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Preparation And Properties On Adsorbents For Sulfur Removal In High Sulfur-containing Diesel

Posted on:2007-03-17Degree:MasterType:Thesis
Country:ChinaCandidate:Z X WuFull Text:PDF
GTID:2121360212470987Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
A series of adsorbents contained Cu2+ and Zn2+ ions were prepared by hydrothermal synthesis and ion-exchange methods, respectively. Then, adsorption desulfurization was carried out in a fixed-bed absorber with FCC diesel as a raw. In the meantime, the total sulfur contents in diesel before and after adsorption was measured using a microcoulomb method. The capacity and selectivity of sulfur adsorption observed over Cu-MCM-41 adsorbent were evaluated by a dynamic experiment at room temperature and under the atmospheric pressure. The results showed that 1 g of Cu-MCM-41 would be up to saturation after treating 16 ml of high sulfur-containing diesel fuel, and 0.25 mmol of sulfur can be removed at per gram of adsorbents. Meanwhile, the sulfur contents in diesel were reduced by a cycle procedure from 1600 to 300 ppm. The Cu-MCM-41 adsorbent has been proven to be by far the most sulfur-selective as well as present the highest sulfur capacity. The results of model diesel adsorption experiment showed that the adsorption of thiophene and benzothiophene observed over Cu-MCM-41 adsorbent.were higher than that of naphthalene.The impact factors of adsorption desulfurization are studied in this experiment. Firstly, Compared to different adsorbens, MCM-41 exihibited in large specific surface area and pore diameter as an adsorbent support. Secondly, Desulfurization efficiency was influenced by different metal ions. The better desulfurization performance, the smaller radius of positive metal ion; in addition, metal ion lowered the surface area and pore diameter of adsorbents. The exchange capacity of Cu2+ was stronger than that of Zn2+. Finally, metal-loading capacity changed with difference of preparation methods as following the order: solid-state ion-exchange > liquid-phase ion-exchange at high pressure > liquid-phase ion-exchange. In addition, if adsorbents are pretreated at vacuum and high temperature before use, the desulfurization performance can be improved further.
Keywords/Search Tags:High sulfur-containing diesel, Desulfurization, Adsorbent, Specific surface area
PDF Full Text Request
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