Green chemistry aims to reduce or eliminate the use of hazardous substances in chemical products and processes. It has various principles for more sustainable chemistry, such as preventing waste through better design, using safer solvents and catalysts, making chemical products that degrade harmlessly after use, and developing renewable feedstocks and energy-efficient processes. Green chemistry provides both environmental and business benefits like lower costs, improved safety, and reduced environmental impact.

1. Presented by: Puja R. Basule
Department of Pharmaceutical Chemistry
M-Pharm 1st year (2nd sem)

2. Green Chemistry
• Definition: Green Chemistry is the utilisation
of a set of principles that reduces or
elimination the use or generation of hazardous
substances in the design, manufacture and
application of chemical products
OR
“Use of chemistry for pollution prevention by
means of proper design of chemical product &
process that reduce/elimination the use of
generation of hazardous substances”

3. Benefits of Green Chemistry
• Business benefits of green chemistry include:
Improved resource efficiency and lower raw
material and utility bills
• Reduced waste treatment and disposal costs
• Improved health and safety for staff and
customers
• Environmental benefits include: fewer raw
materials and natural resources used
• Lower level chemical released to the
environmental
• Cleaner production technologies
• Reduced emissions and product impacts

4. Principle of green chemistry
• In 1998, Paul Anastas & John C. Warner
published a set of principle to guide the practice
of green chemistry.
• The twelve principle of green chemistry
1. Prevention
2. Atom economy
3. Less hazardous chemical synthesis
4. Design of safer chemical & product
5. Use of safer solvent & auxiliaries
6. Energy efficiency
7. Use of renewable feedstock

5. 8. Reduce Derivatives
9. Use of catalysts
10. Design for degradation
11. Real time analysis for pollution prevention
12. Inherently safer chemistry for accident prevention
1. Prevention
It is better to prevent waste than to treat or clean up
waste after it has been created.
Ability of chemist: to redesign chemical
transformation to minimize generation of
hazardous waste is important step
Chemical
process

6. 2. Atom economy
Synthetic method should be designed to maximize
the incorporation of all material used in the
process into the final product.
%
In general organic chemistry consider 90% yield or
better – Excellent
20% yield or less – Poor
Ratio of total mass of atom in desired product to
the total mass of atom in reaction

7. • Sum:- Find the atom economy with respective
cinnamaldehyde?
C6H5CHO + CH3CHO ------------ C6H5CH=CHCHO + H2O
Benzaldehyde acetaldehyde cinnamaldehyde
C- 7*12= 84 C- 12*9 = 108
H- 1*6 = 6 H- 1*8 = 8
O- 16*1= 16 O- 16* 1= 16
Total = 106 Total = 132
C- 12*2= 24 %Atom economy= 132 * 100 = 88%
H- 1*4 = 4 150
O- 16* 1= 16
Total = 44
O O
OH
Cl
+
O

8. 3. Less hazardous chemical synthesis
• Synthetic method should be designed wherever
practicable to use and generate substance that
possess little or no toxicity to human health and
the environment
• Starting material such as aniline, pyridine not
use because they are carcinogenic or toxic
• Application :- Synthesis of Indigo: dye use to
colour blue jeans.
Conventional Route:

9. Green Route: Use of reaction in which side chain of
tryptophan is removed enzymatic ally to give idol it can be
dehydroxylated enzymatically & then oxidized with
oxygen to Indigo.

10. 4. Design of safer chemical & product
Chemical product should be designed to achieve
their desired function while minimizing their
toxicity.
Medical drug to be introduced in market , first put
on trials to check toxic effect on human.

11. 5.Use of safer solvent & Auxiliaries
• Unnecessary use of auxiliary substances
(solvents, separation agents, etc.) should be
made unnecessary whenever possible and,
made innocuous when used.
• Solvent such as acetone, benzene, ether are
highly inflammable & other chemical such as
ccl3, CHCl3, aniline are harmful for health &
some are carcinogenic in nature thus should be
avoided.
• If solvent is necessary water is good medium
eco-friendly solvent which do not form smog
or destroy ozone layer can be used.

12. 6. Energy efficiency
• Energy requirement of chemical processes should be
recognized for their environmental & economic impact
and should be minimized. If possible, synthetic
methods should be conducted at ambient temperature &
pressure.
Energy in chemical process
• Thermal (electric)
• Cooling (water condensers, water circulators)
• Distillation
• Equipment (lab hood)
• Photo
• Microwave
Source of energy:
• Power plant – coal, oil, natural gas

13. Energy usage
• Chemicals and petroleum industries account
for 50% of industrial energy usage.
• ~1/4 of the energy used is consumed in
distillation and drying processes.
7. Use of renewable feedstock:
Whenever technically & economically
practicable. Raw material or feedstock should
be renewable rather than depleting it.

14. Raw Materials from Renewable Resources:
The BioFine Process
Paper mill sludge
Agricultureresidue
wastewood
Levulinicacid
Municipalsolidwaste
andwastepaper
Green Chemistry
Challenge Award
1999 Small Business
Award

15. Renewable resources can be made increasingly viable
technologically and economically through green
chemistry.
Biomass , carbon dioxide, waste utilization , solar,
Nanoscience.

16. 8. Reduce derivatives
• Unnecessary derivation (use of blocking
group, protection / deprotection, temporary
modification of physical/ chemical process)
should be minimized or avoided if possible
• because such step require additional reagents
and can generated waste.
• Example synthesis of Ibuprofen.

19. 9. Use of catalysts
• Catalytic reagents (as selective as possible ) are
superior to stoichiometric reagents.
• Catalysts Used in small amount Carry
single reaction many time
• Stiochimetric reagent Used in excess
Work once time.
• Reduces energy
• Increases efficiency
• Reduces by-product formation

20. 10. Design of Degradation
• Chemical product should be designed so that at
the end of their function they break down into
innocuous degradation product and do not
persist in the environment.
• Essentially we want chemicals to degrade to
molecules that are not harmful to humans,
animals or the environment.
• Example: Bio degradable polymers
• Polypropylene carbonate (PPC) is a common
example for bio degradable polymers

21. 11. Real time analysis for pollution
prevention
• Analytical methodologies need to be further
developed to allow for real-time, in-process
monitoring and control, prior to the formation
of hazardous substances.
12. Inherently safer chemistry for accident
prevention
• Substance and the form of a substance used in
chemical process should be chosen so as to
minimize the potential for chemical accidents,
including releases, explosions, and fires.