This document discusses the key principles of Green Chemistry. It introduces Green Chemistry as the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. It then outlines 12 principles of Green Chemistry, including preventing waste generation, designing safer chemicals and products, using renewable feedstocks, and developing environmentally friendly solvents. Specific examples are provided, such as synthesizing adipic acid from glucose rather than benzene to be more sustainable. The document emphasizes the importance of Green Chemistry in reducing environmental pollution from the chemical industry.

1. Green
Chemistry
By :Faik

2. Outline:
• This chapter comprises manly of this
topics:
1. Introduction to Green Chemistry.
2. 12 principles of Green Chemistry.
3. Synthesis of Adipic acid.
4. Synthesis of Indigo.
5. Green solvents.

3. Introduction to Green Chemistry:
1. The knowledge of chemistry and development of it in
last few decades,eg.drugs,fabrics,etc.
2. The more dependence of humans on this chemicals
lead to increase in production.
3. The chemical reactions involved are associated with
by-products harmful for environmental pollution.

4. 4. Modify&review chemical process are toxic in
varying extent & causes environmental
Pollution.
5. Thus design of harmless process to produce
various products is termed as Green Chemistry .
6. It came in existence decades back but it’s
becoming popular now.

5. 7. It involves any chemical process that improves the
environment.
8. It is effective to prevent pollution.
9. There are 12 principles of Green Chemistry
accepted all over the world.

7. 12 Principles of Green
Chemistry

8. Productively stands for:

9. Prevention of waste:
• There is a saying that prevention is better than cure.
• It’s better to prevent waste than treating and
cleaning it.
• Our common practice is to dump waste in water,
land or release in air.

10. • Thus Green Chemistry involves chemical process
with less by-products/waste to be cleaned.
• The government has made compulsion to the
industries for water treatment & disposal units
attached to manufacturing plants.

11. Maximize Atom Economy:-
 Atom economy is defined as the ratio of the formula
weight of the target molecule to the formula weight of all
the starting materials and the reagents.
 It indicates the intrinsic efficiency of the desired
transformation.
 The design for synthesis of products should be such
that all chemicals/materials used should be converted
into product to maximum extent.

12.  It is seen that most organic reactions release
undesired products.
 The unutilized material is considered as waste
which causes trouble & the process becomes
uneconomical.
 Green chemistry requires new processes so that
most of starting material gets converted into
product & it’s called Maximising atom economy.

15. Non-hazardous Chemical
Synthesis
• Synthetic method should be such that it produce
little or no toxicity to human health and the
environment.
• Starting material selected should be least toxic.
For e.g. Pyridine,or β-naphthyl amine known as
carcinogenic should be avoided as starting
materials.

16. • In reactions alternative pathways be followed for
synthesis where interdmediates or reagents are
toxic.
• For example:In 1984,due to leakage of MIC at Bhopal
(Bhopal gas tragedy).It was an intermediate of
agricultural pesticides&it was highly poisonous.
• Green chemistry suggests design of synthesis to be
little or not toxic to human and environment.

17. Safer chemicals & products
• While reducing toxicity,the efficiency of the desired
function should be preserved.
• For medicinal formulation, should be put on trial
before marketing to check toxic effect on human.
• If it is toxic then alternates are to be made keeping
function of medicine & toxicity reduction in mind.

18. • For example. DDT,ALDRIN etc.which are
toxic to humans so alternate biological
pesticides are used.
• Green Chemistry emphasize to design chemicals to
be fully effective , yet lower toxicity.

19. • The solvents, separating agents should not be used
unnecessary.
• Acetone, benzene, ether , highly inflammable should
be avoided.
• CCl4,CHCl3 ,because of health risk they are avoided.
• Water is universal solvent, certain eco-friendly
solvents can be made.
Auxiliary substance

20.  For Dry cleaning perchloroethylene was used, it
is replaced by liquid CO2

21. Energy Efficiency
• Minimizing energy required for chemical
process.The synthetic method to be at ambient
temperature & pressure.
• Aim is to increase energy efficiency.
• It can be achieved by use of catalysts, and
reducing fossil fuels, which release pollutants.

22. • Recent found, microwave & ultra sound is used
where very less energy is required.
• Energy efficiency can be increased by:
a) Minimum waste of energy
b) Proper heat transfer
• Fermentation is used as energy requirement is
low and product is also less harmful.

23. Renewable Feedstock
• Raw materials should be renewable &
economically feasible.
• Renewable feedstock are made from agri-
products,while depleting feedstock are from
fossil fuels or are mined.
• For example:in adipic acid preparation benzene is
repleased by corn starch/cellulose.

24. Avoid chemical Derivatives
• Unnecessary derivatisation blocking or
temporary modification should be avoided.
• Derivatives increases in steps.
• Additional reagent are required.
• More waste products.

25. `
• Alternate reagent are required to avoid this.
• For example: Synthesis of Ibuprofen, with Atom
economy of 70% & recoverable catalyst.

27. Catalysts
• Catalytic reagent are preferred over
stoichiometric reagent.
• Minimize waste by catalytic reaction.
• Small amount of catalysts can carry single
reaction many times

28. • Stoichiometric reagent are used in excess and
work only once.
• Reactions are faster so less energy is required.
• In recent years non-toxic recoverable &
biocatalysts is used.

29. Degradable products
• Chemical products be designed that break down
simple substance as they do not accumulate.
• DDT used as pesticides, it's causes pollution.
Alternate is biological residues insecticides.
• Plastic is non-biodegradable which causes solid
waste. So biodegradable
plastic containing
cellulose is used.

30. New Analytical methods
• Analytical processes are developed to do on-line
monitoring & control.
• Preparation of ethylene glycol, toxic substance are
produced at higher temperature.

31. Prevent Accidents
• Substances and chemical process used should
have less accident potential.
• Safer chemicals, minimizing temperature,
pressure & catalysts used minimizes the accident
potential.

32. Synthesis of Adipic acid.
• In traditional pathway:
• Benzene was starting material.
• But in Greener pathway:
• D-Glucose is used as raw material which is
absolutely safe.

34. Synthesis of Indigo
• It is basically a dye.
• Aniline used is highly toxic so waste
products are more.
• Greener way is to produce indigo
enzymatically.

36. Green solvents
• The concept of conventional solvent extraction as
to eliminate need of organic solvents.
• Supercritical fluid possess properties of both
gases & liquid in intriguing manner.
• It could offer wide application in synthetic &
analytical chemistry.

37. • SFE CO2 is energy conserving, waste reducing
alternate to organic solvents.
• It can lead reactions that are difficult to achieve in
conventional solvents.
• It is a new technology with large potential for
industries.

38. Principle:
• SFE technology is feed material is contacted with a
supercritical fluid the volatile substance will partition in
supercritical phase.
• After dissolution of soluble material SCF containing
dissolve substance is removed for feed.

40. • The extracted component is completely
separated from the supercritical fluids by
temperature/pressure change.
• The SCF can then be recompressed to
extraction conditions and recycled.

41. Choice of SFE solvent:
• The choice of SCF solvent is same as regular
solvents.
• Good solvent property.
• Inert in the product.
• Easy separation from product

42. • Low cost.
• Carbon dioxide is the most commonly used
SCF,due to it’s critical
parameters(31.1o
,73.8bar),low cost and non-
toxicity.
• Several other SCF’s are also used in
industries.

43. Plant as source of New Drugs :
• Plants play important role in pharmacy also.
• Different efficient pharmacophores are made from
plants.
• Example are
Mepridine(Demerol),Pentazocine(Darvon) which
are totally synthetic drugs.