITZ Oy, Metsä Fibre Oy
France: Grenoble INP-Pagora
Poland: IBWCh Institute of
Biopolymers and Chemical Fibres
Germany : Solvay Acetow GmbH
Project Information

4. Insight Publishers | Projects4
AT A GLANCE
MAIN CONTACT
Professor Monica Ek
Monica Ek is professor in wood
chemistry and head of the
division of Wood Chemistry and
Pulp Technology at KTH Royal
Institute of Technology, Sweden,
and works primarily with natural
products chemistry and polymer
chemistry. She has participated in
national and international projects
targeting wood biorefinery
processes and cellulose chemistry.
She was the coordinator of
WOBAMA.
Contact:
Tel: +46 8 790 6000
Email: monicaek@kth.se
called cellulose nanocrystals (CNCs). NCPs
and CNCs were mixed in water, and the
suspension was dried to prepare thin films.
These films are excellent oxygen barriers
that could be used in packaging materials.
By coating their surfaces with the
aforementioned polyesters, the oxygen
barriers also became hydrophobic. This
could enlarge the application areas of these
renewable materials.
Wood adhesives are mainly derived from
petroleum, some of which also contain
harmful chemicals. Researchers from KTH
evaluated polysaccharides in the form of
gums and hemicellulose as binders in wood
adhesives. Locust bean gum showed
remarkable results even without any
crosslinkers or additives, with results are
comparable to a commercial wood
adhesive. Xylan with small additions of
crosslinkers and/or dispersing agents
showed good bond strength and
surprisingly good water resistance.
Looking to the future
Optimistic about the potential for the
discoveries made through the project to
branch out into industry, Ek anticipates
that the methodologies could quickly take
root in progressive, independent
businesses. “The systems we’re pioneering
aren’t overly complicated or expensive. In
fact, indeed, several of our bio-refinery
techniques are primarily reliant on water.”
The WOBAMA project supported one
postdoctoral programme and five doctoral
programmes, from which three PhDs have
graduated. The project has resulted in more
than 40 scientific publications and
conference contributions. Ek explains how
working with numerous partners from
across the EU has helped the project in
many ways: “You need new partners and
firms to engage with the group, to
comprehensively assess the opportunities
available,” says Ek. “It’s important to have
relationships with associates that offer
different competencies and specialisms to
fulfill this ambition. This policy has
nurtured some unique experiences,
especially for our PhD students. They have
had opportunities to visit other institutions,
train in analytical techniques and access
facilities that have helped diversify their
individual skills.” ★
Pulping
Bark
Cellulose
Hemicelluloses
Adhesives
Composites
Films
Cellulose
deriva;ves
Composites
The WOBAMA model
“It is important for us
to consider alternative
ways of using the raw
materials provided
by trees”