title: Effect of precursor and preparation method on manganese based activated carbon sorbents for removing H2S from hot coal gas.
abstract: Activated carbon (AC) supported manganese oxide sorbents were prepared by the supercritical water impregnation (SCWI) using two different precursor of Mn(NO(3))(2) (SCW(N)) and Mn(Ac)(2)·4H(2)O (SCW(A)). Their capacities of removing H(2)S from coal gas were evaluated and compared to the sorbents prepared by the pore volume impregnation (PVI) method. The structure and composition of different sorbents were characterized by XRD, SEM, TEM, XPS and XANES techniques. It is found that the precursor of active component plays the crucial role and SCW(N) sorbents show much better sulfidation performance than the SCW(A) sorbents. This is because the Mn(3)O(4) active phase of the SCW(N) sorbents are well dispersed on the AC support, while the Mn(2)SiO(4)-like species in the SCW(A) sorbent can be formed and seriously aggregated. The SCW(N) sorbents with 2.80% and 5.60% manganese are favorable for the sulfidation reaction, since the Mn species are better dispersed on the SCW(N) sorbents than those on the PV(N) sorbents and results in the better sulfidation performance of the SCW(N) sorbents. As the Mn content increases to 11.20%, the metal oxide particles on AC supports aggregate seriously, which leads to poorer sulfidation performance of the SCW(N)11.20% sorbents than that of the PV(N)11.20% sorbents.
authors.affiliation: Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, Taiyuan 030024, PR China. jc_wang2008@yahoo.com
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Wang
authors.forename: Biao
authors.initials: B
authors.lastname: Qiu
authors.forename: Lina
authors.initials: L
authors.lastname: Han
authors.forename: Gang
authors.initials: G
authors.lastname: Feng
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Hu
authors.forename: Liping
authors.initials: L
authors.lastname: Chang
authors.forename: Weiren
authors.initials: W
authors.lastname: Bao
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D003031:Coal / Q000032:analysis*; D005740:Gases / Q000737:chemistry; D006358:Hot Temperature; D006862:Hydrogen Sulfide / Q000302:isolation & purification*; D008345:Manganese / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D010087:Oxides / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D016062:Porosity; D013440:Sulfides / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D003031:Coal; D005740:Gases; D017895:Manganese Compounds; D010087:Oxides; D013440:Sulfides; D008345:Manganese; C027424:manganese oxide; D002244:Carbon; D006862:Hydrogen Sulfide