Changing shopping habits and trends to convenience products have precipitated a
plastic waste disposal crisis. Relief is expected by recycling, however, due to the
high cost of collection, separation and purification recycling is considered as
economically ambiguous. Assuming that biodegradable plastics meet the price
expectation, it would be better to use biodegradable plastics which are easily
compostable. The estimated EEC market (year 1998) for such products is of
significant size : approximately 4-5 x l05 tons/yr.
The overall goal of the present project is the synthesis of biodegradable polyesters
from two main monomers, 1,3-propanediol and succinate (produced by
fermentation from renewable sources) and from other dicarboxylic acids (like
terephthalic acid) used as an auxiliary monomers to modified the chemical and
physical properties of the polyester. The advantages of this approach compared to
polyhydoxyalkanoates or polylactides (two biodegradable polyesters that can be
produced from renewable sources) are the lower cost of production and the
possibility to easily modify the physical properties of the polyester to the qualities
required for the article made of plastic.
Therefore the main items of this project are :
Production of 1,3-propanediol out of glycerol coming from the oleochemical
industry (fatty acids, fatty alcohols) and rape seed oil production. Development of
genetically modified microorganisms for maximal yield of 1, 3-propanediol
production and evaluation of their performances in fermentor up to the m3 scale
and in high volumetric productivity membrane bioreactor.
Production of succinic acid from starch hydrolysates using Anaerobiospirillum
succiniproducens in high performance bioreactor (membrane bioreactors with
optimized ratio of cell bleeding and effluent flow rates and in situ product recovery
by electrodialysis), to increase the productivity and decrease the waste water
treatment of the process. This fermentation is original by the fact that carbon
dioxide is consumed for succinate production. Several patents have been deposited
regarding the process of succinate production but the productivities reported are
low due to low cell density.
Development of polyesters based on 1, 3-propanediol and succinic acid optimised
regarding processability and thermo-mechanical properties by means of utilization
of improved polymerization-copolymerization methods and blending. Manufacture
of prototypes of product using the referred optimised polymers, copolymers and
blends. Biodegradation studies using various test systems including C-balances,
isolation and characterization of degradative microbial consortia and involved
enzymes systems (lipases, hydrolases).
Funding SchemeCSC - Cost-sharing contracts
100 44 Stockholm