Preparation of mesoporous MCM‐41 supported zinc sorbents by microwave in‐situ oxidation for H₂S removal in coal gas

Abstract

Zn‐based MCM‐41 supporter sorbents were prepared using the microwave in‐situ oxidation method. Other sorbents were heated using a conventional heating method to contrast the performance for H2S removal. The sorbents were tested at 500°C in fixed reactor and dried simulated Texaco coal gas was employed for the sulphurized atmosphere. The results show that sorbents prepared by microwave oxidation had a better toleration for the adsorption of H2S. A 13.2% improvement occurred in the sulphur capacity of the sorbents heated by the microwave method. XRD, SEM with EDS‐element mapping, TEM, N2 adsorption, and XPS were used to characterize the properties of the sorbents. Due to the selective heating of the microwave and the superiority of the in‐situ oxidation method, the sorbents heated by microwave exhibited more appropriate structures for sulphurization. Meanwhile, the even heating environment supplied by the microwave resulted in a more uniform distribution of the active component. The microwave also had an effect on the chemical bond and reduced the binding energy of the active component, which enhanced the reactivity between the H2S and the sorbents. The preferable features generated by microwave in‐situ oxidation accelerate the replacement of S to O, and therefore the Zn‐based MCM‐41 sorbents prepared by the microwave method have an increased capability for H2S removal in high temperature coal gas.

Pd−Zn Alloy Nanoparticles Encapsulated into Mesoporous Silica with Confinement Effect for Highly Selective Semi‐Hydrogenation of Phenylacetylene

“…Therefore, the formation of PdZn alloy is further proved. The XPS analysis of O element and Si element is shown in Figure S5 and S6, and the peak of O is concentrated at 532.1 eV, while the peak of Si is mainly located at 103.0 eV [41] . This result is completely consistent with the mesoporous silica reported by the previous researchers [42] .…”

Preparation and stability of zinc‐based mesoporous sorbent modified with aluminium for high temperature coal gas desulphurization

“…ZnS has a larger molecular radius compared to ZnO, and thus the volume of the active component shrinks after oxidation, which reserves pore space and avoids pore structure collapse caused by volume expansion of the active component during the later desulphurization. [ 20 ]…”

“…The sorbents were prepared using an in‐situ oxidation method based on our previous work. [ 20 ] After dissolution of cetyl trimethyl ammonium bromide (CTAB), NaSi 2 O 3 solution was dropped in. Then NaAlO 2 was then dissolved in a small amount of deionized water and slowly added to the solution.…”

“…ZnS has a larger molecular radius compared to ZnO, and thus the volume of the active component shrinks after oxidation, which reserves pore space and avoids pore structure collapse caused by volume expansion of the active component during the later desulphurization. [20] Figure 2C is the wide angle XRD pattern of sorbent after oxidation. Active components existed in ZnO (JCPDS 36-1451) and Zn 2 SiO 4 (JCPDS 37-1485), which manifested that active metal oxides were prepared after calcination in the oxygen atmosphere.…”

“…In our previous study, [ 18,20 ] MCM‐41 molecular sieve sorbent loaded with zinc demonstrated excellent controllability and repeatability in preparation and high reactivity for hydrogen sulphide removal. However, in the case where load capacity, which is the determining factor to the sulphur capacity, is high, the performance of sorbent is fatiguing over multiple desulphurization–regeneration cycles and the sulphur capacity shrinks sharply, which limits the application of the sorbent.…”