Adsorption and plasma-catalytic oxidation of acetone over zeolite-supported silver catalyst

Abstract

The abatement of acetone using a combination of non-thermal plasma, catalysis and adsorption was investigated in a dielectric barrier discharge plasma reactor packed with silver-coated zeolite pellets serving as both adsorbent and catalyst. The removal of acetone in this reactor system was carried out by cyclic operation comprising two repetitive steps, namely, adsorption followed by plasma-catalytic oxidation. The effects of the zeolitesupported silver catalyst on the reduction of unwanted ozone emission and the behavior for the formation of gaseous byproducts were examined. The experimental results showed that the zeolite-supported catalyst had a high acetone adsorption capacity of 1.07 mmol g %1 at 25°C. Acetone with a concentration of 300 ppm was removed from the gas stream and enriched on the zeolite surface during the adsorption step of the cyclic process (100 min). In the succeeding step, the adsorbed acetone was plasma-catalytically treated under oxygen-flowing atmosphere to recover the adsorption capability of the surface. The plasma-catalytic oxidation of the acetone adsorbed in the previous 100 min adsorption step was completed in 15 min. The abatement of acetone by the cyclic adsorption and plasma-catalytic oxidation process was able to increase the performance of the reactor with respect to the energy efficiency, compared to the case of continuous plasma-catalytic treatment. The use of the zeolite-supported silver catalyst largely decreased the emission of unreacted ozone and increased the amount of gaseous byproducts such as carbon oxides and aldehydes due to the enhanced oxidation of the adsorbed acetone and intermediates.

Non-Thermal Plasma Combined with Cordierite-Supported Mn and Fe Based Catalysts for the Decomposition of Diethylether

“…Details of the voltage measurement are described elsewhere [29]. The discharge power was calculated from the so-called voltage-charge Lissajous figures.…”

“…Hence, the selection of an ozone decomposition catalyst with a long-term stability at low temperature should be considered, especially for the two-stage arrangement. The use of oxygen plasma is ineffective unless a cyclic treatment (i.e., VOC adsorption followed by oxygen plasma oxidation) is applied [28,29].…”

Improvement of Ethylene Removal Performance by Adsorption/Oxidation in a Pin-Type Corona Discharge Coupled with Pd/ZSM-5 Catalyst

“…where: C1 = 28958, C2 = 9390, C3 = 3012, C4 = 7580, and C5 = 1484 Using Equation (4), for heating the feed gas from room temperature (25 °C ) to activation temperature of the Pd/ZSM-5 (470 °C ), SIE was calculated to be 13,309,079 J/kmol, which corresponded to 544 J/L. Meanwhile, the SIE of continuous plasma and adsorption and plasma-catalytic oxidation was calculated through Equations (5) and (6) To perform a comparison between thermal catalyst oxidation, plasma-catalytic oxidation, and cyclic adsorption and plasma-catalytic oxidation, the specific input energy (SIE) for these processes was calculated. According to TPO of C 2 H 4 , the operating temperature required to activate all catalyst sites is 470 • C, suggesting heating up the feed gas from 25 • C (room temperature) to 470 • C. The SIE for heating the feed gas can be estimated through Equation (2).…”

“…Using Equation (4), for heating the feed gas from room temperature (25 • C) to activation temperature of the Pd/ZSM-5 (470 • C), SIE was calculated to be 13,309,079 J/kmol, which corresponded to 544 J/L. Meanwhile, the SIE of continuous plasma and adsorption and plasma-catalytic oxidation was calculated through Equations (5) and (6) To sum up, the SIE for the thermal oxidation, continuous plasma oxidation, and the adsorption and plasma-catalytic oxidation are plotted in Figure 7. This figure indicates that the continuous plasma not only oxidizes the C 2 H 4 at low temperature but also decreases the requirement of input energy (450 J/L) in comparison with the thermal oxidation process.…”

Enhancement of the non-thermal plasma-catalytic system with different zeolites for toluene removal

“…As shown in Fig.3b the particle size of metallic silver granules on the surface of Ag/HY was about 20nm. Moreover, in the plasma combined catalysis system, the effect of ozone, adsorption/desorption and the direct interaction of gas phase radicals with catalyst surface was also related to toluene removal 10,11,29 . Moreover, Baek suggested that the metals which possessed empty s-orbits and available electrons in the d-orbits could form strong π-complexation bonding 23 , and the πcomplexation adsorption with toluene on Ag also contributed to the enhancement of adsorption abilities of Ag/HY catalyst.…”