Sandra B Waters

US Patent:

49005294, Feb 13, 1990

Filed:

Dec 23, 1985

Appl. No.:

6/812163

Inventors:

Moises G. Sanchez - Severna Park MD
Charles C. Chang - Columbia MD
Norman R. Laine - Rockville MD
Sandra M. Waters - Ellicott City MD

Assignee:

W. R. Grace & Co.-Conn. - New York NY

International Classification:

C01B 3328
C01B 33113

US Classification:

423328

Abstract:

ZSM-5 crystallites are produced with very low levels of blocking tetrapropyl ammonium ions (Q). The reaction mixture contains sources of silica, soda, alumina and trace amounts of Q ions as nucleation agents. Because the crystallites as synthesized from the aqueous medium exhibit only a very small fraction of blocking cations, there is always a diffusion path for the hydrated sodium ions to be exchanged without the need of prior removal of the blocking cations by calcination or otherwise. The small size crystallites can be exchanged, blended with other materials, and formed into catalyst particles. The silica to alumina ratio can be varied and when no aluminum is added, silicalite may be formed. The systhesis can be done in 24 hours or less.