Physikalische Methoden als Hilfe für die Herstellung und Entwicklung von Tensiden II: Mikroskopische Untersuchungen

The Use of Physical Methods in the Manufacture and Development of Surfactants II: Microscope Examinations When surfactants are used, high surfactant concentrations, which often have liquid crystal properties, can easily form on the active surfaces. Knowledge of the range of existence and the structure of such anisotropic surfactant solutions or gels may be of vital importance for the manufacture and development of new surfactants. With the aid of polarization microscopy it is possible to make these liquid crystal structures visible. Pentadecyl and dodecyl benzene sulphonic acids are mixed with water and photomicrographs are made of the structures which form. A melting-point diagram is drawn up to determine the composition of the hydrate complexes which form between the surfactant and the water. The interference figures of the occurring phases are determined as far as possible and this in turn provides information on the structure of the liquid crystals. The structure of the occurring phases is discussed on the basis of the R-theory.     

Wirtschaftlichkeit als Kriterium für die Entwicklung,Auslegung und Auswahl von Apparaten und Maschinen für Prozeßstufen

Economy as a criterion for development, design, and choice of equipment and machines for process steps . The object of this paper is to show how a supplier of individual machines can influence the total costs of a chemical processing plant. This influence is quantified using actual examples based on the development of a product range, the optimizing and matching together of mechanical and thermal separation processes, and the selection of the most suitable types of equipment. Studies show that the products and services of an equipment manufacturer can influence substantially more than just capital investment costs and interest charges with their consequent effects on the annual running costs of a plant. It is possible to reach more economical solutions for important stages in a manufacturing process if the plant designers and the equipment manufacturers work closely together. A too tightly specified enquiry can prevent a manufacturer from offering the technically and economically optimized solution. By involving equipment manufacturers and correctly using their know-how one can tap a substantial potential for the reduction of plant running costs.     

Desaktivierung von technischen Silber-Trägerkatalysatoren für die Herstellung von Ethylenoxid

Deactivation of industrial supported silver catalysts for ethylene oxide production. In view of the model character of the reaction and the unique nature of the catalyst system, it is of interest to study the deactivation behaviour of technical supported silver catalysts for the production of ethylene oxide. In the present study the influence of the catalyst components support, silver, promoter and inhibitor upon the deactivation behaviour is described. The results of chemical, physical and technical investigations of various catalysts and catalyst components are presented. The investigations show that a decrease in the surface area of the exposed silver and increased deposition of chloride are responsible for catalyst deactivation. The possible influence of alkali promoters is discussed and modifications to the catalyst which have been described in the literature as influencing the deactivation are also evaluated.