Decomposition of Gaseous Acetone in an Annular Photoreactor Coated with TiO2 Thin Film

Photocatalytic decomposition of gaseous acetone was studied with a fixed-bed annular reactor using TiO₂ as the photocatalyst. The relation of UV light intensity to the reaction rate was found to be roughly first-ordered. The decomposition of acetone was obviously enhanced with increasing retention time. Removal of acetone was slightly increased with the relative humidity for experiments conducted with relative humidity below 20%. However, the removal of acetone was decreased drastically with relative humidity for experiments conducted with relative humidity greater than 20%. Decomposition of acetone was promoted considerably with increasing oxygen concentration for experiments conducted with oxygen less than 200,000 ppmv, yet the decomposition of acetone was kept relatively constant for experiments conducted with oxygen above 200,000 ppmv. Based on the mass balance for carbon species, the amount of organic intermediates formed for experiments conducted under various conditions were found to be minimal. Experimental results for the decomposition of gaseous acetone by UV/TiO₂ process can be adequately described by the developed two-site Langmuir–Hinshelwood (L–H) kinetic model.