INFLUENCE OF SURFACE-ACTIVE SUBSTANCES ON IMPREGNATION PROCESS IN PRODUCTION OF METHANE CONVERSION CATALYSTS

Abstract

The effect of various surfactants on the corundum carrier impregnation process using solutions of nickel and aluminum nitrates in steam condensate used in the production of supported methane steam reforming catalysts is compared. It has been shown that the use of surfactants to eliminate the “hang” of the impregnating solution in the carrier layer (catalyst or intermediate with multiple impregnation) in the holes of the granules, as well as in the contact points of the granules between themselves and the walls of the apparatus is an effective method of improving the quality of the resulting catalyst. Using for this purpose, synthanols (ethoxylated alcohols, which are non-ionic surfactants), compared with diethylamine, polyvinyl alcohol and ethylene glycol, can significantly (by 3 orders of magnitude) reduce their required content in solution, which is confirmed by many years of production experience. The high efficiency of synthanol in reducing the surface tension of the solution at its minimum concentrations was confirmed. The results of spectral studies and quantum-chemical calculations of the syntanols molecules interaction with nickel ions are presented. The presence of intermolecular interaction in the solution between the surfactant molecules and nickel ions, leading to the binding of some of the ions in the solution, is shown. The use of synthanol can significantly reduce the chance of the catalyst surface carbonization that decreases its activity. Also the probability of possible some metal ions entrainment with the impregnating solution decreases. The use of synthanol, taking into account its widespread use in sanitary goods and hygiene products, also allows reducing toxicity and explosion hazard at workplaces inside the methane conversion catalysts production area.