430195 Engineering Faster Reactions: Catalysis and Transport from Energy to Pharmaceutics

Sunday, November 8, 2015
Exhibit Hall 1 (Salt Palace Convention Center)
Andrew Teixeira, Chemical Engineering, MIT, Cambridge, MA

By identifying and systematically characterizing rate controlling phenomena in complex reacting systems, it allows for the development of new approaches to a diverse set of problems. Applying this fundamental approach to reaction engineering, several complex systems are simplified to their underlying rate controlling phenomena, revealing key insight into their mechanisms and potential future optimizations. Four distinct systems are considered: 1) biomass fast pyrolysis, 2) surface barriers in hierarchical zeolites, 3) microreactor design for multiphase catalytic reactors, and  4) amino acid activation for automated peptide synthesis.
  1. High speed imaging techniques on a micron-scale are combined with extensive chemical analyses to understand the fluid dynamics of biomass fast pyrolysis including the revelation of the reactive liquid intermediate, identification of the aerosol ejection method for nonvolatile transport, and the presence of the Leidenfrost effect with controllable heat flux with tunable surface properties.
  2. Surface barriers are shown to dominate transport in extremely small zeolites, with diffusivities diminished by three orders of magnitude in hierarchical materials. Several dynamic experimental techniques (ZLC, frequency response) and computational methods (kinetic Monte Carlo), are utilized to systematically characterize the barrier limitation in zeolites, resulting in the conclusion that the vast majority of the surface is dominated by a structural restrictions that act as effective pore blockages.
  3. By incorporating small amounts of catalysts into micropacked beds, systematic reaction analysis (kinetic, transport) is performed for gas/liquid/solid systems. Automation of all reactor components and in line analytics allow for rapid and comprehensive system mechanism and kinetic analysis and catalyst screening.
  4. Amino acid activation becomes rate relevant during automated peptide synthesis  over Merrifield resins. Mechanistic analysis and reaction kinetics are assessed using a rapid flow-based microfluidic platform to characterize the reaction and optimal conversion conditions.

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