demystifying green chemistry my goal today371.82 atom economy = 41% 154.24 three levels of green...
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Demystifying Green Chemistry
Bob Hanson
Department of Chemistry
St. Olaf College
Northfield, MN 55057
Michigan State UniversityAug. 10, 2005
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My Goal Today
�Tell you a bit about St. Olaf and our Green Chemistry project
�Present a brief introduction to Green Chemistry
�Introduce a new way of working with Green measures
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�Founded in 1874 by Norwegian immigrants
�Liberal arts college
�Known for music, international, and science-mathematics programs
�2900-3000 students – 40% majoring in science and mathematics
�Average of 45 chemistry majors/year
�Construction on Phase 1 of new science facilities will begin in June 2007
St. Olaf College
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www.stolaf.edu
Boe Chapel Holland Hall Old Main
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St. Olaf Chemistry Green Chemistry Group not shown: Paul Campbell, Paul Jackson
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“ Green Chemistry Throughout the Curriculum” Project Goals
�Design a suite of experiments that exemplifies the principles of GC for use at all levels of our laboratory curriculum.
�Develop these experiments in such fashion that they demonstrate an intentional thread, illustrating GC principles throughout the chemistry curriculum.
�Design these experiments such that they are based upon work reported in the contemporary chemical literature.
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�Increase student awareness of the principles of GC throughout our curriculum
�Produce future scientists who will be leaders in the implementation of GC in their workplace.
�Tie in the principles of GC with the ethical perspective central to St. Olaf College’s mission statement.
“ Green Chemistry Throughout the Curriculum” Project Goals
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�Demonstrate that the use of GC provides a guiding principle for the design and use of our new science building and other future science buildings.
�Provide a model for a green chemistry laboratory experience suitable for use at other colleges and universities.
“ Green Chemistry Throughout the Curriculum” Project Goals
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“ Green Chemistry Throughout the Curriculum” Timeline
�Organic lab (2003)
�WM Keck Foundation Grant (2004)
�Chemistry 121 pilot (2005)
�Chemistry 125 (2006)
�Analytical Chemistry (2007)
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My Role
�Bring Green Chemistry ideas into the first-year curriculum
�Use Green Chemistry as a means of introducing a wide range of ideas
�Design a web-based introduction to Green Chemistry measurements
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So, What is “ Green Chemistry” ?
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Three Levels of Green Chemistry
Equations
HCl (aq) + NaOH (aq)�
NaCl (aq) + H2O (l)
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Three Levels of Green Chemistry
Reactions
http://www.uncw.edu/smec/gk_fellows/askscience.html
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Three Levels of Green Chemistry
Processes
www.shelldeerpark.com/chemical.htm
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Three Levels of Green Chemistry
Equation – PCC Oxidation of Menthol
Atom Economy = 41%371.82
154.24
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Three Levels of Green Chemistry
Reaction
Atom Economy = 41%
theoretical yield
0% reaction
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Three Levels of Green Chemistry
Reaction
25% reaction
coproducts
desiredproduct
Atom Economy = 41%
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Three Levels of Green Chemistry
Reaction
50% reaction
coproducts
desiredproduct
Atom Economy = 41%
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Three Levels of Green Chemistry
Reaction
75% reaction
coproducts
desiredproduct
Atom Economy = 41%
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Three Levels of Green Chemistry
Reaction
Atom Economy = 41%100% reaction
coproducts
desiredproduct
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Three Levels of Green Chemistry
Reaction
Atom Economy = 41%
before… …after
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Three Levels of Green Chemistry
Reaction – Limiting Reactant
Experimental Atom Economy = 26%
before… …after
excess PCC
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Three Levels of Green Chemistry
Reaction – Actual Yield
Reaction MassEfficiency = 13%
before… …after
50% Product Loss
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Three Levels of Green Chemistry
Reaction – General Measures
Reaction Mass Eff iciency = 13%Exper. Atom Economy = 26%Atom Economy = 40%
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Three Levels of Green Chemistry
Process – Includes all inputs
Process MassEff iciency = 1%solvent silica gel
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Three Levels of Green Chemistry
Process MassEff iciency = 13%
Process – May involve more than one step
David Harris, ’ 06
Atom Economy= 81%
catalysts
bypoduct (H2O)
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Three Levels of Green Chemistry
H2O2/Na2WO4
Process MassEff iciency = 13%
…allows for comparison
Process…PCC
Process MassEff iciency = 1%
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Three Levels of Green Chemistry
E-factor = 0.3:1
Process – Allowing for solvent recovery
E-factor = 6.5:1
solventlost
solvent recovered
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Three Levels of Green Chemistry
Equation, Reaction, and Process
Wouldn’t it be nice to have access to a tool that would allow us to quickly make comparisons like this?
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
�Based on the EPA “Green Chemistry Expert System”
�User-friendly interface designed to assist students in analyzing the atom economy, and safety of chemical processes
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
http://fusion.stolaf.edu/gca
http://fusion.stolaf.edu/gca?file=samples/menthol_pcc.htm
http://fusion.stolaf.edu/gca?file=samples/menthol_h2o2.htm
http://fusion.stolaf.edu/gca?file=samples/uo_aldol.htm
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
Lessons learned:�
Students need help just writing the balanced chemical equations.
�Process is important, as most realexperiments involve more than one process step.
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
Lessons learned:�
Introducing Green Chemistry provides a context for discussing safety, including MSDS sheets, health, and environmental hazards.
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
Lessons learned:�
Lab manuals could be more explicit in guiding students to an understanding of the overall set of process steps they will be doing in lab.
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
Lessons learned:�
Web applications can provide accessible methods of introducing students to Green Chemistry calculations and issues.
�The key is a smooth, well-tested interface, utilizing lots of student feedback.
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Green Chemistry Assistanthttp://fusion.stolaf.edu/gca
Things to do:�
Add the final post-process analysis page “Account for Material Recovery”
�Generate Final Green Process Reports
�Get ideas from user feedback!
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St. Olaf Faculty
St. Olaf Students
St. Olaf Technology Support
U.S. EPA
Financial support
Acknowledgments
Gary Spessard, Marc Klingshirn, Paul Jackson
Paul Campbell, Allison Christensen, Tim Barker, Tyler Drake, David Harris
Dan Beach
Rich Engler
WM Keck FoundationHoward Hughes Medical Institute
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St. Olaf Chemistry Green Chemistry Group not shown: Paul Campbell, Paul Jackson