Microsoft Word - Environmental benefits of recycling 2010 update.doc

Table 46 Overview of the end-of-life alternatives compared within each case for biopolymers

Case Recycling Composting

Incineration

with

electricity

recovery

only

Incineration

with heat or

combined

heat/

electricity

recovery

Incineration

without

energy

recovery

Landfill Anaerobic^

digestion

Pyrolysis Gasification

1[MB] xx x

1[OCT] xx x

2[PLA] xxx

2[MB] xxxx

2[BIO] xxx

3[PLA1] x^1 xx

3[PLA2] x^2 xx

4[MUB1] xxx

4[MUB2] xxx

5[PLA] xxxx

6[PLA] xx

6[CE] xx

7[MAS] x^1 xx x

Total number

of cases

5123728300

(^1) Feedstock recycling scenario
(^2) Chemical recycling scenario

Ranking between the various end-of-life options within each scenario

Table 47 compares the end-of-life options compared within each scenario. When the indicator is not taken into
account in a given case the line is coloured in grey. This table should be interpreted with care. It shows the
relative ranking of the end-of-life solutions within a given case study for specific assumptions and system
boundaries. It does not provide sufficient information to be able to give an overall conclusion regarding which
alternatives are the best.

Study no 1

In study no 1, composting, landfill and incineration with energy recovery are compared. The biopolymers under
study (Mater-Bi and Octopus) satisfy the biodegradability and compostability requirements of EN 13432. For
depletion of natural resources and climate change, composting appears as the least preferable option. However,
regarding eutrophication, it is the landfill alternative that has the most impacts. For acidification, composting and
landfill present similar potential impacts and are less preferable than incineration with energy recovery. The high
impacts for composting can be explained by the high degradation rate (90%) assumed for the carbon content.

Study no 2

Study no 2 compares the same alternatives but also includes a prospective recycling scenario for Mater-Bi.
Whenever taken into account, recycling appears as the preferable option. In the other cases, incineration with
energy recovery is the best option regarding energy consumption and depletion of natural resources. This is due
to the avoided production of electricity. Composting and landfill are more favourable regarding climate change.
This is explained by the fact that the sequestration of the carbon contained in the material is taken into account
and thus some CO 2 emissions are avoided. The degradation rate is assumed to be higher for landfill thus the rate
of sequestered carbon is higher for composting. Nevertheless, for Mater-Bi and Biolice, landfill is more beneficial
than incineration with energy recovery for this indicator. This is because some methane and CO2 emissions are
emitted during composting, while in the case of landfill methane emissions and energy production are avoided
thanks to the valorisation of the biogas produced. Incineration with energy recovery appears more favourable for
PLA than for the other polymers as PLA contains a higher rate of carbon from biomass thus incineration of PLA
leads to the production of CO 2 neutral energy that replaces fossil fuel energy.