Methyl Tertiary-Butyl Ether (MTBE) contamination of groundwater and surface waters has become a relevant environmental and public safety concern in recent years. This anthropogenic compound is now persistent at low concentrations in several valuable ground and surface water locations within the United States due largely to the widespread production of MTBE for use as a fuel oxygenate in conjunction with negligent underground storage practices during the 1980's and 1990's. Though there are several treatment strategies for the remediation of MTBE spill sites, the most efficient strategy may be adsorption of MTBE by a packed column of silicalite-1 adsorbent. Effective adaption of this technology requires cheap production of silicalite-1 sorbent packing particles on the order of 3 millimeters diameter. This work entails the development of a new synthesis process which results in sufficient in-situ crystallization of silicalite-1 aggregates within a 3 millimeter spherical amorphous silica gel source. The crystal aggregates sizes can be tuned from 5 to 70 µm, depending on synthesis parameters, and the finished silicalite-1 aggregate particle takes the shape of the amorphous gel source. These aggregate particles, when containing a small amorphous core, should be suitable for packed adsorption column applications. Multiple hydrothermal synthesis experiments were performed by batch methods featuring silica gel spheres as the sole silica source for the batch. Zeolite nucleation and crystal growth were demonstrated throughout the amorphous bead. Synthesis parameters were optimized both for short synthesis times, optimal mechanical properties, and cost effectiveness. The influence of product crystal size on particle hardness was also investigated. The packing production process is sufficiently ready for supporting pilot scale adsorption studies.

Hydrothermal synthesis of ZSM-5 is an often applied but incompletely understood procedure. In comparison to current research efforts that aim to produce complex micro-mesoporous catalysts for the conversion of biogenic and bulky hydrocarbons, this work focuses on the dependency between Si/Al ratio and zeolite morphology of microporous ZSM-5 to understand and to control the synthesis process. In two series of time dependent crystallization, kinetics were analyzed at Si/Al ratio 20 and 100 to optimize the crystallization time. Subsequently, zeolites with different Si/Al ratio were obtained and characterized. The results show a transition from a slow dissolutionrecrystallization process to a fast solid-state-transformation with increasing Si/Al ratio. This is followed by a switching morphology from clusters of small agglomerates to bigger spherical particles. Respective acid site density and zeolite morphology determine local residence time, hydride transfer behavior and finally selectivity towards aromatics and higher hydrocarbons during methanol conversion. This background should provide control of even more complex syntheses of porous catalysts.