Physicochemical properties and desulfurization activities of metal oxide/biomass-based activated carbons prepared by blending method

Abstract

Column activated carbons were prepared from walnut shell chars and transition metal oxide powders (i.e. Co 2 O 3 , Ni 2 O 3 , CuO and V 2 O 5 ) with blending method. Samples were characterized by N 2 adsorption-desorption, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The texture properties of all modified activated carbons with metal oxides dosage of \5 wt% did not change evidently. The basic functionalities of these activated carbons increased relative to blank carbon. Moreover, metal species with different oxidation states coexisted on the modified activated carbons. The optimal dosage of all metal oxides was 2 wt%. The sulfur capacities of these modified activated carbons were 7.7-46.0 % higher than that of blank activated carbon and the highest occurred for V 2 O 5 modified activated carbon. The improved desulfurization performance was mainly attributed to the higher catalytic activity of the active metal oxides formed in the presence of O 2 during the desulfurization process.

The effects of metal oxide blended activated coke on flue gas desulphurization

“…Some metal oxides were detected in the XPS spectra, such as FeO, CoO, CuO and NiO, while XRD results only showed metallic particles on most modied activated coke. 12 As a result, the metals on activated coke had a lower valence state in this study since metal oxides had a stronger reduction atmosphere during activation process than calcination, possibly resulting from using the steam as activation agent. The scanning depth of XPS method is about 3 nm generally, while the XRD has a deeper scanning depth.…”

“…12 Gao et al 11 investigated the metals modied activated carbon by impregnation method. Some metal oxides were detected in the XPS spectra, such as FeO, CoO, CuO and NiO, while XRD results only showed metallic particles on most modied activated coke.…”

“…[2][3][4] Activated coke desulphurization technology has been proven to be particularly promising for the removal of SO 2 from ue gas because of its many advantages, such as simultaneous removal of various pollutants (SO 2 , NO x , dioxins, etc. 11,12 On the other hand, the surface chemical properties of activated coke, such as oxygencontaining functional groups, could have an important role in the removal of SO 2 due to their high affinity. [5][6][7][8] It was reported that desulphurization performance of activated coke mostly depends on its physicochemical characteristics.…”

“…[5][6][7][8] It was reported that desulphurization performance of activated coke mostly depends on its physicochemical characteristics. 7,12,[16][17][18] However, the physicochemical properties of activated coke are mostly based on the raw materials, the additives and preparation methods. 11,12 On the other hand, the surface chemical properties of activated coke, such as oxygencontaining functional groups, could have an important role in the removal of SO 2 due to their high affinity.…”

Preparation and desulfurization performance of pyrolusite modified activated coke

“…Previous studies showed that the textural properties of pyrolusite modified activated coke change, because the added pyrolusite could react with the carbon substrate during the activation process . High ratio of pyrolusite could introduce excessive metal particles, which might promote the aggregation and the formation of large crystals on activated coke, resulting in the blockage of pores . Thus, an appropriate pyrolusite ratio in activated coke could help to develop good textural properties, which is beneficial for the improvement of its iodine value.…”