green chemistry - clu-in · 2005-02-23 · •green chemistry is the use of chemistry for pollution...

Green Chemistry 2/23/2005

Green ChemistryGreen Chemistry

Richard Engler Office of Prevention, Pesticides, and Toxic

Substances U.S. Environmental Protection Agency

Environmental Technology Council February 24, 2005

•Green Chemistry is the use of chemistry for pollution prevention. • More specifically, Green Chemistry is the design of chemical products and processes that do not use toxic or otherwise hazardous substances or generate pollutants. • This environmentally conscious design of chemical products and processes is the central focus of EPA’s Green Chemistry Program, a Design for the Environment initiative launched in 1991 under the administration of President George H.W. Bush. • I’ll give you a brief overview of green chemistry and then talk about some examples that apply to “Beyond RCRA”

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Chemical ReleasesChemical Releases1.6 billion lbs to airIn 2002, 4.3 billion (38%)

pounds of Toxics TRI releases

Release Inventory(TRI) chemicals were reported as released to the environment by TRI-reporting facilities.

2.2 billion lbs to land (51%) 220 million 230 million lbs lbs to to surface under- water (5%) ground injection (5%)

• Why are Green Chemistry technologies important? • Despite all of the progress that we in the US and around the world have made in protecting our homes, communities, and workplaces from environmental hazards, we still have a long way to go. • We depend on chemicals to improve every aspect of our lives. • But as long as we continue to depend on the manufacture of chemical products, there will be risk. • [2002 TRI data – volume of releases, number of chemicals] • We can greatly minimize risk associated with the manufacture and use of chemicals through Green Chemistry, because Green Chemistry focuses on reducing or eliminating hazard at the source.

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Pollution Prevention Act:Pollution Prevention Act:Risk Management HierarchyRisk Management Hierarchy

Pollution Prevention Source

Reduction

Recycling

Disposal

Treatment

The Green Chemistry Program was initiated in response to the Pollution Prevention Act of 1990. It established a Risk Management Hierarchy. At the bottom is proper disposal. That is, at a minimum, dispose of waste properly don’t just dump it. Next up is treatment. It is better to treat waste to reduce its hazard before disposing of it. Recycling is even better. By using the substance again, you reduce the need for virgin materials. Finally at the top of the hierarchy is Source Reduction. This is true pollution prevention, where you avoid making the waste in the first place. If you have no waste, you don’t have to worry about any of the lower-tier activities. Green chemistry is pollution prevention at the molecular level.

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Reducing Risk:Reducing Risk:Two ApproachesTwo Approaches

Reduce risk by

• reducing exposure

• reducing hazard.

Risk = f(Hazard, Exposure)

Risk is a function of both hazard and exposure. Historically the focus has been on exposure controls. The Green Chemistry approach to risk reduction is quite simple: The best way to reduce risk is to reduce the hazard of the chemical or the process.

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Green ChemistryGreen Chemistry –– DefinitionDefinition

Green Chemistry is the design ofchemical products or processesto reduce or eliminate the use or generation of hazardoussubstances.

We focus on the chemistry part of the design. Our sister program, the Green Engineering program focuses on the engineering aspects, but there is a lot of overlap.

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1) Design chemical syntheses to prevent waste, leaving no waste to treat or clean up.

2) Design syntheses so that final products contains the maximum proportion of the starting materials.

3) Design syntheses to use and generate substances with little or no toxicity 4) Design chemical products to be fully effective, yet have little or no toxicity

Principles of GreenPrinciples of GreenChemistryChemistry

• Prevent waste • Maximize atom economy • Design less hazardous

syntheses • Design safer chemical products



• Use safer solvents and reaction conditions

• Increase energy efficiency • Use renewable feedstocks • Avoid chemical derivatization

1) Avoid using solvents, separation agents, or other auxiliary chemicals. If necessary, minimize their toxicity

2) Maximize energy efficiency 3) Use renewable feedstocks whenever possible. 4) Avoid blocking or protecting groups or any temporary modification,if possible

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• Use catalysts, notstoichiometric reagents.

• Design chemical products todegrade after use

• Analyze in real time to preventpollution

• Minimize the potential foraccidents

1) Choose catalysts whenever possible instead of stoichiometric reagents.2) Design chemicals and products to degrade at the end of their useful lifetime

3) Analyze in real time to prevent pollution.4) Design chemicals and their physical forms to minimize the potential for

chemical accidents including explosions, fires and releases to the environment

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Education

International CollaborationResearch Awards

Green Chemistry Mission:Green Chemistry Mission:“To promote the research,development, and implementation of innovative chemical technologiesthat reduce or eliminate the use or generation of hazardous substances from chemical Outreach manufacture and use.”

• The Green Chemistry Program was launched shortly after the passage of the Pollution Prevention Act to promote the research, development, and implementation of innovative chemical technologies that do not pollute, and that do not use hazardous substances, where possible, thereby reducing the risk associated with the manufacture and use of chemicals. • Green Chemistry is a highly effective approach to pollution prevention because it applies innovative scientific solutions to real-world environmental problems, all through voluntary partnerships. • Primary partner is the chemical industry; input from the broader scientific community is critical. • This program is really about educating chemical manufacturers, marketers, and users. This has been accomplished through research, education, awards, outreach, and international collaborations.

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Demonstrated BenefitsDemonstrated Benefits

Presidential Green Chemistry ChallengeAwards demonstrate scientific, economic, environmental benefits of greenchemistrytechnologies.

• The Green Chemistry Program provides recognition for outstanding Green Chemistry technologies through the annual Presidential Green Chemistry Challenge Awards. • This national recognition has been very successful in educating chemical manufacturers and users on the scientific, economic, and environmental benefits that Green Chemistry technologies offer. • This in turn has been very effective in promoting necessary behavior change, thereby encouraging further developments in the area. •The success of the awards program has lead to several other countries including Australia, Italy, Japan, and the UK, to launch similar, if not identical, awards programs.

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GreenGreen SynthesisSynthesis

Ibuprofen process

O

OH

Traditional: six steps, including aluminum trichloride, ethyl chloroacetate and hydrazine; 40% atom efficiency

BHC: three steps, all catalytic; 99% atom BHCefficiency

•Some examples of award winning technologies show what can be done when chemists look for ways to green their reactions. •The traditional ibuprofen process uses aluminum trichloride, acetic anhydride, followed by ethyl chloroacetate and sodium ethoxide, acid hydrolysis, hydrazine, dehydration, and another hydrolysis step. Overall, the atom economy (the percentage of atoms used that end up in the final product) was 40%.

•A joint venture of BASF and Hoecst-Celenase deveoped an alternative that uses only three catalytic steps that, when coupled with recycling of acetic acid back to the

11anhydride, achieves a 99% atom economy


Green SolventsGreen Solvents

Bio-derived solvent to replace chlorinated or glycol ether solvents.

O OH

O

Glucose fermentation followed by esterification and membrane separation provide low-cost ethyl lactate.

�Organic solvents are used on vast scales, and may only used once before being discarded. Halogenated solvents, glycol ethers, aromatic solvents all have drawbacks, but they’re used because they are cheap and they provide the properties necessary. Ethyl lactate has been known for some time, but was not cheap enough. Argonne National Lab developed a method to convert the fermentation product to the ester and purify it in an energy efficient way. The new method produces ethyl lactate under $1/lb making it competitive with many solvents.

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Green ProductsGreen Products

Pyrocool FEF Fire Extinguishment Agent (Pyrocool)

¾ Formulation of biodegradable surfactants and cooling agents

¾ Mixing ratio with water of only 0.4%

¾ Replaces Halons and aqueous film forming foams

• Formulation of biodegradable surfactants and cooling agents comprised of nonionic surfactants, anionic surfactants, and amphoteric surfactants • Mixing ratio with water of only 0.4% • Translates into an 87-93% reduction in product usage is realized compared to conventional extinguishment agents typically used at 3-6% • Replaces problematic fire extiguishment chemicals traditionally used such ozone depleting Halons and persistent aqueous film forming polyfluorinated foams • Carries the distinction of extinguishing the last large oil tanker fire at sea on board the Nassia tanker in the Bosphorous Straits in just 12.5 minutes (a fire estimated by Lloyd’s of London to require 10 days to extinguish) • Saving 80% of the ship’s cargo and preventing the spillage of 78,000 tons of crude oil into the sea • Only product used at the WTC site after 9/11

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Green ProductsGreen Products

Engelhard Corporation • New line of pigments replaces

• Heavy-metal-based pigments(Pb, Cd, Cr)

• Organic pigments

• Eliminates 6.5 million pounds ofheavy-metal-based pigments

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Measurable ResultsMeasurable Results

The 46 award-winning technologies prevent the use and generation of 120 million pounds and 2.2 million gallons of hazardous chemicals and save 55 million gallons of water each year.

• In summary, through education and assistance, this voluntary partnership program is enabling the U.S. chemical industry to design chemical products and commercialize chemical processes that have proven, measurable benefits to human health and the environment and that are economically competitive. • This is allowing U.S. industry to maintain its global competitiveness, and even providing a competitive advantage, while ensuring for a sustainable future. • This is being demonstrated through the measurable benefits to human health and the environment. •These numbers represent the “best of the best” of Green Chemistry technologies. We are currently developing a metrics tool to help us better quantify the benefit of all 600 nominated technologies. We expect the total to be 1-2 orders of magnitude larger.

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http://www.epa.gov/greenchemistry

Richard Engler (202-564-8587)

For more information, visit the Green Chemistry Program web page at http://www.epa.gov/greenchemistry or contact Richard Engler, Green Chemistry Program Director.

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green chemistry - clu-in · 2005-02-23 · •green chemistry is the use of chemistry for pollution...

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