A series of xMnyCe/hexagonal mesoporous silica (HMS) sorbents with wormhole-like structure was prepared by a sol−gel method, and their performance for hot coal gas desulfurization was investigated at 600 °C. All xMnyCe/HMS sorbents exhibited high breakthrough sulfur capacity, and the utilization of these sorbents was much higher than that of 10Mn/HMS. The breakthrough sulfur capacity over 4Mn1Ce/HMS sorbents was 121.7 mg of S/g of sorbent with the utilization of 82.4%. Such a behavior was maintained in eight consecutive desulfurization−regeneration cycles. The effects of the desulfurization temperature, H 2 concentration, and 7% steam on the performance of 4Mn1Ce/HMS were examined. The fresh, used, and regenerated samples were characterized by means of X-ray diffraction, N 2 adsorption, Fourier transform infrared absorption spectroscopy, and high-resolution transmission electron microscopy techniques. The results confirmed that the manganese oxide was dispersed highly on the HMS support because of the synergetic effects of manganese oxide and ceria oxide, and the wormhole-like structure in sorbents promoted the diffusion of H 2 S molecules. The Brunauer−Emmett−Teller results revealed that the wormhole-like mesoporous structure in sorbents remained intact even after the eighth successive desulfurization/regeneration cycle.

The improved deactivation kinetic model over mesoporous LaFeO3/MCM-41 sorbents for hot coal gas desulfurization was established with mass-transfer correlation based on elementary stoichiometric equation, which consisted of both the spatial and the time partial differential equations. MATLAB software was used to solve partial differential equations by means of forward finite differential method and to estimate kinetic parameters via nonlinear least-squares fitting. The rate constants k a and k d were obtained via aforementioned kinetic model over different LaFeO3/MCM-41 sorbents. The calculated results were in accordance with experimental data under various operating conditions. The kinetic model can be used successfully to predict the distributions of H2S concentration at different times and spatial positions within fixed-bed layers, compared to unreacted shrinking core model, random pore model, or grain model. It is of very great significance to obtain basical chemical engineering data for the design of new reactor. For 50%LF2/MCM-41 sorbent, the calculated apparent activation energy (E a) and deactivation energy (E d) for chemical reaction of LaFeO3 active sites are 32.1 and 15.1 kJ·mol–1, respectively, based on the experimental data of desulfurization process.

Hexagonally ordered mesoporous MSU-S was assembled from nanoclustered zeolite seeds. The XRD and BET results verified that after treated in 10%H 2 O/N 2 atmosphere at 800°C for 2 h, MSU-S still remained a well-ordered hexagonal structure due to rich acidic sites and excellent hydrothermal stability. A series of Sm x Mn y O z /MSU-S sorbents were prepared by a sol−gel method. The desulfurization performances of the 55%Sm 5 Mn 95 /MSU-S sorbent were improved significantly due to high hydrothermal stability of MSU-S with high surface area as well as the synergistic effect between Mn and Sm 2 O 3 . The result of eight successive sulfurization/regeneration cycles of sorbent illustrated that high breakthrough sulfur capacity and endurable stability of 55%Sm 5 Mn 95 /MSU-S correlated closely with the existence of the framework 4-coordination aluminum (NH 3 -TPD, 27 Al MAS NMR) and high dispersion of Sm/Mn species on MSU-S (XRD, TPR) for H 2 S removal. HRTEM images and SAED patterns confirmed that fresh 55%Sm 5 Mn 95 /MSU-S existed in high ordered mesoporous structure and the nanosized Sm 2 O 3 and Mn 3 O 4 particles occurred in highly dispersive polycrystallites. The valence state of Mn species and the regeneration process of used sorbent were characterized by X-ray photoelectron spectroscopy (XPS) and TG/DSC. In addition, the effects of reaction temperature, feed composition and Sm/Mn atomic ratio in sorbents on desulfurization performance were investigated.