The Petroleum Refining Industry & Ultra Low Sulfur Fuels

1. The Petroleum Refining Industry & Ultra Low Sulfur Fuels • Fuel Value Chain

2. Section Overview • Refining Industry Overview • Crude Oil Quality • Refinery Types and Configuration • Key Refining Technologies • Product Blending and Qualities • India’s Transition to ULSFs – A Case Study • Discussion Exercise

3. Purpose of the Refinery Value Added Refined Oil Products • Converts crude oil to usable products • Adjusts yields to match product demand • Adjusts qualities to meet product specifications

4. Typical Refinery Products • Liquefied Petroleum Gas (LPG) • Naphtha (for petrochemical feed) • Motor Gasoline • Middle Distillates (Jet, Diesel, Heating Oil) • Fuel Oil • Lubricants, Waxes • Asphalt

5. Crude Oil Definitions 60 35 oAPI gravity 26 10

6. Typical Crude’s Yield Pattern

7. Crude Oil Characteristics – Sulfur 1 wt% = 10,000 ppm

8. Refinery Functions by Class

9. Refinery Configuration Overview

10. Refinery Characteristics

11. Schematic of Topping Refinery

12. Schematic of Hydroskimming Refinery

13. Reformer • Straight run naphtha is hydrotreated and split; heavy part (heavy naphtha) is catalytically processed and reformed to a highly aromatic stream called reformate • Advantages • High octane, low sulfur product • Produces hydrogen (to be used in other processes) • Disadvantage • Benzene/aromatics are toxic and are limited in clean fuel specifications

14. C5/C6 Isomerization • Straight chain paraffins are catalytically converted to their branched counterparts (isomers) • Advantages • 10 to 12 numbers octane gain • Reduction of toxic benzene • Disadvantage • Product has higher RVP

15. Diesel Hydrodesulfurization (HDS) Standard Diesel HDS • Sulfur is catalytically removed in the presence of hydrogen Deep HDS • Higher activity catalyst and catalyst volume • More hydrogen consumed • High severity, high temperature and pressure operation • Loss of diesel yield

16. Schematic of Conversion Refinery

17. Fluid Catalytic Cracking (FCC) • Using intense heat (over 500°C), low pressure and a powdered catalyst, the “cat cracker” converts heavy fractions into smaller gasoline molecules • Traditionally vacuum and coker gasoil feeds, also residual feed • Makes gasoline and some diesel out of gasoil • Diesel stream is high in sulfur, difficult to process and has poor cetane • Source of propylene for petrochemicals and can be designed for high propylene yield • Source of heavier olefins (C4/C5) for high quality gasoline and oxygenate (MTBE/ETBE)

18. Alkylation • Combines FCC olefins (propylenes/butylenes) with isobutane to produce a high octane stream called Alkylate • Catalyst is sulfuric or hydrofluoric acid (environmental concerns) • Alkylate is an excellent diluent for other gasoline blending components

19. Schematic of Complex Refinery

20. Hydrocracking • Similar and preferably lighter feeds than cat. cracking • More flexible • Can optionally maximize gasoline, jet or diesel • Uses a different catalyst, much greater pressure than FCC and uses a lot of hydrogen (can be sourced from reformer) • Products have minimal sulfur and high cetane (diesel) • Can be used as diesel upgrade process (i.e. upgrade low quality diesel from cracking)

21. Coking • Vacuum residue feed • Thermal cracking process (no catalyst involved) • Uses heat and moderate pressure to turn heavy residues to lighter products and coke (a hard coal-like substance used as an industrial fuel) • Lighter products are further processed downstream

22. Global Downstream Capacity % CDU

23. Blending • Blending is physical mixing of a number of refinery streams to a finished product • Options include: • Batch blending via manifolds into a tank • In-line blending via injection of proportionate components into a main stream • Additives/Improvers such as octane enhancers, detergents etc. are added either before or after blending

24. Gasoline Blending Components Quality

25. Gasoline Sulfur Management • Pretreatment of the FCC feed • FCC feed must be desulfurized to such level that resulting FCC naphtha can achieve the targeted sulfur spec • Pretreatment has some other benefits • Reduction of sulfur in all FCC products • Reduction of SOX and NOX emissions • Higher conversion, improved product yields • FCC naphtha gains can offset volume losses from distillation regulations • Disadvantages • Capital cost intensive • High hydrogen requirement

26. Distillate Blending Component Qualities

27. Diesel Desulfurization to ULSD • In summary, higher-severity operation requires • Higher process pressure • Higher hydrogen consumption • More active catalysts • Increasing catalyst volume (lowering LHSV) or accepting shorter catalyst life • And… • Increasing the purity of makeup hydrogen • Installing scrubbing to remove recycle gas (H2S) • Efficient reactor internals (distribution) • Increasing recycle-gas compressor capacity

28. Refining Processes for Producing ULSF

29. Conclusions • Crude oil quality and refinery configuration affecting fuel quality • Change in refinery configuration takes time • Product blending and additional of additives may be used to reach certain fuel quality • Change in fuel quality specification may affect yield of refinery