(672g) Millisecond-Modulated Dynamic Gas Pulsing for Enhanced Surface Activity during Partial Oxidation of Methane to Syngas
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Emerging Catalytic and Dynamic Reactor Designs
Wednesday, November 8, 2023 - 9:48am to 10:06am
Thereâs a need for reactors with sharp input modulation at kinetic timescales and fast transport to study the contribution of each phenomenon to catalytic enhancement, without competing transport effects. To this end, we have designed a microreactor platform for oxidant/reductant feed switching to study the induced effects on reaction rate, selectivity, and catalyst deactivation for the partial oxidation of methane. The reactor is a wash-coated glass capillary designed to operate in plug flow for precise gas pulses and negligible thermal gradients. Pressure tests and residence time distributions validated near plug flow operation and millisecond residence times, critical for modulation above 1Hz. Feed modulation achieved square waveforms at frequencies up to 25Hz. The reactor is integrated in a gas chromatograph, providing fast MS/FID for analysis of products and temperature programmed oxidation to measure catalyst activity, selectivity, and coking. Dynamic experiments revealed that turnover responds to input concentration oscillations and time-averaged conversion at low temperature was maximized at the stoichiometric duty of complete oxidation which is dominant in an isothermal condition.