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.