Process for making molecular sieves
AssigneeExxonMobil Research and Engineering Company
InventorsPreeti Kamakoti, Scott J. Weigel, Karl G. Strohmaier, Helge Jaensch, Marc H. Anthonis, Martine Dictus, Brita Engels, Darryl D. Lacy, Sina Sartipi
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Abstract
Processes are provided for preparing molecular sieves for use as catalysts. The process involves preparing a synthesis mixture for the molecular sieve wherein the synthesis mixture includes a morphology modifier which may be selected from cationic surfactants having a single quaternary ammonium group comprising at least one hydrocarbyl group having at least 12 carbon atoms, nonionic surfactants, anionic surfactants, sugars, and combinations thereof.
Claims18
1) A process of preparing crystals of a molecular sieve, the process comprising the steps of:
- a. combining at least a source of a tetravalent element X, a morphology modifier L, and water to form a synthesis mixture;
- b. heating said synthesis mixture under crystallization conditions for a time of about 1 hour to 100 days to form the crystals of the molecular sieve;
- and
- c. recovering said crystals of the molecular sieve from the synthesis mixture;
- wherein the morphology modifier L is selected from the group consisting of cationic surfactants having a single quaternary ammonium group comprising at least one hydrocarbyl group having at least 12 carbon atoms, nonionic surfactants, anionic surfactants, sugars and combinations thereof, and is present in the synthesis mixture before nucleation or crystallization of the crystals begins;
- wherein if the molecular sieve is one which requires a structure directing agent Q, the morphology modifier L is different from and is present in addition to the structure directing agent Q;
- wherein the molar ratio L:X in the synthesis mixture is in the range of from 0.0001 to 0.03;
- and
- wherein the synthesis mixture is a liquid, or a mixture of solid and liquid, and the liquid is substantially a single phase.
Dependencies are inferred from the claim text.