applications of catalyst enhancement solutions in oil ... · 11th aiche southwest process...

11th AIChE Southwest Process Technology Conference | October 1-2, 2019

Applications of Catalyst Enhancement Solutions in

Oil Refining Processes

Soni O. Oyekan

President & CEO

Prafis Energy Solutions

October 1, 2019


Outline

Acknowledgements

Catalysis in Oil Refining Processes

Beneficial Usage of Additives

Optimizing Promoter Activities and Contributions

Optimizing Productivity of Complex Process Units

Summary


Acknowledgements

• Special honor and glory to God for our lives, and for the opportunity to share this presentation with you

• For my wife, Priscilla, with special thanks for her love of over 50 years

• My doctoral advisor, friend and mentor, Professor Tony L. Dent, who instilled agood foundation in catalysis and reaction engineering in me

• For those I had the privilege to work with over the years at ExxonMobil Research and Engineering, Engelhard, DuPont, Sunoco, BP/Amoco, Marathon Petroleum Company

• For collaborations and work on projects, studies, and “process units challenges”, Albemarle, Alfa Laval, Axens, Cetek, Criterion & UOP

• For companies that I have provided consulting services for, Ascent Engineering, CHEP, Custom Products International (CPI), Gerson Lehman Group, Haldor Topsoe, IGT-Cetek, Lion’s Eldorado Refinery, Matheson Gas, P66 Borger Refinery & Roddey Engineering Services


Block Diagram of an Oil Refinery


Catalysts and Catalytic Processes

❑ Acid catalysis; HF, H2SO4,

Olefins Alkylation

❑ Base metal oxides; CoMo, NiMo, CoNiMo

Hydrotreating processes

❑ Hydrogenation/dehydrogenation; Pt/alumina

Benzene saturation, Cyclohexane dehydrogenation


Catalysts and Catalytic Processes

❑ Base metal oxides, cracking; zeolites, silica/alumina

Hydrocracking, Fluid catalytic cracking

❑ Dual functional; zeolites and hydrogenation/dehydrogenation

Benzene alkylation, Light naphtha isomerization (TIP),

C8 Aromatics isomerization

❑ Multifunctional; hydrogenation/dehydrogenation and acidic

Butane isomerization, Light naphtha isomerization, Catalytic naphtha reforming


A Model for Optimizing Multifunctional Catalytic Systems

•Used primarily in naphtha reforming

process catalysis

•Special great credit to UOP

•Applicable to other multifunctional

heterogeneous catalytic systems with some

variations

• Sound knowledge of processes, operations

and catalysts are required


Light Naphtha Isomerization

• Upgrade light naphtha octane via

Isomerization of linear paraffins

• Saturate benzene

• Lead/lag reactors

• Pt/Al2O3.Clx catalyst; Cl of 4.5 to 5.5 wt.

%

• Temp: 280 to 400 F

• Press: 400 to 900 psi;

• Recycle Gas H2/HC molar: 1 to 2

• LHSV 1 to 2

C5/C6 Isomerization Unit


Active Sites Protection Via “Buffering”

• Concept is also applied in the Butane isomerization process

• A key concern is irreversible catalyst chloride

• Activity and octane losses

• Feed and hydrogen drying systems are required.

• Organic Chloride is added at startup and onstream

• 100 to 300 wppm organic chloride addition levels.

• Organic chloride is converted to HCl in reactors.

• Produced HCl provides “buffering” over catalyst sites

• Rate of catalyst chloride loss is minimized

• Effluent hydrogen chloride is neutralized in the caustic scrubber

• Chloride addition leads to good catalyst performance and activity stability.


Attenuation of Hyperactive Sites

C8 Aromatics Isomerization Processes

• Produce para-xylene from ethylbenzene and meta-xylene

• Multi-functional Pt/Al2O3/Zeolite catalysts

• Product selectivity is a key concern

• Moderation of acidic and hydrogenation/dehydrogenation functionalities may be required

• ARCO/Engelhard use ammonia during startup for moderating the acidic functionality of the Octafining Process

• ExxonMobil Chemical two stage catalysts process use sulfur pretreatment for attenuation of the hydrogenation/dehydrogenation functionality.

• US Patent 8,835.705. Cao, C., Andrew, J. L., Molinier, M


Key Platinum Naphtha Reforming Catalysts

❑ Pt/Alumina, Vladimir Haensel, US Patent 3,415,737 (1949)➢ Replaced Molybdenum oxide catalyst

➢ Significant gains in reformate selectivity, hydrogen production, and lower coking rates

❑ Pt/Re/Alumina, Harris Kluksdahl, US Patent 4,012,313 (1975)➢ Improved catalyst stability and increased reformate

productivity

❑ Staged Pt/Re/Alumina, High Re, Soni Oyekan & George Swan, US 4,436,612 (1984)➢Higher yields of reformate and improved stability

❑ Pt/Sn/Alumina, UOP and several other companies that led to CCR process technologies by UOP and IFP Axens CCR Reformer


Catalytic Naphtha Reforming Process

❑ High octane reformate, hydrogen and

BTX compounds are the main products

❑ 3 Process technologies – fixed bed semi-

regenerative, fixed bed cyclic

regenerative, continuous catalyst regenerative

CCR)

❑ Broad range of process conditions:

Press: 35 to 700 psi; WAIT of 800 to

1010 F; Recycle Gas H2/HC molar ratio, 2 to

8; C5+ octane of 70 to107 RON

C5+ yields are as shown in the figure from US

Patent 4,539,307 (1985) by Soni Oyekan


Key Properties of Naphtha Reforming Catalysts

Physical

• Surface Area, m2/gm, 180 to 250

• Bulk Density, lb/cu ft, 35 to 54

• Crush Strength, lb/pill, 3.0 to 10.0

• Pore Volume, cc/gm

Other Characterizations: Attrition

Resistance, Surface Area Retention,

Catalysts fines, Catalyst Porosity, Catalyst

age, Alumina Phases

Characterizations of fresh, spent and

regenerated catalysts

Chemical

• Pt, wt. %, 0.2 to 0.8

• Promoter: Re, Sn, Ge, Ir, P, W; wt. %,

0.1 to 0.7

• Chloride, wt. %, 0.6 to 1.2

• Trace metals: Fe, Si, S, Na, Co, Ni, Mo

wt. %, 0.01 to 0.3

• Carbon, wt. %

Other Characterizations: Metals and Cl

Distributions, Pt Dispersions, Cl

Retention


Optimize Promoter Performance in Bimetallic Catalysts

M. F. L. Johnson, B. D. McNicol, W. Sachtler, C. Bolivar, H. Charcosset, O. A. Scelza, O. A., etc., contributed separately on the active Pt and Re reduction states

PtO2 + 2H2 Pt + 2H2O

Re2O7 + 7H2 2Re + 7H20

Pt is reduced to its zerovalent state at about 600 F, and Re is reduced to the zerovalent state at about 1100 degrees F

❖ Reduced Platinum catalyzes activation of second metal

❖ Activation of Pt containing reforming

catalysts. Soni Oyekan US 4,539,307 (1985)


Catalytic Enhancements for the CCR Process Unit

• Simplified diagram of UOP CycleMaxTM CCR technology

• Axens offer similar CCR process technologies

• Reactors, catalyst circulation, catalyst fines management and catalyst regeneration systems

• Catalyst circulation ensures delivery of activated catalyst to reactors

• Catalyst coke production rate is critical for profitable operations

• Excessively low catalyst coke rate negatively impacts unit productivity, profitability and reliability

• Diesel/Gasoline price differentials indirectly impact the performance of high performing CCR process units


Catalytic Enhancements for CCR Units

❖ Optimal range of coke make is necessary for profitable CCR naphtha reforming operations

❖ Usually 4.0 to 6.0 wt. %

❖ Regenerations of low catalyst coke of < 2.5 wt. % usually lead to poor reforming, equipment damage, and CCR unit reliability challenges

❖ Soni Oyekan, US Patent 9,371,493 (2016)

❖ Use of additives to cause metals/acidic functionality imbalance and increase catalytic coke. Comparative data are as provided


Apply Process knowledge and Catalysis❖ Higher boiling compounds, C11+ hydrocarbons, in feeds lead to increased coking

rates in naphtha reforming

❖ Use of high boiling kerosene compounds is the basis of US Patent 8,778,823 (2014) granted to Soni Oyekan, Kenneth Rhodes and Nicholas Newlon

❖ Lower rates of sulfur addition relative to those discussed in the previous slide are used in improving the reliability of reactor internals and heater tubes in low pressure naphtha reforming operations

❖ Use Recycle gas H2S based on naphtha feed sulfur of 0.3 to 0.5 wppm sulfur

❖ Enhances metals surfaces “passivation”

❖ Minimize rates of metal catalyzed coking, metal carburization and dusting

❖ To optimize CCR performance, mixed diesel and sulfur compounds additives are used as exploited in US Patent 9,371,494 (2016) by Soni Oyekan and Michael Robicheaux


Cocktail of Catalysts & Additives in FCCU

❖ Fluid Catalytic Cracking Units, FCCU,

Equilibrium catalyst, Ecat, contain mixes of

catalyst and additives

❖Cracking catalysts

❖CO Promoter additives

❖NOx Reduction additives

❖SOx Reduction

❖High Olefins, Octane Enhancers

❖High Propylene

❖ Average concentrations and ages of

constituent Ecat catalysts and additives impact

FCCU performance

❖ Additives and competing chemistries could

negate meeting respective environmental

objectives

Inside.mines.edu


Summary

✓ Additives are used for buffering, passivation, attenuation and in the

startup of process units

✓ Improved catalyst activation patent based on Pt catalyzation of a second

metal is discussed

✓ Strategies for optimizing the CCR process unit for low coke

naphtha operations are shared.

✓ Catalytic enhancement strategies discussed should provide bases for

developing innovative solutions for hydrocarbon conversion units in oil

refining


Thank you for your attendance and time

applications of catalyst enhancement solutions in oil ... · 11th aiche southwest process...

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