1. The Importance of Green Chemistry Sarah Gunderson April 26, 2005

2. What is Green Chemistry?

3. Use of chemistry for pollution prevention –Reduce or eliminate use and generation of hazardous substances –Alternative pathways or reaction conditions –Design of safer chemicals (less toxic, inherently safer) –Benign processes and products pose no risk Launched in 1991 by EPA

4. What is Green Chemistry? EPA –Presidential Green Chemistry Challenge –Partner with NSF to sponsor research –Small Business Innovation Research Program Green Chemistry Institute (1997) –Focuses on research, education, conferences, public awareness –Allied with ACS in 2000

5. 12 Principles of Green Chemistry 1.Prevent waste 2.Design safer chemicals and products 3.Design less hazardous chemical syntheses 4.Use renewable feedstocks 5.Use catalysts, not stoichiometric reagents 6.Avoid chemical derivatives 7.Maximize atom economy 8.Use safer solvents and reaction conditions 9.Increase energy efficiency 10.Design chemicals and products to degrade after use 11.Analyze in real time to prevent pollution 12.Minimize the potential for accidents

6. 12 Principles of Green Chemistry 1.Prevent waste Easier than cleaning up later 2.Design safer chemicals and products Give desired function with lower toxicity 3.Design less hazardous chemical syntheses Use and generate non-toxic substances whenever possible

7. 12 Principles of Green Chemistry 4.Use renewable feedstocks Non petrochemically dervied 5.Use catalysts, not stoichiometric reagents Increased selectivity 6.Avoid chemical derivatives Blocking groups Protection/deprotection Using additional steps and reagents

8. 12 Principles of Green Chemistry 7.Maximize atom economy Incorporate all materials into final product if possible 8.Use safer solvents and reaction conditions Minimize risk of serious accidents and injuries 9.Increase energy efficiency Operate at ambient conditions whenever feasible

9. 12 Principles of Green Chemistry 10.Design chemicals and products to degrade after use Break down into biocompatible products 11.Analyze in real time to prevent pollution Recognize problems before they turn into tragedies 12.Minimize the potential for accidents Releases, explosions and fires Check operability and sizing of safety equipment

10. Atom Economy vs. Yield Different way of measuring reaction efficiency, using formula weight Yield definition is flawed –Does not account for co-product production Example: CH 4 + 1.5 O 2  CO 2 + 2 H 2 O –If desire H 2 O yield ~100% Atom economy=

11. Successful Applications Supercritical CO 2 processing –Caffeine extraction, dry cleaning –Semiconductor processing Ionic liquid solvents –Emit no VOCs, quicker reactions, tunable Catalysts Biobased / Renewable feedstocks –Agricultural wastes -> alcohols, ketones, carboxylic acids

12. Successful Applications Microreactors –Higher purity, faster –More efficient heat transfer From [4]

13. Successful Applications www.pyrocool.org

14. Green Chemistry Problems Development can be expensive Determining toxicity of new compounds is difficult Difficult to transition from a reactive to a proactive methodology

15. Pharmaceuticals One of the leading industries to adapt Allowed to use toxic chemicals restricted in other industries Want to minimize environmental impacts IndustryAnnual Product Tons Kg waste / Kg product Oil refining10 6 -10 8 0.1 Bulk Chemicals10 4 -10 6 <1-5 Fine Chemicals10 2 -10 4 5-50 Pharmaceuticals10-10 3 25-100

16. Ibuprofen Synthesis Originally developed and patented in 1960’s by Boots Company Green process patented in 1991 by BHC

17. www.chemistry.org

19. Other Green Pharma Processes Viagra (Pfizer) From [7]

20. Other Green Pharma Processes Pfizer has a team at each R&D site –Zoloft Bristol Myers Squibb –Taxol process Abbott Laboratories educates at main R&D site

21. Education in Green Chemistry Few colleges offer this option Industry has taken the initiative for training Should colleges focus more on training?

22. Changes in Education Need to train new scientists in these techniques Replacement of “yield” with “atom economy” Modification of organic chemistry laboratory Basic concepts of chemical toxicology and the molecular basis of hazards [2]

23. Personal Responsibility Ability to challenge current process operation Educate co-workers Green process development

24. Conclusions Green chemistry is a new way of thinking Concepts apply in all industries

25. Questions?

26. References 1.http://www.epa.gov/greenchemistry/http://www.epa.gov/greenchemistry/ 2.Anastas, P.T., Kirchhoff, M.M., Origins, Current Status and Future Challenges of Green Chemistry, Acc. Chem. Res. 2002, 35, 686-694 3.http://www.chemistry.org/portal/resources/ACS/ACSContent/education/gre enchem/case.pdfhttp://www.chemistry.org/portal/resources/ACS/ACSContent/education/gre enchem/case.pdf 4.Haswell, S.J., Watts, P., Green Chemistry: Synthesis in micro reactors, Green Chemistry, 2003, 5, 240-249. 5.Hjeresen, D.L., Schutt, D.L., Boese, J.M., Green Chemistry and Education, J Chem Ed, 2000 (77), 12, 1543-1547. 6.http://www.pyrocool.orghttp://www.pyrocool.org 7.Dunn, P.J., Galvin, S., Hettenbach, K., The development of an environmentally benign synthesis of sildenafil citrate (Viagra) and its assessment by Green Chemistry Metrics, Green Chemistry, 2004, 6, 43-48.