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Green Chemistry Across the CurriculumAt St. Olaf College

Bob HansonBCCE20, Indiana University, July 28, 2008

A Project Supported By the W.M. Keck Foundation

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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/

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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

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Wittig ReactionAtom Economy – 30.3%E-Factor – 58.5 : 1

Ring Closing Metathesis of Diethyl Diallylmalonate Atom Economy – 88.3% E-Factor – 25.5 : 1

Desired Product

Coproduct

Catalysts

Solvents

Other materials

GCA Graphical Output

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GCA graphics

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GCA graphics

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1st Year: Periodic Trends & Solubility

• Lab Manual includes “Green Connections” and new pre-/post-lab questions

• Replace heptane with ethyl acetate Volatile but with lesser hazards Option as a renewable resources Potentially less harmful degradation

products• Observed color differences

Chlorine: colorless, Bromine: orange, and Iodine: yellow

• Replace chromate anion with thiosulfate anion and eliminate barium cation

Heptane EtOAc

Cl2

Br2

I2

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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

9CuCl2·2H2O CuCl2

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1st Year Waste Management Introduction

Efforts:

• Students typically work in groups of two or three.

• 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.

Results (unquantified):

• Students are far more aware of waste issues.

• Students like taking some responsibility in this regard.

• Faculty become more aware of waste issues as well.

• Safety discussions and awareness arise spontaneously.

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2nd Year: Sonogashira Coupling Reaction

CH3

O

+ +Methanol, Water

KI KIO3

HCl, 25O C, 20 hours

I

CH3

O

Figure 1: Iodination of anisole

I

CH3

O

OH

CH3

CH3

CH

OH

CH3CH3

CH3

O

PEG, Triethylamine

PdCl2(PPh3)2, CuI, Heat

Figure 2: Sonogashira reaction with 2-methyl-3-butyn-2-ol

+

Palladium (5%) and copper (8%) catalyzed coupling of terminal alkynes with aryl halides

Uses product made in 1st lab of second semester,

PEG 200 solvent

Microwave 1 minute at 240 Watts

Moderate success recycling catalysts and PEG solvent

20+ experiments evaluated and 7 changed

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More 2nd Year Experimental Pursuits

• 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

EtO OEt

O OOO

EtO OEt

CH2 CH2

+

1 .0 m m ol

CH2

CH2

6 .5 % m o l G ru b b s C a ta lys t

.5 m L P E G , m ic ro w a v e h e a t in g

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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 BenchmarksLab Topics NFPA 3 Solvent Use Waste/Group

Glassware Calibration

Cleaning &Stats EtOH-KOH H2O (2 L) Neutralized - Sewer

CaOxalate Gravimetry & AAS HCl H2O (17.4 L) 1.04 L

low pH

Weak Acid Titrations NaOH H2O (4.5 L) Neutralized – Sewer

MockRobot IsosPt & Automat. H2SO4, NaOH H2O (2.1 L) Neutralized – Sewer

Easter Egg Grass

Food dyes UV/VIS - H2O (3 L) Neutralized – Sewer

Downsizing Fe-bipy, UV/VIS & Automation

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

Discovery HS C18 75 x 3 mm (3.5 m dp), 20 L 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.

-6.0

-4.0

-2.0

0.0

2.0

0 2 4 6 8 10

Minutes

Sig

na

l

Mixed Flow 0.5Original

dc

b

a

a

c

d

b

*

75% solvent reduction, 50% time reduction

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Analytical MetricsMetric 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 chemicalreaction.

Method Mass Efficiency MME

Comprehensive material use necessary for entire analysis method.

 

Energy per Analytical Unit EPAU

Energy use for entire analysis method relative to the mass of analyte in sample.

 

100 x Reagents ofFW

Analyte ofFW AAE

100 x )Solvents(g Reagents, ofFW

Analyte(g) of MassAME

100 x

(g) Prep Cleaning,

Solvents, Reagents, ofFW

(g) Analyte of MassMME

100 x (g) analyte of Mass

(kJ)energy method TotalEPAU

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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

water 1031 mL 511.5 mL

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

SAMPLING STRATEGIES

• Solid Phase Microextraction Peel / zest into vial PMDS-DVB fiber

• Supercritical CO2 extraction

Peel / zest into centrifuge tube Dry ice & water bath

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?.

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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 ZestHeadspace Samples of Citrus Zestings

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7 7.5 8 8.5 9 9.5 10 10.5 11

Minutes

Inte

nsity

Limonene

-Pinene-Pinene -Terpinene

GC Conditions: VF-5 capillary column (30 m x 0.25 mm x 0.23 m film), 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 40-350 m/z. SPME: PDMS-DVB fiber, 65 m, 30 s retracted headspace exposure.

Grapefruit

Lemon

Lime

Orange

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New Science Facility Sept. 1, 2008 Opening

• 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)

• 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 curriculumPiloting 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!)