2 results about "Solid phase crystallization" patented technology

The present application relates to a kind of high selectivity molecular sieve based on high-silicon low-calcium fly ash preparation and its preparation method and application, belong to molecular sieve preparation technical field.To solve the problem that molecular sieve crystallization process and high-silicon low-calcium fly ash raw material characteristics do not match, the present application provides the preparation method of high selectivity molecular sieve based on high-silicon low-calcium fly ash preparation, steps include targeted removal Fe2O3 Impurity, silicon-aluminum is activated and dissolved to obtain the silicate gel of controllable water content, using seed and mechanical force coupling direction solid phase crystallization and forming calcination obtain SiO2-Al2O3 Type molecular sieve.The present application improves the purity of molecular sieve crystal to 90~98%, the deviation of pore size distribution is reduced to below 5%, greatly improves the regularity and stability of molecular sieve crystal structure, also improves its adsorption capacity to NH4 + , CO2 And the separation coefficient of NH4 + And other cations, has wide application prospect in wastewater denitrification and carbon capture field.

The application discloses a shape-selective alkylation catalyst and a preparation method and application thereof, and relates to the field of chemical industry. The in-situ doped Mg-ZSM-5 molecular sieve crystal with multistage pores is obtained by an in-situ hydrothermal synthesis method, Mg dispersion and fixation are promoted while the acidity of ZSM-5 is adjusted, and the migration change of Mg in the shape-selective alkylation reaction process is effectively inhibited. The molecular sieve crystal is used as a precursor, neutral transparent nanometer silicon sol is used for bonding and forming, and then secondary crystallization is carried out through the in-situ gas-solid phase crystallization conversion method, so that the nanometer silicon sol completely covered on the surface of the Mg-ZSM-5 is in-situ converted into full-silicon S-1 molecular sieve crystal phase with the same topological structure as the ZSM-5 molecular sieve, the acid sites on the outer surface of the molecular sieve are effectively and completely passivated through the complete coverage of the full-silicon S-1 molecular sieve on the outer surface of the Mg-ZSM-5, and the good connectivity of the molecular sieve channel is reserved. The shape-selective alkylation catalyst can be applied to the alkylation process of synthesizing p-methyl ethyl benzene from toluene and ethanol or ethylene.