Organic waste in farming of salmon 153
struggling financially, and although the sludge was of economic value to the
biogas producers, the firm had an agreement to give it away and pay for the
transport. The firm took the longer view in that they wanted to support
the biogas producers as an outlet for this waste stream. The firm’s representative said that they would later consider negotiating a price for the sludge, but
only if the biogas producer was in a position to pay for it. The representative
said it was not a high priority in terms of the fish farm’s economy.
Combustible material for heating
Dried sludge can serve as a fuel in industrial production of different products,
e.g. cement. In cement production, clinker is heated to 1,400–1,500°C.
There is currently a collaboration between one of the salmon firms in our
sample and a cement- producing firm, where the dried sludge is used to fuel
the clinker ovens.
8.4.2 Challenges with current system
Waste volumes are expected to increase
One of the biggest challenges with today’s waste stream management is the
expected increase in volume in the years to come. The valorisation pathways
are still in a nascent stage and are unlikely to be able to handle the expected
increase in volume of organic waste. Because the volume is currently small,
the firms have entered into simple agreements with farmers, and, in some
cases, biogas producers are given the waste free or even paid to remove it.
While many fish production firms have local agreements with other actors to
handle the organic waste, as the scale increases, the interviewees noted that
these actors may not be able to handle the increased volume of sludge, and
new strategies would have to be explored.
Transport
A substantial challenge related to organic waste from salmon production is
transport. If the sludge, which has a high water content, needs to be moved
over large distances (which is to be expected), it is both a practical and economic issue. There is considerable distance between the smolt production
facilities and the places where it can be used: typically, fish farms are located
on the coast and agricultural areas are further inland. Sludge can only be economically transported short distances. The interviewees noted that the
logistics are not yet in place for increased volumes of stored sludge, so transport and distribution is one of the bottlenecks in the full valorisation of fish
farm waste.
struggling financially, and although the sludge was of economic value to the
biogas producers, the firm had an agreement to give it away and pay for the
transport. The firm took the longer view in that they wanted to support
the biogas producers as an outlet for this waste stream. The firm’s representative said that they would later consider negotiating a price for the sludge, but
only if the biogas producer was in a position to pay for it. The representative
said it was not a high priority in terms of the fish farm’s economy.
Combustible material for heating
Dried sludge can serve as a fuel in industrial production of different products,
e.g. cement. In cement production, clinker is heated to 1,400–1,500°C.
There is currently a collaboration between one of the salmon firms in our
sample and a cement- producing firm, where the dried sludge is used to fuel
the clinker ovens.
8.4.2 Challenges with current system
Waste volumes are expected to increase
One of the biggest challenges with today’s waste stream management is the
expected increase in volume in the years to come. The valorisation pathways
are still in a nascent stage and are unlikely to be able to handle the expected
increase in volume of organic waste. Because the volume is currently small,
the firms have entered into simple agreements with farmers, and, in some
cases, biogas producers are given the waste free or even paid to remove it.
While many fish production firms have local agreements with other actors to
handle the organic waste, as the scale increases, the interviewees noted that
these actors may not be able to handle the increased volume of sludge, and
new strategies would have to be explored.
Transport
A substantial challenge related to organic waste from salmon production is
transport. If the sludge, which has a high water content, needs to be moved
over large distances (which is to be expected), it is both a practical and economic issue. There is considerable distance between the smolt production
facilities and the places where it can be used: typically, fish farms are located
on the coast and agricultural areas are further inland. Sludge can only be economically transported short distances. The interviewees noted that the
logistics are not yet in place for increased volumes of stored sludge, so transport and distribution is one of the bottlenecks in the full valorisation of fish
farm waste.