Volatile organic compounds decomposition using nonthermal plasma coupled with a combination of catalysts

A series of experiments were performed for toluene decomposition from a gaseous influent at normal temperature and atmospheric pressure by nonthermal plasma coupled with a combination of catalysts technology. Nonthermal plasma was generated by dielectric barrier discharge. gamma -Al[2]O[3]3 was used to be a sorbent and a catalyst carrier. Nanocatalysts were MnO[2]/ gamma-Al[2]O[3] coupled with modified ferroelectric of nano-Ba[0.8]Sr[0.2]Zr[0.1]Ti[0.9]O[3]. gamma-Al[2]O[3] played an important role in prolonging reaction time of nonthermal plasma with volatile organic compounds molecules. MnO[2]/ gamma-Al[2]O[3] has an advantage for ozone removal, while nano-Ba[0.8]Sr[0.2]Zr[0.1]Ti[0.9]O[3] is a kind of good ferroelectric material for improving energy efficiency. Thus these packed materials were incorporated together to strengthen nonthermal plasma power for volatile organic compounds decomposition. The results showed the synergistic technology resulted in greater enhancement of toluene removal and energy efficiencies and a better inhibition for ozone formation in the gas exhaust. Based on the data analysis of the Fourier transforms infrared spectrum, the reaction process of toluene decomposition and the mechanism of synergistic effect are discussed. The results showed in a complex oxidation mechanism of toluene via several pathways, producing either ringretaining or ringopening products. The final products were carbon dioxide and water

Gaseous phase benzene decomposition by non-thermal plasma coupled with nano titania catalyst

Synergistic effect of atmospheric non-thermal plasma generated by dielectric barrier discharge and nano titania photocatalyst for benzene decomposition was tested. The paper indicated the effect of photocatalyst on removal efficiency of benzene, the compare of photocatalyst characteristic in different high temperatures by heat treatment, analysis of by-products. The results showed that the effect of degradation was visible by added photocatalyst in the plasma reactor. When concentration of benzene was 600 mg/m[3] and electric field strength was 10 kV/cm, the removal efficiency of benzene was increased up to 81% without photocatalyst. At the same condition, the removal efficiency was increased to 15% higher with photocatalyst. Nano titania crystal was anatase crystal in 450 °C heat treatment which is best for benzene removal. The plasma reactor packed with photocatalyst shows a better selectivity of carbon dioxide than that without photocatalyst. By-products are mostly carbon dioxide, water and a small quantity of carbon monoxide

Decomposition of benzene by non-thermal plasma processing: Photocatalyst and ozone effect

Plasma technology has some shortcomings, such as higher energy consumption and byproducts produced in the reaction process. However non-thermal plasma associated with catalyst can resolve these problems. Therefore this kind of technology was paied more and more attention to treat waste gas. A hybrid system comprising a non-thermal plasma reactor and nanometer titanium dioxide catalyst was used for benzene removal in the air. The paper described the synergistic effect of ozone and photocatalyst in the plasma reactor. Except of electric field strength, humidity and flow velocity, the synergistic behavior of ozone and photocatalyst was tested. The removal efficiency of benzene reaches nearly 99% when benzene concentration is 600 mg/m[3], and the removal efficiency of benzene also reaches above 90% when benzene concentration is 1500 mg/m[3]. The plasma reactor packed with photocatalyst shows a better selectivity of carbon dioxide than that without photocatalyst. The final products is mostly carbon dioxide, water and a small quantity of carbon monoxide