Methanol conversion on ceramic

Methanol Conversion on Ceramic Honeycombs Coated with Silicalite... 

A pentasil type zeolite (ZSM-5) is being used in a methanol to gasoline (MTG) conversion process (7) in a fixed bed reactor. This type of zeolite when washcoated on ceramic honeycomb substrates should offer the advantages of lower pressure drop and high geometric surface area in the reactor. Such washcoated zeolite catalysts must be strongly bound to the honeycomb substrate and should have the maximum number of active sites for highest catalytic activity for chemical process applications. 

Thus the objective of this study is to find the best combination of binder and zeolite composition for washcoating silicalite (a pentasil type zeolite) on a ceramic honeycomb substrate, and to evaluate the catalytic activity for methanol conversion. This will demonstrate the utility of zeolite honeycomb catalysts for chemical processing. 

Wanat et al. investigated methanol partial oxidation over various rhodium containing catalysts on ceramic monoliths, namely rhodium/alumina, rhodium/ceria, rhodium/ruthenium and rhodium/cobalt catalysts [195]. The rhodium/ceria sample performed best. Full methanol conversion was achieved at reaction temperatures exceeding 550 °C and with O/C ratios of from 0.66 to 1.0. Owing to the high reaction temperature, carbon monoxide selectivity was high, exceeding 70%. No by-products were observed except for methane. 

Effluents from resin production have a high COD (19,500 mg/L) and contain phenol, formaldehyde, and methanol. They could be treated by CWAO using a 3 wt% Ru on ceramic spheres coated with carbon. With this catalyst, the conversion of COD was about 92% at 200 C and 1.5 MPa of O2. The catalyst was stable for about 30 days. 

---