Transformation of Gaseous Benzene in the Presence of Carbon Dioxide to Salicylic Acid Using Dielectric Barrier Discharge Technique

Abstract

Critical atmospheric pollutants of various types continue to challenge researchers to develop their mitigation methodologies. In this study, we report our recent results on a simple and convenient approach for chemical conversion of gaseous benzene (Bz) and carbon dioxide (CO2 mixtures with and without argon diluent to salicylic acid (SA) employing dielectric barrier discharge (DBD) cold plasma technique. Online reactants’/products’ concentrations are analyzed and estimated with gas chromatograph–flame ionization detector–thermal conductivity detector (GC-FID-TCD) system, whereas the products SA along with phenol (PH) and benzoic acid (BA) are analyzed offline with gas chromatograph-mass spectrometer (GC-MS) from low-volatile deposits on electrode surfaces during DBD. Efficient removal of pollutants, thus, suggests a new utilitarian and combo approach toward pollutant alleviation, wherein dissimilar pollutant chemicals (CO2 and Bz) are simultaneously transformed to usable products such as SA. Products’ analyses reveal that the presence of PH (10 ppm) and BA (< 1 ppm) perhaps assist to elucidate the formation mechanism of SA (5 ppm) in CO2-Bz DBD systems. Interestingly, the Bz transformation to SA is 10 times more in 90% Ar and 10% CO2-mixed carrier systems containing Bz.