Interactive comment on “ Gasoline aromatic : a critical determinant of urban secondary organic aerosol formation ” by Jianfei
The authors presented the contribution of gasoline vehicle exhaust to SOA formation in urban atmosphere. The manuscript indicated the importance of the vehicular gasoline compositions and clarified the principal problem of vehicular emissions for haze pollution in China. However, in your literature review, the authors missed some new findings. E. g. Tang et al. (2015) illustrated the differences of gasoline compositions between China and USA and found alkenes and aromatics in China were 4.9% and 9.6% higher than that in USA, respectively. After a while, they also found mortality was correlated with vehicular emissions in Beijing (Tang et al., 2017). Therefore, I suggest the authors discuss these new findings on the chemical compositions of gasoline and the relationship between vehicular emissions and human health, which can emphasize the motivation of this study. C1
Organic composition of gasoline and its potential effects on air pollution in North China
When gasoline is burned to power an automotive engine, a portion of the fuel remains unburned or is partially burned and leaves the engine as hydrocarbon and oxygenated compounds. In addition, a small portion of the fuel can escape the vehicle through evaporation. Changes in alkanes, olefins and aromatics each affect emissions differently, which could complicate control strategies for air pollution. In this study, we collected 31 gasoline samples over five provinces and cities (Beijing, Tianjin, Hebei, Shandong, and Shaanxi) in North China between 2012 and 2013. The organic composition of the gasoline samples was analyzed using the gas chromatography-mass spectrometry (GC-MS) method, and the aniline compounds were analyzed by solvent extraction and the GC-MS method. The ratios of alkanes, aromatics, olefins and other organic compounds in gasoline were 40.6%, 38.1%, 12.9% and 8.4%, respectively. The aromatic and benzene exceedances were 15 and 8 based on the China’s gasoline standards (III), and they accounted for 48.4% and 25.8% of all the gasoline samples, respectively. Strong carcinogen aniline compounds were detected in all 31 samples, and the content of aniline compounds in 3 samples exceeded 1%. The high proportion of aromatics and olefins in the gasoline increased the emissions of carbon monoxide (CO) and toxics, as well as the atmospheric photochemical reactivity of exhaust emissions, which could hasten the formation of secondary pollutants. Our results are helpful for redefining government strategies to control air pollution in North China and relevant for developing new refining technology throughout China.
OPTIMIZING REFINING PROCESSING FOR THE DEVELOPMENT OF CHINA′S PETROLEUM REFINING INDUSTRY
An integrated industrial system has been formed in (China's) petroleum refining industry. Although the expectation of (China's) demands for petroleum products is to be increased at a higher speed before 2020, the severe situation is seen with the problems concerning the shortage of crude resources, low gradation of product quality, the conspicuous conflicts of market supply versus demands for petrochemical light oils, and environmental protection, etc. To speed up the development of China's petroleum refining industry, suggested routes of refining processes are configured as: (1) to optimize the refining processing by focusing on heavy oil upgrading combining with (China's) practice; (2) production of transportation fuels and petrochemical raw materials which can not be replaced by other resources currently; (3) to keep catalytic cracking playing the backbone role for producing final product oils; (4) to speed up the development of hydrocracking to achieve the integration of petroleum refining and petrochemical production; (5) combination of the pre-treatments of raw materials, new processes of catalytic cracking with post-treatments to improve the quality of final products; (6) reuse of treated waste water, the control of exhausted SO_x to alleviate the air pollution, etc.