Development of an Efficient and Green TNT Manufacturing Process

Transcription

1 Development of an Efficient and Green TNT Manufacturing Process Prepared For 2004 IM/EM Technical Symposium November 15-17, 2004 San Francisco, CA Authors Paige Holt, Gene Johnston, Andrew J. Sanderson*, Pete Wesson and Jim Worthington

2 Why investigate TNT manufacturing? US Government issued an RFP for TNT supply and a flexible energetic materials manufacturing facility 5-15 million pounds TNT The legacy TNT manufacturing process is environmentally unacceptable Waste from traditional TNT production has severe environmental consequences K047 prohibited from land disposal 40 CHR Ch TNT production stopped in US 15 years ago It has not been restarted in a large part because of the environmental cost

3 Flexible Ingredient Facility Program Chemistry Research Program Objectives Design safe, efficient and green processes for energetic ingredient manufacture Design processes that fit available infrastructure Add minimal infrastructure to maximize flexibility Demonstrate practicality of new processes Provide data for full scale plant design Meet schedule and budget Notes The Flexible Ingredient Facility is a concept for making a variety energetic materials available at production scale for propellants and explosives It is one of the most significant ingredient production facility changes in this country in over 30 years. The facility will be able to make both legacy energetics such as TNT and new ingredients such as NTO, Dinitroanisole, CL-20 and TEX It is designed to be efficient and exceed environmental requirements for hazardous emissions Radford AAP Promontory M53 Laboratories

4 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

5 Traditional TNT Processes Needs oleum facilities Make up acids (inc. Oleum) Acids concentration Acid purification Yellow water Generates yellow water Generates red water Requires toluene Toluene Nitration Sulphite wash Water wash Traditional TNT process Red water Flake TNT

6 Nitration Considerations for the synthetic route? Starting material By-products Reagents Catalysts? Materials handling Cost, toxicity, compatibility, environmental, facilities impact What engineering process? Batch, continuous, single line, multiple lines Oxidation O 2N O 2N TNT 3/(O 2N) 2 COOH O 2N O 2N CHO ONT O 2N O2N Toluene O 2N Nitration O 2N Oxidation HO 3/(O 2N) 2 () 2/ 3

7 Purification Tradition TNT purification Basic wash with sodium sulphite (sellite) removes off isomers, benzoic acids, alcohols and tetranitromethane Product is purer TNT and basic aqueous solution of TNT and sulphonated organics Only current disposal option is incineration Washing doesn t remove DNT, bibenzyl and biphenyl impurities, and it leaves the TNT contaminated ppm with red water Poor process upset recovery possibilities Other option is recrystallization

8 Sellite purification Na 2 SO 3 O 2 N O 2 N SO 3 Na Na 2 SO 3 C( ) 4 C( ) 3 SO 3 Na + Na... O 2 N O 2 N Na 2 SO 3 slow SO 3 Na

9 New TNT Purification Technology Crystallization is key to avoiding Red-Water Traditionally, impurities reacted with sodium sulphite to give water soluble products K % of all starting material + water Make up acids (oleum free) Acids concentration ONT Nitration Crystallization Wash New TNT process Acid cleanup By-products: Explosive or fuel Flake TNT 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

10 Spent acid Other process streams The sulfuric acid left after nitration, saturated with organics 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

11 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

12 Acid Treatment Nitration process Pure dry acids NAC/SAC Organic saturated spent acid Weak nitric acid Organic free acid Nitric acid recovery Organic saturated dilute sulfuric acid SCCO2 Extraction - Existing equipment - New equipment SCE uses low temperature and non-flammable solvent CO2 recycle Organics recovery 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

13 Support for scale-up of process Precise nitration conditions Yields, kinetics vs. conditions, process sensitivity to all variables 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

14 TNT Nitration Kinetics extent extent of of reaction reaction TNTRates TNTRates time/min time/min 1/2/4.7 DNT/NA/SA 1/2/4.7 DNT/NA/SA 1/2/03 DNT/NA/SA 1/2/03 DNT/NA/SA 1/2/06 DNT/NA/SA 1/2/06 DNT/NA/SA 1/2.5/5 DNT/NA/SA 1/2.5/5 DNT/NA/SA ONT ONT Pure TNT 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 composition and temperature (all vary with extent of reaction) Nitrating ability is a function of acid composition

15 New TNT Process Oleum free Acceptable acid clean up No yellow or red water Minimal infrastructure changes Acid clean-up Crystallization Additional process equipment readily available Make up acids (oleum free) Acids concentration ONT Nitration Crystallization Wash Proposed new TNT process Acid cleanup By-products: Explosive or fuel Flake TNT

16 New Dinitroanisole Process NaOMe in MeOH Solvent recovery Waste water treatment CDB Reaction Filter/wash Solids waste New DNANs process Calculated DNANs structure DNANs Increased reported synthesis reaction rate 100 fold Very high potential production rate Patented new chemistry MAXIMUM USE OF CURRENT INFRASTRUCTURE - Equipment in common with TNT

17 TEX/NTO/CL-20 Processes TEX 50-gal synthesis run 1 TEX 50-gal synthesis run Temp 80 (F) Temp (F) : :42 08:54 10:06 11:18 12:30 13:42 14:54 16:06 17:18 18:30 06:30 07:42 08:54 10:06 11:18 12:30 13:42 14:54 16:06 17:18 18:30 Time Time Processes were designed based on previous lab and pilot-plant experience New NTO chemistry was devised specifically for RFAAP equipment Thermal and analytical data was gathered for all processes Percent per Channel TEX Crystals Diameter (microns)

18 Acid feed TNT Pilot plant runs Processes Validated Pure TNT from ONT (or (or DNT) Co-current nitration Oleum free nitration Continuous crystallization PURE PURE TNT TNT Filter ONT Feed Nitrators Crystallizers

19 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 at equilibrium Overflow to quench Crude DNANs being quenched

20 Conclusions The 1970s TNT plant at Radford AAP is being made into a modern, flexible energetics facility, able to realize practical, green production of TNT and a range of new materials. You can teach an old dog new tricks if: You have a great team doing the training You can add an extra limb or two