NON DESTRUCTIVE PROCESS FOR THE ELIMINATION OF SILICON FROM ALUMINA BASED MATERIALS

摘要

The present invention relates to a process for eliminating silicon and/or silicon compounds contained in alumina-based materials without destruction thereof, permitting reutilisation thereof, and consequently application principally lies in regeneration of silicon-contaminated alumina-based catalysts used in hydrotreatment processes in the petroleum industry to eliminate sulphur and remove silicon from process streams. In this respect it is important to note that known conventional procedures and/or methods for eliminating or removing silicon contained in alumina-based materials utilise an inorganic acid or mixtures thereof by digestion, the same modifying the properties of the alumina and of any other element contained in the material, destroying the alumina and preventing reutilisation thereof. The non-destructive process of the present invention is characterised in that it employs an extraction agent which depolymerises silicon compounds deposited on alumina-based materials without modifying the properties of the alumina-based material and without substantially modifying the content of other substances or metals present in the alumina-based material. The extraction agent is an alcohol, preferably a polyol, more preferably glycerol, a commercially-available material not requiring a high degree of purity for the application thereof. The silicon contained in the alumina-based material to which the non-destructive process of the present invention is applied is preferably in inorganic form, oxide and silanol: Si-(OX)4 (X = Al, H, Si) and/or in organic form, organosilanes: (OX)3-Si-CH3 and/or (CH3)2-Si-(OX)2 (X = H, Si); both structures are depolymerised through employing this removal process.