Preparation of CuNaY zeolites with microwave irradiation and their application for removing thiophene from model fuel

To produce ultralow-sulfur fuels, copper ions have been introduced into the framework of Y zeolite by a novel, simple liquid-phase ion exchange method taking advantage of microwaves irradiation. Removal of thiophene from model fuels were studied over activated copper ion-exchanged zeolite samples using column breakthrough experiments at ambient temperature and pressure. The effects of the microwave irradiating power, duration time and the copper ion concentration in aqueous solutions on the ion exchange level and the structure of copper ion-exchanged zeolite samples were investigated by atomic absorption spectrophotometer, X-ray powder diffraction, NZ adsorption and scanning electron microscope and X-ray photoelectron spectroscopy. The results demonstrated that ion exchange under microwave irradiation was a more attractive zeolite preparation method compared with conventional ion-exchange process. The maximum exchange level of 75% could be obtained after only 10 min irradiation while the exchange level was 71% after conventional ion exchange for twice and the copper can be better dispersed in zeolite framework under microwave irradiation. Microwave-irradiated CuNaY zeolites could efficiently remove thiophene from model fuel with a high sulfur removal capacity of 1.22 mmol/g. (C) 2008 Elsevier B.V. All rights reserved.