A kind of double microporous
zeolite and preparation method thereof belong to the technical field of
fine chemical industry, it is characterized in that adopting two-step
crystallization method, the first step first synthesizes Beta, then with the synthetic Beta reaction mixture as the
raw material of the second step synthesizing Y
zeolite, The composite
zeolite product with BEA / FAU structure is obtained by supplementing the aluminum source, adjusting the basicity of the
system, adding the directing agent for synthesizing Y zeolite for reaction
crystallization, filtering, washing,
drying, and calcining. The method successfully solves the problems of pouring part of the
clear liquid and difficult control of the amount of aluminum source and base added in the synthesis because the
clear liquid contains components such as
silicon, aluminum and alkali, and the product
repeatability is difficult to control. The synthesized Beta / Y composite zeolite products can be used as various catalysts, catalyst assistants and adsorbents. After
ion exchange, they have strong acidity and good thermal and hydrothermal stability. They can be used as various catalysts, catalyst assistants It is bound to have potential application value in catalytic
cracking and hydrocracking of
petrochemical industry.