CHRIST JUNIOR COLLEGE

2012

GREEN CHEMISTRY

[ T Y P E T H E C O M P A N Y A D D R E S S ]

DEFINITION

Green Chemistry is the utilisation 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

Why do we need Green Chemistry?

• Chemistry is undeniably a very prominent part of our daily lives.

• Chemical developments also bring new environmental problems and

harmful unexpected side effects, which result in the need for ‘greener’

chemical products.

• A famous example is the pesticide DDT.

• Green chemistry looks at pollution prevention on the molecular scale and

is an extremely important area of Chemistry due to the importance of

Chemistry in our world today and the implications it can show on our

environment.

• The Green Chemistry program supports the invention of more

environmentally friendly chemical processes which reduce or even

eliminate the generation of hazardous substances.

• This program works very closely with the twelve principles of Green

Chemistry.

The 12 Principles of Green Chemistry

1. Prevention

It is better to prevent waste than to treat or clean up waste after it has been created.

2. Atom Economy Synthetic methods should be designed to maximise the incorporation of all materials used in the process into the final product.

3. Less Hazardous Chemical Synthesis Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to people or the environment.

4. Designing Safer Chemicals Chemical products should be designed to effect their desired function while minimising their toxicity.

5. Safer Solvents and Auxiliaries The use of auxiliary substances (e.g., solvents or separation agents) should be made unnecessary whenever possible and innocuous when used.

6. Design for Energy Efficiency

Energy requirements of chemical processes should be recognised for their environmental and economic impacts and should be minimised. If possible, synthetic methods should be conducted at ambient temperature and pressure.

7 Use of Renewable Feedstocks

A raw material or feedstock should be renewable rather than depleting whenever technically and

economically practicable.

8 Reduce Derivatives

Unnecessary derivatization (use of blocking groups, protection/de-protection, and temporary modification of

physical/chemical processes) should be minimised or avoided if possible, because such steps require

additional reagents and can generate waste.

9 Catalysis

Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.

10 Design for Degradation

Chemical Eucts and do not persist in the environment.

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

Substances and the form of a substance used in a chemical process should be chosen to minimise the

potential for chemical accidents, including releases, explosions, and fires.

SOME EXAMPLES OF GREEN CHEMISTRY:

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.

• Biodegradable polymers from renewable resources.

GREEN CHEMISTRY WORKS TOWARD SUSTAINABILITY BY:

• Making chemical produc

• Using industrial processes that reduce or eliminate hazardous chemicals, and

• Designing more efficient processes that minimize the production of waste materials.

Getting the lead out of automobile paints.

Recyclable carpeting.

Biodegradable polymers from renewable resources.

GREEN CHEMISTRY WORKS TOWARD SUSTAINABILITY BY:

Making chemical products that do not harm either our health or the environment,

Using industrial processes that reduce or eliminate hazardous chemicals, and

Designing more efficient processes that minimize the production of waste materials.

GREEN CHEMISTRY WORKS TOWARD SUSTAINABILITY BY:

ts that do not harm either our health or the environment,

Using industrial processes that reduce or eliminate hazardous chemicals, and

Designing more efficient processes that minimize the production of waste materials.

SYNTHESISOF IBUPROFEN:

Ibuprofen is a popular over-the-counter drug that has pain relief and anti-inflammatory

properties. It was originally developed in the 1960’s by the Boots Company of England. The

Boots synthesis of Ibuprofen involved a six-step process that generated millions of pounds

of unwanted waste This became known as the Brown process due to reactants of the

process not being incorporated into the product because of poor atom utilization. The

solution to this problem was developed by the BHC Company in 1991. They implemented

the green synthesis of Ibuprofen, which only required three steps. This process also

incorporated most of the reactants into the final product, reducing or eliminating most of the

waste by-products. The switch from the Boots process to the BHC process has resulted in a

more efficient creation of Ibuprofen.

Boots Method (Brown)

The making of Ibuprofen begins with the compound Isobutyl benzene.

Step1: A Friedel-Crafts acylation that uses the catalyst aluminum-chloride that generates aluminum

trichloride hydrate as waste by-product.

Step 2: a Darzens reaction with ethyl -chloroacetate that results in an epoxy ester compound.

Step 3: involves decarboxylation and hydrolyzation forming an aldehyde.

Step 4: a reaction with hydroxylamine giving an oxime.

Step 5: the oxime is converted to a nitrile.

Step 6: Hydrolyzation of the nitrile resulting in the final product 2, 4-isobutylphenyl-propanoi acid.

This process has a 40% atom economy which translates into 60% waste products. This means

that if 30 million pounds of Ibuprofen is produced each year, then more than 35 million pounds of

waste is generated.

BHC Method (Green)

The green synthesis of Ibuprofen also begins with the compound isobutyl benzene.

Step 1: a Friedel-Crafts acylation using hydrogen fluoride as the catalyst that can be recovered and reused.

Step 2: involves hydrogenation with Raney nickel, which is recovered and reused, to produce an alcohol.

Step 3: the alcohol undergoes carbonylation with the catalyst, palladium, also recovered and reused, to

produce Ibuprofen or 2, 4-isobutyl-phenylpropanoic acid.

This process has a 99% atom economy, includes the recovered acetic acid that was generated in Step

1.This means that only 1% is waste by-products which Translated to less than 500,000 pounds of waste for

the production of 30 million pounds of Ibuprofen.

Ibuprofen is the leading active ingredient in brand name drugs

developed by the Boots Company, the process generated millions of

dispose and posed hazardous risks to the environment. The greening of Ibuprofen production by the BHC

Company has significantly reduced this waste

innovation earned the Presidential Green Chemistry Award in 1997.

• GREEN CHEMISTRYGREEN CHEMISTRYGREEN CHEMISTRYGREEN CHEMISTRY

ENVIRONMENTAL PROBLEMS

FUNDAMENTAL APPROACH TO PREVENTING

POLLUTION

Ibuprofen is the leading active ingredient in brand name drugs such as Motrin and Advil. When first

Company, the process generated millions of pounds of waste

dispose and posed hazardous risks to the environment. The greening of Ibuprofen production by the BHC

gnificantly reduced this waste and the hazards making it environmentally friendly. This

d the Presidential Green Chemistry Award in 1997.

GREEN CHEMISTRYGREEN CHEMISTRYGREEN CHEMISTRYGREEN CHEMISTRY NOTNOTNOTNOT A SOLUTION TO ALL

ENVIRONMENTAL PROBLEMS BUTBUTBUTBUT THE MOST

FUNDAMENTAL APPROACH TO PREVENTING

such as Motrin and Advil. When first

pounds of waste that was costly to

dispose and posed hazardous risks to the environment. The greening of Ibuprofen production by the BHC

the hazards making it environmentally friendly. This

A SOLUTION TO ALL

THE MOST

FUNDAMENTAL APPROACH TO PREVENTING

Poly lactic acid (PLA) for plastics production

THANK YOU