02 | 2008

Concerning the second option, NatureWorks made the decision
that beginning in 2006 it would purchase renewable
based electricity to cover all electricity needs in the cradle-to-polymer-pellet
production system. The preference
is for the local utility to supply the Green Power directly.
During 2006 limited volumes were available, but during
2007 already about 1/3 of the electricity required came
from Green Power generated by the local utility. Since this
was/is still not sufficient, NatureWorks LLC purchases so
called Renewable Energy Certificates (RECs). In this case
the renewable energy is not produced by the local supplier,
but in a neighboring state which shares the same
power grid. However, for the environment itself it does not
make a difference where the renewable energy is being
produced, as long as it is being produced in increasing
quantities. NatureWorks LLC is purchasing RECs since
the beginning of 2006 to cover all it electricity needs in
its cradle-to-pellet NatureWorks biopolymer production
system.
NatureWorks LLC has calculated four eco-profiles (see
box 1-3 for some explanation) for NatureWorks biopolymer
(PLA) production:
• PLA5: Represents the 2005 cradle-to-pellet Nature-
Works biopolymer production system.
• PLA6: Represents the current, 2006/2008, cradle-topellet
NatureWorks biopolymer production system. In
this eco-profile the fossil fuel-based electricity has been
replaced by renewable energy-based electricity through
investments in Green Power and RECs.
• PLA/NG no WP: Represents the next generation (NG)
cradle-to-pellet NatureWorks biopolymer production
system. It includes the implementation of major changes
in the lactic acid production and purification. This
new technology will reduce energy and raw material
use and co-product creation and is expected within 3-5
years. Electricity is imported from the public grid and is
mainly fossil fuel-based. (‘no WP’ means that no wind or
renewable power is used in this eco-profile).
• PLA/NG: The same as PLA/NG no WP, but now Green
Power is used to supply electricity in the Cargill / NatureWorks
controlled production processes. This combination
will make the cradle-to-pellet NatureWorks
biopolymer a greenhouse gas sink.
Renewable Energy Certificates - REC
A REC represents the environmental attributes – for example
the avoided CO2 emissions – that are created when
electricity is generated using renewable resources instead
of using fossil fuel sources. NatureWorks purchases
Green-e certified RECs. The Center for Resource Solutions
operates this certification and auditing program. A certified
REC assures that the green energy is being produced
and delivered, and that the attributes are being claimed
only once. Green-e certified RECs also assure that they
are from qualifying ‘new facilities’ (up to several years),
Appendix:
Politics
PLA Plant East Green Grass
1) Eco-profile gives the total energy use, the total
raw material use, the total air and water emissions
and the total solid waste produced from the cradle
to a factory gate. An eco-profile always starts with
the extraction of the raw materials from the earth
and ends with the production of the product of
interest. Eco-profiles are not limited to a particular
product. In addition to the eco-profile for Nature-
Works biopolymer, eco-profiles can also be calculated
for products like lactic acid, dextrose, corn,
electricity and steam production. An eco-profile is
the same as what is often referred to as ‘cradle-topellet’
or ‘cradle-to-polymer-factory gate’ data.
2) Life cycle inventory (LCI) gives the total energy
use, the total raw material use, the total air and
water emissions and the total solid waste produced
from the cradle to the grave ( = the ultimate disposal).
An LCI is basically the same as an eco-profile,
but it covers the complete life cycle. So, the LCI of
NatureWorks biopolymer ‘pellets’ does not exist, one
can only have an LCI of a Ingeo product. For an LCI
one has to define among others the application, the
production location and technology, the use phase
and waste collection and processing.
3) Life Cycle Assessment is a systems analysis tool
to account for all the environmental impacts associated
with a product or service, covering all stages
in a product’s life, from the extraction of resources
to ultimate disposal. The basic data set for an LCA
is an LCI. In the life cycle assessment the inventory
data is converted into a limited series of impact categories,
such as fossil energy use, climate change
and acidification, followed by an assessment of how
relevant these impacts are.
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