Abstract: A model was established to simulate the process of p-xylene adsorption and separation on a moving bed to study the effects of the cycle period and the reflux ratios of each area of the adsorption tower on the adsorption performance of the adsorption and separation process. The simulation results show that: keeping the reflux ratio of each region unchanged, with the gradual shortening of the cycle period, the production WHSV is greatly increased, the purity of paraxylene and the yield indexes are gradually reduced, and when the cycle period is more than 24 min, the paraxylene product can still maintain a higher purity, and the yield is slightly reduced; to continue to shorten the cycle period, the reflux ratio of each region needs to be adjusted to ensure the purity of the product. Under the premise of ensuring product purity, the maximum production WHSV was obtained at a cycle time of 17.6 min, but at this time, the yield was lower at 82.2%, and the desorbent dosage per unit of product was about 19.9% higher than that at a cycle time of 32 min.

Key words: simulated moving bed, process simulation, adsorptive separation, p-xylene