Process for removing peroxide impurities from acrylonitrile monomers

Abstract

A process is provided for removing peroxide contamination from acrylonitrile. The process includes contacting the acrylonitrile with an activated alumina adsorbent and separating the acrylonitrile product from the alumina. The contaminated acrylonitrile is contacted with the activated alumina adsorbent for a time sufficient for the peroxide contaminate to be adsorbed by the activated alumina. The activated alumina may also be used to selectively remove color promoting contaminates in an acrylonitrile product.

We claim: 
     
       1. A process for removing peroxide contamination from acrylonitrile which comprises contacting the acrylonitrile with an activated alumina adsorbent for a time sufficient for the peroxide contaminate to be adsorbed by the activated alumina and to produce an acrylonitrile product having less than about 0.2 ppm peroxide, and separating the acrylonitrile product from the alumina. 
     
     
       2. A process for treating a material comprising acrylonitrile and minor amounts of color promoting contaminants, which process comprises contacting said material with alumina so as to selectively remove said color promoting contaminants and produce an acrylonitrile product having a reduced content of said contaminants. 
     
     
       3. A process for treating a material consisting essentially of not less than 99 weight percent acrylonitrile, between about 0.25 and about 0.5 weight percent of a color stabilizing system comprising water and p-methoxyphenol, and greater than 0.5 ppm of color promoting contaminants, which process comprises contacting said material with an adsorbent comprising activated alumina having a surface area of between about 150 and about 400 square meters per gram at a temperature no greater than 75° C. with a contacting time of between about 0.5 and about 2.0 minutes so as to selectively adsorb said color promoting contaminants and produce an acrylonitrile product having less than about 0.2 ppm of said contaminants but not less than 85 percent of the concentration of said color stabilizing system in said material.