Research On VOCs Accounting And Traceability Of Circulating Water System In Petrochemical Enterprises

In recent years,China’s air pollution situation is more and more serious,regional compound air pollution has become increasingly prominent,haze,ozone-based heavy pollution of the weather into a high incidence,seriously affecting people’s health.As PM_2.5and O₃ common precursor,more and more attention was paid to volatile organic compounds.As a pillar industry of China’s economic development,petrochemical enterprises is a major emissions of VOCs in China.The problem of VOCs emissions from circulating water installations in refineries has been overlooked.Therefore,it is of great theoretical and practical significance to establish a practical and scientifically regulated method for the calculation of circulating VOCs and the traceability of VOCs in circulating water.It has important theoretical and practical significance for enterprises to carry out VOCs management.In this paper,analyze the enterprise circulating water system based on the accounting issue of VOCs emissions for some refining companies of the ministry of environmental protection,research on the accounting method for VOCs emissions from circulating water systems and traceability methods for VOCs in circulating water.The analysis of the components of recirculating water in a refining enterprise shows that the main VOCs pollutants in the circulating water of the refining enterprises are halogenated hydrocarbons and benzene.The three substances of chloroform,toluene and acetic acid were selected to carry out dilution solution,the results showed that the efficiency of stripping was related to the ratio of gas to water.The blowing efficiency of water-insoluble volatile organic compounds reached more than 95%when the ratio of gas-to-water is 40.Dissolved with water,the solution of organic matter in the gas-water ratio of 40 when the blow-off efficiency of50%.The experimental results show that it is feasible to carry out the calculation of volatile organic matter by the detection method of purgable organic compound（POC）.Using the material balance-POC method for a business cycle of VOCs emissions accounting,annual emissions of VOCs is 294.7t,material balance method accounting results mainly with the△POC and the amount of circulating water,using emission coefficient method the annual emissions of VOCs is 372.6t.The results of the emission coefficient method are only related to the circulating water flow.Mass balance relying on field monitoring data,accounting results more real and reliable,it is recommended to use the material balance method for field measurement.By selecting the accounting results for several different firms,it is shown that the accounting method of the study is feasible and the accounting results are superior to the emission coefficient method.