Wasted energy in Canada

June 4, 2014, Jönköping – Canadian Biomass was treated
to a discussion on waste to energy on the second day of the World Bioenergy
Conference in Sweden. This is a country in which less than one per cent of
household waste ends up in the landfill. Fifty per cent is going to energy
generation and, in fact, it is in so much demand that the country is buying it
from other countries. So what can Canada do to make household waste a moneymaker
instead of a load of garbage? We need to see the waste in our trash.

Karolina Norbeck told her audience that waste is a design
problem since much of the products in the stores are not designed for
recycling. A shift in public behaviour started in 2000 with a landfill tax but
with technological developments, waste became a valuable commodity powering CHP
plants across the country.

Now that waste has been incorporated into the country’s
energy plans, there is still room for improvement and Canadians should take
note. Karin Granström is a Swedish researcher who was looking into the rumoured
substrate shortage in her country. She found a wealth of underused feedstocks
in pulp and paper mill sludge and municipal waste.

In Sweden, it is forbidden to dump organic waste in
landfills but what’s the best use of this watery waste? She found that rather
than going through the expensive process of dewatering it, it should be used
for anaerobic digestion for biogas.

Combining municipal sewage treatment with food industry,
agriculture, sorted food waste and manure and adding it to pulp and paper mill
sludge generates more methane than those feedstocks would generate on their
own. Pulp and paper mill sludge combines particularly well with municipal
sewage sludge to balance nitrogen and carbon. Her research also found that pure
pulp and paper sludge produced the most methane of the test groups but adding
up to 50 per cent sewage sludge to the mix worked well too.

Biogas is in great demand in Sweden where it is used for
public transportation (buses) and even in Canada, it is a large, untapped
resource for biogas production. Granström explained that in Sweden, there was a
lot of positive response to the idea of using sludge from the mills to make
biogas but when her researchers approached the pulp and paper mill owners, the
response was hesitant.

In Canada, we’re looking to extract value from every part of
the tree harvested and we’re making progress but until we begin to use the
sludge from our pulp and paper mills, municipal waste and trash, a valuable
resource is escaping our grasp.