Antiknock Quality Problem
Low Octane Rating of Gasoline vs. Demand
Noise and Loss in Energy
Solutions to the Problem
Addition of High O.N. Compounds
Tetra Ethyl Lead (TEL)
Oxygenates (MTBE & TAME)
Alteration of the Chemical Composition
Thermal Reforming
Catalytic Reforming
Catalytic vs. Thermal Reforming
Catalytic
Higher Octane Number: 90 to 100
Lower Temp. ≈ 500°C
Higher H2 Production
Trace Olefins Contents
Pt/Alumina Catalyst
Thermal
Lower Octane Number: 65 to 80
Higher Temp. ≈ 600°C
Lower H2 Production
High Olefins Contents
Without Catalyst
Feed Treatment By Hydrogen
Removal of:
Nitrogen as Ammonia
Sulfur as H2S
Oxygen as Water
Saturation of Olefins Present in Special Feeds
The Catalytic Reforming Process
Aims of Process:
Max. ON ………… By Conversion
Min. Capacity to form Gums …… By Saturation
Production of Hydrogen for other Processes
Production of BTX for the Petrochemical Industry
Feed To Catalytic Reforming
Sources of Feed:
HSR Naphtha (90°C to 160°C)
Not LSR ……………Why?
Not Heavier ……………Why?
Visbreaking & Coking Gasolines
Hydrocracking
Two Typical Feeds Composition
Fixed-Bed Technology
Reactor Configuration
Total Change to The Feed
Catalytic Reforming Product
Relation between ON and Reformate Yield
Catalytic Reforming
Under Supervision of
Dr. El-Shazly Salem
Eng. Hossam Hosny Mohamed El-Ghareeb
Eng. Mohamed Mohamed Refaat Ibrahiem
Eng. Mahmoud Ibrahiem Mohamed Mohamed
Eng. Mustafa Mahmoud Abd-ALLAH
Eng. Mohamed Saied Abu Basha
Reformate Composition
Reformate Composition
Reformate Composition
Catalytic Reforming Technology
Fixed-Bed Technology
Non-Regenerative …… Replacement (months)
Semi-Regenerative …… Shutdown (years)
Regenerative (Cyclic) …… Switching (days)
Moving-Bed Technology
Fluid-Bed Technology
Fixed-Bed Technology
Type of Reactors
Fixed-Bed Technology
Temperature Variation in Reactors
Fixed-Bed Technology
Variation in Effluent Composition
Fixed-Bed Technology
Non-Regenerative Technique
The First Technique to be used (used by UOP)
High Pressures (above 35 bars)
Catalyst Life of 10 months
Catalyst is replaced & Regenerated off-site
Low Severity & High Pressures…… led to switching to the (semi-regenerative) Technique
Fixed-Bed Technology
Semi-Regenerative (SR) Technique
Catalyst life of 7-10 years
Regeneration causes the Total Shutdown of System
Regeneration is carried out inside the system
Fixed-Bed Technology
Semi-Regenerative (SR) Technique
Fixed-Bed Technology
Regenerative (Cyclic) Technique
Shutting Down is avoided by an Extra Reactor
Complex Valve System, Reactor Central Position
Modes of Run: (Cyclic) or (Swing)
Catalyst Life of about 5-15 days
Higher ON for the same Yield, and vice versa
5 Units higher ON than Semi-Regenerative
“Ultraforming” and EXXON “Powerforming”
Fixed-Bed Technology
EXXON Powerformer
Moving-Bed Technology
Moving-Bed Advantages:
Higher ON even from difficult feeds
All-year run, producing the H2 that refineries need
Catalysts are less stable over time but more selective making it possible to improve yields
Lower recycle rates, which improve yields and reduce operating costs
Lower operating pressures which favors reformate yields and hydrogen production
Moving-Bed Technology
Reactor Configuration:
“One on the top of the other”, which is carried out by UOP
“Side by Side”, which is carried out by IFP
UOP regeneration is “Continuous”
IFP can be either “Continuous” or “Batch”
Moving-Bed Technology
UOP: “CCR Platformer®”
Moving-Bed Technology
IFP: “Octanizer®”
Fluid-Bed Technology
(Molybdena/Alumina) Catalyst is used
Excellent temperature control prevents over- & under-reforming
More selectivity for optimum yield of the desired product
Reactions & Thermodynamics
Dehydrogenation of Naphthenes
Isomerization of Paraffins and Naphthenes
Dehydrocyclization of Paraffins
Hydrocracking and Dealkylation
Dehydrogenation of Naphthenes
Main Reaction in producing Aromatics
Very Rapid, goes to Completion,& Highly Endothermic
Favored by High Temperatures & Low Pressures
Naphthenes is the most desirable component for the production of H2 & the Speed of Reaction
Isomerization
Isomerization of Alkylcyclopentane to Alkylcyclohexane before converting to Aromatics
Possible Paraffin Formation, for ring rearrangement
Thermodynamic Equilibrium favors isomer formation, which increases the ON
Dehyrocyclization of Paraffins
The most difficult Reaction to promote
Consists of molecular rearrangement of P to N
High M.wt Paraffins are easier to Cyclize & Crack
Favored by Low Pressures & High Temperatures
Hydrocracking of Paraffins
Not Desirable as it consumes hydrogen and reduces liquid product
Favored by High Temperatures & High Pressures
Concentrates Aromatics and increases ON
Dealkylation of Aromatics
Shortening of the Alkyl Group
Removal of the Alkyl Group
Favored by High Temperature & High Pressures
Long side chains lead to similarity to paraffin cracking
Reaction Thermodynamics
Reaction Thermodynamics
Reaction Thermodynamics
Reaction Thermodynamics
Heats of Reactions
Catalytic Reforming Catalyst
Catalytic Characteristics
Activity
Selectivity
Stability
Non-Catalytic Characteristics
Mechanical Properties
Thermal Properties
Morphology of Catalyst (Shape & Granulometry)
Catalytic Reforming Catalyst
Monometallic Catalyst
Bimetallic Catalyst
Consists of two metals:
Pt/Re for Semi-Regenerative Processes
Pt/Sn for moving-Beds
Achieving this combination is of the manufacturers’ secret
Active Sites:
Metal Site (Pt) for Hydrogenation & Dehydrogenation
Acid Site (Alumina), for Isomerization
Catalytic Reforming Catalyst
Catalytic Reforming Catalyst
Effects of Platinum Content in the Catalyst Structure
Range of Content: (0.3% to 0.8% wt)
Higher (Pt), affect Naphthene ring opening
Lower (Pt), Decreases resistance to, poisoning and deactivation
High (Pt) content (0.6-0.8% wt) is used for sever operations (100 ON from low Naph. Feeds)
Combination of other metals (Bimetallic) also enables operating at lower H2 Partial Pressure
Hydrogen Action
Effects On Product & Yield
Low H2 increases olefinic content in the reformate
(1%) Olefinic Content …… for (5 bar) H2 Pressure
Effects on Reaction Kinetics
Next figures will show this effect better
Hydrogen Action
Hydrogen Action
Hydrogen Action
Factors Affecting Catalyst Deactivation
Hydrogen Partial Pressure
Factors Affecting Catalyst Deactivation
Temperature of the Reaction:
High Temperatures increases Coke Deposition on the Catalyst ………. (Olefins are Coke precursors)
High Temperatures increases the rate of Graphitization of Coke
Coke growth occurs mainly on the Support
Temperature doesn’t change the coke location, whether on the Support or on the Metal
Factors Affecting Catalyst Deactivation
Nature of Feed:
Heavier Cuts produce more Coke
Factors Affecting Catalyst Deactivation
High (S) conc. cause Poisoning & Activity Loss
Hence, Concentration should be < 0.1 ppm in feed
High (S) conc. Increases the Temperature requirements for the same ON
Factors Affecting Catalyst Deactivation
Mechanism of Coke Formation
On Metal Sites (Two Models):
Series of Dehydrogenation & Fragmentation leading to the formation of (C) atoms
Polymerization
On Acid Sites (One Model)
Polymerization (Ex: Cyclopentane to naphthtalene)
Poisoning of Reforming Catalyst
Poisoning by Sulfur:
Adsorbed at very low gas conc. & form very stable Poisonous species
Sulfur limits in feed:
Monometallic (Pt/Al2O3) ………below 20 ppm
Bimetallic (Re-Pt/Al2O3) ……… below 1 ppm
Higher Re/Pt Ratio is more sensitive … below 0.5 ppm
↑Increasing Acidity which affects Dehydrogenation
↑Accelerates Cat. Deactivation, Inhibits Aromatics
Poisoning of Reforming Catalyst

Poisoning of Reforming Catalyst
Poisoning by Nitrogen:
In the form of organic Comp. (decom. to Ammonia)
↑Inhibits Acidity with no effect on Dehydrogenation
Poisoning by Metals:
Very aggressive attack, with inability of regeneration (permanent poisoning)
Effects are not well studied (all precautions are taken into account)
Catalyst Regeneration
Regeneration with Hydrogen:
Mechanism: Catalytic Hydrogenation Reaction
Temperature Effect:
The Carbon remaining is Decreased
Activity for Benzene Hydrogenation is Increased
Time Effect:
The Carbon remaining is Decreased
Carbon deposits become more & more Dehydrogenated
Catalyst Regeneration
Regeneration with Oxygen:
Burning Sequence:
Burning Coke on (Pt), for high H2 content in Coke
Burning Coke on Support, for lower H2 content
Burning Coke on the most distant location from (Pt), for very poor H2 content in Coke
Lower Temperature is for Higher Metal/Acid ratio
Parameters Controlling the Catalytic Reforming Process
Temperature Effect
Parameters Controlling the Catalytic Reforming Process
Continue Temperature Effect
Parameters Controlling the Catalytic Reforming Process
Parameters Controlling the Catalytic Reforming Process
Pressure Effect
Parameters Controlling the Catalytic Reforming Process
Space Velocity Effect
Definition
Types:
LHSV = (vol. feed/hr)/(vol. Catalyst) = hr-1
WHSV = (weight feed/hr)/(weight Catalyst) = hr-1
No effect on Aromatization & Isomerization for high rates (reach equilibrium)
A compromise between Hydrocracking & Dehydrocyclization shoul be carried out
Parameters Controlling the Catalytic Reforming Process
Continue Space Velocity Effect
Parameters Controlling the Catalytic Reforming Process
Feed Range Effect
Parameters Controlling the Catalytic Reforming Process
Type of Feed Effect
Parameters Controlling the Catalytic Reforming Process
Hydrogen / H.C ratio
Advantage of increasing H2/H.C (decreasing Coke)
Disadvantage of increasing H2/H.C (decreasing aromatization & increasing Hydrocracking)
H2/H.C is maintained by the use of recycle
Operating Condition for Present-Day Processes