Characterization of non-methane hydrocarbons emitted from Chinese cooking

EPA Method TO-14/15 for measurement of toxic organics in air samples was applied to examine non-methane hydrocarbon(NMHC) emissions from 5 Chinese restaurants in Beijing.The 5 restaurants use 4 different cooking styles.A total of 72 components of VOCs were observed.The distinguishing characteristics of NMHC emissions from different restaurants are attributed to their cooking style,business scale,number of customers and restaurant grade.Based on the calibrated baseline ventilation volume,the NMHC concentrations of the examined restaurants were in the range of 9.13×103~14.2×103μg · m-3.Alkanes,alkenes and aromatics were the major NMHC components,which were in the ranges of 28.4%~47.9%,8.9%~58.3% and 10.8%~50.4%,respectively,according to the specified parameters set for the individual restaurant.However,the proportion of chlorohydrocarbons and naphthalene varied significantly,especially that of naphthalene.Based on our sampling results and catering industry data from the Beijing statistical yearbook the total amount of NMHCs emitted from commercial restaurants in Beijing was roughly estimated,to be 10559 tons per year.The data suggest that commercial cooking might be an important source of ozone precursors.