Catalytic Applications for Enhanced

Production of Transportation Fuels

Soni O. Oyekan Reforming & Isom Technologist

Marathon Oil 2009 NOBCChE Percy L. Julian

Lecture April 14, 2009

Lecture Outline

• Introduction and Acknowledgement • Overview of Oil Refining Processes • Hydroprocessing and Hydrogen • Catalytic Reforming Process • Staged Platinum/Rhenium Catalysts • Two Stage Reduction of Platinum Catalysts • Summary

Introduction & Acknowledgements• Dr. Percy L. Julian’s pioneering work led to foam,

paint, hormones and cortisone • ExxonMobil and George Swan for work leading to

US Patent 4,436,612 and 8 other patents in late 1970s in Baton Rouge, LA

• Engelhard for oil refining catalyst work in the 1980s in Edison, NJ

• Marathon for opportunities to apply my expertise to oil refining processes in the past 10 years and support of my professional organization activities

• Catalytic studies were conducted between 1977 and 1984 and the ideas have been incorporated into hundreds of catalytic reformers

Overview of Oil Refining Processes

CRUDE OIL

GASOLINE

DIESEL

ASPHALT

Oil Refiners 6-3-2-1 Crack Spread▪ 6-3-2-1 Crude Oil Crack Spread = {(Revenue from 3 barrels of gasoline + 2 barrels of diesel + 1 barrel of asphalt) – (Cost of 6 barrels of crude oil)}/6 ▪ 3-2-1 Crude Oil Crack Spreads are based on gasoline & diesel only

!!

A Simplified Refinery Flow Diagram

NHTCatalytic Reformer

Gas Recovery

Sulfur Plant

FCCU

H/C

Coker Unit

Gasoline Blending

DHT Distillate Fuels

Atm Unit

Vac Unit

CokeAsphalt

Diesel Fuels

Gasoline

Sulfur

LPG, C3= Hydrogen

Crude Oil

Marathon Garyville CCR Platformer

Hydroprocessing and Hydrogen

A Typical Hydrotreater Flow Diagram

Hydroprocessing Reactions✓ Sulfur, Nitrogen and Oxygenates Removal

– Hydrodesulfurization is the major reaction in hydroprocessing – Hydrodenitrogenation is essential in FCC and Hydrocracker feed

pre-treatment – Hydrodeoxygenation is not common, except in the processing of

synthetic (coal, shale) oils and with rerun streams (MTBE, EtOH)

✓ Olefins and Aromatics Saturation – Olefin saturation for product stability and color – Aromatic saturation for solvents, transportation fuels production and

FCC feed pretreatment.

✓ Hydrocracking like FCC is used for conversion of gas oils to gasoline, diesel, heating oil and jet fuel

✓ Hydroprocessing reactions consume significant amounts of hydrogen

Refinery Process H2 Consumption

LSR H/TNHTDHT LPGO H/TDHT HPH/C

H2 consumption is a function of: ▪ Process type ▪ Feed boiling range ▪ Composition ▪ Sulfur ▪ Nitrogen ▪ Metals ▪ Oxygenates ▪ Unit pressure ▪ Unit temperature !

Avg. H2 price ~ $4/MSCF

H2 consumption for a 70 MBPD Hydrocracker ~ $220 MM/yr

Catalytic Reforming Processes

Catalytic Naphtha Reforming Basics

• Upgrade the octane of a naphtha feed to produce – High octane gasoline blending component – Hydrogen – Aromatics

• Platinum reforming catalysts – Dual functionality

• Hydrogenation/dehydrogenation • Acidic/isomerization

• Pt/Al2O3/Cl, Pt/Re/Al2O3/Cl, Pt/Sn/Al2O3/Cl

Catalytic Naphtha Reforming Basics• Hydrotreated Naphtha Feed

– Sulfur < 0.3 wppm – Nitrogen < 0.2 wppm – Metals < 10 ppb – Paraffins, naphthenes and aromatics – Carbon range of C6 to C11

• Typical Process Conditions – 35 to 300 psig, 900 to 1000 F, LHSV 1.0 to 4.0, – H2/HC molar ratio of 1.5 to 6

• Principal Reactions – Naphthenes dehydrogenation – Naphthenes isomerization – Paraffin dehydrocyclization – Paraffin hydrocracking – Hydrodealkylation of aromatics – Paraffin hydogenolysis

Catalytic Reforming Reactions

Reference: UOP Platforming

Paraffin Dehydrocyclization

4H2

Adapted from G. A Mills, H. Heinemann, T. H. Milliken and A. G. Oblad, Ind. Eng. Chem. 45, 134 (1953)

C-C-C-C-C-C-C

+C2H5

C2H5

CH3

Coke

M/A

M/A

AM

A

M

CH3

M metal sites A acid site

C2H5

Heptane, 0 RON

Toluene, 120 RON

Semi Regen & CCR Reformers

Staged Platinum/Rhenium Catalysts

Platinum/Rhenium Catalysis• First assignment in Exxon was to determine the

mode of promotion of Rhenium in Pt/Re catalysts • Fundamental Pt/Re catalysis and naphtha reforming

process • Cleaned a 4 reactor Hydrotreating catalyst sulfiding

unit for “clean sulfur” platinum/rhenium naphtha reforming studies

• Isopropyl alcohol used in cleaning the unit in 8 weeks!

• 4 reactors shared a common heater • Developed close working relationship with other

Exxon researchers and surface characterization specialists

Catalyst Test Program

• Assess rhenium effects at various rhenium concentrations • Catalysts with varying rhenium content on a constant Pt

catalyst – 0.3 %Pt/0.3 %Re, O.3 % Pt/0.6 % Re, relative Re/Pt ratios – 0.3 % Pt/Al2O3, 0.3 % Re/Al2O3,

• Activate catalysts and characterize for start of run (SOR) coke, chloride and sulfur

• Conduct test runs in a common sand bath heater with four separate reactor and product separation systems

• Use the same operating conditions and naphtha feed – 935 F, 200 psig, 5000 SCF/B H2/HC

• Obtain C5+, H2 and light gases (C1 – C4) yields • Characterize spent catalysts for coke, chloride and sulfur • Conduct model compound reforming studies with Heptane

and methyl cyclopentane.

Isothermal Unit Data for Pt/Re Catalysts

Rel Re

C5+, vol. %

Catalyst Activity

EOR Coke

EOR Sulfur

1.0 70.8 85.0 8.4 0.03

1.5 71.2 83.0 9.2 0.05

2.0 70.7 81.0 8.5 0.07

2.7 70.3 95.0 7.3 0.12

3.9 69.9 109.0 7.3 0.14

Test Summary ▪ Lower coke make with higher Rhenium ▪ Lower C5+ and H2 yields ▪ Higher sulfur retention ▪ Higher activities with Rhenium content ▪ Different H/C ratios for the coke ▪ Shift in aromatics to BTX !!

Feed: P, 69.1 vol. %; N + A, 30.9, vol. % !Process Conditions; 935 F, 200 psig, H2 rate of 5000 SCF/B !Rel. Re = wt % Re/wt % Pt in catalyst

Commercial Simulation Unit Data

Catalyst Cat A Cat B DeltaActivity No. 72.0 96.0 +24

C5+, vol. %

72.0 69.3 -2.7

Cat A 0.3 % Pt/0.3 % Re Cat B 0.3 % Pt/0.6 % Re !Cat B = Rel 2 !Feed: Light Arabian Naphtha !Process Conditions: 950 F, 175 psig, 3000 SCF/B, 102 RON !Test Summary • 2.7 vol. % lower C5+ for B • Lower H2 yield • Higher C1 to C4 gas • Lower coke make

Combination/Staged Catalyst DataCatalyst Catalyst A

0.3 Pt/0.3 Re (A)Catalyst A & Catalyst B

Delta

Activity 77.0 92.0 +15

H 2.26 2.31 +0.05

C1 – C4, wt. % 18.82 17.86 -0.96

C5+ yield, vol. % 74.30 75.50 +1.2

• Production gains for C5+ (gasoline) and H2

• $5+ MM dollars a year for a 40 MBPD Platformer • Introduced staged Pt/Re catalyst systems based on Rel. Re • Combination Pt/Re catalyst systems are now used worldwide • Determined that rhenium promoted platinum catalysis via minimization of steric hindrance for intermediate compounds • Studies led to KX-160, US Patent 4,436,612 and 8 other patents

Paraffin Dehydrocyclization

4H2

Rhenium modifies sterically hindered intermediate compounds

C-C-C-C-C-C-C-C-C

+C4H9

C4H9

C4H9

C3H7

COKE

M/A M

AM

A

M

, X

M metal sites A acid site

Where X is CH3, or C2H5

Two Stage Reduction of Platinum Catalysts

Reforming Catalyst Reactivation

• Burn coke off spent catalyst – CXHy + (x+y/4) O2 xCO2 + (y/2)H20 !

• Re-disperse agglomerated platinum and promoter metal sites

• Reduce platinum and promoter – Manage water evolution – Manage reactions with hydrocarbons – Optimize reduction of platinum and promoter – Manage catalyst chloride loss

• Sulfide Pt/Re catalysts to temper hyperactive sites

Platinum & Rhenium Reduction

Past work had shown the following: !• Platinum is reduced at 600 F • Rhenium reduction is not facile and requires temperatures > 1100 F !Scelza et. al: TPR work shown here !Hypothesis: Use reduced Platinum to catalyze the reduction of rhenium oxide or a promoter metal oxide

PtO2 + 2H2 Pt + 2H2O !Re2O7 + 7H2 2Re + 7H2O

Two Stage Reduction Enhances Gasoline and H2 Yields

Standard Red.

2 Stage Red.

Delta

H2, wt. % 2.44 2.52 +0.08

C1, wt. % 1.27 1.18 -0.09

C2, wt. % 1.81 1.65 -0.16

C3+C4, wt. %

6.87 5.63 -1.24

C5+, vol. % 82.54 83.77 +1.23

Novel activation Procedure US Patent 4,539,307 !(1)Reduction at a temp between 600 F and 750 F (2)Nitrogen purge to remove water (3)Another reduction at temp between 900 F and 1000 F !!Feed: P/N/A 46.9/37.0/16.1 Process conditions: WHSV 4 200 psig, H2/HC 3, 98 RON

Summary

• Pt/Re catalysis work by Soni Oyekan and George Swan led to increased production of hydrogen and gasoline blending components for oil refiners

• The Pt/Re studies led to use of terms such as equi-molar, balanced, unbalanced and skewed by technology providers and oil refiners

• Two stage reduction of platinum containing catalysts is now used worldwide in over 120 high performance catalytic reformers

• Platinum catalyst inventions have enhanced economic benefits for oil refiners due to increased production of hydrogen, gasoline, diesel and jet fuel

• My catalytic reforming process contributions have improved understanding of the impact of feed sulfur in naphtha reforming over platinum containing catalysts !

Thank You For Your Time 2005 Marathon Garyville Refinery

Sulfur Studies of Platinum Catalysts

Bimetallic Catalysts Are Sulfur Sensitive

• Gasoline blending component and H2 yields are reduced drastically

• Catalyst activity is significantly lowered • Process cycles are shortened for feed sulfur > 0.5 wppm • Sulfur negatively impacts productivity over Pt/Sn catalysts in

CCR reformers • Worse for High rhenium Pt/Re catalysts in semi-regenerative

reformers • Liquid and vapor phase sulfur guard technologies

Platformer Feed Sulfur History

Feed Sulfur, wppm

Semi Regen & Cyclic: 1948 Pt Catalysts

10 to 20 wppm SR and CCR: 1967 Pt/Re

1970 Pt/Sn< 0.5 wppm

0.1 wppm

1998: CCR & Cyclic Reduce NH4

Salting Rates

Platforming Technology Progression, years

1984 Skewed Pt/Re

< 0.2 wppm

Low Feed Sulfur Correlation

▪ Establish a better understanding of feed sulfur in Reformers !!• A 4-year pilot plant studies led to feed sulfur correlations for the refining industry !• Correlations developed for balanced and skewed Pt/Re catalysts !!!!!!!!

AXENS OCTANIZER REFORMER

Marathon Garyville Refinery in 2005

Marathon Garyville Hydrocracker in 2009

Coker Drums for Increased Profitability

Marathon Garyville Refinery in 2009

Catalytic Reforming Reactor !!!Radial Reactor with Scallops and center pipe or center screen

Oil Sands Processing for Energy