| 摘要 |
<p>Described herein is a continuous process for the production of dinitrotoluene characterized by the following steps: (a) reacting toluene with dilute nitric acid to produce a product mixture containing mononitrotoluene, water and unreacted nitric acid; (b) then separating the mononitrotoluene from the mixture; (c) then reacting the mononitrotoluene recovered from step (b) with concentrated nitric acid to produce a product mixture containing dinitrotoluene, water and unreacted nitric acid; (d) then separating a portion of the nitric acid from the mixture for recycle to step (c); (e) then adding water to the mixture of water, unreacted nitric acid and dinitrotoluene; (f) then separating the dinitrotoluene from the mixture by crystallization; (g) then recycling the remaining dilute nitric acid from step (f) to step (a).</p> |
