(173y) UV LED Photocatalytic Device for Reducing Evaporative Fuel Vapor Emissions

An annulus-type of photocatalytic reactor was designed, constructed, and characterized for its performance for the oxidation of ethanol, hexane, cyclohexane, benzene, and fuel vapors in air. The photocatalytic device utilized ultraviolet (λ=365 nm) light emitting diodes (UV-LEDs) as light sources and photocatalytic (Degussa P25 TiO₂) films coated on the inside surfaces of the reactor. These reactor systems can be applied to mobile and niche applications. UV-LEDs are small, robust light sources that require low direct current (DC) power, which could be provided by a battery. The study results demonstrate that the UV-LED-based photocatalytic system is capable of reducing or eliminating ethanol and hexane vapors in air. Test results have demonstrated the sensitivity of the effectiveness of the UV-LED-based photocatalytic system on operating parameters, including flow rate, concentration, type of VOC, humidity, and longevity.