Solarized photoreactors for degradation of chlorinated organics in air

Abstract
In contrast to other Advanced Oxidation Technologies (AOTs), Photocatalytic Oxidation (PCO) has the advantage of being solarizable and can be considered as a mild technology. Titanium dioxide (TiO₂) is a photostable and cheap catalyst, and the process may run at ambient conditions of temperature and pressure. In gas phase, some chlorinated high quantum compounds have been reported to achieve photoefficiencies above 100%. TCE has been selected as target compound for solarization of photoreactors. A careful exercise during design is needed to connect the solar photons source and related technology, to the photoreactor itself, and subsequently to optimise the mass and photon transfer mechanisms. We have tested two different options for well-known collectors/concentrators. A first reactor at labscale has been used to proof the concept for possible application in flat-plate collectors, and a second option (a pyrex tube containing a tubular matrix), has been adapted for possible parabolic trough and CPC applications. In this paper the authors provide an analysis of performances, make a comparison among designs discussing some applications for each solar technology. Converse results regarding conversion and reactor photonic efficiency have been obtained. A compromise between efficiency of the reaction and the reactor should be found.