Abstract:
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.
Abstract:
A damping element implemented for damping a vibration transmitted between an injection valve and a cylinder head of an internal combustion engine may include a base body substantially shaped as a ring washer and at least one first contact segment fixedly coupled to the base body and protruding past the base body in a first axial direction and a second contact segment fixedly coupled to the base body and protruding past the base body in a second axial direction opposite the first axial direction. The first at least one contact segment has a radial offset from the longitudinal axis that is unequal to a radial offset of the second contact segment from the longitudinal axis.
Abstract:
The invention relates to a method for improving the performance of nickel electrodes in alkali chloride electrolysis by adding water-soluble platinum compounds to the catolyte.
Abstract:
A method for the installation of oxygen-consuming electrodes in electrochemical cells includes sealing one or more oxygen-consuming electrodes in an electrochemical half cell having damaged regions and/or overlap regions and applying a sealing paste. The sealing paste includes silver oxide, a hydrophobic polymer component, and a perfluorinated or partially fluorinated solvent. The method may be used, in particular, for chloralkali electrolysis. An electrochemical cell, having one or more adjoining oxygen-consuming electrodes with damaged and/or overlap regions sealed with a sealing paste having silver oxide, a hydrophobic polymer component, and a fluorinated solvent, is also disclosed.
Abstract:
The present invention relates to an electrode comprising an electrically conductive substrate and a catalytically active layer, wherein the catalytically active layer is based on two catalytically active components and comprises iridium, ruthenium or titanium as metal oxide or mixed oxide or mixtures of the oxides, wherein the total content of ruthenium and/or iridium based on the sum of the elements iridium, ruthenium and titanium is at least 10 mol %, and wherein the electrode comprises at least one oxidic base layer which is applied to the electrically conductive substrate and is impermeable to aqueous electrolytes comprising NaCl and/or NaOH and/or HCl.
Abstract:
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).
Abstract:
An electrode material, an electrode and a process for hydrogen chloride electrolysis based on platinum metal as catalyst, in which the electrode material has a nanosize mixture of platinum particles and silver particles, is described.
Abstract:
Apparatus for hydrogen chloride electrolysis, comprising a cathode that has a layer of nitrogen-doped carbon nanotubes having functional groups containing nitrogen.
Abstract:
The invention relates to a process for preparing methylenediphenyl diisocyanates which comprises at least the steps: A) reaction of aniline with formaldehyde in the presence of hydrochloric acid as catalyst to give a mixture of diamines and polyamines of the diphenylmethane series (MDA) and subsequent at least partial neutralization of the hydrochloric acid by means of alkali metal hydroxide, B) reaction of the mixture of diamines and polyamines of the diphenylmethane series obtained in step A) with phosgene to give a mixture of diisocyanates and polyisocyanates of the diphenylmethane series (MDI) and hydrogen chloride, wherein C) the hydrochloric acid which has been neutralized in step A) is separated off in the form of a solution containing alkali metal chloride and is subsequently at least partly fed to an electrochemical oxidation to form chlorine, alkali metal hydroxide and optionally hydrogen and D) at least part of the chlorine produced in step C) is used for preparing the phosgene used in step B).
Abstract:
The invention relates to a method for improving the performance of nickel electrodes in alkali chloride electrolysis by adding water-soluble platinum compounds to the catolyte.