Abstract:
The present invention relates to a process for the preparation of zeolitic catalysts comprising zeolite and oligomeric silica, which can be used in industrial reactors. The process consists in directly mixing the suspension, resulting from the synthesis of the zeolite, with an oligomeric silica sol, obtained from the hydrolysis of a tetra-alkyl ortho silicate in the presence of tetraalkylammonium hydroxide, and in subjecting the mixture to rapid drying, by feeding to a spray-dry.
Abstract:
PURPOSE: A method of removing a casting agent from synthetic zeolite is provided. CONSTITUTION: In the method in which a casting agent is removed from synthetic zeolite, especially from silicalite, titanium silicalite, and a composite material containing zeolite, the zeolite is activated as a catalyst, and the above materials are treated by a solvent comprising 20-100mol.% of methanol, ethyl ester or methyl halides at a temperature range of 250 to 280deg.C for 0.25-72 hours in a gas phase.
Abstract:
PURPOSE: A process for producing a zeolite catalyst containing zeolite and oligomeric silica which can be used in industrial reactors is provided. CONSTITUTION: The process for the preparation of zeolitic catalysts based on the rapid drying of an aqueous dispersion comprising crystalline zeolite, oligomeric silica and tetra-alkylammonium hydroxide, is characterized in that the aqueous dispersion is prepared by directly mixing the suspension resulting from the synthesis of the zeolite with an oligomeric silica sol obtained from the hydrolysis of a tetra-alkyl ortho silicate in the presence of tetra-alkylammonium hydroxide.
Abstract:
The present invention relates to a method for the removal of the templating agent from synthetic zeolites in general and in particular from silicalite, titanium silicalite and from composite materials containing zeolites and for their activation as catalysts. The method consists in treating the above materials with solvents in vapor phase and at a low temperature.
Abstract:
PURPOSE: An MFI-type zeolite based catalyst and its preparation method are provided, which catalyst is useful for the transformation of oximes into amides. CONSTITUTION: The MFI-type zeolite based catalyst is prepared by: preparing silicate oligomer by hydrolyzing silicon alkoxide; mixing the oligomer with an aqueous or aqueous alcoholic dispersion solution of sub micro particles of MFI-type zeolite which is acidified to pH below 5; emulsifying the aqueous or aqueous alcoholic ligand/zeolite mixture in an organic solvent; contacting the emulsion with a basic solution to bind the dispersed micro drops; and washing calcining the obtained micro sphere. Preferably the MFI-type zeolite is selected from the zeolite whose mole ratio of Si/Al (or Si/B, Si/Ga, Si/In, or Si/Ti) is more than 1,000, and silicalite-1. The MFI-type zeolite based catalyst is such that the silicate ligand represented by SiO2 is more than 30 wt%, the outer surface area is 60-80 square meter per gram, the specific volumes of micro pore and mesopore are 0.2-0.3 ml/g and 0.1-0.4 ml/g, respectively, the bulk density is 0.7-0.85 g/ml, and the Davison index is less than 6.