Research On Decomposition Of Dilute Gaseous Toluene Using Dielectrical Barrier Discharge Combined With Photocatalyst

Recently,dilute volatile organic compounds(VOCs) controlled by non-thermal plasma and photocatalysis technologies has been paid much more attention,of that the main investigative problems lie in synergetic mechanism,reactor configuration, power supply parameters,selection and regeneration of photocatalysts.The paper made a research on synergetic effect of dilute VOCs decomposition using dielectric barrier discharge plasma and photocatalysis.The experiment selected gaseous toluene as study subject,and mainly investigated some factors that affected the decompositon efficiency of toluene,such as grounding electrodes,voltage, residence time,the initial concentration,gas relative humidity,the TiO₂ photocatalyst in nanometer,and so on.Meanwhile,the paper discussed the synergetic decomposition process of toluene.Furthermore,to promote its industrial application,reactor in series, power consumption,energy yield,pressure drop,and erosion of grounding electrode were also researched in the paper.The results indicated:1) Decomposition efficiency of toluene increases with increasing voltage,gas residence time,but decreases with increasing initial concentration.It reaches its highest value when gas relative humidity is about 30%.Furthermore,The reactor using copper strip as grounding electrode have a better decompositon efficiency than copper mesh and stainless steel mesh.2) Decomposition efficiency of toluene are obviously improved with TiO₂ photocatalyst in nanometer,that also can inhibit ozone in reactor.When the voltage is 22kV,the decomposition efficiency of reactor with TiO₂ photocatalyst was advanced by about 10%.3) Energy yield decreases with increasing specific input energy,but increases with increasing gas-flow rate and initial concentration.Under the same operational condition, the reactor using copper mesh has lower power and higher energy yield.4) Decomposition efficiency of toluene are improved with two reactors in series. For low concentration,less than 1000 mg/m³,the overall decomposition efficiency can attain over 80%,and can also reach over 70%for 2000 mg/m³.5) The airflow resistance of packed-reactor is too large,especially the pressure drop is much larger when two reactors in series.As a result,the collocation of filler needs to improve.Besides,it would be better to select stainless steel mesh than copper strip and copper mesh as Grounding electrode.Because it can avoid erosion of copper materials to reduce the bad influence to discharge.