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Development of an Efficient andGreen TNT Manufacturing Process
Development of an Efficient andDevelopment of an Efficient andGreen TNT Manufacturing ProcessGreen TNT Manufacturing Process
Prepared For2004 IM/EM Technical Symposium
November 15-17, 2004 San Francisco, CA
AuthorsPaige Holt, Gene Johnston, Andrew J.
Sanderson*, Pete Wesson and Jim Worthington
Why investigate TNT manufacturing?• US Government issued an RFP for TNT
supply and a flexible energetic materialsmanufacturing facility– 5-15 million pounds TNT
• The legacy TNT manufacturing process isenvironmentally unacceptable– Waste from traditional TNT production has
severe environmental consequences• K047 prohibited from land disposal 40 CHR Ch.
1 §286.33
• TNT production stopped in US 15 years ago– It has not been restarted in a large part because
of the environmental cost
Chemistry Research Program ObjectivesDesign safe, efficient and “green” processesfor energetic ingredient manufactureDesign processes that fit availableinfrastructureAdd minimal infrastructure to maximizeflexibilityDemonstrate practicality of new processesProvide data for full scale plant designMeet schedule and budget
NotesThe Flexible Ingredient Facility is a concept formaking a variety energetic materials available atproduction scale for propellants and explosives
It is one of the most significant ingredient productionfacility changes in this country in over 30 years. The facility will be able to make both legacyenergetics such as TNT and new ingredients suchas NTO, Dinitroanisole, CL-20 and TEX
It is designed to be efficient and exceedenvironmental requirements for hazardousemissions
Radford AAP Promontory M53Laboratories
Flexible Ingredient Facility Program
TNT Chemistry – the problem• Nitration of toluene gives TNT AND OTHER STUFF
– 95% crude yield of organics– 5-10% not 246TNT (mostly 3-isomer derivatives)– TNT purity of ca. 99.5% is required
• Where has the 5% gone?• How do your remove the 5-10% from the crude
product?– What do you do with 5-10%?
• Approximately 1M lb year!
• What do you do with nitration medium
Traditional TNT Processes
Needs oleumfacilities
Generatesyellow water
Generates redwater
Requirestoluene
Make upacids(inc.
Oleum)
Toluene Nitration Sulphite wash Water wash
Flake TNT
Acids concentration
Red water
Yellowwater
Acidpurification
Traditional TNTprocess
Nitration
NO 2
NO2NO2
NO2
NO 2
NO2O2N
NO2
O2N
NO2O2N
NO2
NO2
NO2
NO2
NO2
NO 2
NO 2
NO2
O2N
NO2
NO2
NO2
NO2
NO2
O2N
NO 2
NO2
NO2
NO2
O2N
O2N
O2N
HO
NO2
COOHCHO
3/(O2N)2
3/(O2N)2 (NO 2)2/3
Oxidation
TNT
Toluene
ONT
Nitration
Oxidation
• Considerations for thesynthetic route?– Starting material– By-products– Reagents– Catalysts?– Materials handling
• Cost, toxicity,compatibility,environmental,facilities impact
• What engineeringprocess?– Batch, continuous,
single line, multiplelines
Purification• Tradition TNT purification
– Basic wash with sodium sulphite (sellite) removes “offisomers”, benzoic acids, alcohols and tetranitromethane
– Product is purer TNT and basic aqueous solution of TNTand sulphonated organics
• Only current disposal option is incineration
– Washing doesn’t remove DNT, bibenzyl and biphenylimpurities, and it leaves the TNT contaminated ppm with“red water”
– Poor process upset recovery possibilities
• Other option is recrystallization
“Sellite” purification
NO2O2N SO3NaO2N
Na2SO3
Na2SO3C(NO2)4 C(NO2)3SO3Na + NaNO2 ........
NO2
NO2
O2N NO2
SO3Na
O2NNa2SO3slow
New TNT Purification Technology• Crystallization is key to avoiding
Red-Water• Traditionally, impurities reacted
with sodium sulphite to give watersoluble products – K047– 10-15% of all starting material +
water• Pure TNT can be crystallized by careful
cooling and seeding of acid mixture.• Crystallization gives two acceptable
streams– Pure TNT, wet with acid– Spent acid containing the impurities
• TNT is washed with water• Water and acid combined for
purification
Makeup
acids(oleumfree)
ONT Nitration Crystallization Wash
FlakeTNT
Acidsconcentration
Acid clean-up
By-products:Explosive or
fuel
New TNT process
Other process streams• Spent acid
– The sulfuric acid left after nitration, saturated withorganics and containing nitrous and nitric acid
– Needs to be reusable (organic free) or disposable(stable) CHEAPLY
• Fumes– Acid vapor, NOx, SOx, VOC
• Water– Washing the product and cleaning vessels
Acid Purification treatment• Before concentration and reuse, spent acid must be free from organic materials• Options
– Extract organics• Toluene/Butane• Super-critical carbon dioxide (SCCO2)
– New approach for acid clean-up– Patented new technology– Very environmentally attractive– Developing with Chematur and INEEL– Treatment of extracted material
» Incinerate» Isotrioil
– Destroy organics• Pyrolysis• Oxidation/reduction
• New approach gives optimal solution• Options give risk minimization
Acid Treatment
• New Acid Treatment was essential for any restart of our TNT facilities• SCCO2 extraction fits well with existing process• Can be used for different processes with no modification• Demonstrated partition coefficient and obtained IP
Nitrationprocess
Nitric acidrecovery
SCCO2Extraction
NAC/SAC
Organic saturatedspent acid
Organic saturateddilute sulfuric acid
Weak nitric acid
Organic free acid
Pure
dry
aci
ds
Organics recovery
CO2 recycleSCE uses low temperatureand non-flammable solvent
- Existing equipment
- New equipment
Support for scale-up of process• Precise nitration conditions
– Yields, kinetics vs. conditions, process sensitivity to allvariables
• Waste stream management– Every single process stream MUST be accounted for
• Precise crystallization conditions– Purity, morphology, washing
• Acid purification– Waste stream management– Demonstrate CO2 technology
TNT Nitration Kinetics
• Reaction rates are key for process control and obtaining pure TNT• Rates are dependant on:
– TNT partition coefficient between acid and organic phases– Nitrating ability of acid
• Partition coefficient is a function of acid composition, organic compositionand temperature (all vary with extent of reaction)
• Nitrating ability is a function of acid composition
TNTRates
00.10.20.30.40.50.60.70.80.9
1
0 100 200 300time/min
exte
nt o
f rea
ctio
n
1/2/4.7 DNT/NA/SA1/2/03 DNT/NA/SA1/2/06 DNT/NA/SA1/2.5/5 DNT/NA/SAONT
TNTRates
00.10.20.30.40.50.60.70.80.9
1
0 100 200 300time/min
exte
nt o
f rea
ctio
n
1/2/4.7 DNT/NA/SA1/2/03 DNT/NA/SA1/2/06 DNT/NA/SA1/2.5/5 DNT/NA/SAONT Pure TNT
New TNT Process
Oleum freeAcceptable acid clean upNo yellow or red waterMinimal infrastructure
changesAcid clean-upCrystallization
Additional processequipment readilyavailable
Make upacids
(oleumfree)
ONT Nitration Crystallization Wash
Flake TNT
Acidsconcentration
Acid clean-up
By-products:Explosive or
fuel
Proposed new TNTprocess
• Increased reported synthesis reaction rate 100 fold– Very high potential production rate
• Patented new chemistry• MAXIMUM USE OF CURRENT INFRASTRUCTURE
NaOMein
MeOH
CDB Reaction Filter/wash Solidswaste
DNANs
Solventrecovery
Wastewater
treatment
New DNANs processCalculated DNANs structure
- Equipment in common with TNT
New Dinitroanisole Process
• Processes were designedbased on previous lab andpilot-plant experience
• New NTO chemistry wasdevised specifically forRFAAP equipment
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
704.00
592.00
497.80
418.60
352.00
296.00
248.90
209.30
176.00
148.00
124.50
104.70
88.00
74.00
62.23
52.33
44.00
37.00
31.11
26.16
22.00
18.50
15.56
13.08
11.08
9.25
7.78
6.54
5.50
4.63
3.89
3.27
2.75
2.3 1
1.9 5
1.6 4
1.3 8
1.1 6
0.9 7
0.82
0.69
Diameter (microns)
Percent per Channel
TEX 50-gal synthesis run 1
0
20
40
60
80
100
120
140
06:30 07:42 08:54 10:06 11:18 12:30 13:42 14:54 16:06 17:18 18:30
Time
Temp (F)
TEX 50-gal synthesis run 1
0
20
40
60
80
100
120
140
06:30 07:42 08:54 10:06 11:18 12:30 13:42 14:54 16:06 17:18 18:30
Time
Temp (F)
•Thermal and analyticaldata was gathered for allprocesses
TEX Crystals
TEX/NTO/CL-20 Processes
Processes Validated• Pure TNT from ONT
(or DNT)• Co-current nitration• Oleum free nitration• Continuous
crystallization
Processes Validated• Pure TNT from ONT
(or DNT)• Co-current nitration• Oleum free nitration• Continuous
crystallization
ONT Feed Nitrators Crystallizers
Filter
Acid feed
PURE TNTPURE TNT
TNT Pilot plant runs
Pilot Plant Dinitroanisole• Quality material produced on first
run• High production rate (5-10lb/hour)• Data recorded included:
– Hard measurements - temp.– Practical observations – slurry
behaviour
DNANs reactors atequilibrium
Overflow to quench
Crude DNANs beingquenched
ConclusionsConclusions
You can teach an old dog newtricks if:You have a great team doing the training
You can add an extra limb or two
The 1970s TNT plant at Radford AAP is being madeinto a modern, flexible energetics facility, able torealize practical, green production of TNT and a
range of new materials.
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