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This project is implemented through the CENTRAL EUROPE programme co-financed by the ERDF
www.plastice.org Gimnazija Idrija, April 10, 2013
Can Plastics be Sustainable?
Andrej Kržan, National Institute of Chemistry, Ljubljana
Plastics
• Large group of materials
• Wide use and growth
• An ambivalent relationship (love/hate)
Are Plastics good or bad?
• is it safe?
• does it harm health/environment?
•What is the (best) way forward?
Goal:
To show how plastics can be(come) sustainable
Plastics – an unwanted friend
Polymer vs. Plastics
• Polymer: a chemical substance
- High molar mass
- Composed of repeating units
(monomers)
• Plastics: a material
- Formulated and prepared for use
- Main component are polymers
History of plastics
• Natural materials - limitations
properties, availability, processing
• Search for new materials that are:
- simpler for processing
- have “good“ properties
- cheap
Nitrocellulose - first plastic
- Made from a renewable resource
- 1851 colloidon (viscous solution)
- 1862 Parkesine (first plastic)
- 1869 Celluloid Hyatt
(first commercially succesful plastic)
History of plastics
• Initially use of natural raw materials
proteins, cellulose, oils, phenol, formaldehyde
• Emergence of petrochemistry, new raw materials (kerosine 1840)
• Development of understanding:
Hermann Staudinger 1920 (Nobel prize 1953)
A polymer is a substance of high molar mass
composed of repeating units.
• Poliethylene
1898 chance discovery, heating of diazomethane
1933 ehylene at high pressure, 1935 repeatable
1939 production for military use
1953 Ziegler Natta catalysts for production at low pressures
UHMWPE
History of plastics
• Polyamid / nylon
First synthesis 1935
Fibers prior to 2nd WW 80 % cotton, 20 % wool
1945 25 % artificial fibers
• Polystyrene
First synthesis 1839
Production 1931
Foamed (expanded) PS (EPS) 1949
Use
• After 2nd WW
• Extremely fast growth
• 280 million tons 2011
• 5 commodity plastics > 75 %
• HDPE, LDPE, PP, PVC, PET
Uses
• Use in all areas – almost irreplaceable
• Basis for our modern lifestyle:
safety, food, health, accomodation, entertainment…
Use
• Uporabe na vseh področjih
Future uses
• Polymers are entering into new uses…
(medicine, electronics, technology, energy, construction)
…and give answers to important challenges
• Polymers = lowering CO2 emissions
- sustainable
- unsustainable
Sustainability from use
• Insulation
• Lower mass (transport + vehicles)
• Lower food waste
• Production of green energy
• Replacement of more burdening materials
Sustainable
Raising sustainability through better (sensible) use
• Efficient use – product mass
• Reuse
X times 100%
• Recycling
• Energy use (incineration)
• Don’t use!
Plastics increasingly banned? Yes: 2 problems 1. Pollution with plastic waste
• Durable – unnatural materials – non-degradable • Omnipresent due to large use
2. Based on non-renewable resources • Inherently unsustainable
But plastics are bad?
Durable and harmful in environment
Waste: many options
… some ends in environment
EU 50 % landfilling
Waste
Based on fossil resources
A cycle that doesn’t function!
(CO2 – environmental aspect)
Price of oil in future?
(economic aspect)
Production
Crude oil
Natural gas plastics
CO2
waste
10 years
biomass
106 years
Bioplastics
Bioplastics = Biodegradable and/or biobased plastics
(European Bioplastics – used in industry)
Biodegradable
Biobased
Torej:
Source can be renewable (biomass) or non-renewable (fossil)
Material can be biodegradable or nondegradable
Biodegradable ≠ biobased
Biodegradable plastics
• Functionality of artificial polymers
• In certain time and under certain conditions
degrade to natural harmless substances
• Degradation includes biological step!
Biodegradation means that (micro)organisms digest BP.
So it makes sense to use natural or similar building blocks
By source:
• natural polymer (starch, collagen, chitosan...)
• modified natural polymer (viscose, methyl cellulose..)
• synthetic polymers (PGA, PLA, PCL ...)
Thermoplastic starch
Polymer structure of starch is retained but granular structure desroyed through application of heat, mixing and plasticisers (e.g. water, glycols)
Used in composites, blends and multi-layer materials
Blends with PCL, PHA etc.
Biodegradable
Collection of organic waste, vapour permeable packaging
Mater-bi (Novamont) cap. 60.000 t/a Foamed starch for packaging
L. Averous, University Strasbourg:
www.biodeg.net/biomaterial.html
Polylactic acid = Polylactide
Aliphatic polyester
Monomer produced by
fermentation
Chemical polymerization
- co-polymers
Natureworks (US)
cap. 140.000 t/a
Purac (NL)
Biodegradable
C
C
O
C
C
O
O
O
H
H
CH3
CH3
C
C
O
C
C
O
O
O
H
H
CH3
CH3
C
C
O
C
C
O
O
O
H
H
CH3
CH3
LL-Laktid
(mp 97 C)
LD-Laktid
(mp 52 C)
DD-Laktid
(mp 97C)
Polyhydroxyalkanoates
• Natural thermoplastic aliphatic biopolyesters
• produced by bacteria
• Monomers: β-hydroxy acids
• Large variety of structures
• - Poly(β-hydroxy butyrate)
• - Poly(β-hydroxy butyrate-co-valerate)
• - Poly(β-hydroxy butyrate-co-hexanoate)
• etc
• Current production based on sucrose, glucose
• Established methodology using waste sources
• - whey (lactose, salt conditions)
• - glycerol
• - bone and meat meal (N source)
• - animal fats
Synthetic polyesters
Polyestes – hydrolysis of ester bond
(kondensation polymers)
Aliphatic polyesters (no aromatic groups) kot PHA
PBS polybutylene succinate
PBSA polybuthylene succinat adipate
PCL polycaprolactone
Aliphatic aromatic polyesters
Modifikacations of PET
PBAT polybuthylene adipate terephthalatetalat
PBMAT
(Ecoflex BASF, Eastar bio)
Wter soluble polymers
PVOH polyvinylalcohol
EVOH ethylenevinyl alcohol (O2 $$)
Biodegradation
• Degradation must be complete
• Effect of abiotic and biotic factors
• First stage: Fragmentation
macroscopic degradation and conversion to oligomers
• Second stage: Mineralization
digestion by microorganisms
Chemical mehanisms
• hydrolysis
• oxidation
(both can be enzimatic)
• biodegradationcija
• fotodegradaci
• oksidacija
• termična degradacija
• degrad. zaradi stresa
...itd
Naravni krogotok snovi
Degradation
Measurement
• Degradation is always a question of rate
>> need to set conditions and limits
>> standards
• Unchanged natural materials biodegradable by definition
Basic principle
• conversion of carbon into CO2
Testing for degradation
Respirometry
Standards and Certification
• Standards for establishing biodegradability (anaerobic, aerobic, in soil, in water…), composting, toxicity…
• Certificates based on standards • Guarantee for consumer • Use of labels • cooperation between systems Examples of certification labels:
Biobased plastics
CO2 neutral
Biobased plastics are not always biodegradable
Approach:
- Synthesis of building blocks (basic chemicals) from
bioresources
- Replacement of same or similar chemical chemical from
fossil sources
- Fermentation and various chemical conversions
- Biorefineries
Crude oil
Natural gas plastics
CO2
waste
10 years
biomass
106 years
• “Back to the future” Not new !!! How polymer chemistry got started:
• 1869 Nitrocellulose Hyatt Billiard balls
• 1897-1900 Galalith Casein + formaldehyde
• 1930 Nylon 11 11amino-undecanoic acid from castor oil
• 1940’s Henry Ford Soy based phenolic plastic
• Driver: only resource-convenient resource-environmental aspect
Historically
1. generation: food and feed sources
short term solution
2. generation: non-food and waste resources
wood, straw, waste
3. generation: microorganisms
algae, GMO?
Renewable resources
Nature (2008), p. 891
from CO2 in H2O
Bio Polyethylene
Biobased, nondegradable
• Equivalent to PE from fossil sources
-CH2-CH2-CH2-
• 100 % biobased
• Not biodegradable
• Braskem 2009, 200.000 t/a
• Dow Sovay
• Efficiency of ethanol fermentation?
Sugar cane
fermentation, distilation
Ethanol
dehydration
Ethyilene
polymerization
PE
Bio PET
• Bio PET / Coca Cola, Heinz: on the market
• 30 % bio C TA EG PET
Bio
+ =
Petro
⌃ ⌃
Bio PET
• Bio PET / Coca Cola, Heinz: in development
• 100 % bio C
• Partner for TA: Virent
• BTX also for:
PS, PA, PC, PU,
Phenolic resins
EG
Bio
+ =
⌃ ⌃
Bio
TA PET
New polymers
• Isosorbide (Roquette, F)
Polyethylene isosorbide terephthalate
PU
Isosorbide polycarbonate
Polyisosorbide succinate 100% biobased
Produced in a …
Biorefinery
Bioeconomy
- Very active development
- A number of players
- Preparing to have an alternative to oil
Sources
- www.eurobioref.org
- IEA Bioenergy report: Bio-based Chemicals,
Value added products from biorefineries
A GREEN INDUSTRIAL REVOLUTION IS TAKING PLACE
Biobased monomers
New and Old!
• 1,3 propanediol (DuPont, 45.000 t/a, Sorona)
• 1,4 butanediol (BDO)
• succinic acid
• levulinic acid
• glycerol
• furan dicarboxylic acid
• polyols based on soy oil
• Olefin metathesis: plant oiljs waxes, funktional oils, lubricants
Approach “Direct replacement for chemicals from fossil sources”
• Neeed for success: technology, low prices of resources, high price
of oil
Standards and measurement
Currently one established standard:
ASTM D6866
- EN standard is new
• Measuring the ratio C12 / C14
C14 is formed in atmosphere and is
characteristic of all renewable
(biological) material
in fossil sources its concentration is low
• C14 t1/2 = 5730 let
• After 50.000 years C14 conc. very low
Certification
Certification based on ASTM D6866 standard
Biobased carbon content (0-100 %)
Biobased C content marked on certification logos
Advantages of Bioplastics
In production: use of renewable resources
towards CO2 neutrality
CO2
footprint
After use: bioconversion into natural degradation products
… plastics can be a part of the natural material cycling
NATURE
P
CO2
Biodegradable vs. biobased?
Will a product made from biodegradable plastics go into
composting? - labeling?
- does biodegradability make sense?
If production is efficient biobased plastics always bring an
advantage
Conclusion
Plastics can have
substantial contribution to higher sustainability
Unwanted friend should become our partner
www.plastice.org
www.sustainableplastics.eu
Thank you!