Abstract
In the ionic liquid desulfurization system, the repeated circulation and regeneration of the ionic liquid lead to the continuous accumulation of Cl(-), resulting in decreased desulfurization performance, increased ionic liquid loss, and exacerbated equipment corrosion. Therefore, the effective removal of Cl(-) from the desulfurization of ionic liquids is of great significance. This paper discusses the use of modified 717 resin for the removal of Cl(-) from a desulfurization ionic liquid. First, the adsorption equilibrium, adsorption thermodynamics, and adsorption kinetics of the modified 717 resin for Cl(-) were studied. The adsorption isotherm conforms to the Langmuir model, with an adsorption enthalpy of 1.971 kJ mol(-1), indicating that the process is a monolayer endothermic reaction. The adsorption kinetics follow a pseudo-second-order kinetic model, suggesting that the adsorption rate is controlled by chemical adsorption. Second, through dynamic adsorption experiments, it was determined that the optimal process parameters for Cl(-) removal were: liquid flow rate of 2 mL/min, bed height of 10 cm, initial Cl(-) concentration of 2300 mg/L, and reaction temperature of 45 °C. The dynamic behavior of the modified 717 resin in adsorbing Cl(-) conforms to the Thomas model and the Yoon-Nelson model. Then, the equilibrium adsorption capacity of Cl(-) of the modified 717 resin decreased by only 1.42 mg/g after five regeneration experiments, indicating that the resin has good renewability. Finally, the modified 717 resin removes Cl(-) from the actual desulfurization ionic liquid with good results. This study provides a theoretical basis for the industrial application of ion exchange resins for the removal of Cl(-) from desulfurization ionic liquids.