Aerosolbildung durch spontane Phasenübergänge bei Absorptions- und Kondensationsprozessen

Formation of aerosols by spontaneous condensation or desublimation in condensers or absorbers often causes serious problems in industrial processes. The fine aerosol particles, formed under special operating conditions, remain suspended in gases and are carried over into downstream stages or lead to high pollutant concentrations in the exhaust gas. The present paper describe under what conditions aerosols are formed. The characteristic behaviour of aerosols is discussed with the aid of experiments and computer simulation.     

Absorption der Reaktionspartner am Katalysator bei der Fetthydrierung

Absorption of Reactants on Catalyst in the Hydrogenation of Fats The study involves selective hydrogenation of fatty oils containing polyenoic fatty acids. In the initial stage of hydrogenation the catalyst surface is probably predominently occupied by the polyenoic acids. At that stage the monoenoic acids are hardly hydrogenated and also the isomerisation of the monoenoic acids is largely suppressed. Analysis of the monoenoic acid formed from linoleic acid shows that the reaction product is so composed as if an equimolecular mixture of 9-cis,11-trans- and 10-trans, 12-cis-conjugated isolinoleic acids were taken as starting material. Obviously, the catalyst surface is occupied by the conjugated polyenoic acids.     

Anwendung der UV-Spektrophotometrie bei der Untersuchung der Oxydation und Polymerisation von Fetten

Application of UV-Spectrophotometry in the Investigation of Oxidation and Polymerisation of Fats In the direct UV-method, the first maximum of extinction at wave-length 243 nm of heated sunflower oil is related to viscosity, refractive index and specific weight, but not related to peroxide value and aldehyde content. In these experiments the oils were heated in air, in air current and in current of nitrogen.