Catalytic Consequences of Catalyst Pellet Architecture on the Methanol to Oxymethylene Process
Abstract
A critical step for the synthesis of renewable oxy methyl ethers (OME) targeted towards diesel substitution, is the catalytic production of a dimethoxymethane/formaldehyde mixture from methanol and air. The bifunctional catalyst requirements needed for methanol to undergo both the acidic and oxidative steps required for dimethoxymethane formation have been recently established for TiO2-supported vanadia catalysts. However, translating these requirements to a catalyst capable of industrial operation remains a challenge. This thesis examines the considerations and adjustments needed to translate the molecular active phase to a large-scale catalytic pellet, including active phase distribution and possibility of hot-spot creation during catalysis. Multiple formulations are explored to evaluate the consequences on catalytic performance of systematic changes on vanadia dispersion as well as its distribution throughout the solid catalyst pellet. By controlling the distribution of vanadia, we constrained undesirable pathways in the reaction maximizing dimethoxymethane production; however, formaldehyde production was still slightly limited.