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Efficient Co-production of Cyclohexanone and Phenol
Dr. C. Morris Smith
Project Chief Scientist
ExxonMobil Chemical Company
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C Morris Smith, Ph.D.ExxonMobil Chemical Company
Efficient Co-production of Cyclohexanoneand Phenol
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Shanghai Technology Center
Baytown Technology Center
European Technology Center
Integrated Global Technology
Baytown, TXClinton, NJ
Brussels
Bangalore
Shanghai
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Focused Strategic Effort
� Advantaged feeds• Feed flexibility
� Lower-cost manufacturing processes• Advanced process and catalysts• Improved energy efficiency and reliability
� Premium products• Higher performance • Higher value
Industry-leading technology creates innovative solu tions
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Advanced Capabilities
Expertise in catalysis and process, products, appli cations 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
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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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Alkylation
Zeolite
Oxidation
O2
Cleavage
H2SO4
++
Conventional Hock Process
ExxonMobil Advances Enable New Route
� 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
OH
New Route
Cumene Cumylhydroperoxide
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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
� Scoping for commercial design underway
New EM Process – Baytown, TX Pilot Plant Facility
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New EM Process: Hydroalkylation
� Highly selective production of Cyclohexylbenzene (CHB)
� No Propylene feed
� Cyclohexene generated in-situ and undergoes hydroalkylation over noble metal / zeolite catalyst
� Cyclohexane recovered using selective catalytic dehydrogenation
� Heavies transalkylated to CHB
� Minimal yield loss from unrecoverable alkylation / isomerization products
� Enabled by proprietary catalysts
Hydroalkylation
Dehydrogenation
Transalkylation
2H2 + ++
Cyclohexylbenzene
Yield ~ 97%
Hydroalkylation
Zeolite
Oxidation
O2 NHPI
Cleavage
H2SO4
+OH
2H2 +
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New EM Process: Oxidation
� Thermal oxidation of CHB not selective to desired PCH-HP
� Selectivity improved by NHPI, a chain propagating agent
� NHPI radical (PINO•) abstracts only the benzylic H, accelerating oxidation to desired PCH-HP
� Low levels of secondary hydroperoxides formed; some recoverable to CHB
� Minor yield loss also occurs by PCH-HP decomposition
� High oxidation yield enabled by NHPI under optimized conditions
Hydroalkylation
Zeolite
Oxidation
O2 NHPI
Cleavage
H2SO4
+OH
2H2 +
Oxidation
Hydrogenation Dehydration
+
Phenyl Cyclohexyl Hydroperoxide (PCH-HP)
NHPI
HeavyOxygenates
Yield ~ 94%
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New EM Process: Cleavage
� PCH-HP cleaved to Phenol and Cyclohexanone
� Rates controlled to eliminate Cyclohexanone loss reactions
� 1-Phenylcyclohexene formed but easily recovered
� β-scission can lead to the loss of PCH-HP by forming 6-Hydroxy-hexaphenone (6HHP)
� When optimized, product selectivity is nearly stoichiometric
Hydroalkylation
Zeolite
Oxidation
O2 NHPI
Cleavage
H2SO4
+OH
2H2 +
Cleavage+
O
Phenol
Cyclohexanone
1-phenylcyclohexanol 1-phenylcyclohexene
6-hydroxyhexaphenone (6HHP)
Cyclohexylbenzene
O
HeavyOxygenates
Yield ~ 99%
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Oxygenates SeparationOxygenates Separation
Hydrocarbon LoopHydrocarbon Loop
OxidationLoop
OxidationLoop
New EM Process Flow Diagram
Benzene
Hydrogen
Transalkylation
CyclohexaneDehydrogenation
HydroalkylationBenzene
Purification
HydrocarbonFractionation
HydrogenPurification
Cleavage
Air
Spent Air to Scrubber
Oxidation
Ventto Flare
Hydrogenation
Phenol
Cyclohexanone
Cleavage Product
Fractionation
PhenolPurification
Cyclohexanone Phenol
Fractionation
Overall Product Yield ~ 90%
WO2009131769
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Efficiency, Co-production Drive Advantage
Hydroalkyation
50% Cx-one
50% Phenol
New EM Process Conversion 25%
CHB
SeparationsOxidationCleavage
Benzene
H2 � Co-production of Phenol and Cyclohexanone in one large-scale line
• 45% lower equipment count
� Higher conversion / yield process
• Smaller equipment
• Reduced energy requirements
� Avoids Acetone, no Propylene feed
� Products for highest quality applications
Phenol Conversion 25%
62% Phenol
38% Acetone
C3=
Alkylation SeparationsOxidationCleavage
De-phenolization
AMSHydrogenation
Benzene
Cumene
CyclohexanolDehydration
100% Cx-one
Cyclohexanone Conversion 4%
CyclohexaneRecovery
SeparationsOxidationCleavage
Cyclohexane
Hydrogenation
Benzene
H2
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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