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

Green Chemistry Is About...Green Chemistry Is About...

MATERIALS

HAZARDS

WASTE

RISKS

Cost

Energy

1. Prevention of Waste1. Prevention of Waste

It has been a common practice to dump waste on :It has been a common practice to dump waste on :o LandLando WaterWatero Air. Air. This resulted in soil, water and air pollutionThis resulted in soil, water and air pollution.. Green Chemistry is involved to design chemical synthesis in Green Chemistry is involved to design chemical synthesis in

such a way that the process involves pathway to give such a way that the process involves pathway to give products, leaving no waste or cleanup.products, leaving no waste or cleanup.

Prevention is better than the Prevention is better than the cure.cure.

““It is better to prevent waste It is better to prevent waste than to treat or cleanthan to treat or clean

up waste after it is formed”up waste after it is formed”

Chemical

Process

2. Atom Economy2. Atom EconomyNew processes should be New processes should be

designed such that most designed such that most of the starting material of the starting material gets converted into useful gets converted into useful products. This is called as products. This is called as maximum atom economymaximum atom economy

3. Less Hazardous 3. Less Hazardous Chemical SynthesisChemical Synthesis

The synthetic method should be The synthetic method should be designed to generate substances designed to generate substances having little or no toxicity to human having little or no toxicity to human health and the environmenthealth and the environment..

Eg :Synthesis of IndigoEg :Synthesis of Indigo

Traditional way – from AnilineTraditional way – from Anilineo Inflammable, carcinogenic, organic solventInflammable, carcinogenic, organic solvent

Green way Green way – from Amino acid L-Tryptophan– from Amino acid L-Tryptophano Non-toxic, safe & easy for use!!!Non-toxic, safe & easy for use!!!

4. Designing Safer Chemicals4. Designing Safer Chemicals

Chemical products should be Chemical products should be designed such that they break designed such that they break down to innocuous substances down to innocuous substances after use so that they do not after use so that they do not accumulate in the environmentaccumulate in the environment

Eg: Biological insecticides Eg: Biological insecticides instead of traditional DDT, instead of traditional DDT, biodegradable plastics biodegradable plastics containing cellulosecontaining cellulose

5.Safer Solvents & 5.Safer Solvents & AuxillariesAuxillaries The use of auxillary substances like solvents, The use of auxillary substances like solvents,

separating agents, etc. should be made separating agents, etc. should be made unnecessary where ever possible and unnecessary where ever possible and innocuous when used.innocuous when used.

Eg. For dry cleaning the fabrics, Eg. For dry cleaning the fabrics, toxic solvents like perchloroethlyene toxic solvents like perchloroethlyene was used, which is replaced during was used, which is replaced during recent years by liquid COrecent years by liquid CO22

““The use of auxiliary substances (e.g. The use of auxiliary substances (e.g. solvents,solvents,

separation agents, etc.) should be made separation agents, etc.) should be made unnecessaryunnecessary

wherever possible, and innocuous when wherever possible, and innocuous when used”used”

6. Design for Energy 6. Design for Energy EfficiencyEfficiency

► The aim of Green Chemistry is to increase The aim of Green Chemistry is to increase Energy EfficiencyEnergy Efficiency

► It can be achieved by:It can be achieved by: Use of CatalystUse of Catalyst By stopping the use of Fossil fuelsBy stopping the use of Fossil fuelso By stopping the use of Gaseous fuelsBy stopping the use of Gaseous fuels► The Energy Efficiency of process can be The Energy Efficiency of process can be

increased by increased by o Proper heat transferProper heat transfero Minimal wastage of energy during the process.Minimal wastage of energy during the process.

7 Use of Renewable 7 Use of Renewable FeedstocksFeedstocks

The raw materials should be The raw materials should be renewable rather than depleting renewable rather than depleting where ever tecwhere ever tec

technically and economically technically and economically feasible.feasible.

Eg:synthesis of adipic acid.Eg:synthesis of adipic acid.

““A raw material of feedstock should be A raw material of feedstock should be renewablerenewable

rather than depleting wherever rather than depleting wherever technically andtechnically and

economically practical”economically practical”Non-renewable Renewable

8.8. Reduce Derivatives Reduce Derivatives

• The uses of derivatives increases the The uses of derivatives increases the steps of the processsteps of the process

• Additional reagents are requiredAdditional reagents are required

• Eg. Synthesis of Ibuprofen where Eg. Synthesis of Ibuprofen where traditional pathway larger steps are traditional pathway larger steps are involved having low atom economy involved having low atom economy whereas the greener way is more whereas the greener way is more efficient.efficient.

Classic Route to Ibuprofen

Ac2O

AlCl3

COCH3

HCl, AcOH, Al Waste

ClCH2CO2Et

NaOEt

OEtO2C

HCl

H2O / H+

OHC

AcOH

NH2OH

OHNN

H2O / H+

HO2C

NH3

H o e c h s t R o u t e T o I b u p r o f e n

O

H F

A c O H

A c 2 O

H 2 / N i

OH

C O , P d

H O 2 C

Catalyst facilitates transformation without it Catalyst facilitates transformation without it being involvedbeing involved

Leads to better utilization of starting material Leads to better utilization of starting material and minimum wastageand minimum wastage

Reactions become fasterReactions become faster Increases energy efficencyIncreases energy efficency

9.Increase use of catalyst9.Increase use of catalyst

10.DEGRADDABLE PRODUCTS10.DEGRADDABLE PRODUCTS

Design should be for proiper disposal Design should be for proiper disposal of itemsof items

Product after its use should break Product after its use should break into NON-TOXIC substancesinto NON-TOXIC substances

EG: use of:EG: use of: biodegradable plastics having biodegradable plastics having

cellulosecellulose Biological pesticides to protect cropsBiological pesticides to protect crops

11.NEW 11.NEW ANALYTICALANALYTICAL METHODS METHODS

Technique should be designed to reduce Technique should be designed to reduce use of chemicalsuse of chemicals

Placement of accurate sensor to monitor Placement of accurate sensor to monitor generation of hazards during product generation of hazards during product formationformation

Eg:Eg: Preparation of ethylene glycol, in which if Preparation of ethylene glycol, in which if reaction conditions are not monitored, toxic reaction conditions are not monitored, toxic substances are produced at higher temperaturesubstances are produced at higher temperature

12.ACCIDENT 12.ACCIDENT PREVENTIONPREVENTION

Substances used should minimize Substances used should minimize potential for chemical potential for chemical releases,accidents,explosions and fire.releases,accidents,explosions and fire.

Use of safer chemicals. minimizing Use of safer chemicals. minimizing temperature and pressure helps in temperature and pressure helps in reducing potential of accidentsreducing potential of accidents

EXAMPLES OF GREEN EXAMPLES OF GREEN CHEMISTRYCHEMISTRY

1.1. BIODISEL PREPARATIONBIODISEL PREPARATIONOBTAINED BY NATURAL SUBSTANCESOBTAINED BY NATURAL SUBSTANCESOBTAINED BY TRANSESTERIFICATION OBTAINED BY TRANSESTERIFICATION

REACTIONREACTIONUSED AS A FUEL BY MIXING WITH DISELUSED AS A FUEL BY MIXING WITH DISELGLCEROL OBTAINED DURING GLCEROL OBTAINED DURING

TRANSESTERIFICATION REACTION CAN BE TRANSESTERIFICATION REACTION CAN BE CONVERTED INTO PROPAN-1,2DIOL,WHICH CONVERTED INTO PROPAN-1,2DIOL,WHICH IS USED AS IS USED AS AUTOMOBILE ANTIFREEZEAUTOMOBILE ANTIFREEZE

2.SUPERCRITICAL FLUID2.SUPERCRITICAL FLUID

Acts as an intermediate between liquid and gaseous phaseActs as an intermediate between liquid and gaseous phase Has solvent properties like liquid and penetration properties Has solvent properties like liquid and penetration properties

like gaseslike gases APPLICATIONS:APPLICATIONS: Extraction process Extraction process Paint and varnish industryPaint and varnish industry In nano-electronics replaces ulta high purity water(eg:SCCO2)In nano-electronics replaces ulta high purity water(eg:SCCO2) To prepare teflon(eg:SCCO2)To prepare teflon(eg:SCCO2) Pharmaceutical industryPharmaceutical industry Petrochemical industryPetrochemical industry Environmental productEnvironmental product Supercritical fluids combine properties of gases and liquids, Supercritical fluids combine properties of gases and liquids,

which offer a range of applications in which offer a range of applications in synthetically synthetically andand analytical analytical chemistry chemistry

SOME OTHER SOME OTHER APLLICATIONS APLLICATIONS

Palm,coconut,soya oils etc used to produce Palm,coconut,soya oils etc used to produce fatty acids,gycerol,etcfatty acids,gycerol,etc

Production of adipic acid from glucoseProduction of adipic acid from glucose Biorefineries Biorefineries :1.used to separate biomass into :1.used to separate biomass into

liquid and solid extractliquid and solid extract2.Produce plastic from corn2.Produce plastic from corn DMC(dimethyl carbonate)DMC(dimethyl carbonate) used as methylating used as methylating

agent due to its good selectivityagent due to its good selectivity

GREEN SOLVENTS:GREEN SOLVENTS:SCFSCFWaterWaterIonic liquidIonic liquidEthyl lactateEthyl lactateGreen fuel(Biodisel)Green fuel(Biodisel)BiocatalystsBiocatalystsMiningMiningFood industryFood industryElectronic industryElectronic industryPaper and textile industryPaper and textile industry

Credits:Credits:

Aditya IyerAditya Iyer Harshita KotianHarshita Kotian Khushboo SharmaKhushboo Sharma Jinesh KachharaJinesh Kachhara Viraj ManjrekarViraj Manjrekar MayurMayur shardulshardul