Study On The Emission Characteristics And Control Technologies Of VOCs From The Cooking Oil Fume

In recent years,the pollution of cooking oil fumes has becoming serious,and gradually drawing more and more attention.Except for the particulate matter（PM）,there is also volatile organic compounds（VOCs）in oil fume.Studies found that cooking oil fume is one of the sources of PM_2.5 and has complicated components of VOCs.This is not only a threat to the health of the kitchen staff,but also has an obviously affection on the quality of regional atmospheric environmental.Therefore,it is of great significance to study the emission characteristics and control technologies of VOCs in cooking oil fume.The study was involved five kinds typical vegetable cuisines,from which oil fumes were sampled in the city of Shijiazhuang.The present situation of emission characteristics and control technology of the cooking oil fume were analyzed.Specific thought of fume purification was proposed.The main conclusions of the study are as follows:The emission concentration of VOCs in barbecue was the highest,12909.71μg·m^-3,and others were arranged in order of concentration,the sequence was Sichuan cuisine,western fast food,Shanghai cuisine,and Chinese fast food,concentrations were 7955.32μg·m^-3,6114.99μg·m^-3,4141.68μg·m^-3,3686.23μg·m^-3,respectively.The main ingredients of VOCs in barbecue were 1-butene,propylene and n-butane with a emission concentrations exceeding 1000μg·m^-3.The main ingredients of VOCs in non-barbecue cuisine were ethanol(especially Sichuan cuisine,with an ethanol concentration of more than 5000μg·m^-3),and other ingredients were pentoses,acetone and acrolein which were less than ethanol.The main emission components of the VOCs for barbecue were olefins,alkanes and aromatic hydrocarbons as well as aldehydes and ketones compounds.The components of VOCs in Sichuan cuisine,Shanghai cuisine and Chinese fast food were similar in the composition to the former.The main emission components of VOCs of western fast food in the order from high to low were aldehydes and ketones,alcohols and alkanes.The final emission concentrations of the five cuisines were all less than 2 mg·m^-3,which were all reached the requirements of the emission standard.All the restaurant which were studied had a high oil fume removal efficiency and even met the standard request.According to the removal efficiency of the five cuisines from more to less in proper order were Shanghai cuisine（95.76%）,western fast food（92.29%）,Chinese fast food（92.18%）,Sichuan cuisine（91.71%）,and barbecue（87.64%）.According to the analysis of the components of VOCs,emission concentration,oil fume concentration and removal efficiency,it is concluded that the lampblack of barbecue has a serious impact on the environment,and also the main source of pollution of cooking oil fumes in urban area.It should be strengthen the supervision of barbecue restaurants firstly.Secondly,Sichuan cuisine.Through a wide range survey of emission and treatment of cooking oil fume in the restaurants,it is found that most of the catering enterprises of the main urban area of Shijiazhuang and its surrounding areas have installed oil fume purifiers,of which electrostatic fume purification technology has been widely used,and all the fume has been released after purification.But there are phenomena in restaurants-aging facilities,lacking of maintenance,upgrading slowly and mismatching of blowing rate of air blower with the practical necessity of the kitchen.According to the actual demand,a purification ideas has been proposed,which combines with electrostatic fume purification technology in order to simultaneously eliminate cooking oil fume such as PM and VOCs.