PURPOSE: To increase the strength of a pentasil-type zeolite compact by bringing the compact into contact with the water contg. gas, liq. or alkali.
CONSTITUTION: The pentasil-type zeolite (e.g. ZSM-5) is usually produced by hydrothermal synthesis and further subjected, as required, to drying, sintering, ion exchange, etc. This zeolite compact is obtained from any of the hydrothermally synthesized, dried, sintered and ion-exchanged zeolites. The zeolite is dipped in water or the water is passed through a column packed with the zeolite, the water is kept at 30-100°C, and the contact time is controlled to 5min to 10hr. When water vapor is used, water at 30-200°C is used in the column and brought into contact with the zeolite for 5min to 72hr. When a liq. alkali is used, the water is regulated to about pH 9-13. A basic gas such as ammonia is used as the alkali when the alkali is incorporated into the water vapor.
MURATA SHUZO
TSUCHIMOTO KAZUYA
