Patent ID: 9738592
Date: 2017-08-22
CPC Classifications: B01D,B01J,C07C,Y02P

Claim:
1. A process for purifying crude dinitrotoluenes resulting from the nitration of toluene in the presence of a nitric acid/sulfuric acid nitrating acid mixture wherein the process comprises the following steps: (a) the crude dinitrotoluenes, after separation from the spent nitrating acid mixture, are first subjected to a washing with at least one wash medium, followed by a removal of the wash medium; and (b) subsequently, the washed dinitrotoluenes resulting from process step (a) are subjected to a stripping via stripping gas treatment with at least one stripping gas, wherein the stripping gas used is a gas which is non-reactive with respect to dinitrotoluenes and is selected from the group consisting of nitrogen, oxygen, noble gases, hydrogen, carbon oxides and mixtures thereof and wherein the stripping is conducted in the absence of steam.