One man’s waste – another man’s gold

By Jan Aagaard

Straw is traditionally seen as a waste product, that is either used
as litter for pigs and cows, or is incinerated. But in the future,
straw will be a valuable resource from which biofuel is made. At
Kalundborg in eastern Denmark, they are already testing the idea.
At the centre of the industrial area lies Inbicon – currently the
world’s biggest demonstration plant for 2nd generation bioethanol,
which is made from organic waste material. One of the uses
of bioethanol is as a sustainable fuel for cars.

From the outside, Inbicon looks like a modern factory where
almost anything might be manufactured within its neutral grey
walls. Only an enormous truck arriving with massive bales of straw
gives a hint of what takes place inside.



The straw bales are unloaded into a warehouse with cranes in
the roof. Every hour, the cranes lift four straw bales, each weighing
500 kilos, up onto a ramp that automatically pushes them into
the plant. The straw then goes through a number of processing
steps involving steam, enzymes and yeast, that convert each straw
bale into around 100 litres of pure bioethanol which after a few
days can be tapped at the other end of the plant.

Bioethanol is however not the only product that comes out of
the plant. The process also produces molasses, which is used as
animal fodder, and bio-pellets that are suitable for use as fuel in
power stations. On an annual basis, the Inbicon plant can convert
30,000 tons of wheat straw into 5.4 million litres of bioethanol,
11,000 tons of molasses and more than 8,000 tons of bio-pellets.

A green industrial centre
The Inbicon plant, together with other biofuel and biorefinery
initiatives, form part of an ambitious plan to make Kalundborg
Denmark’s green industrial municipality in 2020.

Although Kalundborg, with a local population of 49,000, is a
relatively small town, it is home to a number of large industrial
companies, such as the world’s largest enzyme and insulin factories,northern Europe’s largest industrial wastewater plant and
northern Europe’s second largest oil refinery.

Eight to nine percent of Denmark’s CO 2 emissions come
from Kalundborg’s industry. The potential for improving energy
efficiency and increasing sustainability is therefore considerable,
and Kalundborg Municipality has chosen, in collaboration with
industry, to launch a number of activities in the climate, energy
and environment area.

“We have made Kalundborg Municipality into a demonstration
centre for tomorrow’s green technologies and solutions by
engaging ourselves with some of the leading companies in a
number of areas,” says Martin Andersen, the head of Kalundborg
Municipality’s EU office in Brussels, and one of the key figures
behind the municipality’s green growth strategy.

“For Europe’s innovative industrial companies, it is a recurring
problem getting the opportunity to test new technologies in
practice on a large scale in order to move closer to commercialisation.

We are creating this opportunity in Kalundborg, where the
municipality serves not only as an authorising and controlling
body, but also as an active player in the development work,” says
Martin Andersen.

“For example, we are helping to build bridges between
industry and research institutions, create the right framework
conditions, and obtain funding for the various projects,” he says.

Turning garbage into gold
A key tool in the strategy to make Kalundborg Denmark’s green
industrial municipality is a close cooperation between a number of
industries, waste management companies and utilities, which can
turn waste products or by-products into something commercially
useful. One man’s waste becomes another man’s starting material,
helping to lower production costs and reduce the burden on
the environment and climate.

The Industrial Symbiosis, as the network cooperation is called,
began in Kalundborg in the 1960s as a result of a lack of water
resources for the very water-demanding industrial companies in
the area. By recycling water and recirculating it between the symbiosis

partners, the pressure on water supplies has diminished, and
the companies have saved money. The cooperation between the
companies has continuously expanded, and Kalundborg now has
the biggest and most advanced industrial symbiosis in the world.
The symbiosis today comprises eight members, who utilise a
wide range of waste products and by-products between them.
For example, Inbicon heats the straw supplied by local farmers
with surplus heat in the form of steam from a nearby power
station. The StatoilHydro refinery, Novo Nordisk and Novozymes
also take a portion of the power station’s surplus heat as process
steam to drive part of their production.

Collectively, the symbiosis reduces CO 2 emissions by around
265,000 tons per year, which corresponds to the annual CO 2
emissions from the electricity consumption of more than 80,000
single family houses. At the same time, the cooperation between
the companies on recycling and recirculating water helps reduce
water consumption by 30 percent.

By-products find a new use
The exploitation of the companies’ by-products is also systematised.

For example, the power station scrubs sulphur out of the
flue gases with limestone and recycled water, which produces
gypsum (calcium sulphate) as a waste product. The gypsum –
around 100,000 tons annually – is used by local company Gyproc
to manufacture plasterboard for the construction industry. And
ash from the combustion of coal at the power station is used in
the manufacture of cement and concrete.

Another waste product is yeast from the insulin production
at Novo Nordisk. This is turned into food for about 800,000 pigs
annually. Sludge from Kalundborg Municipality’s water treatment
plant is used as a soil nutrient, while Novo Nordisk and
Novozymes annually produce 150,000 tons of fertilizer from their
wastewater treatment and deliver it to local farmers.

At present the municipality is seeking to attract innovative
companies to the symbiosis and create new cooperations that
can further improve energy efficiency. The municipality is also
looking at the possibility of extending the network with alternative
energy sources.

Targeted investment in biorefinery processes
In 2008, the municipality established a cluster initiative in biorefinery
processes, Cluster Biofuels Denmark (CBD).

CBD is working to establish partnerships and attract investments
in pilot and demonstration biorefinery plants, and thereby
help companies and researchers to turn their ideas and technologies

into commercial products. In the first year, CBD concentrated
its efforts on production of bioethanol, based especially on waste
products from the production at Inbicon. The cluster initiative is
now also focusing on projects concerning waste and biogas, and
most recently on microalgae which can be used for the treatment
of wastewater.
CBD is also working on plans – with the help of EU funding
– to establish a larger-scale test and demonstration platform for
various technologies and products in the biorefinery area.
The idea is to extract and develop new high-value products to
replace oil-based chemical and pharmaceutical products, using
waste products from agriculture. This could for example be products
that are added to foods to improve their nutritional content,
or other ingredients.

Ultimately it is hoped that Kalundborg can become a north
European ‘Biocon Valley’, bringing together a number of companies
and research institutions that can benefit from each other’s
knowledge in the biotechnology area and so develop new ideas,
products and technologies for export.

Ambitions are high in Kalundborg, and the many projects in
the thriving industrial municipality hold great prospects for tomorrow’ssustainable society.

This article is from Focus Denmark Magazine, June 2011