NUMERICAL-SIMULATION OF A SIMULATED COUNTERCURRENT MOVING-BED CHROMATOGRAPHIC REACTOR

A mathematical model of a simulated countercurrent moving bed chromato graphic reactor (SCMCR) has been developed. The model represents a mul tiple column reactor consisting of a series of either four or five tub ular fixed beds packed with a mixture of catalyst and adsorbent, with a port that can serve either as an inlet or an outlet between each. A reversible first order reaction, A reversible arrow B, with rate coeff icients and rate parameters taken from the hydrogenation of 1,3,5-trim ethylbenzene is incorporated into the model. The partial differential equations governing the isothermal reactor at 463 K are solved by an a daptive finite element method with uneven grid points. Model predictio ns of concentration profiles in the columns, and overall reactor perfo rmance, are obtained. It is shown that reaction and separation occur s imultaneously, and that the conversion of this equilibrium limited rea ction is greatly increased over the 0.62 that would be the maximum obt ainable in a non-separative system. Under appropriate operating condit ions, the model calculations predict that high product purity streams (98-99%) and nearly unit conversions can be obtained.