Investigation of the relative reactivity of volatile organic compounds in the air plasma of a pulsed corona discharge by the method of competing reactions

A method for determining the relative reactivity of volatile organic compounds (VOCs) with respect to the air plasma of a pulsed corona discharge is proposed. It is based on the use of specially selected mixtures of organic compounds. The approach is based on the method of competing reactions: all components of the mixture are in equal conditions, so the relative reactivity can be determined with high accuracy using the gas chromatography. The parameters of scaling processes are proposed – plasma chemical yield, relative reactivity, formal reagent as a set of plasma components. In this paper, using the example of a number of VOCs, we demonstrate the extended capabilities of the method using a special technique for processing experimental data. More accurate data on the relative reactivity of a number of VOCs of wide application have been obtained. It is proposed to use the energy yield of ozone as a criterion for the energy efficiency of a plasma chemical installation.

Oxidation of Aqueous Toluene by Gas-Phase Pulsed Corona Discharge in Air-Water Mixtures Followed by Photocatalytic Exhaust Air Cleaning

The treatment of wastewaters containing hazardous volatile organic compounds (VOCs) requires the simultaneous treatment of both water and air. Refractory toluene, extensively studied for its removal, provides a basis for the comparison of its abatement methods. The oxidation of aqueous toluene by gas-phase pulsed corona discharge (PCD) in combination with the subsequent photocatalytic treatment of exhaust air was studied. The PCD treatment showed unequalled energy efficiencies in aqueous and gaseous toluene oxidation, reaching, respectively, up to 10.5 and 29.6 g·kW−1·h−1. The PCD exhaust air contained toluene residues and ozone in concentrations not exceeding 0.1 and 0.6 mg·L−1, respectively. As a result of the subsequent photocatalytic treatment, both airborne residues were eliminated within a contact time with TiO2 as short as 12 s. The results contribute to the possible application of the studied approach in closed-loop energy-saving ventilation systems.