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A Novel, Highly Efficient andEconomic Purification ProcessRevolutionizing PTA Production
Presented byRandi Wytcherley
2006 Texas Technology ShowcaseDecember 6 and 7, 2006 Galveston, TX
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Outline
•Introduction•Project Objectives•Technical Approach•GTC Purification Process•Project Impacts•Future Plans•Summary
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Introduction
•US polyester production hasgrown from 2MM tons 5MMtons per year
•Polyester used for consumergoods
•PTA is polyester precursor•Substantial energy savings•Reduced environmental
impact
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PTA Production Capacity vs.Consumer Demand
59,96268,8752014
46,28755,2902010
39,49446,2832008
33,75237,4802006
ConsumerDemand (Mt/y)
World PTAProduction
Capacity (Mt/y)Year
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PTA Production Capacity
70 to 3000~55/902014
70 to 1740~55/802006
ProductionCapacity (Mt/y)Producers/SitesYear
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Project Objectives
•Commercialize a revolutionarynew PTA process
•Reduce energy consumed•Eliminate use of hazardous
chemicals•Accept lower-cost feedstocks•Increase fundamental
understanding
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Technical Approach
•Low temperature, lowpressure crystallization•Highly selective solvent•Simplified process
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Typical Oxidation Products
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Conventional PTA Process
PTAp-Xaircatalysts
OxidationSection
Crude TA
Use ofspecial
metallurgy inpurification
process
Use expensivehydrogenation
catalyst
HAC and PXlosses impactthe economics
of theprocess
Purification process limits4-CBA content ~0.3% in
the crudeFinal product:4-CBA <25ppm
p-toluic <170ppmother acids <300ppm
High temperatureand pressure
process
Use bromineas promoter
PurificationSection
(hydrogenation)
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GTC PTA Technology
OxidationSection
GTC PurificationSection
(crystallization)
Crude TAp-Xaircatalysts
PTA
PatentedprocessPotential
savingsbring the
possibilityto upgrade
currentPTA plants
Relaxed oxidationconditions
results in muchlower
pX and HAClosses
Use of veryselectivesolvent toremove
impurities
Non-corrosivelow pressure
low temperatureprocess
GTC purification canprocess higher impuritiescontent: 4-CBA up to 5%
Increased pX yields byfull conversion/recycle ofoxidation intermediates
Final product:4-CBA<20ppm
p-toluic acid <20ppmother acids <100ppm
•~39% lower energy costs comparedto conventional process
•~16% lower capital investment
Use of bromine aspromoter is not
required
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Simplified PTA Purification Process
Crude TA
1st Stage
SolventRecovery
Drying
PTA
Purge –Impurities Removaland Recycle
2nd Stage
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Solubility Curve
TEMPERATURE
GR
AM
S/1
00G
RA
MS
OF
SO
LV
EN
T
TPA
4-CBA
P-TOLUIC ACID
MMT
BENZOICACID
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Bar Type Crystals by Crystallization:Before and After
•Ham et. al. reported ‘salt complex’•Selective solvent•Washed to fines
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Globular PTA
•Further understanding of crystallization•Selective solvent•Washed to crystals
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GTC PTA Typical Product Purity
PARAMETER CONVENTIONAL GTC
4-CBA, ppm < 20 < 20
p-Toluic Acid, ppm < 170 < 20
Other Acids, ppm < 300 < 100
Optical Density < 0.1 < 0.1
Particle Shape / AverageSize, microns
Globular / 110 Globular / 130
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Uniqueness & Flexibility of GTC’sProcess
Oxidation
Purification
HAC basedconventional
(relaxed)
GTCPurification
DMTbased
WATERbased
HAC basedbromine-free
PTA
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0 100 200 300 400 500 600 700 800
Conventional
GTCNew
OperatingCost Comparison(600Mt/y - cost in$/Mt)
RawMaterials Energy Other
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0 1 2 3 4 5 6 7 8 9 10
Millions of Dollars per Year
Conventional
GTC New Process
Utility Consumption Comparison
Power CW BFW Natural Gas Steam Inert Gas
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Operating Cost Advantages of the GTCPTA Process
•Estimated ~39% reduction in utilityconsumption and ~10% operating costs.
•Improved raw materials consumption.
•Lower compression costs.
•Low temperature and pressure incrystallization and residual solventremoval sections mean lower energyconsumption
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0 50 100 150 200 250 300 350 400
$x 10^6
Conventional
GTCNew
Capital InvestmentCost(600Mt/y)
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Capital Cost Advantages of the GTC PTAProcess
•Estimated ~16% lower capital cost.
•Savings on reactor and compressor.
•No dissolver/hydrogenationreactor/catalyst required.
•Non-corrosive crystallization operates atatmospheric pressure and lowtemperatures and does notrequirespecial alloys.
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Project Impacts
•1.9E13 Btu/yr US energy savings•2.0E14 Btu/yr world energy savings•16% lower Capital Investment
compared to conventional technology•39% reduced utility consumption
compared to conventional technology•Higher purity product and flexibility•Adaptable to non-bromine oxidation
systems
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Future Plans•Finalize industrial evaluation•Continue optimization of
technology for further energysavings
•Finalize process forcommercialization
•Implement technology atcommercial scale
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GTC-PTA Purification TechnologySummary
•Significant energy savings•Low temperature/low pressure
crystallization•Selective solvent•16% lower Capital Investment•39% reduced utility consumption•Higher purity product and flexibility•Adaptable to non-bromine oxidation
systems
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Acknowledgements•Department of Energy•Team members:
–George Ball•Manager of Technology Development
–Costantino Braggiato•Sr. Design Engineer
–Tai-Li Chou•Research Engineer
–Mircea Cretoiu•Project Manager
–Randi Wytcherley•Principal Investigator
–Qiao ZhiHui•Technology Manager PTA/Polyester
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