Study On Current And Future Anthropogenic Emissions Of Volatile Organic Compounds In China

Volatile organic compound (VOC) is the key precursors of ozone and secondary organic aerosols. Accurate VOC emissions are the essential prerequisite to study regional air pollution complex and are of significant importance to formulate air pollution control strategy in China. This study developed the high resolution anthropogenic VOC emission inventories and analyzed their sectoral, spatial and temporal distributions, species profiles and atmospheric chemical characteristics.Anthropogenic VOC emission sources were classified into more than 130 categories. Chemical species of VOC is categorized mainly according to their physical and atmospheric photochemical reactivity. Then an integrated model, incorporating the databases of activity information, emission factors, and chemical profiles, was established to develop the anthropogenic VOC emission inventory in China. The Monte Carlo method was used to quantitatively evaluate the uncertainties of the emission inventory.It is found that VOC emission factors and chemical profiles of bio-fuel combustion and solvents use, which both are important emission contributors, are of large uncertainty. Therefore, field measurements and surveys on these sources were conducted to supplement and improve the VOC emission factor database in China. A VOC sampling and analysis system was designed to determine the emission factors and chemical profiles of VOC emitted from two types of bio-fuel stoves. In addition, 10 kinds of solvents were surveyed to obtain their VOC emission characteristics during use in various industries.Current anthropogenic VOC emission inventory and future emission scenarios were compiled based on the above work. In 2005, total VOC emissions were 19,406 kt, of which the important emission sources were stationary fuel combustion, road transportation, solvent use and industrial processes, respectively accounting for 28.3%, 24.2%, 17.6% and 15.8%. The distributions of VOC emissions presented significant spatial differences. Jiangsu, Shandong, and Guangdong were the largest VOC emitters with emissions over 1,500 kt. Alkanes, alkenes and alkynes, and aromatics were the most important chemical species of VOC emissions, respectively accounting for 30%, 20%, 21%, and30% of total emissions and resulting high atmospheric oxidation activities. The Photochemical Ozone Creation Potential was about 53.7 and the percentage of toxic pollutants was about 30%.By year 2020, national total VOC emissions will increase to 26,523 kt with the current emission legislations. By applying strict regulations to solvent uses and industrial processes as adopted in developed countries, national total VOC emissions will decrease to19,943 kt.