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The mechanochemical S/FeS modified high sulfur petroleum coke (HSPC) were prepared in this work. The mercury removal performance of the adsorbents was evaluated in a simulated flue gas fixed bed experimental device. The Brunauer-Emmett-Teller (BET), Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), Hg temperature-programmed desorption (Hg-TPD) and thermogravimetric (TG) were used to obtain the physical and chemical properties of some typical samples. It shows that the mercury removal efficiency (MRE) of mechanochemical S/FeS modified HSPC (MC-S/FeS-PC) increases with increasing the S or FeS addition amount under the same mechanical conditions (600/300 rpm, 60 min), where S is superior to FeS. The mass ratio of carbon to sulfur (RCS) of 4.5 for the MC-S-PC is the optimal sulfur addition amount with the MRE of 98.6%. Mechanochemical S/FeS modification is conducive to the development pore structure of raw HSPC with certain effects. S is the main sulfur form on the surface of MC-S-PC, while thiophene, FeS, and Fe 2 (SO 4) 3 are the main sulfur forms of MC-FeS-PC. The mercury compound on used adsorbents is mainly HgS (black). Moreover, another immature mechanism hypothesis about the mercury removal by MC-S-PC is proposed. [Display omitted] • Mechanochemical S/FeS modified high sulfur petroleum coke (MC-S/FeS-PC) were prepared. • Mercury removal efficiency (MRE) of MC-S/FeS-PC increases with increasing S or FeS addition amount. • RCS of 4.5 for the MC-S-PC is selected as the optimal sulfur addition amount with MRE of 98.6%. • Modification mechanism and mercury removal mechanism of MC-S/FeS-PC were deeply explored. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effects of activation parameters on demercuration of PPC and RPC/PPC-M were studied. • Final pyrolysis temperature and medium and small balls benefit for pore structure development. • Pyrolysis and mechanochemical activation cause changes in surface S total and sulfur forms. • Sulfone acts avital role in mercury removal of petroleum coke-based adsorbents. • Needing additional additives to further improve demercuration ability of PC-based adsorbents. With the signing of the Minamata Convention , the task of reducing mercury emission from coal-fired power plants is imminent. High-sulfur petroleum coke (PC), a by-product of the petrochemical industry, has the potential to prepare high-performance mercury removal adsorbents. The effects of activation parameters of pyrolysis, mechanochemistry, pyrolysis + mechanochemistry on the mercury removal ability of activated PC were systematically studied in this work. The TG, BET, FTIR, XPS and Hg-TPD were used to characterize physical and chemical properties, and adsorbed mercury compounds of some selected samples. The results show that pyrolysis, mechanochemistry, pyrolysis + mechanochemistry can enhance the mercury capture performance of Raw PC (RPC). PPC10-60–900, RPC-M-15 M, and PPC-M-15B have the best mercury removal rate of 29.15%, 25.68%, and 27.86%, respectively. Influence of pyrolysis parameters, mechanochemical activation parameters (R bm , R ms) on mercury removal of activated RPC or pyrolyzed petroleum coke (PPC) are not regular, while final pyrolysis temperature plays a vital role on mercury capture for the PPC. At the fixed R bm , mechanochemical activation with R ms = 1.08 g/cm2 (M) and 0.62 g/cm2(S) benefits for the pore structure improvement of RPC and PPC. The pyrolysis will make the C–H, C-O, C-O-C, and C = O disappear from PC, while mechanochemical activation almost has no effect on it. The conversion of sulfur forms occurs in both the pyrolysis and mechanochemical activation process. Sulfone acts an important role in the mercury removal of PC-based adsorbents. The mercury captured on the PPC, mechanochemically activated RPC (RPC-M) and PPC (PPC-M) mainly exists in the more stable form of HgS. Additional modifiers are needed to further improve the mercury removal performance of the PC-based adsorbent to facilitate its large-scale industrial application. [ABSTRACT FROM AUTHOR]

• Mercury removal from coal-fired flue gas by PC-based adsorbent is reviewed. • Physicochemical and demercuration properties of modified PC are discussed. • Mechanochemically modified PC is a promising mercury removal adsorbent. • Optimal modification parameters for each PC-based adsorbent need further study. Mercury pollution from coal combustion has attracted widespread attention. Petroleum coke (PC), a by-product from petrochemical industry, is a potential substance to replace activated carbon mercury removal adsorbent. Most of the published articles on PC-based mercury removal adsorbent are reviewed in this work. It shows raw PC has little mercury removal ability (5%). Pyrolysis can increase mercury removal ability of PC with limited improvement effect (below 60%). KOH activation benefits for pore structure development but results in sulfur removal. SO 2 activation improve surface pore structure and sulfur content of the PC, which can realize Hg0 capture rate higher than 90%. The mercury species on the used SO 2 impregnated PC are mainly HgS black and HgS red. The mechanochemical liquid bromine modified PC can achieve very high mercury removal efficiency of above 98%. However, the effects of pyrolysis, SO 2 activation, and mechanochemical modification parameters on the surface physical–chemical properties especially sulfur forms of PC, as well as the modification mechanism and mercury removal mechanism need to be further studied. Mechanochemically modified PC is a promising mercury removal adsorbent. This work hopes to provide guidance for the development of high-performance PC-based mercury removal adsorbents and its industrial application. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effects of O 2 , CO 2 , SO 2 and NO on the Hg0 removal characteristics of S 2 Cl 2 -MC were revealed. • Hg0 removal characteristics were discussed by Hg0 removal efficiency, Hg2+ escape ratio, and Hg0 adsorption amount. • O 2 + CO 2 , 1200 ppm SO 2 , NO promote Hg0 removal while O 2 and low-concentration SO 2 have little effect. • Adsorbent surface structure plays an important role in the Hg0 adsorption. The effects of flue gas components (O 2 , CO 2 , SO 2 and NO) on the Hg0 removal of mechanochemical S 2 Cl 2 -modified BC (S 2 Cl 2 -MC) were explored based on the Hg0 removal efficiency/amount, Hg0 adsorption amount and Hg2+ escape amount/ratio. The BET, FTIR, XPS, and Hg-TPD were used to obtain relevant physicochemical properties. It shows O 2 and CO 2 promote the Hg2+ escape but inhibit Hg0 adsorption. O 2 slightly affects Hg0 removal, while CO 2 promotes it. 400 ∼ 800 ppm SO 2 slightly affect Hg0 removal, while 1200 ppm SO 2 facilitates Hg2+ escape and Hg0 adsorption. SO 2 affects Hg2+ escape ratio little. As NO concentration increases, the Hg2+ escape is promoted while Hg0 adsorption is inhibited. O 2 and CO 2 do not change the mercury forms. SO 2 and NO promote the production of HgSO 4 and Hg(NO 3) 2 , respectively. The Hg0 adsorption might mainly depend on the physical properties of adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation conditions of mechanochemical S 2 Cl 2 -modified biomass coke based on mercury removal were optimized. • BC-10B-8S 2 Cl 2 -MC has the best Hg0 removal rate of 97.12%. • Thiophen/element sulfur and sulfoxide benefit for mercury removal. • Mechanochemical method has more application prospects than impregnation method. Mercury is a global pollutant. In this work, wood sawdust-based biomass coke and S 2 Cl 2 were selected as the raw material and modifier, respectively. Two modification methods were adopted to prepare the mechanochemical S 2 Cl 2 -modified biomass coke (BC-S 2 Cl 2 -MC) and S 2 Cl 2 impregnated-modified biomass coke (BC-S 2 Cl 2 -IM). The flue gas fixed mercury-removal experiment rig was used to evaluated the mercury removal performance of the adsorbents. The Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS) were adopted to characterize the surface physical and chemical properties of some typical samples. Hg temperature-programmed desorption (Hg-TPD) was used to analyze the main mercury forms in the used adsorbents. The results show both mechanochemistry and impregnation methods can significantly improve Hg0 removal performance with the addition of S 2 Cl 2. Increasing S 2 Cl 2 addition amount increases the Hg0 removal efficiency of BC-S 2 Cl 2 -MC overall. Considering the economy and mercury removal performance, 800 μL is the optimum addition amount for the 3 g raw biomass coke with the Hg0 removal rate of 91.94%. The change of ball milling parameters within a certain range has little effect on the mercury removal performance of BC-S 2 Cl 2 -MC. The best ball milling parameters in this work are a ball-to-material ratio of 10:1 and big balls (diameter = 20 mm), which corresponds to the Hg0 removal rate of 97.12%. Chemical adsorption plays a great part in the Hg0 removal of BC-S 2 Cl 2 -MC and BC-8S 2 Cl 2 -IM. The surface functional groups such as O–H, C = O, C = S and thiophen/element sulfur and sulfoxide are the main Hg0 adsorption active sites. HgS (black) is the main mercury form in the used BC-S 2 Cl 2 -MC and used BC-S 2 Cl 2 -IM. The mechanochemical method has more prospects for industrial application than the impregnation method. [ABSTRACT FROM AUTHOR]

• The pyrolysis temperature and atmosphere have great influence on Hg0 removal of BC. • N 2 + 7% O 2 , higher pyrolysis temperature and heating rate develop the pore structure. • BC-N 2 + 7% O 2 -800-10 has the best Hg0 removal rate of 34.89% under all the pyrolysis conditions. • Hg0 removal of BC mainly by chemical adsorption with main content of HgO. Effects of pyrolysis conditions, including pyrolysis temperatures, pyrolysis atmosphere, and heating rate, on Hg0 removal of wood chip-based biomass coke (BC) under the basic simulated flue gas were systematically studied. The BET, SEM, FTIR, XPS and Hg-TPD were used to analyze the physicochemical properties and specific mercury compounds. The results show that the final pyrolysis temperature and pyrolysis atmosphere have greater influence on the mercury removal performance while heating rate affects little. The BC-N 2 + 7%O 2 -800-10 has the best Hg0 removal efficiency under all the pyrolysis conditions, mainly due to the good pore structure and abundant surface oxygen-containing functional group. N 2 + 7% O 2 , higher pyrolysis temperature and heating rate benefit for BC's pore structure development. Oxygen-containing functional groups of O H, C O and C O O are the main functional groups on the BC surface, which promotes Hg0 adsorption. The physically adsorbed Hg0 and more chemically adsorbed HgO are the main mercury compounds in the used BC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanochemical sulfur modified biomass coke was firstly prepared. • Hg0 removal follows BC-4-S 2 Cl 2 -MC > BC-CaHS-MC > BC-ES-MC > BC-NaHS-MC > BC-Na 2 S-MC > R-BC. • BC-S 2 Cl 2 -MC with 800 μL S 2 Cl 2 has the best Hg0 removal rate of 96.17%. • Sulfoxide benefits for mercury removal among all the sulfur forms. • Mercury forms in the used MC-organic sulfur-BC are HgS with good stability. Coal-fired power plants are the main anthropogenic source of mercury emissions in the atmosphere. In this work, the raw material of biomass (wood chips), modifiers of sulfur-containing substances (Na 2 S, NaHS, S, CaHS, S 2 Cl 2), and mechanochemical method were adopted to prepare the mechanochemical sulfur-modified biomass coke (BC-S-MC). The effects of sulfur addition types and sulfur addition amounts on mercury removal performance of BC-S-MC were investigated by the mercury removal experimental device. The modification mechanism and mercury removal mechanism was explored with the help of BET, XPS, FTIR, and Hg-TPD. The results show that the mercury removal efficiency of BC-S-MC under the same sulfur addition amount meets BC-4-S 2 Cl 2 -MC > BC-CaHS-MC > BC-ES-MC > BC-NaHS-MC > BC-Na 2 S-MC > R-BC. As S 2 Cl 2 addition amount increases, the mercury removal rate of BC-S 2 Cl 2 -MC firstly increases and then decreases with best value of 96.17%. Mechanochemical sulfur modification severely destroys the pore structure of R-BC, but affects the surface chemistry properties like sulfur forms, C = O, C = S, O–H, etc. Sulfoxide plays an important role in improving the mercury removal ability. The mercury forms in the used mechanochemical organic sulfur modified biomass coke are mainly HgS (black) and HgS (red), which have good stability. [ABSTRACT FROM AUTHOR]