Oxidation/adsorption desulfurization of natural gas by bridged cyclodextrins dimer encapsulating polyoxometalate

In order to obtain the ultra low-sulfur natural gas, deep desulfurization by polyoxometalate has been paid a great attention. The host/guest inclusion complex CDP is obtained by a bridged cyclodextrins dimer encapsulating polyoxometalate H-9[P2Mo15V3O62], which has been characterized through Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. H-9[P2Mo15V3O62] and inclusion complex CDP are utilized for the removal of hydrogen sulfide from natural gas. Desulfurization experimental results show that the desulfurization efficiency is inclusion complex CDP > H-9[P2Mo15V3O62] > physical mixture of cyclodetreins dimer and H-9[P2Mo15V3O62] > commercial desulfurizer CT8-6B (mixture of hydrated ferric oxide and gamma-Fe2O3) > bridge cyclodextrins dimer, and the desulfurization efficiency of inclusion complex CDP can reach 99.6% after being used for 2 h, besides, the desulfurization product from inclusion complex CDP mainly contained sulfur. In addition, space velocity has little effects on sulfur capacity of inclusion complex CDP, and inclusion complex CDP can be recycled five times with a slight decrease in desulfurization efficiency. These advantages present a potential application of inclusion complex CDP for desulfurization of natural gas. (C) 2012 Elsevier Ltd. All rights reserved.