Breakthrough studies of Co3O4 supported activated carbon monolith for simultaneous SO2/NO removal from flue gas

Abstract

This work investigates the deposition precipitation, pore volume impregnation and hydrothermal methods of synthesizing activated carbon monolith supported metal oxide adsorbent (Co3O4/ACM). The hydrothermally synthesized Co3O4 activated carbon monolith adsorbent (Hm-Co3O4/ACM) demonstrate better adsorption capacity (SO2 is 123.1, NOx is 130.2 mg/g) than the adsorbents synthesized by the other methods. The adsorbent displayed high affinity to NOx adsorption where this influence was associated to operation conditions, physical and chemical properties of the adsorbent which were expressed in the plot of the breakthrough curve. Moreover, the surface properties (BET), thermal decomposition (TGA), functional groups (FTIR), chemical composition (XRD) and surface morphology (FESEM) of the adsorbent were investigated. The Langmuir adsorption isotherm fitted the experimental results meanwhile, the thermal regeneration of the adsorbent over two cycles showed an average regeneration efficiency of 94.4% for SO2 and 94.8% for NOx. Finally, the post regeneration characterization analyses were discussed.

Synthesis of Nano-Magnetite from Industrial Mill Chips for the Application of Boron Removal: Characterization and Adsorption Efficacy

“…To achieve this, log q e is plotted against log Ce built on the linear form of the Freundlich model [ 70 ]. In Langmuir model linear expression, Ce/q e is plotted against C e ( Figure 13 ) [ 71 , 72 ]. As shown in Figure 13 , the initial concentration correlation coefficient with an R 2 value of 0.9464 proves the Freundlich adsorption isotherm to be more favorable in the determination of the effectiveness of magnetite for the removal of boron.…”

Comparative Study of the Flue Gas Desulfurization Using Different‐Grade Natural Manganese Oxides

“…The tunnel has a big sectional area as it is a double‐chain structure, which enables it to accommodate the cation with a radius of 0.15 nm in order to stabilize the structure. The γ ‐MnO 2 model is a close‐packed hexagonal structure generated from the interlaced manganese ore tunnel and the ramsdellite tunnel. Manganese atoms in the manganese ore crystallized with the δ ‐MnO 2 phase occupy the octahedral cavity, while oxygen atoms are in the hexagonal close‐packed arrangement.…”

“…On the one hand, the direct contact of the flue gas and the dry sorbents in dry FGD favors the desulfurization reactions. On the other hand, dry FGD is regarded to be the more suitable way of FGD because of its low operating costs, no water consumption, the easy treatments of the byproducts, and the applicability at lower pollutant concentrations . As an important factor, the selection of the sorbents is of critical importance.…”

“…Traditional sorbents including metal oxides (CuO, MnO 2 , Co 2 O 3 , etc.) have been of prime importance , . These metal oxides have gained popularity because of their outstanding adsorption capacity for SO 2 , but most of the sorbents need to be synthesized by a relatively strict preparation process, causing increased production costs .…”

Regeneration/Optimization of Activated Carbon Monolith in Simultaneous SO2/NOx Removal from Flue Gas

“…Co 3 O 4 shows unique low-temperature activity, its oxidation state was reported to change between Co 3 O 4 , Co 2 O 3 , CoO, and Co [27,28], and it shows high catalytic activity [29]. The mechanisms for SO 2 /NO x are discussed in our previous work [30]. This remarkable characteristic of Co 3 O 4 maximizes the adsorption of both SO 2 and NO x .…”