Efficient Co-production of Cyclohexanone and Phenol
Dr. C. Morris Smith
Project Chief Scientist
ExxonMobil Chemical Company 10th China International Polyamide & Intermediates Forum
Efficient Co-production of Cyclohexanone and Phenol
C Morris Smith, Ph.D. ExxonMobil Chemical Company
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Integrated Global Technology
European Technology Center
Brussels Clinton, NJ Baytown, TX Shanghai
Baytown Technology Center Bangalore
Shanghai Technology Center
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Focused Strategic Effort
Industry-leading technology creates innovative solutions
Advantaged feeds • Feed flexibility
Lower-cost manufacturing processes • Advanced process and catalysts • Improved energy efficiency and reliability
Premium products • Higher performance • Higher value
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Advanced Capabilities
Expertise in catalysis and process, products, applications and manufacturing
State-of-the-art capabilities • Fast catalyst discovery • Advanced chemical characterization • Scale-up
World-class expertise • Catalyst discovery and scale-up • Process development and manufacturing • New products and applications
Globally leveraged • Application development • Strong customer support 4
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Hurdles to Cyclohexanone + Phenol Co-production
First identified by Rhone-Poulenc in 1954, EP # 6B712264
Significant work in the patent literature by Texaco, Phillips and Phenolchemie over 50+ years did not lead to a commercial process
Poor selectivity and low yield continued to limit commercial potential
Cyclohexylbenzene (CHB) yield affected by over-alkylation to heavies and over-hydrogenation to lights
Poor oxidation selectivity due to 10 secondary H’s that are also subject to oxidation, but don’t yield the desired products
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ExxonMobil Advances Enable New Route
Conventional Hock Process
Alkylation Oxidation Cleavage + +
Zeolite O2 H2SO4 Cumene Cumylhydroperoxide
New Route OH
In 1993, ExxonMobil introduced a new zeolite Cumene process that was rapidly commercialized worldwide New process greatly improves CHB selectivity using a new Hydroalkylation catalyst Selective oxidation of benzylic H achieved using N-Hydroxyphthalamide (NHPI)
New EM Process Co-produces Cyclohexanone and Phenol at high yields Decouples the production of Phenol and Acetone All in a process with leading-edge energy efficiency 6
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New EM Process Technology Development
Research scoping from 2000 to 2005
Process development began in 2008
More than 100 patents filed
Pilot plant demonstrating integrated process
Integrated process design and model
Seven reactive steps, multiple separations
VLE data generation for non-ideal oxygenate species
Detailed CFD modeling / design of critical mechanical systems New EM Process – Baytown, TX Pilot Plant Facility
Scoping for commercial design underway
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New EM Process: Hydroalkylation
Hydroalkylation Oxidation Cleavage OH
2H2 + + Zeolite O2 NHPI H2SO4
Highly selective production of Yield ~ 97% Cyclohexylbenzene (CHB)
No Propylene feed Transalkylation Cyclohexene generated in-situ and undergoes hydroalkylation over noble metal / zeolite catalyst Hydroalkylation 2H2 + + + Cyclohexane recovered using
selective catalytic dehydrogenation Cyclohexylbenzene
Heavies transalkylated to CHB Dehydrogenation Minimal yield loss from unrecoverable alkylation / isomerization products
Enabled by proprietary catalysts 8
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New EM Process: Oxidation
Hydroalkylation Oxidation Cleavage OH
2H2 + + Zeolite O2 NHPI H2SO4
Thermal oxidation of CHB not Yield ~ 94% selective to desired PCH-HP
Selectivity improved by NHPI, a Hydrogenation Dehydration chain propagating agent
NHPI radical (PINO•) abstracts only the benzylic H, accelerating oxidation to desired PCH-HP Oxidation + Low levels of secondary NHPI
hydroperoxides formed; some Phenyl Cyclohexyl Hydroperoxide (PCH-HP) recoverable to CHB
Minor yield loss also occurs by Heavy PCH-HP decomposition Oxygenates High oxidation yield enabled by NHPI under optimized conditions 9
New EM Process: Cleavage
Hydroalkylation Oxidation Cleavage OH 2H2 + + Zeolite O2 NHPI H2SO4
PCH-HP cleaved to Phenol and Yield ~ 99% Cyclohexanone
Rates controlled to eliminate Cyclohexanone loss reactions 1-phenylcyclohexanol 1-phenylcyclohexene Cyclohexylbenzene
1-Phenylcyclohexene formed but O easily recovered Cleavage + β-scission can lead to the loss of Pheno Cyclohexanone PCH-HP by forming 6-Hydroxy- l hexaphenone (6HHP)
When optimized, product O Heavy selectivity is nearly stoichiometric Oxygenates 6-hydroxyhexaphenone (6HHP)
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New EM Process Flow Diagram
Hydrocarbon Loop Overall Product Yield ~ 90%
Oxygenates Separation Hydrogen Hydrogen Cyclohexane Purification Dehydrogenation Cyclohexanone
Cleavage Cyclohexanone Product Phenol Fractionation Fractionation Benzene Benzene Hydroalkylation Purification
Phenol Phenol Purification
Hydrocarbon Fractionation
Spent Air to Oxidation Scrubber Loop
Transalkylation Hydrogenation Oxidation Cleavage
Vent Air to Flare WO2009131769 11
Efficiency, Co-production Drive Advantage
New EM Process Conversion 25%
H2 50% Phenol Co-production of Phenol and Oxidation Hydroalkyation Separations Cleavage Cyclohexanone in one large-scale line Benzene 50% Cx-one CHB • 45% lower equipment count
Higher conversion / yield process Phenol Conversion 25%
C3= 62% Phenol • Smaller equipment Cumene Oxidation Alkylation Separations Cleavage • Reduced energy requirements Benzene 38% Acetone
AMS De- Hydrogenation phenolization Avoids Acetone, no Propylene feed
Cyclohexanone Conversion 4%
Cyclohexane Cyclohexanol Products for highest quality Recovery Dehydration applications
H2 Oxidation 100% Cx-one Hydrogenation Separations Cleavage Benzene Cyclohexane 12
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Summary
New EM Process produces two high value products in the Benzene derivative chain
Breakthrough catalysis enables efficient co-production of Cyclohexanone and Phenol eliminating Acetone co-product and Propylene sourcing
Leading-edge process design leads to substantial reduction in equipment count, increased scale, and improved capital utilization
Significantly improved energy efficiency supports more sustainable production of petrochemical intermediates
Commercial-scale facilities scoping is underway
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