A class of atmospheric pollutants that receives significant attention is volatile organic compounds (VOCs), which are produced and used in numerous industrial activities. Current technologies for reducing VOCs in industrial settings rely on techniques that either separate and isolate unwanted compounds (adsorption, absorption, condensation processes) or eliminate pollutants through oxidation (biological, thermal, catalytic processes). The most commonly used industrial processes for VOC removal are catalytic combustion, which, however, requires high temperatures and thus incurs significant operating costs. An interesting alternative is photocatalytic oxidation, which offers high removal efficiency at ambient temperature and produces harmless final products (CO₂ and H₂O).

To investigate the efficient applicability of photocatalysis for treating gaseous effluents with significantly lower energy costs compared to conventional technologies, a photocatalytic pollutant removal system was established in RSE’s laboratories during the reporting period. This system includes a feed section, a photocatalytic reactor, and an analysis section. The feed section consists of a valve system (which allows for feeding the reactor to measure conversion efficiency or bypassing it for calibration of the mixtures), a diaphragm pump, and flowmeters for the introduction and regulation of gases (VOC mixtures, air, nitrogen, and calibration mixtures). The reactor is a steel cylinder with a volume of about 23 liters, equipped with 5 Wood’s lamps (also known as black lights) of 15 W each (emission at 360 nm).

The method for preparing the photocatalyst was also developed during the reporting period, involving the deposition of nanometric titanium dioxide (TiO₂) powders onto a support made of hollow Pyrex glass cylinders (6×6 mm). Finally, the analysis section includes a continuous analyzer for quantitatively measuring CO₂ produced in the photocatalytic mineralization reaction, and a micro-gas chromatograph for monitoring VOC concentrations. In the coming year, the system will be tested with synthetic mixtures containing varying VOC concentrations to evaluate removal kinetics and identify potential reaction byproducts. Specifically, the system will be operated in a single-pass mode using dry air mixtures containing benzene.