Progress of crystallization into zeolite beta in the absence of steam

The role of steam on the crystallization of zeolite beta by the steam-assisted crystallization (SAC) method was studied. It was found that after an aluminosilicate dry gel with SiO₂/Al₂O₃ molar ratio = 100 was treated with steam in an autoclave at 130°C and autogenous pressure, thermal treatment of a resultant product at 130°C without the addition of water in an autoclave gave zeolite beta with a high crystallinity. Zeolite beta obtained by this method consisted of nano-particles with a diameter of ca. 30 nm. It was presumed that intermediates of zeolite beta was formed during steam treatment, and the dehydration between silanols in the intermediates during the thermal treatment in the absence of steam possibly caused the transformation from ill-ordered structures to zeolite beta crystals with a periodicity in long-range order.