Crystallization of a Pelletized High-Crystallinity SAPO-11 Molecular Sieve with a Hierarchical Pore Structure

A way of synthesizing a pelletized high-crystallinity SAPO-11 molecular sieve with a hierarchical pore structure is proposed for the first time. Crystallization is based on preparing pellets composed of 70 wt % of powdered SAPO-11 and 30 wt % of a silicoaluminophosphate binder that is transformed into SAPO-11 during crystallization to form a single system of silicoaluminophosphate crystal aggregates. This crystallization allows the creation of pelletized SAPO-11 characterized by a high degree of crystallinity and phase purity, specific surface area SBET of 212 m2/g and micro-, meso-, and macropore volumes of 0.08, 0.11, and 0.55 cm3/g, respectively. It is shown that meso- and macropores formed between the SAPO-11 crystal aggregates.