Chemical Reactivity in Confined Space-Times

Deniz Uner, Chemical Engineering, Middle East Technical University, Ankara, Turkey


Confinement effects are frequently encountered in chemically reacting systems. The most common examples are species adsorbed on the surfaces by strong bonds, i.e., enthalpic effects or trapped in pores present in the structure, i.e. entropic effects. In addition to these well acknowledged confinement effects, it is also possible to induce confinement in reacting flows through eddies, Taylor vortices and membrane walls as well as creating confinements in delivering the reactants through well-defined pulses of given periods and intensities. The influence of confinement in pulses on the activity and selectivity is not as straightforward. Because, little is understood about the reflection of the deliberate changes in the gas phase on a gas solid catalytic surface reaction. In this talk, I will present the results of three different studies on confinement effects. The first example will be artificial photosynthesis conducted in a batch low pressure reactor to describe the role of confinement in space. The second example will be on dry reforming of methane in a tubular packed bed reactor to describe the role of confinement in time. The third example will be on Fischer Tropsch synthesis in a Taylor flow reactor to describe the role of confinement in space-time.