DevelopmentDevelopment ofof anan EfficientEfficient andand GreenGreen TNTTNT ManufacturingManufacturing ProcessProcess 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 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. 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 Flexible Ingredient Facility Program Chemistry Research Program Objectives Notes z Design safe, efficient and “green” processes z The Flexible Ingredient Facility is a concept for for energetic ingredient manufacture making a variety energetic materials available at z Design processes that fit available production scale for propellants and explosives infrastructure z It is one of the most significant ingredient production facility changes in this country in over 30 years. z Add minimal infrastructure to maximize flexibility z The facility will be able to make both legacy energetics such as TNT and new ingredients such z Demonstrate practicality of new processes as NTO, Dinitroanisole, CL-20 and TEX z Provide data for full scale plant design z It is designed to be efficient and exceed environmental requirements for hazardous z Meet schedule and budget emissions Radford AAP Promontory M53 Laboratories 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 oleum Make up Acids concentration Acid Yellow facilities acids purification water (inc. Oleum) Generates yellow water Toluene Nitration Sulphite wash Water wash Generates red water Traditional TNT process Red water Requires Flake TNT toluene Nitration Toluene Oxidation • Considerations for the Nitration synthetic route? NO 2 – Starting material ONT NO 2 NO 2 – By-products – Reagents NO 2 NO 2 –Catalysts? NO 2 O2N O2N NO 2 NO 2 – Materials handling NO 2 NO 2 NO 2 NO O2N 2 • Cost, toxicity, Oxidation compatibility, environmental, O2N NO 2 facilities impact NO 2 O2N NO 2 O N 2 NO 2 • What engineering NO 2 NO 2 NO 2 NO 2 O N NO TNT 2 2 O2N NO 2 NO process? NO 2 2 NO 2 – Batch, continuous, COOH single line, multiple CHO lines HO 3/(O 2N) 2 NO 2 3/(O 2N) 2 (NO 2)2/3 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 “Sellite” purification Na2SO3 O N NO 2 2 SO Na O2N 3 Na2SO3 C(NO2)4 C(NO2)3SO3Na + NaNO2 ........ O N NO 2 2 O2N NO2 Na SO slow2 3 NO 2 SO3Na New TNT Purification Technology Make Acids Acid clean- By-products: up concentration up Explosive or • Crystallization is key to avoiding acids fuel (oleum Red-Water free) • Traditionally, impurities reacted ONT Nitration Crystallization Wash with sodium sulphite to give water soluble products – K047 New TNT process – 10-15% of all starting material + Flake water 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 Other process streams • Spent acid – 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 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 Nitration Organic saturated Nitric acid spent acid process recovery d Organic saturated aci ric dilute sulfuric acid nit Weak Pure dry acids Organic free acid NAC/SAC SCCO2 Extraction SCE uses low temperature and non-flammable solvent CO2 recycle - Existing equipment - New equipment 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 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 TNT Nitration Kinetics TNTRatesTNTRates 11 0.90.9 0.80.8 0.7 0.7 1/2/4.7 DNT/NA/SA 1/2/4.7 DNT/NA/SA 0.6 1/2/03 DNT/NA/SA 0.6 1/2/03 DNT/NA/SA 0.5 1/2/06 DNT/NA/SA 0.5 1/2/06 DNT/NA/SA 1/2.5/5 DNT/NA/SA 0.4 1/2.5/5 DNT/NA/SA 0.4 ONT ONT 0.30.3 Pure TNT extent of reaction extent of reaction 0.20.2 0.10.1 00 00 100 100 200 200 300 300 time/mintime/min • 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 New TNT Process Oleum free Make up Acids Acid clean- By-products: acids concentration up Explosive or Acceptable acid clean up (oleum fuel No yellow or red water free) Minimal infrastructure changes Acid clean-up ONT Nitration Crystallization Wash Crystallization Additional process equipment readily Proposed new TNT available process Flake TNT New Dinitroanisole Process NaOMe Solvent Waste in recovery water MeOH treatment CDB Reaction Filter/wash Solids waste New DNANs process Calculated DNANs structure DNANs - Equipment in common with TNT • Increased reported synthesis reaction rate 100 fold – Very high potential production rate • Patented new chemistry • MAXIMUM USE OF CURRENT INFRASTRUCTURE TEX/NTO/CL-20 Processes TEX 50-gal synthesis run 1 TEX 50-gal synthesis run 1 • Processes were designed 140 140 120 120 based on previous lab and 100 100 80 Temp 80 Temp pilot-plant experience (F) 60 (F) 60 40 40 20 20 • New NTO chemistry was 0 06:300 07:42 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 devised specifically for Time RFAAP equipment •Thermal and analytical data was gathered for all processes 14.00 12.00 10.00 Percent per Channel 8.00 6.00 4.00 2.00 0.00 0.60.80.91.1 1.3 1.61.9 2.3 2.7 3.23.84.65.56.57.79.211.13.15.18.22.26.31.37.44.52.62.74.88.10 12 14 17 20 24 29 35 41 49 59 70 9 2 7 6 8 4 5 1 5 7 9 3 0 4 8 5 08 08 56 50 00 16 11 00 00 33 23 00 00 4.74.58.06.09.38.96.02.08.67.82.04.0 TEX Crystals 0 0 0 0 0 0 0 0 0 0 0 0 Diameter (microns) TNT Pilot plant runs Acid feed ProcessesProcesses ValidatedValidated •• Pure Pure TNTTNT fromfrom ONTONT (or(or DNT)DNT) •• Co-current Co-current nitrationnitration •• Oleum Oleum freefree nitrationnitration •• Continuous Continuous crystallizationcrystallization PUREPURE TNT TNT Filter ONT Feed Nitrators Crystallizers 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 ConclusionsConclusions 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.