ENVIRONMENTAL COMPARISON OF MICHELIN TWEEL™ AND PNEUMATIC TIRE USING LIFE CYCLE ANALYSIS A Thesis Presented to The Academic Faculty by Austin Cobert In Partial Fulfillment of the Requirements for the Degree Master’s of Science in the School of Mechanical Engineering Georgia Institute of Technology December 2009 Environmental Comparison of Michelin Tweel™ and Pneumatic Tire Using Life Cycle Analysis Approved By: Dr. Bert Bras, Advisor Mechanical Engineering Georgia Institute of Technology Dr. Jonathan Colton Mechanical Engineering Georgia Institute of Technology Dr. John Muzzy Chemical and Biological Engineering Georgia Institute of Technology Date Approved: July 21, 2009 i Table of Contents LIST OF TABLES .................................................................................................................................................. IV LIST OF FIGURES ................................................................................................................................................ VI CHAPTER 1. INTRODUCTION .............................................................................................................................. 1 1.1 BACKGROUND AND MOTIVATION ................................................................................................................... 1 1.2 THE PROBLEM ............................................................................................................................................ 2 1.2.1 Michelin’s Tweel™ ................................................................................................................................. 2 1.2.2 Rolling Resistance .................................................................................................................................. 4 1.2.3 Product design issues ............................................................................................................................. 5 1.2.4 Baseline comparison tire ....................................................................................................................... 5 1.2.5 Geographical Boundary ......................................................................................................................... 6 CHAPTER 2. RESEARCH BACKGROUND ............................................................................................................... 8 2.1 INTRODUCTION TO LIFE CYCLE ANALYSIS (LCA) .................................................................................................. 8 2.2 SIMAPRO ................................................................................................................................................ 10 2.3 TIRE LCA LITERATURE REVIEW ..................................................................................................................... 11 2.3.1 Life Cycle Analyses ............................................................................................................................... 11 2.3.2 Raw materials ...................................................................................................................................... 16 2.3.3 Gasoline emissions............................................................................................................................... 16 2.3.4 End of life ............................................................................................................................................. 18 2.4 LITERATURE REVIEW SUMMARY ................................................................................................................... 20 CHAPTER 3. GOAL AND SCOPE DEFINITION ....................................................................................................... 21 3.1 GOALS OF THE STUDY ................................................................................................................................. 21 3.2 SCOPE OF THE INVENTORY PHASE ................................................................................................................. 22 3.3 SCOPE OF THE IMPACT ASSESSMENT ............................................................................................................. 26 3.3.1 ISO Guidelines ...................................................................................................................................... 26 3.3.2 EcoIndicator99 ..................................................................................................................................... 28 3.3.3 EDIP ...................................................................................................................................................... 32 CHAPTER 4. INVENTORY ANALYSIS ................................................................................................................... 34 4.1 PRODUCTION OF RAW MATERIALS ................................................................................................................ 34 4.1.1 Natural Rubber .................................................................................................................................... 36 4.1.2 Synthetic Rubber ................................................................................................................................. 39 4.1.3 Carbon Black ........................................................................................................................................ 40 4.1.4 Silica ..................................................................................................................................................... 42 4.1.5 Sulfur .................................................................................................................................................... 44 4.1.6 Zinc Oxide ............................................................................................................................................ 45 4.1.7 Aromatic Oil ......................................................................................................................................... 47 4.1.8 Stearic Acid .......................................................................................................................................... 49 4.1.9 Coated Wires ....................................................................................................................................... 50 4.1.10 Textile .............................................................................................................................................. 51 4.1.11 Steel ................................................................................................................................................ 52 4.1.12 Polyurethane ................................................................................................................................... 53 4.2 PRODUCTION OF TIRES ............................................................................................................................... 55 4.2.1 Manufacturing of P205/45R17 tire ...................................................................................................... 55 4.2.2 Manufacturing of Michelin Tweel™ ..................................................................................................... 58 4.2.3 Heating and Pressurizing Energy ......................................................................................................... 60 ii 4.3 DISTRIBUTION .......................................................................................................................................... 62 4.4 USE PHASE .............................................................................................................................................. 63 4.4.1 Fuel Consumption ................................................................................................................................ 63 4.4.2 Gasoline Emissions ............................................................................................................................... 69 4.4.3 Tire Debris ............................................................................................................................................ 70 4.4.4 Noise .................................................................................................................................................... 72 4.5 END OF LIFE ............................................................................................................................................. 73 4.5.1 Processing Routes ................................................................................................................................ 73 4.5.2 Tire Recycling ....................................................................................................................................... 76 4.5.3 Tweel™ Recycling ................................................................................................................................. 78 4.5.4 Rubber Derived Fuel ............................................................................................................................ 81 4.5.5 Landfilling ............................................................................................................................................. 84 4.5.6 Retreading ..........................................................................................................................................