Method for producing crystalline gallosilicate similar to zeolite, method for producing catalyst and catalyst for aromatizing lower hydrocarbons

摘要

Process for the preparation of crystalline zeolite-analogous gallosilicates and their use for the preparation of catalysts and adsorbents. …??In the known processes for preparing zeolite-analogous gallosilicates, the latter are prepared from mixtures of reactive silica and gallium(III) oxide by hydrothermal crystallisation in the presence of alkali metal ions and quaternary ammonium compounds. The tetraalkylammonium salts serving as template compounds are, however, expensive educts for the zeolite synthesis and cause a considerable pollutant emission when the crude zeolite products are calcined. An inexpensive process of low energy consumption is to be provided which makes it possible to prepare zeolite-analogous gallosilicates of homogeneous morphology. …??The process according to the invention, using an Si/Ga atomic ratio of /= 5, by hydrothermal crystallisation from a reaction batch is characterised in that an aged, but still X-ray-amorphous gallosilicate nucleation gel having an Si/Ga atomic ratio of /= 5 is added as a crystallisation accelerator to the reaction batch. …??The zeolite-analogous gallosilicates prepared by the process according to the invention are suitable in particular for the preparation of catalysts and/or adsorbents and for the aromatisation of lower hydrocarbons.