Operation and optimization of an oscillatory flow continuous reactor

Oscillatory flow reactors (OFRs) are a novel type of continuous reactor, in which tubes fitted with orifice plate baffles have an oscillatory motion s uperimposed upon the net flow of the process fluid. The combination of baff les and the oscillatory motion creates a flow pattern conducive to efficien t heat and mass transfer while maintaining plug flow. Unlike conventional t ubular reactors, where a minimum Reynolds number must be maintained, tube-s ide mixing is independent of the net flow, allowing long residence times to be achieved in a reactor of greatly reduced length-to-diameter ratio. We h ave evaluated a pilot-scale OFR as a method for continuous production of st erols in an ester saponification reaction. The OFR achieved the required pr oduct specification, in a residence time one-eighth that of a full-scale ba tch reactor. To better understand the effect of the process variables on th e reactor performance, the OFR was modeled using a tanks-in-series residenc e time distribution, combined with the saponification reaction kinetics, gi ving a "flow-conversion" model which predicted conversion based on flow and feed parameters. This simple model has led to a number of insights into th e optimal operation of the OFR, one of which was that the OFR could give de sired conversion selectivity at a lower reaction temperature without signif icant alteration to other process variables. Also, the current product spec ification could be surpassed, if necessary. These predictions were verified by experiment. A full-scale OFR design based on these results would be les s than one-hundredth the volume of a full-scale batch reactor, assuming the same production rate and product quality. The construction of such an indu strial-scale OFR for the saponification reaction is now being considered by an industrial collaborator.