Deep Desulfurization Of Diesel By Ni, Ce Ions Exchanged MCM-41and KIT-6 Mesoporous Materials

Two different pore structures of mesoporous materials MCM-41 and KIT-6 were used as the adsorbents carrier. Ni2+ ions were grafted onto aluminized MCM-41 and KIT-6, a series of mesoporous materials with one metal component of Ni2+ adsorbents were prepared by increasing the ion exchanging temperature and ion exchanging times. At the same time, adsorbents were also prepared by exchanging Ni2+ and Ce3+ of the two metal components onto the aluminized MCM-41. Adsorption desulfurization experiments of model diesel(300 ppmw S) were carried out on a fixed bed. The best of adsorption performance of the adsorbent was selected for commercial diesel(149 ppmw S) adsorption desulfurization experiment. The regeneration performance of the adsorbent was also investigated. The characterization of the adsorbents was analyzed by using XRD, N2 adsorption, ICP and other physical methods.The characterizations of the adsorbents results showed that the prepared adsorbents were mesoporous sturcutre and have the properties of mesoporous materials. The desulfurization performance of the adsorbents were increased by increasing the metal ions contents.The desulfurization experiments of model diesel : the results showed that Ni/AM60-4 adsorbent prepared by the optimum temperatures(60 ℃) and Ni2+ ions exchange for 4 times on the MCM-41 carrier, produced 16 ml clean model diesel(sulfur content is less than 1.0 ppmw). In the breakthrough point, the Ni/AM60-4 adsorbent of sulfur capacity was 0.105 mmol/g that the sulfur capacity was increased 78.0% compared with Ni/AM20-1 adsorbent. Ni based MCM-41 adsorbents adsorption performance improved by elevating the temperature of the ion exchange and the numbers of the ion exchange.KIT-6 as the carrier, by raising the temperature of the ion exchange and increasing the number of the ion exchange modified Ni based KIT-6 adsorbents, adsorption performance of adsorbents has not improved.Ce-Ni/AM60 and Ce/Ni-AM60 adsorbents prepared by two metal components on 60 ℃. In the breakthrough point, the adsorbents capacity of sulfur were 0.052 mmol/g and 0.080 mmol/g that the sulfur capacity was not increased compared with Ni/AM60-1 adsorbent capacity of sulfur(0.085 mmol/g). Ce ions adsorption desulfurization ability compared with Ni ions adsorption desulfurization ability is low.In summary, Ni/AM60-4 adsorbent that prepared by the optimum temperatures(60 ℃) and Ni2+ ions exchange for 4 times had the best adsorption performance in model diesel adsorption desulfurization experiment.The adsorption desulfurization experiments of the commercial diesel was carried out in a fixed bed with Ni/AM60-4 adsorbent. Experimental results show that the produced clean diesel was 3.5 ml(sulfur content is less than 1.0 ppmw) at breakthrough and the adsorption capacity of sulfur was 0.011 mmol/g. And the adsorbent regeneration in situ was carried out by calcining the used adsorbent in air at 300 ℃ for 5 h. The adsorption desulfurization experiment of the commercial diesel was carried out with regenerated adsorbent and the adsorption capacity of sulfur was not decreased. The results showed that the used adsorbents can be completely recycled.