Developing Coal Tar/ Petroleum Pitches

1. Developing Coal Tar/Petroleum Pitches Melvin D. Kiser - Marathon Ashland Petroleum Company Robert H. Wombles - Koppers Industries, Inc.

2. Discussion Topics • Introduction • Coal Tar and Petroleum Supplies • Coal Tar and Petroleum Pitch Manufacturing • Coal Tar/Petroleum Pitch Product Development

3. Introduction • First Coal Chemical Recovery Ovens Installed in the US in 1893 • By 1915, By-product Ovens Accounted for 97% of Metallurgical Coke Produced in US • Since Then Coal Tar Pitch Has Been Binder of Choice for Aluminum, Commercial Carbon, and Graphite Industries

4. Introduction, cont. • Late 1980’s and 1990’s Closing of US Coke Ovens Accelerated Due to Economic and Environmental Pressures • Coke Oven Closures Resulted in Concern for Supply of Coal Tar Pitch and Strategies to Deal with Anticipated Shortage Being Sought

5. Introduction, cont. • Oil Industry As It Is known Today Began with the Discovery of Crude Oil in Ontario and Western Pennsylvania in 1850’s • Refineries Have Concentrated on Producing Transportation and Heating Fuel with Little Interest in Heavy Products Such as Pitch

6. Introduction, cont. • During 1960’s Some Refineries Began to Show Interest in Producing Petroleum Pitch and Some Were Successful in Producing High Aromaticity and Specific Gravity Pitches • Evaluation of These Pitches As Binder Pitches Has Given Mixed Results with Most Often Reported Shortcoming Being Higher Than Desired Carbon Consumption

7. Introduction, cont. • Future Use of Petroleum Pitches Will Probably Not Be Driven By Economics But Raw Material Availability and Regulations

8. Introduction, cont. • Strategies to Deal with Shrinking Coal Tar Supply • Importing Coal Tar • Importing Coal Tar Pitch • Developing Processes to Improve Pitch Yield and Upgrade Non-conventional Coal Tars • Using Petroleum Pitches to Supplement Coal Tar Pitch Supply

9. Coal Tar and Petroleum Supplies

10. North American coal tar supplies to fall by 18% by 2005

11. North American Binder Pitch Demand

12. Petroleum Supplies • Yearly Supply of Coal Tar Is 6 MM Barrels (Less Than the Volume of Crude Oil Processed Each Day) • Yearly Supply of Potential Pitch Feedstocks Is 326 MM Barrels • Assuming Only 10% Available and Acceptable Results in Petroleum Pitch Yearly Feedstock Supply of 32.6 MM Barrels

13. Coal Tar and Petroleum Pitch Manufacturing

14. Coke Flow Diagram One Metric Ton of Coal Yields: Blast Furnace Coke: 600 - 700 kg Coke Breeze: 50 - 100 kg 70% Solids Coke Oven 30% Gas + Liquid Tar 35 - 50 L Ammonium Sulphate 10 - 15 kg Ammonia Liquor 60 - 145 L Light Oil 10 - 15 L Coke Oven Gas 300 - 360 m3

15. PRODUCTION OF COAL TAR PITCH Distillate Stream Steam Flushing Liquor Heater 200°F Distillation Tower Tar Feed Tank 2000°F gas Coal Tar Steam Decanter Sludge Pitch Decanter Coke Oven Liquor

16. Coke Oven Thermal Cracking CH2 CH2 CH2 CH3 1,095°C No catalyst + C4

17. Petroleum Pitch Manufacturing • Many Petroleum Products Referred to as Pitch (Causes Confusion Among Non-Refiners) • Different Pitches Share Only Commonality of Being Black Solids at Room Temperature • Characteristics of Petroleum Pitches Determined by Feedstock and Processing to Produce • Reaction Step Used to Generate or Concentrate the High Molecular Weight Molecules

18. Common Petroleum Pitch Producing Processes • Solvent Deasphalting • Precipitation of High Molecular Weight and Aromaticity Molecules • Specific Gravity of 1.0 g/cc • Contains Non-aromatic Molecules and High Metals Levels • Oxidation • Little Incorporation of Oxygen in Product • Oxygen Generates Free Radicals Which Cause Polymerization • Products Typically Have Low Coking Values and High Viscosities • Thermal Processing • Thermal Processing Temperatures of 300°C to 480°C • Produces High Specific Gravity and Aromaticity Product

19. Crude Oil to Petroleum Pitch Crude Oil Desalting & Dewatering Atmospheric Distillation Other Components Pitch Feed Preparation Fluid Catalytic Cracking Vacuum Distillation Primary Reaction Processes Secondary Reaction Processes Liquid Storage Solidification 1. Feed preparation can consist of any one or a combination of blending, distillation, desulfurization and solids removal. 2. Primary reaction processes may consist of any one or a combination of solvent deasphalting, thermal processing, oxidation or catalytic reactions. 3. Secondary reaction processes may include distillation, desulfurization, oxidation or thermal soaking.

20. Petroleum Refinery Catalytic Cracking CH2 CH2 CH2 CH3 CH3 540°C Cracking catalyst + C3

21. Coal Tar/Petroleum Pitch • Aluminum Industry Experience with 100% Petroleum Pitch Not Acceptable • Suitable Petroleum Materials Must Be Identified (100 Materials Evaluated) • Commercial Testing Began in 1994 • Small Performance Disadvantages Identified • Efforts to Improve Performance Successful • Most Economical Solution with Potential Plentiful Supply

22. Properties of Typical Pitches

23. Conclusions • Supply of Coal Tar in North America Is Declining Because of Environmental and Financial Pressures • One Strategy for Dealing with Declining Coal Tar Supply Is Coal Tar/Petroleum Pitch • Because the Refining Industry Uses Pitch to Describe a Number of Products with Varying Properties, Care Must Be Taken in Selecting the Petroleum Component of a Coal Tar/Petroleum Pitch

24. Conclusions, cont. • Coal Tar/Petroleum Pitch Is the Preferred Long Range Solution to the Tar Shortage Because: 1) It Is Economical, 2) Its Performance Has Been Proven, 3) Potential Feedstock Supply Is Plentiful and 4) Product Quality Is Consistent • Coal Tar/Petroleum Pitches with Significantly Reduced PNA Contents Have Been Developed • Coal Tar/Petroleum Pitch Product Development Efforts Will Continue