Abstract: The invention relates to a method for producing a polycarbonate and the reaction of one or more diaryl carbonates with one or more aromatic compounds, wherein a catalyst combination is used in the process. The invention further relates to a catalyst combination and to the use thereof in a process for producing a polycarbonate.

Abstract: An exemplary process for the production of alkali metal salts of dialkyldithiocarbamic acids produced according to the following steps: i) reaction of one or more dialkylamines, carbon disulphide and alkali metal hydroxides to form alkali metal salts of dialkyldithiocarbamic acids; ii) crystallisation to form a crystal suspension of alkali metal salts of dialkyldithiocarbamic acids; iii) separation of crystals of alkali metal salts of dialkyldithiocarbamic acids from the mother liquor in step ii; (iv) recirculation of the separated mother liquor into the crystallisation process; and v) drying of the alkali metal salts of dialkyldithiocarbamic acids.

Abstract: The invention relates to a method for producing alkali metal cyanides as solids, comprising the steps: i) an absorption step in the form of the absorption of hydrogen cyanide from a syngas containing hydrogen cyanide in an aqueous alkali metal hydroxide solution; ii) a preparation step for the waste gases containing cyanide that have accumulated in step i); iii) a crystallization step in the form of the introduction of the alkali metal cyanide solution into an evaporative crystallizer; iv) a condensation step for the vapour containing cyanide that has accumulated in step iii) to obtain a vapour condensate containing cyanide; v) a recirculation step, in which the vapour condensate containing cyanide that has been obtained in step iv) is used as an aqueous liquid in step ii).

Abstract: The invention relates to a method for producing a polycarbonate and the reaction of one or more diaryl carbonates with one or more aromatic compounds, wherein a catalyst combination is used in the process. The invention further relates to a catalyst combination and to the use thereof in a process for producing a polycarbonate.

Abstract: A method is described for producing a polycarbonate by reacting one or more diaryl carbonates with one or more aromatic hydroxy compounds, which are first mixed in a mixing device and enter, as a raw material mixture, a raw material mixture container to subsequently react in one or more reactors under reduced pressure and increased temperature to form polycarbonate, wherein the mixture of diaryl carbonate and aromatic hydroxy compound is subjected to a purification by an inert gas in a countercurrent process, in a stripping device, before entering the raw material mixture container. The present invention also relates to a stripping device which is particularly suitable for purifying a raw material mixture stream, and to the use of such a stripping device in a method for producing polycarbonate.