Direct synthesis of zeolite Y with large particle size

Abstract

Large zeolite Y particles have been synthesized directly from gels (4.76Na₂O: 1.0Al₂O₃: xSiO₂: 454H₂O: 5TEA, x=5.25–8.75) aged at ∼293 K before static heating at 368 K. Product purity, size, and Si/Al ratio of zeolite Y depended on the gel composition and aging time. Two-day aging of gels (x=5.25 and 7.0) resulted in nearly pure zeolite Y (<5–10 wt.% zeolite P_t) with Si/Al=1.7 and 1.9, and maximum size of 95 and 120 μm, respectively. Sieving of products grown from gels with x=8.75 aged for 7 days resulted in nearly pure zeolite Y in the ∼50–125 μm particle size range. The Si/Al ratio of all zeolite Y grown from gels with x=8.75 did not change with aging time (2–20 days) and was 2.1.