Removal of Volatile Organic Compounds from Gases with Innovative Electrochemically-Assisted Reactive Absorbers

Volatile organic compounds emitted by various industries constitute relevant atmospheric pollutants with a risk to human health. An electrochemically assisted absorption process (electro-absorption) is proposed and evaluated for the treatment of gaseous streams polluted with benzene or xylene as representative VOCs. The main objective of this work is focused on the comparison between the performance of a packed column and a jet mixer as absorption configuration in this electrochemical technology. The results show that the degradation pathway with both configurations is mineralization. The intermediates compounds vary depending on the pollutant, benzoquinone and tolualdehyde are mainly produced in the removal of benzene and xylene, respectively. An increase in the current density applied to the system implies higher removal rates of the pollutants but lower energy efficiencies, with 50 mA cm-2 being the optimum. Furthermore, it was observed that the jet mixer improves the treatment of gaseous streams with VOCs with low water solubility and volatility (as p-xylene) while the packed column is more effective in treating gases polluted with VOCs with high water solubility and volatility (as benzene). The obtained data allow to establish the technical feasibility and functionality of electro-absorption technology as treatment process to remove VOCs from gas streams, which is meaningful for future research perspectives on scalability, economic evaluation and life cycle analysis to validate and expand the current findings.