Life Cycle Assessments of Energy From Solid Waste (PDF)

The results for the food waste fraction are similar to that of the whole system.
For the newspaper fraction emissions contributing to aquatic eutrophication (excluding NO x )
can be avoided through incineration. Recycling gives a net emission a little smaller than
landfilling.
Regarding eutrophication (excluding NO x ) the ranking is the same for PET as for the whole
system, but here the incineration alternative turns out avoiding emissions.
7.2.9 NO x
For the whole system a net avoidance of NO x emissions occur in the recycling alternatives.
Landfill causes a net emission that is a bit lower than that caused by incineration.
For food waste net emissions of nitrogen oxides occur in all of the five treatment options. The
smallest emission is made in the incineration case, followed by landfill, which emits a little
bit less than digestion with heat and electricity production. Composting emits more and the
largest emission is made when digesting and using the gas as bus fuel.
Recycling newspaper gives a net avoidance of NO x emissions, since the virgin production
uses more coal-based electricity. Landfilling results in a net emission of NO x released in the
surveyable time period. A larger net emission is made in the incineration alternative.
For PET net avoidance of NO x emissions is made in the recycling and incineration
alternatives, while landfill results in a net emission. The most NO x is avoided in the recycling
alternative.
7.2.10 SO x
Net avoidance of SO x emissions is made in the recycling and incineration options for all of
the materials studied. Looking at the whole system the greatest amount of SO x is avoided in
the recycling alternatives. The major contribution to this comes from the avoidance of coal
based electricity when replacing virgin newspaper. A little bit less emissions of SO x are
avoided when replacing biomass for heat production in the incineration case. Landfill result in
net emissions of SO x .
For food waste the best options for this category are digestion using the gas as bus fuel or
composting for which the avoided emissions of SO x are equal. Digestion and composting
avoids SO x emissions from production of phosphate fertiliser and for digestion also from
diesel combustion. Not quite as much SO x is avoided when using the digester gas for heat and
electricity production or when incinerating. Landfilling gives rise to net emissions.
Newspaper and PET show the same pattern as the whole system.
7.2.11 Terrestrial eutrophication from NH 3
Looking at the whole system the largest amount of NH 3 is avoided through incineration. This
avoidance is achieved since a larger amount of urea is used when burning forest residues
compared to when incinerating waste. A smaller amount of NH 3 emissions are saved when
recycling is combined with digestion, using the digester gas for electricity and heat
production. Also in this case the saving comes from the avoided heat production from forest
residues. Using the digester gas as bus fuel gives a net emission for the recycling alternative.
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