Green Chemistry Across the Curriculum
At St. Olaf College
Bob Hanson
BCCE20, Indiana University, July 28, 2008
A Project Supported By the W.M. Keck Foundation
1
Goals of Green Chemistry at St. Olaf
• Alter the chemistry curriculum
 1st year, 2nd year, 3rd year
• Design a science facility that reflects this effort
 LEED Gold Building
www.stolaf.edu/sciencecomplex/
2
Web App: Green Chemistry Assistant
http://fusion.stolaf.edu/gca
A collaborative project between St. Olaf College and US EPA - an
extension of the EPA Green Chemistry Expert System SMART module
3
GCA Graphical
Output
Desired Product
Wittig Reaction
Atom Economy – 30.3%
E-Factor – 58.5 : 1
Coproduct
Other materials
Solvents
Catalysts
Ring Closing Metathesis of
Diethyl Diallylmalonate
Atom Economy – 88.3%
E-Factor – 25.5 : 1
4
GCA graphics
5
GCA graphics
6
1st Year: Periodic Trends & Solubility
• Lab Manual includes “Green
Connections” and new pre-/post-lab
questions
• Replace heptane with ethyl acetate
Cl2
 Volatile but with lesser hazards
 Option as a renewable resources
 Potentially less harmful degradation
products
Br2
• Observed color differences
 Chlorine: colorless, Bromine: orange,
and Iodine: yellow
• Replace chromate anion with thiosulfate
anion and eliminate barium cation
I2
Heptane EtOAc
7
1st Year Experimental Changes
Ethanol oxidation: kinetics study
• Eliminate the chromate oxidation
process.
• Uses household bleach (6%
sodium hypochlorite solution)
• Eliminates concentrated
hydrochloric acid
Mystery Product Reactions
• Replace permanganate with
iodine redox system
• Eliminates phosphoric and
hydrochloric acids
• 70% waste reduction (30 L
annually)
7 experiments revised &
changes implemented
8
CuCl2·2H2O
CuCl2
9
1st Year Waste Management Introduction
Efforts:
Results (unquantified):
• Students typically work in groups
of two or three.
• Students are far more aware of
waste issues.
• Each group is required to
appoint one student who will
take responsible for accounting
for group waste and filling out
“waste manifests” for their
group.
• Students like taking some
responsibility in this regard.
• Faculty become more aware of
waste issues as well.
• Safety discussions and
awareness arise spontaneously.
10
2nd Year: Sonogashira Coupling Reaction
20+ experiments evaluated and 7 changed
CH3
CH3
Palladium (5%) and
copper (8%) catalyzed
coupling of terminal
alkynes with aryl halides
O
O
+ KI + KIO3
Methanol, Water
HCl, 25O C, 20 hours
Figure 1: Iodination of anisole
CH3
I
O
Uses product made in 1st
lab of second semester,
PEG 200 solvent
CH3
O
Microwave 1 minute at
240 Watts
OH
+
PEG, Triethylamine
HC
CH3
PdCl2(PPh3)2, CuI, Heat
CH3
I
Figure 2: Sonogashira reaction with 2-methyl-3-butyn-2-ol
H3C
CH3
OH
Moderate success
recycling catalysts and
PEG solvent
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More 2nd Year Experimental Pursuits
O
O
O
O
OEt
EtO
EtO
6.5% mol Grubbs Catalyst
+
.5 mL PEG, microwave heating
H2C
CH2
OEt
CH2
CH2
1.0 mmol
• Ring Closing Metathesis
 Catalytic ring closure with
production of ethylene
 Microwave for heating …
proceeded to 98.3%
conversion
• Polyethylene glycol solvent
 potential to recycle the
catalyst
 low toxicity, biodegradability,
and low vapor pressure
 modest catalyst recycling
success
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3rd Year: Goals & Objectives
• Infuse Analytical & Physical labs
with green chemistry principles
• Develop appropriate metrics
• Test metrics and apply to current
lab experiments (benchmarking)
• Determine labs with the least
green characteristics
 NFPA  3
 High material/solvent use
 High energy use
 Nonrenewable feedstocks
 Stoichiometric reactions
• Reduce waste stream
• Develop new or modified
experiments
 Change chemistry or
chemical system
 Reducing material/solvent
use in currents labs
 Make volumetric reductions
 Analysis of citrus fruit
essential oils by GC, GC/MS,
Raman and/or IR-ATR.
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Analytical Lab Benchmarks
Lab
Topics
Glassware
Calibration
Cleaning &Stats
CaOxalate
Gravimetry & AAS
Weak Acid
Titrations
MockRobot IsosPt & Automat.
Easter Egg
Grass
Food dyes UV/VIS
Downsizing Fe-bipy, UV/VIS &
Automation
NFPA  3
Solvent Use
Waste/Group
EtOH-KOH
H2O (2 L)
Neutralized Sewer
HCl
H2O (17.4 L)
1.04 L
low pH
NaOH
H2O (4.5 L)
Neutralized –
Sewer
H2SO4, NaOH
H2O (2.1 L)
Neutralized –
Sewer
-
H2O (3 L)
Neutralized –
Sewer
HCl,
NH2OH•HCl
H2O (3 L)
1.31 L
Metals
Broken Pill
Machine
Metals & AAS
HCl, HNO3,
Bronze alloys
H2O (4 L)
1.18 L, low pH
Metals
Mysterious
Death
Chromatogr. &
HPLC
MeOH, Acetic
Acid, Et3N
Mobile Phase
Volume
0.32 L
low pH
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3rd Year: Solvent Reduction - HPLC
2.0
b
a
c
d
0.0
Signal
*
c
-2.0
d
-4.0
Mixed Flow 0.5
Original
a
b
-6.0
0
2
4
6
8
10
Minutes
Discovery HS C18 75 x 3 mm (3.5 mm dp), 20 mL inj, 254 nm detection;
68:30:1.5:0.5 Water:MeOH:formic acid:triethylamine; 0.50 mL/min.
Analytes: a) procainamide, b) qunidine, c) lidocaine, d) diisopyramide.
75% solvent reduction, 50% time reduction
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Analytical Metrics
Metric Name
Measures efficiency of
Formula
Analytical Atom
Economy AAE
Transformation of reactant
atoms into a desired product
necessary to prepare the
analyte for analysis.
Analytical Mass
Efficiency AME
Chemical and solvent use
involved in a chemical
reaction.
AME 
Mass of Analyte(g)
x 100
 FW of Reagents, Solvents(g )
Method Mass
Efficiency MME
Comprehensive material use
necessary for entire analysis
method.
MME 
Mass of Analyte (g)
x 100
 FW of Reagents, Solvents,
Cleaning, Prep (g)
Energy per
Analytical Unit
EPAU
Energy use for entire analysis
method relative to the mass of
analyte in sample.
AAE 
EPAU 
FW of Analyte
x 100
 FW of Reagents
Total method energy (kJ)
x 100
Mass of analyte (g)
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3rd Year: Volumetric Reduction - Downsizing
• Iron determination
via bipyridine
complexation
• Automation
(robotic) vs. human
(volumetric)
method.
• Challenge –
maintain # sig figs
and solution
handling.
Starting Materials
Original
Amount
Modified
Amount
iron wire
25 mg
10 mg
HCl, conc.
10 mL
8 mL
HCl, 0.2M
35 mL
17.5 mL
hydroxylamine
hydrochloride, 10%
35 mL
17.5 mL
Na acetate, 2 M
14 mL
7 mL
bipyridine, 0.1%
70 mL
35 mL
1031 mL
511.5 mL
water
AAE
79.87%
79.87%
AME
1.67x10-5%
3.34x10-5%
MME
4.77x10-6%
9.53x10-6%
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3rd Year: New Citrus Oil Analysis
Why is lemon oil used for some consumer products and orange oil
for others? How chemically similar are citrus oil extracts? How
would you determine this when starting with a piece of fruit
(grapefruit, lemon, lime, or orange) and doing as little sample
preparation as possible?
.
SAMPLING STRATEGIES
• Solid Phase Microextraction
 Peel / zest into vial
 PMDS-DVB fiber
• Supercritical CO2 extraction
 Peel / zest into centrifuge tube
 Dry ice & water bath
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Physical Properties of CO2
CO2 (l) Good solvent for small, nonpolar molecules: hydrocarbons
< 20 carbon atoms & some aldehydes, esters, and ketones
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Headspace
Samples
of Citrus
Zest
Headspace Samples
of Citrus
Zestings
Limonene
Intensity
Orange
Lime
-Pinene
-Pinene
-Terpinene
Lemon
Grapefruit
0
7
7.5
8
8.5
9
9.5
10
10.5
11
Minutes
GC Conditions:
VF-5zest
capillaryLemon
column Zest
(30 m x 0.25
x 0.23Orange
mm film),Zest
Grapefruit
Limemm
Zest
splitless inj 250 °C; column oven hold 50 °C 1 min, 10 °C/min, hold 240
°C for 10 min; helium carrier gas 30 cm/s. MS Conditions: EI, Full scan 40350 m/z. SPME: PDMS-DVB fiber, 65 mm, 30 s retracted headspace exposure.
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New Science Facility
•
•
•
•
•
•
•
Interdisciplinary
Investigative
Interactive
Innovative
Interconnected
Inviting
Integrity
 Green Team, Builder (Boldt),
Architect (Holabird & Root)
 LEED Gold target
 Building as Teacher
 Life-cycle costs
 Chemical Fume Hood
Reductions (energy,
operations, first costs)
Sept. 1, 2008 Opening
• 120,000 NASF, 26 teaching labs
• Informal gathering spaces
designed to extend learning
beyond the classroom and
laboratory.
 Green roof terrace
 Adjacent landscape
 Water management basins
65% decrease for intro/2nd year chemistry (2.5 linear ft/student std)
40% decrease across facility compared to initial design
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Future/On-going Work
• Continue development and implementation in first two
years of curriculum, particularly in the area of waste
management and safety
• Ramp up development and implementation in third year of
curriculum
 Piloting upper level p-chem lab (aqueous SEC
w/proteins & dextrans to calculate virial coefficients)
• LEED-NC Innovation Credit – Green Chemistry & Hood
Reduction
• Hire another Post-Doc (Enquire here!)
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