Determination of the fossil carbon content in combustible municipal solid waste in Sweden

The results from this project show that the proportion of fossil carbon in combusted municipal waste in Sweden amounts to about one third.  This corresponds to a fossil carbon content of about 10 percent by weight of the waste mixture.
This is based on investigations of waste, using four different methods of measurement, at seven of Sweden’s waste combustion plants.

The results from the chemical characterisation of the waste show that the difference between those samples that contained a lot of commercial waste (getting on for 80 %) and those that were taken only from domestic waste is not all that great.  Main parameters such as carbon, oxygen and hydrogen show a relative standard deviation of less than 10 %.  The total measured effective calorific values of all samples amounted to about 11 MJ/kg.

The results from the fossil carbon analyses of all the solid samples and the flue gas samples show that the proportions of fossil carbon are 36 % and 38 % respectively, which correspond to a fossil carbon content of about 10 % by weight in a mixed waste body.  In the plants where they were tested, the two other methods (based on assumptions and calculations) gave approximately the same results as the two sampling methods that were tested.  In simple terms, this can be expressed as saying that about one third of the carbon in waste that is burnt in Sweden has a fossil origin.

The proportion of fossil carbon or CO2 in the total quantity of carbon in waste burnt in Sweden.

As well as investigating the fossil carbon content of waste sent for combustion, the project also aimed to investigate the user-friendliness of the various methods.  However, it is difficult directly to compare the methods used in this project as, in addition to estimating the direct fossil carbon emissions, they also provide other information that is of value for the plant owner.  The choice of analysis method can therefore be influenced by other factors than that of direct determination of fossil emissions.

The report is a translation of the Swedish report “Bestämning av andel fossilt kol i avfall som förbränns i Sverige” (U2012:02).

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