Presentation on theme: "1 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."— Presentation transcript:
1 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
2 Goals of Green Chemistry at St. Olaf Alter the chemistry curriculum 1 st year, 2 nd year, 3 rd year Design a science facility that reflects this effort LEED Gold Building www.stolaf.edu/sciencecomplex/
3 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
4 Wittig Reaction Atom 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
7 1 st 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 Cl 2 Br 2 I2I2
8 1 st 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
10 1 st 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.
11 2 nd Year: Sonogashira Coupling Reaction Palladium (5%) and copper (8%) catalyzed coupling of terminal alkynes with aryl halides Uses product made in 1 st 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
12 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
13 3 rd 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.
14 Analytical Lab Benchmarks LabTopics NFPA 3 Solvent UseWaste/Group Glassware Calibration Cleaning &StatsEtOH-KOHH 2 O (2 L)Neutralized - Sewer CaOxalateGravimetry & AASHClH 2 O (17.4 L)1.04 L low pH Weak AcidTitrationsNaOHH 2 O (4.5 L)Neutralized – Sewer MockRobotIsosPt & Automat.H 2 SO 4, NaOHH 2 O (2.1 L)Neutralized – Sewer Easter Egg Grass Food dyes UV/VIS-H 2 O (3 L)Neutralized – Sewer DownsizingFe-bipy, UV/VIS & Automation HCl, NH 2 OHHCl H 2 O (3 L)1.31 L Metals Broken Pill Machine Metals & AASHCl, HNO 3, Bronze alloys H 2 O (4 L)1.18 L, low pH Metals Mysterious Death Chromatogr. & HPLC MeOH, Acetic Acid, Et 3 N Mobile Phase Volume 0.32 L low pH
15 3 rd 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. 75% solvent reduction, 50% time reduction
16 Analytical Metrics Metric NameMeasures efficiency ofFormula 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. 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.
17 3 rd Year: Volumetric Reduction - Downsizing Iron determination via bipyridine complexation Automation (robotic) vs. human (volumetric) method. Challenge – maintain # sig figs and solution handling. Starting MaterialsOriginal Amount Modified Amount iron wire25 mg10 mg HCl, conc.10 mL8 mL HCl, 0.2M35 mL17.5 mL hydroxylamine hydrochloride, 10% 35 mL17.5 mL Na acetate, 2 M14 mL7 mL bipyridine, 0.1%70 mL35 mL water1031 mL511.5 mL AAE79.87%79.87% AME1.67x10 -5 %3.34x10 -5 % MME4.77x10 -6 %9.53x10 -6 %
18 3 rd Year: New Citrus Oil Analysis SAMPLING STRATEGIES Solid Phase Microextraction Peel / zest into vial PMDS-DVB fiber Supercritical CO 2 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?.
19 Physical Properties of CO 2 CO 2 (l) Good solvent for small, nonpolar molecules: hydrocarbons < 20 carbon atoms & some aldehydes, esters, and ketones
20 Headspace Samples of Citrus Zest 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
21 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/2 nd year chemistry (2.5 linear ft/student std) 40% decrease across facility compared to initial design
22 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!)