Abstract: A method for producing phosgene from chlorine and carbon monoxide (1), the method being characterised in that carbon monoxide obtained by catalytic decomposition of methanol (4) is provided and this provided carbon monoxide (2) is reacted with chlorine to form phosgene (3). Using this method, low-emission phosgene for the production of isocyanates and polycarbonates can be provided, despite possible fluctuations in the provision of renewable energies. Methanol serves as the source for carbon monoxide, the methanol used for this purpose preferably being provided using regenerative energy from hydrogen and COx, where x=1 or 2.

Abstract: A process, and a device system suitable therefore, for producing polycarbonates are provided. The process contains the steps of producing at least chlorine and hydrogen by the chloralkali electrolysis of alkali chloride, preferably sodium chloride, in aqueous solution; synthesizing phosgene from carbon monoxide and chlorine; reacting phosgene with diol to form polycarbonate; providing a cleaned carbon dioxide gas stream as a process product of a process containing the steps of providing a CO2 gas stream and purifying the carbon dioxide gas stream by removing secondary constituents; converting the purified carbon dioxide into carbon monoxide and hydrogen by means of an RWGS reaction, which carbon monoxide and hydrogen can be used as raw materials for the polycarbonate production.

Abstract: The invention relates to a method and an electrolysis device for the production of chlorine, carbon monoxide and optionally hydrogen via the electrochemical conversion of carbon dioxide and alkali chloride solution, wherein the carbon dioxide from a carbon dioxide gas source (55) is electrochemically reduced at a gas diffusion electrode, designed as a cathode (11), in an aqueous alkali-chloride-containing solution as the catholyte (17), and chlorine is simultaneously anodically generated from an aqueous alkali-chloride-containing solution as the anolyte (15a).

Abstract: The invention relates to an apparatus and a method for performing electrolysis with an originally oxygen-containing alkali hydroxide solution as an electrolyte precursor, wherein the pressure and temperature of the alkali hydroxide solution and the O2 content thereof are set.

Abstract: The invention relates to a method for producing isocyanates and optionally polyurethanes by at least: synthesising (1) phosgene (20) from carbon monoxide (21) and chlorine (22); reacting (2) phosgene (20) with diamines (23) to form diisocyanates (24) and hydrogen chloride (25); providing a carbon dioxide gas flow (31); and cleaning (4) the carbon dioxide gas flow (31) of additional components, wherein the carbon dioxide is converted by means of an RWGS reaction (6) to form carbon monoxide (21) and hydrogen (29), which are used as raw materials for the polyurethane production, as well as optionally reacting (3) the diisocyanates (24) with polyether polyol (35a) and/or polyester polyol (35b) to form polyurethanes (37).

Abstract: The invention relates to a method for recycling polyurethane material waste (18a) for producing chemical feedstock for the production of isocyanates (10a) and then polyurethanes (16a), in which method, proceeding from polyurethane material waste (18a), carbon dioxide (1a) and hydrocarbons (1c) are generated by pyrolysis (1), the carbon dioxide (1a; 4a) is converted by electrolysis (5) into carbon monoxide (7b) and hydrogen (7a), as appropriate, the carbon monoxide (7b; 7c) obtained is converted via phosgene to isocyanate (10a) and the isocyanate (10a) can be further processed into new polyurethane material (16a).

Abstract: The invention relates to an integrated process for conditioning process water (1) from the production (I) of polycarbonate, which process water contains at least catalyst residues and/or organic impurities and sodium chloride, and subsequently utilizing the process water (1) in a subsequent sodium chloride electrolysis (V).

Abstract: The invention relates to processes for the electrolysis of alkali chlorides by means of oxygen-depolarized electrodes, said processes having specific operating parameters for shut-down and restarting.

Abstract: The invention relates to an electrolysis cell, an electrolyzer and to a method for the electrochemical reduction of carbon dioxide on an industrial scale.

Abstract: Method for the gastight and liquid-tight installation of oxygen consuming electrodes in an electrolysis apparatus, and electrolysis apparatus for use in chloralkali electrolysis, in which particular regions are covered with an additional film having a composition comparable to the oxygen-consuming electrodes.

Abstract: The invention relates to a method for improving the performance of coated nickel electrodes in chloralkali electrolysis by adding water-soluble platinum compounds to the catholyte during the electrolysis at low current density.

Abstract: The invention relates to a method for flexibly controlling the use of hydrochloric acid having an HCl concentration of at least 10 wt %, in particular at a volume flow rate of at least 1 m3/h, obtained from a continuous chemical production process (A). In the method, purified hydrochloric acid (54) from a hydrochloric acid store (E) is optionally fed to a dispatch station (H), an HCl electrolysis station (F) and a chloralkali electrolysis station (L), which are consumption points for the hydrochloric acid, or to a neutralisation station (G) in that if one or more of said consumption points (H, F, L) is not available or if there are bottlenecks at the consumption points (H, F, L), the hydrochloric acid (54) is fed to the neutralisation station (G) and neutralised with concentrated alkali solution (55), in particular with concentrated sodium hydroxide solution, and the resulting salt solution (56) is fed either to the chloralkali process station (L) or to a disposal station (M).

Abstract: The invention describes a process for the manufacture of a gas diffusion electrode involving preparing a powder mixture containing at least a catalyst and a binder, applying the powder mixture to an electrically conducting support, and pressing the powder mixture with the electrically conducting support.

Abstract: A process for the work-up of salt-containing process water which contains an alkali metal chloride as salt in a concentration of at least 4% by weight and organic or inorganic and organic impurities from chemical production processes and reuse of the salt by a combination of prepurification and concentration, crystallization and purification of the salt and optionally subsequently use of the salt in an electrolysis for producing basic chemicals are described.

Abstract: The invention relates to an oxygen-consuming electrode, in particular for use in chloralkali electrolysis, comprising a novel catalyst coating based on carbon nanotubes and a silver-based cocatalyst, and to an electrolysis device. The invention further relates to a method for producing said oxygen-consuming electrode and to the use thereof in chloralkali electrolysis or fuel cell technology.

Abstract: The invention relates to a method for the leakage-proof storage of liquefied chlorine under increased pressure in pressure tanks, in which up to 20 wt. % polyvinyl chloride (PVC) or chlorinated polyvinyl chloride (cPVC) is placed in the pressure tank prior to filling the pressure tank with liquefied chlorine.

Abstract: Described is an osmotic distillation process for concentrating a liquid containing sodium chloride, and in particular a treatment process for used reaction water containing sodium chloride from the production of polymers.

Abstract: The invention relates to a method for flexibly controlling the use of hydrochloric acid having an HCl concentration of at least 10 wt %, in particular at a volume flow rate of at least 1 m3/h, obtained from a continuous chemical production process (A). In the method, purified hydrochloric acid (54) from a hydrochloric acid store (E) is optionally fed to a dispatch station (H), an HCl electrolysis station (F) and a chloralkali electrolysis station (L), which are consumption points for the hydrochloric acid, or to a neutralisation station (G) in that if one or more of said consumption points (H, F, L) is not available or if there are bottlenecks at the consumption points (H, F, L), the hydrochloric acid (54) is fed to the neutralisation station (G) and neutralised with concentrated alkali solution (55), in particular with concentrated sodium hydroxide solution, and the resulting salt solution (56) is fed either to the chloralkali process station (L) or to a disposal station (M).

Abstract: The invention relates to a method for the electrochemical purification of chloride-containing, aqueous process solutions, which are contaminated with organic chemical compounds, using a boron-doped diamond electrode at a pH value of at least 9.5.

Abstract: The invention relates to an oxygen-consuming electrode for use in chlor-alkali electrolysis which, as required, can either evolve hydrogen or can also consume oxygen, on the basis of a silver-based catalyst and an additional electrocatalyst based on ruthenium and/or iridium. The invention further relates to an electrolysis device consisting thereof. When said electrode is used in the chlor-alkali electrolysis, a correspondingly equipped chlor-alkali electrolysis system can be used for example for network stabilization of power supply networks.