Treatment of gaseous effluents by using surface discharge plasma in continuous reactors: Process modelling and simulation

Abstract

In the present work, the oxidation of isovaleraldehyde, a typical pollutant of indoor air, is investigated by using two different plasma DBD reactors: cylindrical and planar reactor. The study of the influence of the specific energy shows that its increment is accompanied by an increase of the removal efficiency. In fact, when specific energy extends three times, the removal efficiency is increased from 5 to 40 %. Moreover an increase of the specific energy induces a higher mineralization due to byproducts oxidation with reactive species production. The same behaviour is observed with ozone production. A generic mathematical model is developed to represent the experimental results obtained. This model is based on several mass transfer steps occurring in series between bulk and plasma phases. The degradation reaction mechanism is supposed to occur on two steps. Firstly, isovaleraldehyde leads to the formation of a fictitious equivalent intermediate (EI). In a second step, EI is transformed into CO and CO2. This approach gives a good agreement between modelling and experiments with a satisfactory overall description of byproducts formation. This original approach allows for the simulation of plasma oxidation kinetics process without knowing the complete chemical pathway.