02 | 2008

Politics
Reducing Environmental
Biopolymer
Bioplastics vs. food ?
• For polymers like polylactide (PLA), fermentable sugars
are required as the basic raw material. Today sugars
can come from e.g. corn, wheat, potatoes, sugar cane,
sugar beets, or rice. In the near future the bio-chemical
industry will use alternatives like straw, corn stover
or bagasse. There are various drivers for this change
including:
• Avoiding competition with food. It is expected that the
world population will grow from 6.7 billion people today
to 10 billion people around 2035, so industry has to look
for non-food feedstock.
• Lowering the costs so more people can afford these
bioplastic-based consumer good products, man-made
fiber articles and packaging materials.
• Improving the life cycle of these biopolymers (less fossil
resource use, less greenhouse gas emissions).
• More efficient use of land.
• More outlets for agricultural waste streams will lead to
additional revenues for farmers.
• Locally grown crops helping developing local economies
which so also become less dependent on the few oilproducing
countries today.
It is not expected that bio-materials will replace all fossil-based
materials, but by replacing a part of them, the
fossil resources will remain available for future generations.
Today there is some tension on the world food market
especially due to increasing prices of agricultural products.
This is caused by several factors. A key factor are the
growing economies in South East Asia where people are
eating more meat and therefore creating the need to produce
more feed for agricultural feedstock. Another factor
is the policy of having lower stocks in place and increased
reliance on the world market. In the past these stocks
were used to balance lower local or regional harvests.
And finally, to a lesser extent, the increased production of
biofuels. All these factors are leading to higher demands
and so higher prices. The effect of producing Nature-
Works biopolymer in this mix is very limited. Assuming a
name-plate capacity of 140,000 metric tons, about 0.12%
of US corn is used. Even if the capacity triples in the next
10 years, the impact remains below 0.5%. Short term, the
increased demand on agricultural feedstock can be balanced
by taking more land into production and increasing
the yield per hectare. In many countries the yields are
still rather low. Longer term, the increased use could be
balanced by switching to the use of agricultural waste
streams in combination with the development of other
more efficient / higher yield crops.
Genetically modified crops are not required to produce
NatureWorks biopolymer. Due to the current plant location
– Blair, Nebraska, - a mixed stream of conventional and
genetically modified corn is used. To meet the needs of the
market NatureWorks LLC has developed a three tiered program
consisting of Certification, Feedstock Sourcing and
Identity Preservation. Certification confirms the absence
of genetically modified material in NatureWorks bio-polymer
by lot, order, and run. This is conducted periodically
through the year by GeneScan, Inc., an internationally
recognized certification organization. With the Feedstock
Sourcing program, our commercial partners are offered
the option to support the production and delivery of conventional
corn in relation to their NatureWorks biopolymer
purchase. For every kilo of NatureWorks biopolymer purchased,
NatureWorks LLC will purchase, verify and deliver
2.7 kilos of conventional corn to the corn mill at a slightly
higher price. The last program is called Identity Preservation
(IP). For the last two years, large-volume customers
with multiple-year supply contracts are given the opportunity
to purchase NatureWorks biopolymer sourced and
produced from 100% conventional corn. This program
requires a minimum volume commitment of 20 million
pounds (approx. 10,000 metric tons). NatureWorks LLC is
finalizing an alternative IP option, in which customers are
given the opportunity to purchase for specific applications
NatureWorks biopolymer produced from lactic acid which
is derived from a 100% GM free feedstock. This route has
the advantage that it can start with lower volume commitments
(approximately 5 million pounds or 3,000 metric
tons). The volumes mentioned can be shared among various
customers. Both options have significant lead time in
order to insure execution.
End of life options
NatureWorks biopolymer (polylactide, or PLA) offers
more disposal options than any other plastic. In addition to
the traditional disposal options for petrochemical-based
polymers (landfill, incineration and mechanical recycling)
bioplastics MAGAZINE [02/08] Vol. 3 29