FIELD: chemistry.
SUBSTANCE: invention relates to a method of producing diaryl carbonate and processing at least a portion of the resultant solution which contains an alkali metal chloride in an alkali metal chloride electrolysis cell down the process chain, which involves the following steps: a) obtaining phosgene by reacting chlorine with carbon monoxide, b) reacting phosgene formed at step a) with at least one monophenol in the presence of a base, optionally a base catalyst, to diarylcarbonate and a solution which contains an alkali metal chloride, c) separating the organic phase which contains the diaryl carbonate formed at step b) and at least one-time washing of the organic phase containing diaryl carbonate, d) separating the solution which contains the alkali metal chloride remaining in accordance with step c) from solvent residue and, optionally, catalyst residue by stripping the solution with water vapour and treating with adsorbents, e) electrochemical oxidation of at least a portion of the solution which contains an alkali metal chloride from step d) to form chlorine, an alkali and, optionally, hydrogen, where during separation d) of the solution before treatment with adsorbents, the pH of the solution is set below or equal to 8 and f) at least a portion of the chlorine obtained according to step e) is returned to producing phosgene according to step a) and/or g) at least a portion of the obtained alkali solution obtained according to step e) is returned to producing diaryl carbonate according to step b).
EFFECT: method enables to obtain an end product with high purity and high output while cutting environmental contamination and solving the problem of waste water.
20 cl, 6 ex
