Method for extracting effective components from o-nitrochlorobenzene tar

Abstract

According to the invention, an azeotropic distillation method is adopted to extract effective components in tar after ortho-nitrochlorobenzene distillation; the method comprises the following steps: adding a certain amount of tar into a distillation container, adding a certain amount of azeotropic solvent into the container, heating the mixture to boil, cooling the azeotropic solvent and organic components, layering the mixture, separating liquid, returning the azeotropic solvent to a distillation system for circulation, distilling the mixture until no organic phase is evaporated, and dehydrating and rectifying the organic phase to obtain the high-purity o-nitrochlorobenzene. According to the method, the tar content in the o-nitrochlorobenzene can be reduced by half; therefore, on one hand, the recovered o-nitrochlorobenzene is sold as a product, the economic benefit can be improved, the market competitiveness of the product is enhanced, and on the other hand, the tar yield can be reduced, and good social benefits are achieved.

Description

technical field [0001] The invention relates to the field of organic chemical separation, and introduces a method for extracting effective components from o-nitrochlorobenzene distillation tar. Background technique [0002] The production of o-nitrochlorobenzene is to obtain the final product through nitration, washing, neutralization and rectification of chlorinated benzene. While nitrochlorobenzene is nitrated to generate mononitrochlorobenzene, there is also a small amount of dinitrochlorobenzene generate. The nitration solution is obtained by rectification to obtain para-rich finished product and high-purity o-nitrochlorobenzene finished product. During the rectification process, due to the continuous high-temperature distillation in the tower kettle, tar is produced in the liquid in the kettle. At the same time, after the rectification of o-nitrochlorobenzene, dinitrochlorobenzene is gradually enriched, which affects the rectification effect, and the tar needs to be di...

AI Technical Summary

Problems solved by technology

During the rectification process, due to the continuous high-temperature distillation in the tower kettle, tar is produced in the liquid in the kettle. At the same time, after the rectification of o-nitrochlorobenzene, dinitrochlorobenzene is gradually enriched, which affects the rectification effect, and the tar needs to be discharged regularly

In the discharged tar, the content of o-nitrochlorobenzene is about 66%, and the trace amount of dinitrochlorobenzene produced in the reaction process reaches about 22% after being enriched. pose a great security risk