INTRODUCTION

2. Science based on research towards the development of new sustainable processes DEFINITION Defined as the invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances INTRODUCTION

3. Major tool in accomplishing Pollution prevention Leads to reduction in waste Reduced use of energy and other perishable resources Carrying out chemical activities leading to safer products significance

4. Term coined by Dr. Paul Anastas known as the “Father of Green Chemistry” Principles of green chemistry • He defined it as the utilization 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

5. 12 principles of green chemistry • Prevent waste • AtomEconomy • Less Hazardous Chemical Synthesis • Designing Safer Chemicals • Use safer Solvents /reaction conditions • Increase Energy Efficiency. • Use of Renewable Feedstocks • Reducechemical derivatives • Use catalysts • Design for Degradation • Real-time Analysis for Pollution Prevention. • Inherently Safer Chemistry for Accident Prevention

6. Design processes which minimize waste Better to prevent waste than to clean and treat it Prevent waste

7. Atom economy =Mass of atoms in desired product x 100 Mass of atoms in reactants Concept developed by Barry Frost Evaluates the efficiency of a chemical transformation Atom economy

8. Choose transformations that incorporate most of the starting materials into the product increases the efficiency and minimizes waste Atom economy

9. Wherever practicable, synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment Less hazardous chemical synthesis

10. Polycarbonate Synthesis: Phosgene Process • Disadvantages • phosgene is highly toxic, corrosive • requires large amount of CH2Cl2 • polycarbonate contaminated with Cl impurities Less hazardous chemical synthesis

11. Polycarbonate Synthesis: Solid-State Process • Advantages • diphenylcarbonate synthesized without phosgene • eliminates use of CH2Cl2 • higher-quality polycarbonates Less hazardous chemical synthesis

12. Chemical products should be designed to preserve efficacy of the function while reducing toxicity 4. Designing safer chemicals

13. Antifoulants are generally dispersed in the paint as it is applied to the hull.  Organotin compounds have traditionally been used, particularly tributyltin oxide (TBTO).  TBTO works by gradually leaching from the hull killing the fouling organisms in the surrounding area Organotin compounds are chronically toxic to marine life and can enter food chain. They are bioaccumulative. Designing safer chemicals

14. The use of auxiliary substances (solvents, separation agents, etc.) should be made unnecessary whenever possible and, when used, innocuous. 5. Use safer solvents/reaction conditions

15. Solvent Substitution • Water as a solvent • New solvents • Ionic liquids • Supercritical fluids Use safer solvents/reaction conditions

16. Energy requirements should be recognized for their environmental and economic impacts and should be minimized. Synthetic methods should be conducted at ambient temperature and pressure 6. Increase Energy Efficiency.

17. A raw material or feedstock should be renewable rather than depleting whenever technically and economically practical 7. Use of Renewable Feedstocks

18. Raw Materials from Renewable Resources:The BioFine Process Paper mill sludge Agricultural residues, Waste wood Levulinic acid Green Chemistry Challenge Award1999 Small Business Award Municipal solid waste and waste paper

19. Levulinic acid as a platform chemical butanediol Acrylic acid Succinic acid MTHF (fuel additive) THF Diphenolic acid gamma butyrolactone DALA (-amino levulinic acid) (non-toxic, biodegradable herbicide)

20. Unnecessary derivatisation(blocking group, protection/ de-protection, temporary modification of physical/chemical processes) should be avoided whenever possible Reduces atom economy Increases waste 8. Reduce chemical derivatives

21. Catalytic reagents (as selective as possible) are superior to stoichiometricreagents Readily regenerated, separated Recyclable Mild conditions 9. Use catalysts

22. Chemical products should be designed so that at the end of their function they do not persist in the environment and instead break down into innocuous degradation products CFCs, DDT Biodegradable polymers 10. Design for Degradation

23. Analytical methodologies need to be further developed to allow for real-time in-process monitoring and control prior to the formation of hazardous substances Real time analysis for a chemist is the process of “checking the progress of chemical reactions as it happens.” Knowing when your product is “done” can save a lot of waste, time and energy! 11. Real-time Analysis for Pollution Prevention

24. Substance and the form of a substance used in a chemical process should be chosen so as to minimize the potential for chemical accidents, including releases, explosions, and fires Various industrial accidents Eg: Bhopal gas tragedy 12. Inherently Safer Chemistry for Accident Prevention

25. Green catalysts