Studies On The Sources Of Vocs In Beijing

Today the petroleum-products has been used as a kind of major energy. And a new kind of pollution photochemical smog becomes more and more common. The photochemical smog is formed from the reactions of VOCs and NO~ in the sunlight. The reactions lead to a lot of product species, which are called photochemical oxidants. As the resent studies showed that the level of photochemical oxidants in Beijing is high. In order to reduce the pollution of photochemical oxidants, decreasing the emissions of VOCs is very important. This paper goes into details about the sources of VOCs in Beijing. The study is the first time of the similar studies in Beijing. It will give some basic data and some experiences to the following researches about photochemical smog. Investigation of emissions inventories is a complex process, because many data are absent, meanwhile ,the sources are numerous, diverse and widely dispersed. In order to get the data needed, the author has red a lots, surveyed several sample sources in details, tested some samples on the spot and used a few of mathematical models. During the estimation emission factors and material balances are used. Besides the estimation of the emissions from biogenic and traffic sources, the paper put emphasis on the survey of emission, pollutants and distribution about the sources of the usage of organic solvents and the store and distribution of gasoline and diesel oil. The emissions from painting industry, printing industry, dry cleaning, adhesives, medicine industry, rubber industry, consumer products and oil deports and gas stations are discussed in the section. At the same time suggestions are given to reduce the emission. The result is that in 1999, 477.4kt VOCs were let out in Beijing. The first major source of VOCs is traffic source, the second is stationary source and biogenic source followed. VOCs emitted from the usage of organic solvents 43 .9kt, and oil depots and gas stations emitted 15 .8kt. In the emissions from the usage of organic solvents, painting industry emitted 21 .3kt, printing industry emits 9.Skt. The two industries are the main important sources. VOCs can easily form the photochemical pollution in the city, for the most part of the emission from transport and a section of emissions from stationary sources are emitted into the city air.