1. “ Chemistry has an important role to play in achieving a sustainable civilization on earth.” — Dr. Terry Collins, Professor of Chemistry Carnegie Mellon University

2. WHAT IS A SUSTAINABLE CIVILIZATION?

3. CONSIDER THIS QUESTION FROM SEVERAL VIEWPOINTS:
The environment and human health.
A stable economy that uses energy and resources efficiently.
Social and political systems that lead to a just society.

4. The environment and human health.
TO UNDERSTAND THE ROLE OF CHEMISTRY IN SUSTAINABILITY, WE WILL LOOK AT THE FIRST TWO POINTS…
The environment and human health.
A stable economy that uses energy and resources efficiently.

5. IN A SUSTAINABLE CIVILIZATION…
Technologies used for production of needed goods are not harmful to the environment or to human health.
Renewable resources (such as plant-based substances or solar energy) are used rather than those, like fossil fuels, that will eventually run out.

6. IN A SUSTAINABLE CIVILIZATION…
At the end of their use, materials are recycled if they are not biodegradable (easily broken down into harmless substances in the environment).

7. IN A SUSTAINABLE CIVILIZATION…
Manufacturing processes are either designed so as not to produce waste products,
– OR –
Waste products are recycled or biodegradable.

8. WHILE WE HAVE MADE SOME PROGRESS IN ACHIEVING THESE GOALS, WE STILL HAVE A LONG WAY TO GO…
Mountains of solid waste are piling up—particularly in industrialized nations.
Air and water pollution continue to be problems in many places.

9. BUT HOW CAN CHEMISTRY HELP US TO ACHIEVE A SUSTAINABLE CIVILIZATION?

10. First, let’s consider chemistry’s benefits… The chemical industry produces many products that improve our lives and upon which we depend.

11. BENEFITS OF CHEMICAL INDUSTRY:
Antibiotics and other medicines
Fertilizers, pesticides
Plastics
Nylon, rayon, polyester, and other synthetic materials
Gasoline and other fuels
Water purification

12. Why Green Chemistry ?

13. SOME WELL-PUBLICIZED INCIDENTS FROM THE PAST FEW DECADES…
Bhopal disaster, ,
methyl isocyanate – SEVEN
Nearly 25,000 people died.

14. SOME WELL-PUBLICIZED INCIDENTS FROM THE PAST FEW DECADES…
2. Dioxin episodes
during vietnam War the U.S. Military sprayed 42 million liltre of herbicide ‘Agent Orange’ (2,4-dichlorophenoxyacetic acid (2,4 D)+ 2,4,5-trichlorophenoxyacetic acid(2,4,5 D)), which was contaminated with dioxin to destroy the forest cover.
Dioxan created a havoc in the life of the millions of victims of the war and other residents of the area
Dioxins most important carcinogenic, number of them suffered with skin tumors
Absorbed to the skin Children born to such women were deformed with low IQ and or mentally retarded
2. In Seveso- Italy, (1976) Roche Holding Ltd.releasing chemicals containing dioxin 37,000 were affected.

15. Thalidomide scare: 1961 Europe
Lessen the effects of nausea & vomiting (morning sickness) during pregnancy
Children of the women suffeed birth defects-missing or deformed limbs

16. Love Canal disaster
NY – a chemical and plastic company had used an old canal at the Love canalin Niagra Falls to dump the chemical wastes for about 20 yrs ( ). . When the site was full , it was given to the city of Niagra falls.
A new school & a housing complex were built on it.
After 20 yrs the dumped chemicals began to leaking and the area was contaminated.
The population in the area were exposed to chemicals and led to birth defects and miscarriagerates as well as liver cancer.
Region wasofficially declared as a disaster area

17. Pesticides
Chemicals to kill unwanted insects, fuungus, rodents, etc
Control certain diseases and increase foood production
Pose health risk to humans and environmental damage
DDT
used against pests, flies & mosquitoes
in India used for the eradication of mMalatia
Resulted in the pollution of crop lands, pests have been resistant to it
Enters into food chain, accumulates in the fatty tissues

18. ENVIRONMENTAL DISASTERS
CFC
Uses: Refrigerant, in air conditionerssolvents in electronic industry, propellants in aerosols
Unraective and stay in the atmosphere for long tome
In the upper atm Reacts with O3 in presence of UV leads to O3 depletion

20. Minamata disease – Hg poisoning
Chisco chemical company had been dumping about 27 tons of Hg into Minamata bayfor more than 30yrs. ( )
In 1950’s more than 50 people were died & a number of people were affected in Minamata, Japanby eating fish contaminated with Hg
Methylmercuric chloride
Caused birth defects and affected neutral tissues mainly brain

21. Itai-Itai disease- JAPAN: Cd poisoning
Cd pollution in Jinzu river :1912
victim,s mostly women suffered with pain in the entire body
Suffered with broken bones when trying to move

22. Methaemoglobinaemie
Excessive use of Nitrogen fertilizers
Nitrate ….> nitrite in digestive canalby bacteria under high pH
Haemoglobin ….> methamoglobin lacks O2 carrying capacity
Severe for infants under six months; infants appear blue

23. Cost to Industry
Industries in the US spend over $100 billion/year on waste treatment, control, and disposal.
1996 Dupont spent $ 1 billion for environmental compliance (research budget $ 1 billion; chemical sales of $18 billion)

24. Chemists Must Place a Major Focus on the Environmental Consequences of Chemical Products and the Processes by which these Products are Made. We must consider our chemical ecological footprint.

25. “Most of the environmental problems of past centuries and decades, such as the biological contamination of drinking water, were solved only when the methods of science in general—and chemistry in particular—were applied to them. The phenomenal rise in human life expectancy and in the material quality of life that has come about in recent decades is due in no small measure to chemicals and chemistry.” — Colin Baird, Environmental Chemistry.

26. LAWS AND SIGNED INTERNATIONAL TREATIES TO REDUCE POLLUTION LEVELS,
Montreal Protocol to Protect the Ozone Layer: Helsinki
Stockholm Convention To Persistent Organic Pollutants: May 2004
Rio Declaration on Environment and Development
Environmental protection Agency:USA

27. PREVENTING POLLUTION SUSTAINING THE EARTH
GREEN CHEMISTRY
GREEN CHEMISTRY
PREVENTING POLLUTION SUSTAINING THE EARTH

28. GREEN CHEMISTRY
Focuses on a process (industry or laboratory) that reduces the use and generation of hazardous substances or by products

29. GREEN CHEMISTRY Pollution Prevention Act 1990
Dealt with the prevention of formation of pollutants
GC Began in 1991 at EPA, Paul T. Anastas
1996 Presidential Green Chemistry Challenge Awards
1997 Green Chemistry and Engineering Conference
1999 Journal “Green Chemistry”
Chemical & Engineering News
2001 Journal of Chemical Education
2005: Nobel prize for GC – Yves Chauvin, Robert Grubbs, Richard Schroch
Its not easy being green

30. This Act led the industries to…..
Devise technologies and processes that avoided the formation and/or production of hazardous substances
Device greener reaction conditions
This was achieved by….
Replacing organic solvents by water / solid state reactions
Using catalyst
Less toxic and biodegradable products

31. Twelve Principles of Green Chemistry
Better to prevent waste than to treat or clean up after formed
Synthetic methods should be designed to maximize the incorporation of all materials into the final product
Synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment
Products should be designed to preserve efficacy of function while reducing toxicity
Avoid the use of auxiliary substances (solvents, separation agents, etc) wherever possible
Energy requirements should be minimized. Synthetic methods should be conducted at ambient temperature & pressure

32. 7. 7. Raw material feedstock should be renewable rather than
7. 7. Raw material feedstock should be renewable rather than depleting wherever technically and economically practicable
Should avoid unnecessary derivatization (blocking groups, protection/ deprotection, etc.) wherever possible.
Use catalytic reagents than stochiometric reagents.
Products should be designed in such away that at the end of their function they do not persist in the environment and break down to innocuous degradation products.
Analytical methodologies need further development to allow real-time, inprocess monitoring and control of hazardous substances prior to the formation.
Substances used in the chemical process should be chosen so as to minimize the potential for chemical accidents including releases, explosions, and fires.

33. 1. Better to prevent waste than to treat or clean up after formed
Design synthetic pathway that at least reduce the formation of waste
waste : starting material or reagent, also pay for it.
waste: separate, treat, and dispose
Cost of disposal > cost of materials
Environmental pollution…> cleaned up

34. Maximize the incorporation of all materials into the final product – Atom economy
% yield = Actual yield x 100
theoretical yield
100% yield: not a green reaction

35. Atom Economy Barry Trost (Stanford University)
Consider the amount of starting material incorporated into final product
How many atoms incorporated into product
Objective:
Waste / by-product is minimum
Develop a ‘greener’ reaction
% atom utilization = MW of desired product x100
MW of product + Waste

36. Atom Economy Quantified by Roger Sheldon % atom economy =
FW of atom utilized x100
FW of all reactants used

37. GREEN CHEMISTRY MEANS…
Saving companies money by using less energy and fewer/safer chemicals, thus reducing the costs of pollution control and waste disposal.

38. Achievements of Green Chemistry
Presidential Green Chemistry Challenge Award Winners
For more informational on Presidential Green Chemistry Challenge
Award Winners:
New syntheses of Ibuprofen and Zoloft.
Integrated circuit production.
Removing Arsenic and Chromate from pressure treated wood.
Many new pesticides.
New oxidants for bleaching paper and disinfecting water.
Getting the lead out of automobile paints.
Recyclable carpeting.
Replacing VOCs and chlorinated solvents.
Biodegradable polymers from renewable resources.

39. LEAD POLLUTION HAS BEEN DECREASED BY…
Replacing lead in paint with safe alternatives, and
Replacing tetraethyl lead with less toxic additives (e.g., “lead-free” gasoline).

40. CHEMICAL FOAMS TO FIGHT FIRES
Millions of tons of chemical fire-fighting foams used worldwide have discharged toxic substances into the environment, contaminating water supplies and depleting the ozone layer.

41. PUTTING OUT FIRES THE GREEN WAY
A new foam called Pyrocool FEF has now been invented to put out fires effectively without producing the toxic substances found in other fire-fighting materials.

42. CHEMICALS FOR DRY CLEANING
Perchloroethylene (“perc”) is the solvent most widely used in dry cleaning clothing.
Perc is suspected of causing cancer and its disposal can contaminate ground water.

43. A SAFER METHOD OF DRY CLEANING
Liquid CO2 can be used as a safer solvent if a wetting agent is used with it to dissolve grease.
This method is now being used commercially by some dry cleaners.

44. GREEN CHEMISTRY DEFINITION GREEN CHEMISTRY IS ABOUT
Green Chemistry is the utilization of a set of principles that reduces or eliminates
the use or generation of hazardous substances in the design, manufacture and
application of chemical products *.
GREEN CHEMISTRY IS ABOUT
Waste Minimisation at Source
Use of Catalysts in place of Reagents
Using Non-Toxic Reagents
Use of Renewable Resources
Improved Atom Efficiency
Use of Solvent Free or Recyclable Environmentally Benign Solvent systems
* Green Chemistry Theory & Practice, P T Anastas & J C Warner, Oxford University Press 1998

45. Some Aspects of Green Chemistry
Safer Reactions
& Reagents
Catalysis
Solvent
Replacement
Separation
Processes
Green
Chemistry
Use of
Renewable
Feedstocks .
Energy
Efficiency
Waste
Minimisation
Process
Intensification

46. IN SUMMARY, GREEN CHEMISTRY IS…
Scientifically sound,
Cost effective, and
Leads toward a sustainable civilization.

47. Goals of Green chemistry
Design synthetic methodologies that reduce or eliminate the use and or generation o f toxic products
All possible routes may be examined
Most appropriate route (without hazardous starting materials and or products) should be used
No chemical accidents
Eg: synthesis of Adipic acid
Used for making nylon, PU, lubricants, plasticizers.

49. Ibuprofen iso-butyl-propanoic-phenolic acid
nonsteroidal anti-inflammatory drug (NSAID)
Analgesic
pain relief, fever reduction, and for reducing swelling
Commercial synthesis developed by
Boot Chemical Company (1960s)

50. Boots synthesis
six step synthesis
Use large number of reagents
AE = 40%

51. BHC synthesis – greener synthesis
three steps
AE = 77%

52. Safer dry cleaning
Initially gasoline and kerosene were used
Chlorinated solvents are now used, such as ‘PERC’
Hazardous waste contain solvent, powdered filter material, carbon, non-volatile residues, lint, dyes, grease, soils, and water.
Supercritical/liquid carbon dioxide (CO2)

53. Designing a green synthesis
Starting materials
# Non hazardous
# Renewable
# No accident
Reagent
Easily available
Efficient
No effect on environment
Green reagents: dimethyl carbonate, polymer supported reagents like peracids, PNBS, polymer supported chromic acid (Amberlyst A-20)

54. Catalyst
# Avoid heavy metals like Ni, Pb, etc.
# Biocatalyst : enzymes,
# polymer supported catalyst
eg: PS- AlCl3, Polymer supported PTC
Solvent
# non toxic
# green solvents
Supercritical CO2, IL, water, solid state

55. Green Chemistry Is About...
Waste
Materials
Hazard
Reducing
Risk
Energy
Environmental Impact
COST