Abstract: Towards the problems that the traditional symmetric operation mode of parallel continuous catalytic reforming (CCR) units cannot fully release the potential of aromatics yield, in this paper, an asymmetric operation strategy based on feedstock fractionation and severity matchingisproposed. In this strategy, hydrotreated naphtha is roughly fractionated and then delivered to two parallel CCR units respectively. The reaction temperature of light feedstock is raised to enhance the conversion of C₆—C₇ hydrocarbons, while the reaction temperature of heavy feedstock is lowered to control the coking rate. The simulation results show that under the constraints of catalyst coke deposition and reaction temperature, the asymmetric operation can increase the total aromatics yield by 1.47 percentage points and the hydrogen yield by 0.15 percentage point, which presents good economic performance. This strategy requires little modifications to the main configuration of existing units and catalysts, and can realize the directional regulation of products only by adjusting feedstock distribution and operating parameters, providing a feasible technical path for the benefit potential exploitation of parallel CCR units.

Key words: continuous catalytic reforming, asymmetric operation, reaction mechanism model, parallel units