Narayan

Ramani NarayanUniversity Distinguished Professornarayan@msu.edu

The Promise of BioPlasticsUnderstanding Value Proposition of Biobased and Biodegradable

Plastics for Reducing Carbon Footprint and Improving Environmental Performance

If you use any of the slides/materials, please reference authorship and affiliation (Ramani Narayan, Michigan State University) – thank you

Copyright Ramani Narayan

• Ramani Narayan, Biobased & Biodegradable Polymer Materials: Rationale, Drivers, and Technology Exemplars; ACS (an American Chemical Society publication) Symposium Ser. 939, Chapter 18, pg 282, 2006;

• Ramani Narayan, Carbon footprint of bioplastics using biocarbon content analysis and life cycle assessment, MRS (Materials Research Society) Bulletin, Vol 36 Issue 09, pg. 716 – 721, 2011

ASHS Plenary lectureJuly 31, 2012 Miami FL

Narayan

• Plastic are pervasive, universally used, and find applications in all parts of our lives

• from agriculture to electronics to construction materials, to transportation, to sports & leisure to medical devices to packaging.

• Packaging prevents spoilage, keep products safe, lightweight (saves energy); hygienic, health care

• From 1.7 million tons in 1950 to 265 million tons in 2010 worldwide expected to grow at a steady pace of 3–4% per year.

• rapid industrialization in populous countries such as India and China has resulted in an accelerated pace of plastic materials growth.

• Plastics offer “value” in every aspect of our life making it safe, functional, energy efficient, improved efficiencies and more –

PLASTICS

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• Horticulture (Plasticulture) -- mulch film, greenhouses, small tunnels, fruit and vegetable coverings, and other uses

• increased yields, earlier harvests, less reliance on herbicides and pesticides, better protection of food products and more efficient water conservation

• improve product quality and yield by mitigating extreme weather changes, optimizing growth conditions, extending the growing season and reducing plant diseases

• About 5 million tons used world-wide and growing

PLASTICS

Biodegradable Mulches for Specialty Crops Produced Under Protective Covers

Debra Inglis and Carol Miles (Project Directors)1;Andrew Corbin, Jessica Goldberger, Karen Leonas, Tom Marsh and Tom Walters1; 

Doug Hayes, Jaehoon Lee, Larry Wadsworth and Annette Wszelaki2; 

Jennifer Moore‐Kucera3; Russ Wallace4; Marion Brodhagen5 ; and Eric Belasco6

1 25

SCRI Grant Award

No. 2009-51181-05897

43 6

ASHS Colloquium Miami, Florida

Tuesday July 31, 20122:00- 6:00 pm

Biodegradable Plastic Mulches for Specialty Crop Production:

Current Status and Future Directions

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• Carbon footprint – material carbon footprint • origin of the carbon in the product • Biological carbon feedstock vs petro/fossil carbon feedstock

• Carbon footprint – process carbon footprint • arising from the conversion of feedstock to product – process

• Life Cycle Assessment (LCA) methodology

• End of life—what happens to the product after use when it enters the waste stream

• Recycling

• Biodegradability – composting & anaerobic digestion

• Soil – agriculture/horticulture films

• Misleading and Deceptive biodegradability/compostabilityclaims – BEWARE !

MAJOR ISSUES FOR CARBON BASED PLASTICS USE

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Switching from the “petro/fossil” carbon in plastics to “biobased” carbon reduces the material carbon footprint

• Reducing heat trapping CO2 emissions -- Minimizing global warming/climate change problems

• Using (renewable) biomass feedstock as opposed to petro/fossil feedstock – energy/environmental security

• Economic development – empowering rural farm, forestry and allied manufacturing industry

Carbon footprint reduction strategy using bio contentWhat Value Proposition does Biobased Plastics offer?

7

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Material Selection for “beginning of life”

bio vs petro/fossil feedstock

BIOBASED PLASTICS

Biobased plastics are not necessarily biodegradable(end-of-life) and biodegradable plastics are not necessarily biobased (beginning of life, origins of the carbon)

BioPlastics encompasses both biobased and biodegradable –compostable plastics

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VALUE PROPOSITION BASICS –MATERIAL CARBON FOOTPRINT – Origins of the carbon

CHCH3

CO

O

PLAn

Bio/renewable feedstock

Crops & residues (e.g. Corn, soybean sugarcane)

Tree plantations Lignocellulosics

Algal biomass

Oil, Coal, Natural gas

MATERIAL CARBON FOOTPRINTPROCESS CARBON FOOTPRINT

PLA, PHA’s

Naptha ethylene/propylene Polyethylene (PE) polypropylene (PP)

BIO monomers

sugars, Oils

EtOH H2C CH2nPE

H2C CH

CH3 nPP

C

O

O CH2 CH2 OC

O nBIOPET

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Carbon footprint reduction strategy using bio contentUnderstanding the Value Proposition based on the origins of the carbon in the product -- bio carbon vs petro/fossil carbon

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CO2 + H2O (CH2O)X + O2photosynthesis

sunlight energy

Biomass, Ag & Forestry crops & residues

NEW CARBON

Fossil Resources (Oil, Coal, Natural gas) -- OLD CARBON

> 106 YEARSUSE – for materials, chemicals and fuels

Rate and time scales of CO2 utilization is in balance using bio/renewable feedstocks (1-10 years) as opposed to using fossil feedstocks

1-10 years

1-10 years

MATERIAL CARBON FOOTPRINT

Short (in balance) sustainable carbon cycle using bio renewable carbon feedstock

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Carbon emissions – the problem

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Global warming –climate change

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Planet temperatures Mercury is the planet closest to the Sun, so one would assume that it is a burning

furnace. While the temperature on Mercury can reach 465°C, it can also drop to frigid temperatures of -184°C. There is such a big variation in Mercury’s temperature because the planet has no atmosphere, and it spends relatively slowly compared to some of the other planets.

Venus, the second closest planet to the Sun, has the highest average temperatures of any planet in our Solar System, regularly reaching temperatures over 460°C. Venus is so hot because of its proximity to the Sun and its thick atmosphere. Venus’ atmosphere is composed of thick clouds containing carbon dioxide and sulfur dioxide. This creates a strong greenhouse effect, trapping the Sun’s heat in the atmosphere and turning the planet into a furnace.

Earth is the third planet from the Sun, and so far the only planet known capable of supporting life. The average temperature on Earth is 7.2°C, but it varies much more than that at its extremes. The hottest temperature ever recorded on Earth was 70.7°C in Iran. The lowest temperature was -89.2°C in Antarctica.

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Carbon emissions – the problem

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What is the impact of the products material carbon footprint on the environment ?

Impact of the carbon’s origins in the product?

Impact of manufacturing 100 Kg of PE and bio-PE or bio-PLA in terms of Kg of CO2 released from the origins of the carbon

Carbon footprint reduction strategy using bio contentMaterial Carbon Footprint

15

C

O

O CH2 CH2 OC

O nPET

H2C CH2nPE

CHCH3

CO

O

PLAn

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314 kg of CO2 emissions reduction for every 100 kg of PE resin in which the petro carbon is replaced with bio carbon

Material Carbon Footprint

0

50

100

150

200

250

300

350

PE/PP PET Bio-PE/PET/PLA

Kg of CO2 per 100 Kg resin

ZERO CARBON FOOTPRINT

314 kg of CO2 emissions reduction for every 100 kg of PE resin in which the petro carbon is replaced with bio carbon

Experimentally determine using ASTM D6866 based on the principle of C-14 analysis

Ramani Narayan, Michigan State University

Cradle to factory gate LCA scenario

Material Carbon FootprintKg of CO2 per 100 kg of resin

-320

-270

-220

-170

-120

-70

-20

30

80

1 2

Zero footprint -- product recycled, no release of gas to the environment

PE/PP BIO-PE

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Ramani Narayan, Michigan State University

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BIO-PET – Value Proposition

Oil, Coal, Natural gas

Naptha Ethylene Ethylene oxide Ethylene Glycol

MATERIAL CARBON FOOTPRINT PROCESS CARBON FOOTPRINT

C

O

O CH2 CH2 OC

O nBIOPET

Bio/renewable feedstock

Crops & residues (e.g. Corn, soybean sugarcane)

Tree plantations Lignocellulosics

Algal biomass

BIO monomers

Sugars, Oils

EtOH

OH CH2 CH2 OH

COOHHOOC

For bottles:37.5 MM tons PET used17.2 MM tons CO2 savings40 million barrels of oil/yr savings

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2009

Introduced innovative PlantBottle® package

2010

Over 2.5 Billion bottles10 Countries

2011

Over 7 Billion bottles20 Countries

2020

All bottles made with PlantBottle® plastic

Scaling across the world

Biobased & compostable PLA products

Courtesy Ford Motor Company

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Carbon footprint reduction strategy using bio contentMeasurement of bio (carbon) content – an important and critical Standard for the bio industry

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C-14 signature forms the basis of Standard test method to quantify biobased content (ASTM D6866)

12CO2

Biomass

Fossil Resources(petroleum, natural gas, coal)

> 106 years

14CO2 – Solar radiation

(12CH2O)x (14CH2O)x

(12CH2)n (12CHO)x

NEW CARBON

OLD CARBON

Narayan, ACS (an American Chemical Society publication) Symposium Ser.939, Chapter 18, pg 282, 2006; Narayan, MRS (Materials Research Society) Bulletin, Vol 36 Issue 09, pg. 716 – 721, 2011

14N 14C 14CO2

Cosmicradiation

12CO2

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Carbon footprint reduction strategy using bio contentMeasurement of biobased (carbon) content – ASTM D6866

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C-product combusted to CO2

14C/12C ratio is compared directly with a oxalic acid radiocarbon standard reference material (SRM 4990c) that is 100% new (bio) carbon.

• 13.56 dpm/g is the absolute value of the primary oxalic acid standard (SRM 4990b) and corresponds to 100% biobased (carbon) content

• 14.27 dpm/g is the value to use to correct for the post 1950 14C injection into the atmosphere.

• pMC values (after correction for isotopic fractionation) must be multiplied by 0.95 (as of 2010) to better reflect the true biobased content of the sample

• Contains concentration of 1.2 x 10-12 % of C-14 isotope equivalent to 100% bio carbon content

IMPORTANT NOTE:To calculate percent bio carbon present in product

multiply the experimental biobased content (from ASTM D6866) with the percent total organic carbon (TOC) (as determined by standard elemental analysis)

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Carbon footprint reduction strategy using bio contentTerminology

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BIOBASED PLASTICS/POLYMERS

Polymers containing in whole or part biogenic carbon (carbon from biological sources)

Biobased (carbon) Content -- The bio content is based on the amount of biogenic carbon present, and defined as the amount of bio carbon in the plastic as fraction weight (mass) or percent weight (mass) of the total organic carbon in the plastic. (ASTM D6866)

% bio or biobased content = Bio (organic) carbon/total (organic carbon) * 100

ASTM D6866 – Standard Test Methods for Determining the BiobasedContent of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis

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1. Product ‘O’ is a fiber reinforced composite with the composition 30% biofiber (cellulose fiber) + 70% PLA (biobased material)

2. Product ‘P’ is a fiber reinforced composite with the composition 30% glass fiber + 70% PLA (biobased material

3. Product ‘N’ is a fiber reinforced composite with the composition 30% PLA + 70% polypropylene (petroleum based organic)

PROBLEM SOLVING EXERCISE

Calculate the biobased carbon content:

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Carbon footprint reduction strategy using bio contentProcess Carbon Footprint -- LCA

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Carbon footprint from the conversion of feedstock to product –cradle to factory gate scenario and total environmental footprint to be calculated using LCA methodology ASTM D7075 or ISO 1440

End of life scenarios – disposal system can give skewed/misused LCA’s

Transport (of product from factory/production point to customer) and disposal can have major impact on carbon footprint

B2B value chain analysis OR carbon to factory gate analysis

• Practitioners and users of LCA need to be careful in comparative analysis of products because of the data used, the boundary conditions

Ramani Narayan, Michigan State University 30

Naturalresources Emiss.

ProductPost-consumerwaste

Land Emiss.

Emiss.

Cradle-to-Factory Gate

Cradle-to-Grave

Processing

Process waste

Mining/ Extraction

Agriculture,Forestry

Use WasteM'mt

Landfill

Sewage Treatment

Emiss.

System boundaries

THE PROCESS -- LCA

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What is Life Cycle Assessment?

Assessment of Environmental impacts of Products/Processes or Services throughout the Life Cycle: resource extraction,

manufacturing, product use, waste management

It is “assessment” not “analysis”

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Kg of CO2 released per 100 kg resin

Process carbon footprint Material carbon footprint

zero

Process Carbon Footprint – the LCA trap

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Includes:• Definition, content verification, ASTM D6866• Biodegradability using ASTM D6400 and D6868 (paper coatings) D7021 (marine)• performance requirements; and• assurance that products are available

U.S. Farm Security and Rural Investment Act of 2002 (P. L. 107-171), Title IX Energy, Section 9002

FARM BILL

Federal Procurement of Biobased Products – the “biopreferred program” (www.biopreferred.gov)• develop guidelines for designating biobased products for federal

procurement• “USDA Certified Biobased Product” labeling program

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What happens to product after use when it enters the waste stream Design for recovery by recycling Mechanical – same product (example bottle to bottle) or another long life

product (example PET bottle to carpets)

Chemical – back to monomer

Design for biodegradability (in what disposal environment and time to complete biodegradation)

Composting -- COMPOSTABLE PLASTICS!

anaerobic digestion

Landfill gas (CO2 + CH4) for energy but digestate residue needs to treated by composting

Marine

Soil – agriculture/horticulture Misleading and Deceptive biodegradability/compostability claims –

BEWARE !

Carbon footprint reduction strategy using bio contentEND OF PRODUCT LIFERECYCLING & BIODEGRADABILITY-COMPOSTABILITY

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Carbon footprint reduction strategy using bio contentBiodegradability – A misused and abused term

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• Can microorganisms present in the disposal environment (soil, composting) utilize/assimilate the plastic carbon substrate – the biotic process

• What extent and in what time frame?

• Need complete microbial assimilation and removal from the environmental compartment in a short time period otherwise may have environmental and health consequences

• Degradable, partial biodegradable not acceptable – serious health and environmental consequences

• Phil. Trans. Royal. Soc. (Biology) July 27, 2009; 364

QUESTION

Misleading and Deceptive biodegradability/compostabilityclaims – BEWARE !

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What does Biodegradable Mean?Can the microorganisms in the target disposal system (composting, soil, anaerobic digestor) assimilate/utilize the carbon substrate as food source completely and in a short defined time period?

Biodegradation(Step 2): Only if all fragmented residues consumed by microorganisms as a food & energy source as measured by evolved CO2 in defined time and disposal environment

Hydrolytic

Polymer chains with susceptible linkages

EnzymaticOxidative

Oligomers & polymer fragments

Environment – soil, compost, waste water plant, marine

STEP 1

CO2 + H2O + Cell biomass

Completemicrobial assimilation

defined time frame, no residuesSTEP 2

Ramani Narayan, Michigan State University

Carbon footprint reduction strategy using bio contentBiodegradability/microbial utilization fundamentals

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Microorganisms extract chemical energy for use in their life processes by the aerobic oxidation of glucose and other utilizable substrates – BIODEGRADBLE PLASTICS, food waste, paper, forest residues biological matter

Glucose/C-bioplastic + 6 O2 6 CO2 + 6 H2O; G0’ = -686 kcal/molAEROBIC (composting environment)

ANAEROBIC

Glucose/C-bioplastic 2 lactate; G0’ = -47 kcal/mol

CO2 + CH4

CO2 is the quantitative measure of the ability of the microrganisms present in

the disposal environment to utilize/assimilate the test C-bioplastic, which is

the sole C-source available for the microorganisms – biodegradation or

bioassimilation

Ramani Narayan, Michigan State University

More Biodegradation/Bioassimilation Facts The aerobic oxidation process (a highly specialized cellular phenomenon) requires the participation of three metabolically interrelated processes:

1. Tricarboxylic acid cycle (TCA cycle)2. Electron transport3. Oxidative phosphorylation

All of the processes take place inside the cell

For these processes to occur:The substrates needs to be transported inside the cell

Thus, molecular weight, hydrophobic/hydrophilic balance, other molecular and structural features govern transport across cell membrane into the cell for utilization of the C-substrate.

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Carbon footprint reduction strategy using bio contentMeasuring biodegradability

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0

10

20

30

40

50

60

70

80

90

100

0 20 40 60 80 100 120 140 160 180 200

Time (days)

% C

con

vers

ion

to C

O2

(% b

iode

grad

atio

n)

lagphase

biodegradation phase

plateau phase

biodegradation degree

O2

Compost & Test

Materials

CO2

ASTM D5338; ISO 14855; EN 13432

level of biodegradation needed to claim safe and efficacious removal of the plastic carbon from the environmental compartment

Visual – COMPOSTING BIO films

Ramani Narayan, Michigan State University

DAY 0 DAY 5 DAY 10 DAY 18

DAY 26 DAY 45 DAY 60

Ramani Narayan, Michigan State University

Carbon footprint reduction strategy using bio content

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Biodegradability Test MethodsASTM • Soil D5988; • Anaerobic digestors D 5511, ISO 15985• Biogas energy plant• Accelerated landfill D 5526• Guide to testing plastics ASTM D 6954

Must provide results from the test methods – could be zero or 50 or 100 percent ---generally not provided but claim of complete biodegradability made

ISOISO 14852, Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous medium – Method by analysis of evolved carbon dioxideISO 14853, Determination of the ultimate anaerobic biodegradability in an aqueous system – Method by measurement of biogas productionISO 14855; Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions – Part 1: Method by analysis of evolved carbon dioxide and Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test

Ramani Narayan, Michigan State University

Carbon footprint reduction strategy using bio content

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Biodegradability under composting conditions

• Specification Standards ASTM D6400, D6868 (coatings)• Specification Standards EN 13432 (European Norm)• Specification Standards ISO 17088 (International Standard)

Biodegradability under marine conditions• Specification Standard D 7021

ISO DIS 18606 “Packaging & the environment – Organic Recycling”

Standard Specification for Aerobically Biodegradable Plastics in Soil Environment ASTM work item 29802

ISO 17556 Plastics -- Determination of the ultimate aerobic biodegradability in soil by measuring the oxygen demand in a respirometeror the amount of carbon dioxide evolved

ASTM D 5988 Standard Test Method for Determining Aerobic Biodegradation in Soil

Ramani Narayan, Michigan State University

Carbon footprint reduction strategy using bio contentProblems with incomplete and partial biodegradation

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plastic pieces can attract and hold hydrophobic elements like PCB and DDT up to one million times background levels. As a result, floating plastic is like a poison pill

• From Algalita Marine Research Foundation –www.algalita.org/pelagic_plastic.html

PCBs, DDE, and nonylphenols (NP) were detected in high concentrations in degraded polypropylene (PP) resin pellets collected from four Japanese coasts.

Plastic residues function as a transport medium for toxic chemicals in the marine environment.

• Takada et al Environ. Sci. Technol. 2001, 35, 318-324

• Blight, L.K. & A.E. Burger. 1997. Occurrence of plastic particles in seabirds from the Eastern North Pacific. Mar. Poll. Bull. 34:323-325

• Phil. Trans. Royal. Soc. (Biology) July 27, 2009; 364

Thompson, R.C. et al. 2004. Lost at sea: Where is all the plastic? Science 304, 838, 2004

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Sorting through facts, hypes, and misleading claims

GREEN WASHING

Additives (oxo or organic) added to polyethylene (PE) or polypropylene (PP) or polyethylene terephthalate (PET) or any polyolefin polymer will “degrade” the polymer to small fragments which will eventually biodegrade or biodegrade in 9 months to 5 years in soil, landfill

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Green Washing Claims -- Additive Technology

“Plastic products with our additives at 1% levels will fully biodegrade in 9 months to 5 years wherever they are disposed like composting, or landfills under both aerobic and anaerobic conditions”

The 50% Bio-Batch film did not degrade as completely or as quickly as the cellulose. At the end of the test, 19% of the film had degraded.The results of the aerobic degradation tests indicate that, in time, plastics produced using Bio-Batch pellets will biodegrade in aerobic conditions.DATA DOES NOT SUPPORT THE CONCLUSIONS!

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MISLEADING BIODEGRADABILITY CLAIMS

Ramani Narayan, Michigan State University

MISLEADING CLAIMS – UNSUPPORTED BY DATA

Oxo-biodegradable polyethylene (PE) film claims –“Combined with an oxo-biodegradable proprietary application method to produce films for bags. This product, when discarded in soil in the presence of microorganisms, moisture, and oxygen, biodegrades, decomposing into simple materials found in nature. Completely breakdown in a landfill environment in 12-24 months leaving no residue or harmful toxins and have a shelf life of 2 years”No scientific substantiation showing complete microbial utilization using established standard test methods

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BIODEGRADABILITY CLAIMS Chem. Commun., 2002, (23), 2884 - 2885

– A hypothesis was developed, and successfully tested, to greatly increase the rates of biodegradation of polyolefins, by anchoring minute quantities of glucose, sucrose or lactose, onto functionalized polystyrene (polystyrene-co-maleic anhydride copolymer) and measuring their rates of biodegradation, which were found to be significantly improved

PRESS Sugar turns plastics biodegradable. Bacteria make a meal of sweetened polythene

and polystyrene.

weight loss of only 2-12%,

Only sugar is being assimilated, PE chain intact – Is this a genuine example of biodegradable plastic?