1. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 1 Natural Oil Polythiols and Polyols– A Life Cycle Comparison Thomas A. Upshaw, William J. Fisher, Eric J. Netemeyer Chevron Phillips Chemical Co., LP ACS Green Chemistry & Engineering Conference June 25, 2008

2. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 2 Outline Study objectives Modeling tools and information sources Modeled systems and assumptions –Mercaptanized soybean oil (MSO) –Petrochemical (flexible polyether) polyol –Castor oil –Soy-based polyol LCA Methodology Impact category results Conclusions

3. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 3 Soy Polythiol – MSO (Polymercaptan 358)

4. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 4 Objectives Develop a soy polythiol life cycle inventory (LCI) platform for product life cycle assessment through the product manufacturing stage (cradle-to-customer) Compare life cycle environmental impacts using updated LCI data for vegetable oil and petrochemical (polyether) polyols to quantify the benefit of using a renewable oil as raw material Future: assess process changes and new process technology for reduced environmental impact

5. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 5 Life Cycle Modeling Tools SimaPro 7.0 software, using SimaPro 7.0 database and U.S. LCI database BEES (Building for Environmental and Economic Sustainability) impact model –NIST sponsored & EPA supported –Methodology used by USDA BioPreferred program –Conducted in accordance with ISO 14040:1997(E) standard TRACI (Tool for the Reduction and Assessment of Chemical and other Environmental Impacts) – EPA life cycle impact assessment method

6. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 6 Data Sources Soybean data –Agriculture data from U.S. LCI database (NREL) –Processing data from NREL LCA report on biodiesel 1998 Soy Polythiol – Chevron Phillips Chemical Co. –Process inputs estimated from commercial production facility, assuming conventional H 2 S process technology Soy-based Polyol –2004 manufacturer-specific BEES input streams Petroleum (flexible polyether) polyol –U.S. LCI database Castor oil –Purdue University article and various internet sources –Incomplete process data supplemented by analogous data on other seed oils in U.S. LCI database

7. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 7 Air emissions Water effluents Waste LCA System Boundaries Product Polyol or Polythiol Manufacturing Stage Transportation to the customer Vegetable oil production & refining Agricultural production Process energy Materials production, transport Crop oil Feedstocks Air emissions Water effluents Waste Raw materials production Petroleum Feedstocks Process energy Materials production, transport Air emissions Energy, materials LCI INPUTS LCI OUTPUTS Upstream Production of Raw Materials

8. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 8 MSO Polythiol Assumptions Commercial process design based on known reaction conditions from trial runs at Philtex plant (Borger TX): –UV reactor –Estimated stoichiometric excess of H 2 S –Stripping and recycle of H 2 S –Known reaction conditions from lab/pilot work Conventional energy sources (nat. gas)

9. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 9 Petrochemical Polyol Assumptions Consolidated proprietary information for 5 North American plants, 2003-5 data Polyether polyol, glycerin-initiated, 3500 mol wt (on average) KOH-catalyzed, solvent, water-washed 7.6 to 1 wt ratio PO/EO

10. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 10 Castor Oil Assumptions Complete data were not available –Significant uncertainty, need better data –Analogous LCI data for other seed oils were used for some LCI inputs (fertilizer usage, energy) Since growth and modernization of castor agriculture has been occurring, mechanized production and irrigation were assumed for 75% of production 8200 mile transport from India to U.S. market assumed before distribution in the U.S.

11. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 11 Soybean Oil Polyol Assumptions 2004 manufacturer-specific BEES data Produced by simple air oxidation of soybean oil No further refinement, purification or derivatization Soy agricultural model Not sure if waste/off-grade is taken into account 1000 mile transport to customer This probably represents the most environmentally benign vegetable oil polyol process possible; a benchmark for comparison of other renewable products

12. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 12 LCA Methodology Life Cycle Inventory – quantified listing of inflows and outflows per 1000 lbs of product (built in SimaPro 7.0) Converted to equivalent units per 1000 lbs and combined into LCIA impact categories (BEES impact model) Normalized to unitless dimensions corresponding to fraction of total U.S. impact per year per capita Overall BEES environmental score: sum of normalized impacts weighted by importance –2006 BEES Stakeholder Panel

13. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 13 LCA Methodology Life Cycle Inventory – quantified listing of inflows and outflows per 1000 lbs of product (built in SimaPro 7.0) Converted to equivalent units per 1000 lbs and combined into LCIA impact categories (BEES) Normalized to unitless dimensions corresponding to fraction of total U.S. impact per year per capita Overall BEES environmental score: sum of normalized impacts weighted by importance –2006 BEES Stakeholder Panel

14. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 14 Impact Comparison (Cradle-to-customer)

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19. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 19 Conclusions LCA is a valuable tool to help assess environmental impact of products and processes at a more detailed level. –more standards and complete, up-to-date publicly available data are needed to improve general utility and consistency. Global warming potential and fossil fuel use of MSO and vegetable oil polyols are significantly lower than for the petroleum-based polyether polyol due to the crop oil raw material source. Agricultural practices, oil extraction methods and shipping also have a significant impact. Future use of renewable energy for MSO production would result in a significant reduction in global warming potential (GWP) and fossil fuel consumption.

20. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 20 Conclusions Next generation process technology currently under development may significantly reduce energy consumption, GWP and SOx generation (i.e., criteria air pollutant and acidification impacts). Castor oil was comparable to MSO overall (BEES), but better life cycle input data for castor oil is needed –Castor suffered from the use of the solvent extraction process and (probably high) estimated water and fertilizer use (vs MSO) and eutrophication and smog potential were high vs soybean oil polyol. A best case soy oil based polyol showed less than 16% the overall impact relative to a petroleum-based polyol –But: best case (simple) process does not necessarily give a product with acceptable end-use properties

21. 6/25/2008 ACS Green Chemistry and Engineering Conference 2008 21 Acknowledgements American Chemical Society Jim Pollack, OmniTech International Ltd. Anne Landfield Greig, Four Elements Consulting, LLC Chevron Phillips Chemical Company, LP