Introduction to Green Chemistry

IN4GC Teaching ResourcesPrepared by Isla Milne

Outline• Why do chemicals matter?• The problem: Global chemical exposure and contamination• The (partial) solution: Green chemistry

– 12 principles

• Green chemistry in action: Case studies– Greener synthesis of ibuprofen– Dry cleaning without Perc– Boat paint without tin– Plastics from renewable sources (NatureWorks)

• Role of business in green chemistry• Drivers for green chemistry: Business case for green chemistry

– Ambec and Lanoie, 2008, Reinhardt, 1999– EVA of 12 principles

• Barriers to green chemistry• Conclusion

Why do chemicals matter? Chemicals and chemistry are

everywhereChemistry is life!

C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy

Why do chemicals matter? Chemicals and chemistry are

everywhereChemistry is life!

Why do chemicals matter? Chemicals and chemistry are

everywhere• Chemicals are the “molecular building

blocks” of our economy

• Daily U.S. Chemical production and importation: 74 billion lbs

• 82,000 chemical substances and millions of products in circulation

Why do chemicals matter? Global chemical production is growing

rapidly

• The chemical industry is valued at ~4 trillion USD (OECD, 2011)

Blue Jean Life Cycle Assessment: where/how are chemicals used?

• Work in groups of 2 or three

• Consider a pair of blue jeans. Brainstorm all of the places in the product life cycle where chemicals would be used

• Pair up with another group and compare answers.

• Report back to the class and discuss

• What are the hazards associated with the chemicals identified in the lifecycle?

Chemicals: Double edged sword

They are the solution to many of our problems....

But the cause of many hazards as well...

The problem: Global chemical contamination

• Chemical pollution in the environment: The “environment” is not somewhere “out there”. We live in our environment

• Synthetic chemicals contribute to a wide range of environmental and health hazards

CancerNeurodevelopmental problemsObesityReproductive anomalies or dysfunctionAsthma and allergiesNeurodegenerative

problemsImmune dysfunctionClimate changeEutrophicationBiodiversity lossAir pollutionOzone depletionEtc...huge data gaps!!~700 new chemicals introduced into the market

each year

Chemical contamination: From disasters in the chemical industry...

In 1984, a methylisocyanate leak at a Union Carbide chemical plant in Bhopal, India, killed thousands of people

In 1976, a chemical plant in Sevesco, Italy that manufactured pesticides and herbicides released a dense cloud of tetrachlorodibenzoparadioxin (TCDD), contaminating tens square miles of land. 2000 people were treated for dioxin poisoning.

...and from gradual chemical pollution and exposure to everyday products

• Examples:– Flame retardants– Cosmetics– Cleaning products– Paint– Plastics

Chemical contamination: Evidence from biomonitoring

Chemicals found in pregnant women, umbilical cord blood, and breast milk:MercuryPCBsFlame retardants (e.g. PBDEs)SolventsPhenols (e.g. Bisphenol A)Stain repellants (e.g. Perfluorinated surfacants)Dioxins (e.g. TCDD)PerchloratePlasticizers (e.g. Phthalates)Furans (e.g. TCDF)Polycyclic Aromatic Hydrocarbons (PAHs)Organochlorine pesticides (e.g. DDT, Hexachlorobenzene)

Woodruff T. et al, 2011 Environ Health Persp.; Needham L. 2010 et al, Environme Sci TochnolLakind, J.S. Et al, 2004 Toxicol Appl Pharma. Modified from the Berkeley Center for Green Chemistry slides.

Chemical contamination: Evidence from biomonitoring

287 synthetic chemical pollutants detected in umbilical cord blood

MercuryPolyaromatic hydrocarbons (9)Polybrominated dibenzodioxins and furans

(7)Perfluorinated chemicals (9)Polychlorinated dibenzodioxins and furans

(11)Organochlorine pesticides (21)Polybrominated diphenyl ethers (32)Polychlorinated napthalenes (50)Polychlorinated biphenyls (147)

Modified from the Berkeley Center for Green Chemistry slides.

Problem: Global chemical contaminationSolution: Green chemistry!

• Green chemistry (sometimes called “sustainable chemistry”) is a designstrategy. It aims to prevent problems rather than clean them up later• Definition: “Design of chemical products and processes that reduce and

eliminate the use and generation of hazardous substances” (Anastas and Warner, 1998)

Risk = f(Hazard, Exposure)

• Green chemistry is a RADICAL approach as the institutionalized and industrially embedded approach is to focus on exposure reduction. Green chemistry focuses on reducing the hazard.

Video (2:31min): Martin Poliakoff on green chemistry: http://www.youtube.com/watch?v=_KYiLFkMQ_E

Key elements in a chemical process

Adapted from presentation by Dr. Audrey Moores

Feedstock: starting material

Energy: Energy used to make reaction work, heating etc

Medium and reagents: Where is the reaction happening? What needs to be added for the reaction to occur?

Products: Desired products and unwanted by-products

How can we make this process greener??

Two different kinds of chemical plants...

12 principles of green chemistry

1. PREVENTION: It’s better and easier to prevent waste than to deal with it after it’s formed.

2. ATOM ECONOMY: We should maximize the amount of material inputs that get incorporated into the final product.

3. LESS HAZARDOUS SYNTHESES: We should minimize hazardous by-products created by syntheses.

4. SAFER CHEMICALS: We should use design to preserve the efficacy of a function while reducing its toxicity.

Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice, Oxfor University press, 1998

12 principles of green chemistry

5. SAFER SOLVENTS AND AUXILIARIES: We should minimize the use of auxiliary substances wherever possible, or use ones that are non-toxic.

6. ENERGY EFFICIENCY: Energy requirements have environmental and economic impacts. We should conduct syntheses at ambient temperature and pressure to minimize energy costs.

7. RENEWABLE FEEDSTOCKS: Use renewable feedstocks

8. REDUCE DERIVATIVES: Unnecessary derivatization (using protecting or blocking groups during synthesis) should be avoided whenever possible to reduce waste. Minimise the number of steps in the reaction.

Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice, Oxfor University press, 1998

12 principles of green chemistry

9. CATALYSIS: Catalytic reagents are better than stoichiometric reagents in that they allow for lower temperatures and energy costs, and are reusable and therefore generate less waste.

10. DESIGN FOR DEGRADATION: Design products that are biodegradable at the end of their use.

11. REAL TIME POLLUTION PREVENTION: We should encourage methodologies to monitor the process of a reaction so as to detect the emergence of toxic by-products.

12. ACCIDENT PREVENTION: By minimizing the use of toxic substances and high energy processes, we also minimize the potential for

Anastas, P.T.; Warner, J.C. Green Chemistry: Theory and Practice, Oxfor University press, 1998

Greening a chemical process

Feedstocks •Use renewable feedstocks• Maximize the amount of inputs that make it into final product

Catalysts•play on activation energy and do more with less

Energy•Use lessEnergy•Conduct reactions at low temperature and pressure

Medium and reagents•Conduct reaction in water if possible• Use safer solvents

Products and byproducts•Minimize waste •Produce byproducts and products that are less toxic and biodegradable

Synthesis design•Minimize number of steps in reaction

12 principles of green chemistry

• GreenER. Not “green”. It’s all relative. There is no reaction in the world that would not have some impact - strive for continuous improvement.

• Not all of the 12 principles will be addressed at the same time: there may be tradeoffs.

Green Chemistry in action: Ibuprofen

Poliakoff, M., 2007

Original Route Green Route

6 steps 3 steps

Stoichiometric reaction• Large amounts of aluminum tricholoride used

Catalysts (recyclable!)• Smaller amounts of hydrofluoric acid used

Atom economy: 40% (60% of inputs end up in waste stream)

Atom Ecomony: 77%

• Developed by BHC (now part of BASF) in 1990s, the green route for Ibuprofen production produces more ibuprofen in less time and using less energy than the original process. This means cheaper products for the consumer with increased profits for the manufacturers. It saves 20,000 of waste/year!

Greening the ibuprofen process

Feedstocks Maximize the amount of inputs that make it into final product (Atom economy = 77%)

Catalysts•play on activation energy and do more with less

Energy•Use lessEnergy Medium and

reagents

Products and byproducts•Minimize waste (Less hydrofluoric acid used)

Synthesis design•Minimize number of steps in reaction (3 vs. 6)

Green chemistry in action: Dry cleaning

without Perc• Dry cleaning industry is heavily dependent on solvents (dry cleaning is not really dry!), 100,00 dry cleaners worldwide use percholorethylyne (perc) as primary solvent

• Perc is toxic: everything perc comes in contact with must be handled as “hazardous waste” except the dry cleaned clothes

• Supercritical carbon dioxide has been developed and demonstrated as a viable alternative

• It is non-toxic, biodegredable, and avoids costly waste disposal and regulatory compliance

• It has been shown to outperform perc in dry-cleaning applications Manley et al 2007.

Greening the dry cleaning process

Feedstocks

Energy

Medium and reagents

Products and byproducts•Minimize waste •Produce byproducts and products that are less toxic and biodegradableSynthesis design

Green chemistry in action: Boat paint

without tin• Tribytyltin (TBT) was widely used as an antifoulant on boats. It

worked by gradually leaching from the hull killing the fouling organism in the surrounding area

• It is extremely toxic to aquatic life, is an endocrine disrupting chemical, and very persistent in the environment

• Regulations now restrict the use of TBT (e.g. banned in EU)

• Rohm and Haas have developed an alternative based on thiazolone chemistry, which works by creating a hostile growing environment

• New product is free of heavy metals, showed no chronic or reproductive toxicity to marine species, degrades readily when released into the environment Manley et al 2007.

Greening boat paint

Feedstocks

Energy

Medium and reagents

Products and byproducts •Produce byproducts and products that are less toxic and biodegradable

Synthesis design

Green Chemistry in Action: Plastics from renewable material

• NatureWorks biobased plastic resins: Joint venture between Cargill Inc and Dow Chemical

• Received Presidential Green Chemistry Challenge Award in 2002

• Developed the first synthetic polymer class to be produced from renewable resources (corn), a potential substitute for petroleum-based polymers

• Biodegradable (compostable)

• Manufacturing sequence reduced consumption of fossil fuels by 30%-50% compared to conventional oil-based plastic resins

Larson et al, 2006, Darden case study

http://www.natureworksllc.com/The-Ingeo-Journey/Eco-Profile-and-LCA/Eco-Profile

Greening the plastic production process

Feedstocks •Use renewable feedstocks (corn)

Catalysts•play on activation energy and do more with less (enzymatic fermentation process)

Energy•Use lessenergy

Medium and reagentsMany steps in the reaction are solvent free

Products and byproducts•Produce byproducts and products that are less toxic and biodegradableSynthesis design

How businesses can contribute to the advancement (or not) of Green

Chemistry• Fund and conduct R&D• Manufacture chemicals and products• Sell chemicals and products containing chemicals• Manage supply chains • Lobby for/against regulations• Distribute products containing chemicals• Run marketing campaigns• Conduct take-back initiatives (recovery and

recycling)• Influence metrics used to measure performance

(is environmental performance valued?)• Collaborate (e.g. with academia)

Drivers for green chemistry: It makes good business sense!

• Reinhardt 1999– Differentiating products– Managing your competitors– Saving costs– Managing environmental risks– Redefining markets

• Ambec and Lanoie 2008– Better access to certain markets– Differentiating products– Selling pollution control technologies– Risk management and relations with external stakeholders– Cost of Materials, Energy and Services– Cost of capital– Cost of Labor

Drivers for green chemistry: Business benefits of green chemistry innovation

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• Data set: Nominations for the Presidential Green Chemistry Awards, 2010• Out of 60 green chemistry innovations coded, ~80% improved performance, ~85% reduced cost, ~45% reduced risk and ~35% increased regulatory compliance compared to the incumbent technology Milne and Maguire, 2011. ACS GCI Green Chemistry conference presentation

“There are rising B2B demands for green chemicals,” says Rich Liroff, executive director of the Investor Environmental Health. Network. “Nike is now highlighting preferred green chemicals in its purchasing requirements. Staples also has developed a list of “bad actor chemicals;” and quite recently, several Group Purchasing Organizations in the health care sector, with buying power estimated at roughly $20 billion, developed a questionnaire for

suppliers that focused on various sustainability

questions, including the presence or absence of specific chemicals of concern.”

- Rich Liroff, Environmental Health Investors Network

Forbes Magazine, 2011, Better profits through green chemistry

Drivers for green chemistry: Rising B2B demands

Drivers for green chemistry: market for green chemicals is growing

Source: Pike Research, 2011, Green chemistry research report

Which of the 12 principles are more likely to have high Economic Value

Added?1. PREVENTION: It’s better and easier to prevent waste than to deal with it after it’s

formed.2. ATOM ECONOMY: We should maximize the amount of material inputs used in the final

product3. LESS HAZARDOUS SYNTHESES: We should minimize hazardous by-products created

by syntheses.4. SAFER CHEMICALS: We should use design to preserve the efficacy of a function while

reducing its toxicity. 5. SAFER SOLVENTS AND AUXILIARIES: We should minimize the use of auxiliary

substances wherever possible, or use ones that are non-toxic.6. ENERGY EFFICIENCY: Energy requirements have environmental and economic

impacts. We should conduct syntheses at ambient temperature and pressure to minimize energy costs.

7. RENEWABLE FEEDSTOCKS: Use renewable feedstocks 8. REDUCE DERIVATIVES: Unnecessary derivatization (using protecting or blocking

groups during synthesis) should be avoided whenever possible to reduce waste.9. CATALYSIS: Catalytic reagents are better than stoichiometric reagents in that they

allow for lower temperatures and energy costs, and are reusable and therefore generate less waste.

10. DESIGN FOR DEGRADATION: Design products that are biodegradable at the end of their use.

11. REAL TIME POLLUTION PREVENTION: We should encourage methodologies to monitor the process of a reaction so as to detect the emergence of toxic by-products.

12. ACCIDENT PREVENTION: By minimizing the use of toxic substances and high energy processes, we also minimize the potential fo

Barriers to green chemistry• Upfront costs (R&D, infrastructure etc)• Uncertainty and risk (regulatory and scientific)• CBI – hard to get suppliers to tell you what is in their products• Data, safety and technology gaps (Wilson and Schwarzman, 2008)

Regulatory barriers• Regulations are very fragmentation (REACH, TSCA, Chemicals

Management Plan etc)• How safe is safe? Two models:

(a) Company must produce evidence of safety (e.g. FDA (drugs)) default assumption is that the chemicals are hazardous

(b) Government must produce evidence of harm (Toxic Substances Control Act, most other laws) default assumption is that chemicals are safe

– REACH (EU legislation) is starting to set a good example, moves towards model (a)

Barriers to green chemistry: Data gaps

“Not enough information is available on how many of the approximately 30,000 substances currently estimated to be covered by the REACH proposals have dangerous properties. [...] However, of the new substances assessed under existing EU legislation, around 70% have been shown to have one or more dangerous properties. An unknown but potentially significant proportion of all chemical substances will enter the environment and reach sufficiently high concentrations to induce adverse effects”

European Commission, 2003, REACH Extended Impact Assessment, p27

Barriers to green chemistry: Data gaps

“All substances are poisons: there is no substance which is not a poison. The right dose differentiates a poison from a remedy”

Paracelsus, 1493-1591

“The dose of the mixture makes the poison, but differently for different individuals and differently at different times during growth and development”

Peter Motague, 2002

• Our understanding of what differentiates a “poison from a remedy” is evolving, but there is still a lot we don’t know

• Traditional methods of testing for toxicology are not effective for many toxicology endpoints: e.g. Endocrine disruption

Conclusion

• To be successful, green chemistry requires an interdisciplinary strategy in education, research and service– You don’t have to be a chemist or a toxicologist, you just

have to know what you don’t know so you can ask one!

• Green chemistry makes good business sense• Chemical exposures and global chemical

contamination:– No single problem– No single solution– Green Chemistry has the potential to be part of the

solution