Vapor phase nitration Nitromethane

At a time when the only practicable methods for the preparation of nitromethane were the interaction of methyl iodide with silver nitrite and the Kolbe reaction from chloracetic acid, the explosive was far too expensive to merit consideration. The present cheap and large scale production of nitromethane by the vapor-phase nitration of methane and of ethane has altered the situation profoundly. Trimethylolnitromethane trinitrate is an explosive which can now be produced from coke, air, and natural gas. Nitromethane too has other interest for the manufacturer of explosives. It may be used as a component of liquid explosives, and it yields on reduction methylamine which is needed for the preparation of tetryl. 

Vapor-phase nitration of paraffin hydrocarbons, particularly propane, can be brought about by uncatalyzed contact between a large excess of hydrocarbon and nitric acid vapor at around 400°C, followed by quenching. A multiplicity of nitrated and oxidized products results from nitrating propane nitromethane, nitroethane, nitropropanes, and carbon dioxide all appear, but yields of useful products are fair. Materials of construction must be very oxidation-resistant and are usually of ceramic-lined steel. The nitroparaffins have found limited use as fuels for race cars, submarines, and model airplanes. Their reduction products, the amines, and other hydroxyl compounds resulting from aldol condensations have made a great many new aliphatic syntheses possible because of their ready reactivity. 

Nitroparaffins are produced by vapor phase nitration with nitric acid vapor. Nitroethane is also prepared in this way. The individual reaction products (nitromethane, nitroethane, nitropropane) must then be separated by distillation. 

Nitromethane is now made by vapor-phase nitration of petroleum hydrocarbons. 

Nitromethane. The industrial method of producing NM is based on a vapor phase reaction of propane and 70% nitric acid. The reaction is carried out at around 410° and 115—175psi press. In essence the production of NM involves five stepst 1) nitration 2) product recovery ... 

Nitromethane is sparingly soluble in water. The compound is of industrial interest as a solvent rather than as an explosive. Its technical synthesis involves nitration of methane with nitric acid above 400 °C (750 °F) in the vapor phase. 

The development of the preparation of nitroparaffins from laboratory scale through pilot-plant to full-scale operation covered a 20-year-long effort by Commercial Solvents Corporation. A full-scale plant with a capacity of more than 10,000,000 lb per year went on stream in 1955. By a process of nitration of propane, the main production of nitroparafl5ns includes nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane. The nitration is done in the vapor phase. A flow diagram illustrating the process is shown in Fig. 4-17. There are five process sections in the nitroparaffin preparation. These involve (1) nitration, (2) products recovery, (3) products purification, (4) products separation, and (5) reactants recovery. A report by Schecter and Kaplan states that conditions for the nitration of propane are 770 F (410 C) at pressures of 115-175 psi. Initially the vapor-phase... 

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