Odor Elimination of Cooking-oil Fumes by Catalytic Incineration

In urban area, serious air pollution can be attributed to the oil fume, which is harmful to human body, emitted from the restaurant kitchens. Nowadays, especially in odor removal, the equipment for oil-fume elimination is low in efficiency, while that of high efficiency usually costs too high to be affordable for many small restaurants. Therefore, to remove oil-fume for most restaurants, it is preferable to find equipment with both high efficiency and reasonable cost. Currently the electrostatic precipitator has been used to remove oil fume in lots of restaurants. Although the collection rate of oil particles was very high up to 85-90%, for odor molecules, the removal efficiency can only reach 40-60%. In this research, we developed a low-temperature catalytic incineration method to further destroy the odor molecules after the treatment of electrostatic precipitation and achieved high removal of odor from cooking-oil fume. Hydrophobic noble-metal catalyst allows low-temperature oxidation of VOCs and high-resistance toward moisture so that less fuel is required to sustain the working temperature and that the moisture will have negligible effect on the performance of the catalyst. Integrating the catalyst in a honeycomb catalytic system, which permits low pressure drop in the ducks of kitchen hoods, we could get 91.3% removal efficiency when using 1.5 wt% Pt/CNT honeycomb reactor under 300℃ and 17200 h-1 in GHSV. Even when the humidity is high up to 95.6% did the removal efficiency still reach 89.4% which proved high water tolerance of the catalyst. In addition, with this catalytic system, we can attain total elimination of the sulfur compound, methyl mercaptan, which is of strong odor. In case of mimicking real French fries cooking, sharp decreases in the amounts of at once species and concentrations of the fume could be found. In the future, it is the whole system that is needed to be constructed to handle cooking oil fume from restaurant kitchens and gives us freshly clean air.