Study On Composition Analysis Of Cooking Fume And Its Treatment By Nonthermal Plasma

The pollutant discharge of cooking fume is large and the harm is high,which seriously affects People’s Daily life.Therefore,it is urgent to deal with it efficiently.Corona discharge has the advantages of fast reaction speed,good effect,low energy consumption,easy realization and low price,which can be applied to the treatment of cooking fume.Starting from the study of pollutant components,this paper analyzed the composition and concentration of lampblack pollutants in different forms,determined the influencing factors of pollutants according to the change of pollutant emission characteristics,and carried out a single factor experimental study of lampblack degradation.On this basis,the range of optimal conditions was further reduced,and the optimal combination was determined by response surface optimization experiment.The main results were as follows:(1)Composition analysis: the concentration of fume,particulate matter and NMHC was proportional to temperature;The average emission concentration of fume and particulate matter in four edible oils was in the order of Rapeseed oil > Peanut oil > Soybean oil > Lard,NMHC concentration was in the order of Soybean oil > Peanut oil > Lard > Rapeseed oil.The emission components of PAHs in particulate matter and gas pollutants were similar,and uniform light PAHs were dominant,and the emission concentration of gas pollutants was higher than that of particulate matter.The emission concentration of PAHs was directly proportional to temperature,and the average emission concentration of all edible oils was in the order of Soybean oil > Rapeseed oil > Peanut oil > Lard.(2)Single factor experiment: the effects of cooking temperature,discharge voltage and gas flow rate(residence time)on corona discharge degradation of pollutants were studied.The removal efficiencies of fume,particulate matter and NMHC at cooking temperature increased firstly and then decreased.When the temperature was 120℃,the average removal efficiencies were 89.4%,89.85%and 79.16%,respectively.The removal efficiencies of fume,particulate matter and NMHC by residence time increased firstly and then decreased.When the gas flow rate was 25 m/s(residence time was 0.012 s),the average removal efficiencies were 93.49%,94.16% and 92.21%,respectively.Before the discharge voltage reached the breakdown voltage,the removal efficiencies of fume,particulate matter and NMHC were positively promoted.When the input voltage reached the critical voltage of 34 k V,the average removal efficiencies were 96.73%,97.36% and 91.40%,respectively.(3)Response surface optimization experiment: the three factors and three levels of temperature,voltage and residence time were combined,including 17 groups of factor structural combinations and5 groups of repeated experiments.When voltage V=34 k V,temperature T=127.726℃ and residence time t= 0.011 s,the optimal removal efficiencies of fume,particulate matter and NMHC were 95.70%,94.12% and 80.23%,respectively.