To investigate the coadsorption of SO 2 , NO, and CO 2 from the flue gas, adsorption equilibrium tests of SO 2 , NO, and CO 2 on coconut shell activated carbon (SAC) and coal-based activated carbon (CAC) were conducted at the temperatures (323, 343, and 363) K by the static volumetric method. The equilibrium data were well fitted by the Toth model. Henry's constant was calculated by the Virial model; the results showed that adsorption affinity followed the order SO 2 > CO 2 > NO > N 2 on SAC, and SO 2 > NO > CO 2 > N 2 on CAC. Then thermodynamics data, including Gibbs' free energy, entropy, and enthalpy, were also calculated to characterize adsorption behaviors. SO 2 had the highest degree of freedom, while CO 2 formed a most regular configuration. The efficiency of molecule packing in CAC was lower than that in SAC. Finally, competitive adsorption of different flue gas components was predicted by the extended Toth model. The adsorption amount followed the order CO 2 > N 2 > SO 2 > NO for both adsorbents. SAC had better adsorption property than CAC in the multicomponent adsorption.

Catalytic hydrolysis technology of carbonyl sulfide (COS) at low temperature was reviewed, including the development of catalysts, reaction kinetics, and reaction mechanism of COS hydrolysis. It was indicated that the catalysts are mainly involved metal oxide and activated carbon. The active ingredients which can load on COS hydrolysis catalyst include alkali metal, alkaline earth metal, transition metal oxides, rare earth metal oxides, mixed metal oxides, and nanometal oxides. The catalytic hydrolysis of COS is a first-order reaction with respect to carbonyl sulfide, while the reaction order of water changes as the reaction conditions change. The controlling steps are also different because the reaction conditions such as concentration of carbonyl sulfide, reaction temperature, water-air ratio, and reaction atmosphere are different. The hydrolysis of carbonyl sulfide is base-catalyzed reaction, and the force of the base site has an important effect on the hydrolysis of carbonyl sulfide.

No abstract

No abstract

A series of active coke (AC)-based adsorbents modified by different metal combinations (Na/Ba/Cu, Na&Cu/Na&Ba, and Na&Ba&La/Na&Ba&Ce), supporting different contents of metal and calcined at different temperatures, was investigated for simultaneous removal of SO2 and NO x . The activity test results showed that supporting 8% NaCO3, 7% Ba­(NO3)2 & 8% NaCO3, and 10% Ce­(NO3)2 & 7% Ba­(NO3)2 & 8% NaCO3 on the AC was best in unitary, bibasic, and ternary metal modifications, respectively. Supporting 10% Ce­(NO3)2 & 7% Ba­(NO3)2 & 8% NaCO3 was the best of all. The Fourier transform infrared spectroscopy result showed that the sodium modification made some unsaturated groups and metal chelate complexes form on the AC, so that the removal performance improved. Barium added to 8% Na–AC augmented the amount of unsaturated groups to improve the performance further. The addition of cerium to 7% Ba–8% Na–AC made more unsaturated groups and metal chelate complexes form, thus raising the performance again. The Brunauer–Emmett–Teller (BET) result showed that the unmodified (AC) and modified (10% Ce–7% Ba–8% Na–AC) ACs were predominantly microporous materials, and the pore size distribution and pore width of the modified AC was more extensive and multiple, which were beneficial for the removal of SO2 and NO x . Moreover, the removal performance improved significantly as the calcination temperature increased from 200 to 600 °C, whereas it slumped as the calcination temperature increased from 600 to 800 °C. It was explained by the results of X-ray diffraction and BET that CeO2, which was one of the active ingredients on the AC, increased with the increase of the calcination temperature and the higher the sample calcined at a temperature, the worse the pore structure of the carrier.