Slide 1 : Green Chemistry V.S.Saravanamani
Assistant Professor
Department of Chemistry
King College of Technology
Green Chemistry : 2 Green Chemistry 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 .
Slide 3 : 3 Green Chemistry is about
Waste Minimisation at Source
Using Non-Toxic Reagents
Use of Renewable Resources
Use of Solvent Free or Recyclable Eco Friendly Solvent systems
Green Chemistry is about... : 4 Green Chemistry is about... Reducing
Why do we need Green Chemistry ? : 5 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. Why do we need Green Chemistry ?
Slide 6 : 6 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 environmental 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 : 7 Prevention
It is better to prevent waste than to treat or clean up waste after it has been created.
Atom Economy
Synthetic methods should be designed to maximise the incorporation of all materials used in the process into the final product.
Less Hazardous Chemical Synthesis
Wherever practical, synthetic methods should be designed to use and generate substances that possess little or no toxicity to people or the environment.
Cont… The 12 Principles of Green Chemistry
Slide 8 : 8 Designing Safer Chemicals
Chemical products should be designed to effect their desired function while minimising their toxicity.
Safer Solvents and Auxiliaries
The use of auxiliary substances (e.g., solvents or separation agents) should be made unnecessary whenever possible and harmless when used.
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.
Cont…
Slide 9 : 9 Use of Renewable Feedstocks
A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable.
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.
Catalysis
Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
Cont…
Slide 10 : 10 Design for Degradation
Chemical products should be designed so that at the end of their function they break down into harmless degradation products and do not persist in the environment.
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.
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.
Slide 11 : 11 GLOBAL WARMING
The major uses of Green Chemistry : 12 Energy
Global Change
Resource Depletion
Food Supply
Toxics in the Environment The major uses of Green Chemistry
Energy : 13 Energy The vast majority of the energy generated in the world today is from non-renewable sources that damage the environment.
Carbon dioxide
Depletion of Ozone layer
Effects of mining, drilling, etc
Toxics
Energy : 14 Energy Green Chemistry will be essential in
developing the alternatives for energy generation (photovoltaic, hydrogen, fuel cells, biobased fuels, etc.) as well as
continue the path toward energy efficiency with catalysis and product design at the forefront.
Global Change : 15 Global Change “Concerns for climate change, oceanic temperature, stratospheric chemistry and global distillation can be addressed through the development and implementation of Green Chemistry technologies”
Resource Depletion : 16 Resource Depletion Due to the over utilization of non-renewable resources, natural resources are being depleted at an unsustainable rate.
Fossil fuels are a central issue.
Resource Depletion : 17 Resource Depletion Renewable resources can be made increasingly viable technologically and economically through Green Chemistry.
Biomass
Nanoscience & Technology
Solar
Carbon dioxide
Waste utilization
Food Supply : 18 Food Supply While current food levels are
sufficient, distribution is inadequate
Agricultural methods are
unsustainable
Future food production intensity is
needed.
Green chemistry can address
many food supply issues
Food Supply : 19 Food Supply Green chemistry is developing:
Pesticides which only affect target organisms and degrade to harmless by-products.
Fertilizers and fertilizer adjuvants that are designed to minimize usage while maximizing effectiveness.
Methods of using agricultural wastes for beneficial and profitable uses.
Toxics in the Environment : 20 Toxics in the Environment Substances that are toxic to humans, the biosphere and all that sustains it, are currently still being released at a cost of life, health and sustainability.
One of Green Chemistry’s greatest strengths is the ability to design for reduced hazard.
Pollution Prevention : 21 Increasing Greenness Disposal Pollution Prevention
Conclusion : 22 Conclusion Green Chemistry Not a solution to all environmental problems But the most fundamental approach to preventing pollution.
Slide 23 : 23 Thank you for your kind
Co-operation
Slide 24 : 24 ?...