摘要:
A combined process for the preparation of polycarbonate from bisphenols and diaryl carbonates, the monophenol liberated being reacted again for the preparation of the diaryl carbonate and the alkali metal halide forming in the preparation of the diaryl carbonate being converted by electrochemical oxidation, optionally over a gas diffusion electrode, into chlorine and alkali hydroxide solution, the chlorine being recycled into the preparation of the phosgene and the alkali hydroxide solution being recycled into the preparation of the diaryl carbonate.
摘要:
A process is described for producing polycarbonate and utilizing at least some of the process waste water by concentrating the sodium chloride-containing waste water phases for the electrolysis using osmotic membrane distillation, if appropriate with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the polycarbonate production process.
摘要:
The present invention relates to an oxygen-consuming electrode comprising at least one support structure having a surface and a gas diffusion coating having a catalytically active component disposed on the surface. The coating contains at least one fluorine-containing polymer, a silver compound, selected from the group consisting of silver particles, reducible silver compounds, and mixtures thereof, and a hydrophilic caustic alkali-resistant filler which is electrically nonconductive or has a poor electrical conductivity and has an average particle diameter from 5 to 200 μm.
摘要:
A process is described for producing polycarbonate and utilizing at least some of the process waste water by concentrating the sodium chloride-containing waste water phases for the electrolysis using osmotic membrane distillation, if appropriate with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the polycarbonate production process.
摘要:
The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.
摘要:
A process is disclosed comprising: (a) reacting hydrogen chloride and oxygen to form a gas mixture comprising chlorine, water, unreacted hydrogen chloride, and unreacted oxygen; (b) cooling the gas mixture to form an aqueous solution of hydrogen chloride; (c) separating at least a portion of the aqueous solution of hydrogen chloride from the gas mixture; (d) removing at least a portion of the water from the gas mixture; and (e) subjecting the gas mixture to a gas permeation such that at least a portion of the unreacted oxygen in the gas mixture is separated to form a chlorine-rich gas stream and an oxygen-containing partial stream.
摘要:
Processes comprising: (a) providing an initial gas mixture comprising chlorine, water, hydrogen chloride and oxygen; (b) cooling the initial gas mixture to form condensed hydrochloric acid and an intermediate chlorine-containing gas mixture; (c) contacting the intermediate gas mixture with a water-containing phase under a set of conditions selected from a pressure, a temperature and combinations thereof to form a chlorine hydrate-containing phase and a remaining gas mixture; (d) separating the chlorine hydrate-containing phase from the remaining gas mixture; (e) subjecting the chlorine hydrate-containing phase to a set of conditions selected from heat, pressure relief and combinations thereof to release chlorine and form a residual chlorine hydrate/water-containing phase; and (f) separating the released chlorine from the residual chlorine hydrate/water-containing phase.
摘要:
An isocyanate is produced by: (a) reacting chlorine with carbon monoxide to form phosgene, (b) reacting the phosgene with an organic amine to form an isocyanate and hydrogen chloride, (c) separating the isocyanate and hydrogen chloride, (d) optionally, purifying the hydrogen chloride, (e) preparing an aqueous solution of the hydrogen chloride, (f) optionally, purifying the aqueous solution of hydrogen chloride, (g) subjecting the aqueous hydrogen chloride solution to electrochemical oxidation to form chlorine, and (h) returning at least a portion of the chlorine produced in (g) to (a).
摘要:
In the production of perfluoroalkylsulfonyl fluorides by electrolytic fluorination of alkylsulfonyl fluoride, the electrolyte contains anhydrous hydrogen fluoride, an alkylsulfonyl fluoride, and at least one additional component selected from alkaline earth fluorides, alkali tetrafluoroborates, alkali hexafluorophosphates, hexafluorophosphoric acid, tetrafluoroboric acid, boron trioxide, boron trifluoride, or mixtures thereof.
摘要:
Electrolyzer comprising at least one single electrolyzer element which comprises at least one anode compartment with an anode, one cathode compartment with a cathode and one ion exchange membrane arranged between the anode and the cathode compartments, with the anode and/or cathode being a gas diffusion electrode. A gap is provided between the gas diffusion electrode and the ion exchange membrane, with an electrolyte inlet arranged at the upper end of the gap and an electrolyte outlet at the lower end of the gap and a gas inlet and a gas outlet. The electrolyte outlet extending into a discharge header, and the electrolyte inlet connected to an electrolyte feed tank and having an overflow, the overflow connected to the discharge header, with a coiled hose connecting the electrolyte feed tank with the electrolyte inlet and with a coiled hose connecting the overflow with the discharge header.