Other

Hoechst Aktiengesellschaft

Solvay (societe Anonyme)

Dieter Schmid

Karl-Heinz Tetzlaff

Jurgen Russow

Oliver Schmid

Werner Krause

Hans-Matthias Deger

Horst Bennoit

Martin Hoeveler

The invention relates to a process for preparing pentafluoroethane (R 125) by reacting perchloroethylene with hydrogen fluoride in the gas phase over a chromium-containing catalyst, wherein the catalyst used comprises chromium and magnesium and is obtainable by reacting a water-soluble chromium(III) salt with magnesium hydroxide or magnesium oxide and, if desired, graphite in the presence of water, converting the reaction mixture into a paste, then drying the paste and treating it with hydrogen fluoride at temperatures of from 20.degree. to 500.degree. C., using such amounts of chromium(III) and magnesium salts and, if desired, graphite that the dried paste before treatment with hydrogen fluoride contains from 4.5 to 26% by weight of Cr, expressed as Cr.sub.2 O.sub.3, and at least 25% by weight of Mg, expressed as MgO, and, if desired, graphite.

Process for preparing pentafluoroethane (R 125)

Sealing cap for cans of various diameters provided with an edge beading

Funnel with level indicator

Clamp made of plastic for clamping sheet-like objects

A process for the manipulation of liquid electrolyte and gas during the operation of an electrochemical cell having at least one gas diffusion electrode and a counter electrode forming an electrolyte space for a flowing electrolyte which flows through the cell, from the upper end of the cell to its lower end, which electrolyte space is nonpartitioned or is partitioned by a separator, the gas diffusion electrode having a surface facing toward the electrolyte space and an opposite surface facing opposite from the electrolyte space, and the cell having a gas space located on the opposite surface, the process comprising:

Electrochemical process for treating liquid electrolytes

In this process for electrically separating the electrolyte-bearing main from the electrolyte spaces of an electrochemical cell pile, the electrolyte is passed via drop sections directly from the main into the electrolyte space or directly from the electrolyte space into the main.

Process for electrically separating the electrolyte-bearing mains from

This process, in which gas bubbles are formed in the electrolyte, is carried out in electrolytic cells which are non-partitioned or partitioned by at least one separator and in which at least one electrode is perforated. For this purpose, the electrolyte is caused to flow by means of gravity through the electrolytic cell in such a manner that a gas space is formed laterally to the main direction of flow of the electrolyte, both electrodes or the separators or one separator and the perforated electrode being wetted.

Process for the electrolysis of liquid electrolytes using film flow

This process can be carried out in an electrolytic cell which is non-partitioned or partitioned by at least one separator and has at least one porous electrode. The electrolyte enters parallel to the surface of the electrode and is forced by at least one restriction point to flow through the porous electrode parallel to the flow of charge.

Electrolysis process using liquid electrolytes and porous electrodes

Zeolites are prepared by hydrothermal crystallization of alkaline aqueous synthesis mixtures. Normally the zeolites are filtered and washed with water until the filtrate shows a pH of about 9 to 12. Sometimes, especially if the resulting zeolite consists of very fine particles, the zeolite filter cake shows thixotropic properties. If the filter cake is washed with diluted sodium hydroxide or only small amounts of water this thixotropy can be avoided.

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Schwalbach, Germany

Dieter Schmid