Principles and Applications of Green Chemistry

12 principles of green chemistry

1. GREEN CHEMISTRY Presented by Akhilesh

2. DEFINITION... Green Chemistry is the design of chemical products and processes that reduce or eliminate the use and/or generation of hazardous substances.

3. GREEN CHEMISTRY IS ABOUT... Waste Minimisation at Source e Use of Catalyst 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

4. THE 12 PRINCIPLES OF GREEN CHEMISTRY

5. Use of Renewable Resources Less Hazardous Chemical Synthesis Atom Economy Safer Solvents and Auxiliaries Designing Safer Chemicals Design for Energy Efficiency 1 2 3 4 5 6

6. Use of Renewable Feedstocks Reduce Derivatives Design for Degradation Catalysis Real-time Analysis for Pollution Prevention Inherently Safer Chemistry for Accident Prevention 12 11 10 7 8 9

7. Use of Renewable Resources 1 It is better to prevent waste than to treat or clean up waste after it has been created.

8. APPLICATION... Solar Energy Conversion Solar energy is an abundant and renewable source of power that could alleviate world energy demand. New materials technologies are rising to the challenge of replacing a silicon-dominated market with the promise of cheaper and more versatile photovoltaics. One of the most highly studied alternatives, the dye-sensitized solar cell (DSSC), is discussed from a historical perspective as well as recent advances in DSSC technologies. In addition, the emerging technology of perovskite solar cells, which bear some similarity to DSSCs, is also introduced.

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

10. APPLICATION... ATOM ECONOMY Atom economy (atom efficiency) is the conversion efficiency of a chemical process in terms of all atoms involved and the desired products produced. Atom economy is an important concept of green chemistry philosophy, and one of the most widely used metrics for measuring the "greenness" of a process or synthesis.

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

12. APPLICATION...

13. Designing Safer Chemicals 4 Covers the design or redesign of chemicals with the specific intent of making them safe for people and the environment. Explains how commercially useful substances of low toxicity can be designed and developed through careful forethought and strategic molecular modification.

14. APPLICATION...

15. Safer Solvents and Auxiliaries 5 The principle states that the use of solvents and other auxiliaries should “be made unnecessary wherever possible and innocuous when used”. Because they do matter it is important that safer solvents are used.

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17. Design for Energy Efficiency 6 Energy efficient design helps to reduce the high demands for energy to combat costs, resource use and negative environmental effects.

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19. Use of Renewable Feedstocks 7 Refers to any material derived from living organisms, usually plants. In contrast to depleting feedstocks like petroleum, we can much more easily grow new plants once we use them up, and maintain a continuous supply.

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21. Reduce Derivatives 8 Unnecessary derivatization (e.g. installation/removal of use protecting groups) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste.

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23. Catalysis 9 In stoichiometric reactions, the reaction can often be very slow, may require significant energy input in the form of heat, or may produce unwanted byproducts that could be harmful to the environment or cost lots of money to dispose of. Most chemical processes employing catalysts are able to bypass these drawbacks.

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25. Design for Degradation 10 Chemical products should be designed so that at the end of their function they break down into innocuous degradation products 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.

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27. Real-time Analysis for Pollution Prevention 11 Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.

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30. Inherently Safer Chemistry for Accident Prevention 12 Inherently Safer Chemistry for Accident Prevention: Substances and the form of a substance used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires.

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33. N A H T K Y O U