Method for separating tetraalkylammonium salts
AssigneePhillips Petroleum Company
InventorGeir Bjornson
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Abstract
Apparatus and method for separating tetraalkylammonium salt from a first stream comprising adiponitrile, dissolved tetraalkylammonium salts, and unconverted acrylonitrile discharging from an electrohydrodimerization process by passing the first stream through a distillation zone for separating unconverted acrylonitrile therefrom, mixing aqueous phosphoric acid with the resultant bottoms stream to form an emulsion, and separating the emulsion into an essentially salt-free organic phase and a tetraalkylammonium salt-containing aqueous phase.
Claims7
In a process for the production of adiponitrile wherein acrylonitrile, an aqueous electrolyte, and a tetraalkylammonium salt, each of the alkyl radicals of which has 1-20 carbon atoms and the tetraalkylammonium has 11-25 carbon atoms, are subjected to an electrolysis in an electrohydrodimerization cell, and wherein the adiponitrile formed is recovered from a first emulsion coming from said cell,
- the improvement which comprises
- separating said first emulsion to form a first organic and a first aqueous phase,
- distilling said first organic phase to remove acrylonitrile therefrom,
- mixing the remaining first organic phase with phosphoric acid to form a second emulsion,
- separating said second emulsion into a second aqueous and a second organic phase,
- and recovering the adiponitrile from the organic phase and the aqueous phase comprising the tetraalkylammonium phosphate salt.
Dependencies are inferred from the claim text.