Microwave was applied to the high-temperature removal of H2S by a Fe-based sorbent supported on active coke (Fe2O3/AC). The influence of the loading content, adsorption temperature, and desulfurization way on the sulfidation properties of sorbents was investigated. N2 adsorption, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques were used to characterize the structure of sorbents before and after desulfurization. The results reveal that the microwave sulfidation performs best at 600 °C, while a further increase of the temperature leads to a lower sulfur capacity and utilization rate of Fe2O3 as a result of the pore structure deteriorating sorbents. The Boltzmann function is suitable for describing the H2S evolution behavior of the Fe2O3/AC sorbent bed. Several advantages of microwave sulfidation over the conventional way are as follows: much better performance of Fe2O3/AC sorbents, less decline in surface area and pore volume per unit sulfur capacity when removing H2S at 400, 500, and 600 °C, and more S2– and oxygen vacancy species on the surface of used desulfurizers. In comparison to conventional desulfurization, there is no notable decrease in the apparent activation energy of the overall sulfidation reaction by the microwave way. The enhancement of the desulfurization rate may be due to quicker ion diffusions and/or better mass transfer under microwave conditions.

Abstract. ZnO sorbents with different CeO 2 loadings were prepared by microwave calcination and tested the performance for H 2 S removal in a fixed-bed reactor at 500 . The results r ℃ evealed that the Ce-doped sorbents have a higher efficiency and longer breakthrough time compared with non-modified sorbents. The optimal sulfur capacity (13.03 gS/100 g) and breakthrough time (17.5 h) were obtained when the content of CeO 2 up to 4 wt.%. XRD, SEM, XPS and mercury porosimetry methods were used to characterize the structure of sorbents. Analysis data indicated that the addition of CeO 2 leads to better pore structure and larger specific surface, which facilitates the diffusion of H 2 S into the active sites. Furthermore, the presence of CeO 2 also results in an increase in the content of surface elements including Zn and O, which contributes to improve the ability of H 2 S removal. IntroductionThe integrated coal gasification combined cycle (IGCC) process is considered as one of the promising clean coal technologies in the 21st century [1][2][3], meanwhile the high temperature gas desulfurization (HTGD) was regarded as one of the key techniques in the IGCC system [2][3][4][5][6][7]. The oxides of Zn, Fe, Ca, Mn and Co as H 2 S sorbents for HTGD are investigated extensively nowadays [7][8][9][10][11][12][13].Among these sorbents, Zinc oxide sorbents are considered to be the most promising material for HTGD because of its large sulfur capacity and excellent desulfurization thermodynamics [7,14,15]. Up to now, many synthesis methods have been investigated [16][17][18][19][20]. In comparison with traditional preparation methods, microwave irradiation is a burgeoning method to prepare desulfurizer by virtue of it can provide a rapid drying and evenly heating [21]. The advantages of microwave heating over conventional heating have been studied in our previous work [22].But under the condition of high temperature, the ZnO sorbents would evaporate thus limit its development [7,23]. Moreover, single ZnO sorbents show many disadvantages such as decrease of sorbent efficiency and degradation of the mechanical properties [24]. In order to improve the performance, ZnO sorbents mixed with many metal oxides have been evaluated [24][25][26][27]. CeO 2 as one of the most promising rare earths has an outstanding oxygen storage capacity and improve the performance of ZnO sorbents for desulfurization [11,[28][29][30].In this paper, the performance of ZnO based sorbents doped with various content of CeO 2 employed for high temperature coal gas desulfurization were studied. Also, the effects of the amount of CeO 2 loaded to the sorbents on the performance for H 2 S removal were studied. The analysis data of structure and textural properties were provided by XRD, XPS, SEM and mercury porosimetry.