(best examples and good practices) on household organic waste ...

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mentioned in earlier. (Chemical Engineering <strong>and</strong> Technology department KTH.,
2007)
By biological treatment, digestion as well as composting is intended. The
quantity of biologically treated waste in 2005 was 2 720 tones, <strong>and</strong> additionally
500 tones by home composting. Accordingly only 10 % of the total goal amount
was fulfilled in 2005. The collection has to be greatly increased to reach the 35
%-goal.
As mentioned earlier, Stockholm Traffic Office together with the Stockholm
Water Company has an experiment in progress. The purpose is to increase the
separation of food waste <strong>and</strong> treat it biologically. Waste mills will be placed in
restaurants, grocery stores <strong>and</strong> school kitchens. The food waste placed in the
mill will be ground <strong>and</strong> transported to a tank, which is emptied by a slurry
exhauster vehicle. (Chemical Engineering <strong>and</strong> Technology department KTH,
2007)
8.4.2. Linköping concept
In Linköping the production of biogas has come a long way <strong>and</strong> the company
Svensk Biogas, subsidiary to the regional company Tekniska Verken, produces
biogas in three different plants, whereas two of them apply solely for biogas
production. The substrates used at the Åby plant are slaughter house waste,
organic waste from industries, restaurants <strong>and</strong> institutional kitchens <strong>and</strong> a
quantity of manure. The waste water treatment plant Nykvarn uses some grease
trap removal sludge in addition to sewage sludge. The gas produced at Nykvarn
is lead through a gas pipe to the Åby plant, where it is upgraded. The concept is
illustrated in (Figure 42.)
The produced gas is distributed to refueling stations <strong>and</strong> to the local bus depot
in Linköping by gas pipes. One of the local refueling stations, located close to
the production plant <strong>and</strong> the bus depot, can be seen in (Figure 4.36). The buses
are slow-filled over the night. Distribution to surrounding cities, without their
own CBG production, is made by vehicles with swap-body units. The refueling
stations in Norrkoping have been supplied by gas from Linköping earlier, but
since the new plant Händelö is in operation the stations are locally supplied.
Except distribution to other surrounding cities, some of the CBG produced in
Linköping is purchased by AGA <strong>and</strong> distributed to Stockholm.
The new plant Händelö in Norrkoping uses refuse from ethanol production <strong>and</strong>
residue from crop production in the agricultural industry as substrates. The