(79c) Improving Methanol-to-Olefins Conversion Performance of CHA Materials By Seeding the Hydrocarbon Pool
AIChE Annual Meeting
2017
2017 Annual Meeting
Materials Engineering and Sciences Division
Materials Innovations Inspired By Acrivos Award Winner Chris Jones II
Monday, October 30, 2017 - 1:04pm to 1:21pm
We report experiments in which seeding the CHA zeotypic materials with acetaldehyde (0.1 kPa CH3CHO, 673K, 0.02-0.5 C/H+) reduces the initial rate of carbon loss by introducing reaction pathways that compete with methanol dehydrogenative transfer events. Increasing seed loadings and inlet methanol pressures lead to lower cumulative carbon loss at early turnovers, consistent with lower formaldehyde formation rates being responsible for the observed reduction in carbon loss. The introduced seed also acts as a co-catalyst, thereby reducing the length of the induction period, leading to higher turnover numbers with increasing seed loadings at equivalent times-on-stream. These studies exemplify a strategy for mitigating the deleterious effects of methanol hydride abstraction events that effect MTO deactivation.