ANALYSIS AND OPTIMIZATION OF CROSS-FLOW REACTORS WITH DISTRIBUTED REACTANT FEED AND PRODUCT REMOVAL

A systematic and general model was proposed for the simulation of cros s-flow reactors with product removal and reactant feed policies. Six t ypes of cross-flow reactors were analyzed for reversible series-parall el reaction systems and their optimal feed distributions were determin ed by maximizing the desired product yield at the outlet of the reacto r. The performances of reactors with different types of feed policies were compared at their optimal operating conditions. For irreversible reaction systems with lower order in distributed reactant for the desi red reaction than those for undesired reactions, a higher yield and se lectivity of the desired product could be achieved with the reactors w ith staged feed than with conventional co-feed reactors and a sufficie ntly high residence time was required by staged feed reactors to signi ficantly improve the desired product yields and selectivities over tho se obtained by a co-feed reactor. However, for reversible reaction sys tems, the desired product yield always reached a maximum value, and th en dropped down as the residence time increased. In addition to the ki netic order and residence time requirements, the rate constants of the reactions involved have to fall within certain ranges for the distrib uted feed reactor to obtain a higher maximum yield than one-stage co-f eed reactors. Optimally distributed feed reactors always give higher m aximum product yields than evenly distributed reactors with the same n umber of feed points. However, the improvement of yields is not as gre at as that between co-feed reactors and evenly distributed reactors. O n the other hand, for reaction systems with higher order with respect to the distributed reactant in the desired reaction than the undesired reactions, co-feed reactors always give higher yield than staged feed reactors.