TNT, again

This is the one-stage process, but one acid mixture is used. This mixture consists of 75 per cent sulphuric acid, and 25 per cent nitric acid. The usual charge for this process is in the ratio of one part toluene to twelve parts mixed acid.

Each kilogram of toluene requires, therefore, 3 kilograms nitric acid and 9 kilograms sulphuric acid.

The toluene is added to the acid in the one-stage process. The termination of the inlet pipe is in a kind of well at the bottom of the nitrator, and the toluene is nitrated before it can separate and spread about.

During the addition of the toluene the temperature must not rise above 30° C. This addition requires from two to two and one-half hours. After the addition is complete, the temperature of the mixture is raised to 90 to 95° C , by means of the steam coils.

This temperature is maintained for two hours, during which time the mononitrotoluene is nitrated to dinitrotoluene.

The temperature is then further increased to 120°C, and is " cooked " for an additional two hours.

The nitration is now considered finished, and the charge is ready for separation, washing, and graining.

In many chemical plants a chemist tests the charge of TNT, and the time of the final cooking is determined by the solidification point of the mixed TNT and acid.

This principle of chemical control is adopted sometimes in the two- and three-stage processes as well as in the one-stage process.

The yield of TNT by the onestage process is 1.9 kilos per kilo toluene used.

One Step TNT Synth.

Preparation of TNT

Materials:
920 grams toluene
2700 grams 99% nitric acid
3000 grams premium unleaded gasoline
1600 grams of 70% sulfuric acid

Procedure:
Place 920 grams of toluene, 2700 grams of 99% nitric acid, and 3000 grams of premium unleaded gasoline into a flask fitted with a stirrer and reflux cindenser. Then heat the mixture to about 80 Celcius and reflux for about three hours with constant stirring (do not let the temperature rise above 85 Celsuis). In some cases the reaction may take less then three hours, or may take longer. Moniter the nitric acid layer (bottom layer) because the reaction will cease when it dissappears.
After about three hours, or when the bottom nitric acid layer disappears, shut off the heat and allow the mixture to cool. Upon cooling, some of the TNT begins to precipitate. Instead of filtering off the precipitated TNT, add 3000 milliliters of hot water and stir the whole mixture for about 2 hours. After which, filter off and precipitated TNT, and then decant the upper organic layer. Then place this organic layer into a shallow pan with a high surface area, and allow the upper organic layer to evaporate to recrystallize the bulk of the TNT.
When about 80% (by volume) of the uppoer organic layer has evaporated (heat may be used to speed up the evaporation, but this is not needed due to the volatility of the gasoline), collect the TNT by filtration using the same filter as before, and then wash all the collected TNT product with 2000 milliliters of water. Then dry the TNT in an oven at 50 Celsius, or vacuum dry or air-dry the product.
Then place 1600 grams of 70% sulfuric acid into a beaker and then add the dry TNT product, and then stir the mixture to form a slurry. Continue to stir the slurry for 2 hours at room temperature and then filter off the TNT product. Then, wash the TNT with 2000 milliliters of cold water, and then vacuum dry or air-dry the TNT product.