Hide/Show Apps

Low temperature synthesis of SAPO-34 in a recirculating-flow system

Topuz, Berna
Oral, Eda E.
Kalıpçılar, Halil
SAPO-34 was synthesized both in recirculating-flow system and in autoclaves at low temperatures. A two-stage, varying temperature synthesis procedure was applied to reduce the crystallization time. The effects of synthesis temperature and synthesis system on the purity, particle size and BET surface area of the crystalline phase were examined. Pure SAPO-34 with high crystallinity was synthesized from a gel with Si/Al ratio of 0.2 at 130 A degrees C following aging at 80 A degrees C. The particle sizes of SAPO-34 crystals produced in stagnant mixture were in the 250-600 nm range, depending on the synthesis temperature. Flow induced crystallization caused a slight increase in the average particle size. SAPO-34 synthesized in the recirculating-flow system had a BET surface area of approximately 470 m(2)/g with a micropore volume of 0.28 cm(3)/g. From industrial standpoint, the stirring-recirculating-flow of synthesis mixture can be beneficial since uniform synthesis conditions can be accomplished during the production of SAPO-34 in large quantities.