Abstract:
An improvement in a process for recovering ammonium sulfate from a contaminated, aqueous ammonium sulfate Solution containing both tarry organic and heavy contaminants (e.g., from Group VIII of the Periodic Table) is disclosed wherein a compound, or several compounds, which can form complexes together with said metal ions, and the solution is then treated with one, or several, water-soluble organic substances which, at least in combination with a saturated ammonium sulfate solution, are capable of forming a two-layer liquid phase system therewith. The resultant two layers may be separated into an aqueous phase containing purified ammmonium sulfate and an organic phase containing the organic substance, organic contaminants and metallic contaminants. The ammonium sulfate can be recovered as waterwhite, cubical crystals.
Abstract:
A process relating to the manufacture of acrylonitrile is described with particular reference to the stripping technique for recovery of small amounts of dissolved acrylonitrile from the acidic aqueous solution obtained by the cooling of the hot reaction gases from the synthesis step itself. The disclosure points out that by maintaining the pH of the feed at a value of 5 or less and desirably also maintaining a bottom product temperature in the distillation column below 100.degree. C, fouling of the distillation column is substantially obviated.