Study on adsorption separation of n-heptane from 120 # solvent oil

摘要

Breakthrough curves and adsorption capacity of 120 # solvent oil on 5A zeolite were detected in fixed-bed adsorber. The length of mass transfer zone was calculated as well for evaluating the performance of adsorption. The experiments covered a temperature range of 423-573K, and adsorption pressure up to 0.6 Mpa (absolute pressure). The effects of temperature, adsorption pressure and feed flow rate on the behavior of the system were studied. Results show that the breakthrough curve of n-heptane has a sharp nature. The adsorption capacity of 120 # solvent oil on 5A zeolite decreases from 0.073 kg/kg to 0.038 kg/kg by increasing the temperature from 423 K to 573 K at 0.1MPa and flow rate of 5mL/min; while the adsorption pressure has a minor influence on it. With the variation of flow rate from 3mL/min to 8mL/min, the largest adsorption capacity of 0.073 kg/kg is obtained at feed flow rate of 5 mL/min due to the bidisperse porous characteristics of 5A zeolite pellets. And the variation of adsorption capacity can be detected by the average temperature increase of the adsorber. Additionally the higher adsorber efficiency can be obtained under the condition of 473K, 0.6MPa, and 3mL/min.