Analysis of combined heat and mass transfer in membrane-assisted thermally coupled reactors containing naphtha reforming and m-xylene hydrodealkylation

Abstract

In this work, the performance of catalytic naphtha reforming in the thermally coupled membrane reactors has been investigated. It is suggested that the hydrodealkylation of m-xylene be placed in the tube side and the catalytic reforming in the shell side of the proposed reactor. The interior reactor wall has been made of palladium membrane, which permits the hydrogen to penetrate from the shell side with higher partial pressure to the tube with lower partial pressure. Thermal coupling of hydrodealkylation of m-xylene with naphtha reforming, as well as the removal of a part of the hydrogen as a by-product from the reforming side leads to an increase in reformate production. Simulation results indicate that the aromatic production rate in this configuration increases by 16.43% relative to the membrane reactors and by 23.52% relative to the conventional reactors. The effect of parameters including the membrane thickness, inlet temperatures of naphtha and HDA feeds, the molar flow rate of the hydrodealkylation side, the hydrogen to hydrocarbon molar ratio and also, the catalyst deactivation on the performance of the system has been studied. Finally, in order to improve the performance of thermally coupled membrane reactors, the effective parameters in the proposed configuration have been optimized by the genetic algorithm. The yield of aromatic was enhanced by about 14% by this optimization. Also, the conversion of m-xylene in each bed was improved in optimized thermally coupled membrane reactors.