Study On Characteristics Of VOCs Emission From The Inland Ships In Shiyan

In recent years,China’s economy has developed rapidly,but the air pollution problems caused by it have become increasingly prominent.especially PM2.5 and O3 as the characteristics of the pollutants of the atmospheric composite pollution occurs from time to time,has caused widespread concern in the society.VOCs(Volatile Organic Compounds)are important precursors for of PM2.5 and O3.The effective control of VOCs emissions can improve the air pollution to a certain extent.In the "Thirteenth Five-Year Plan for Volatile Organic Compound Pollution Prevention and Control Work Plan" released in 2017,VOCs were regarded as the key emission reduction targets.Since then,VOCs emission control has gradually received high attention.However,previous research mainly focused on land-based emission sources such as the fixed sources,motor vehicles,etc.the research on the VOCs emission control of ships involves little,and the emission characteristics of ship sources are not well understood,which restricts the fine management of VOCs emission control in China.Shiyan has developed water transportation,and ship transportation plays an important role in economic development.However,most of ships use diesel or heavy oil as fuel in Shiyan,which emit a large amount of VOCs during sailing.At the same time,due to the lack of emission standards to control,ship exhaust is directly discharged without treatment.In this paper,typical ships on the Han River in Shiyan are taken as the research object,and the characteristics of VOCs emission from inland river ships are explored through the actual sampling and GC-MS analysis.The main conclusions are as follows:(1)Through GC-MS analysis,a total of 97 kinds of VOCs components emitted by ships were found,including 28 kinds of alkanes,14 kinds of alkenes,1 kind of alkynes,16 kinds of aromatic hydrocarbons,24 kinds of halogenated hydrocarbons,and 14 kinds of oxygenated VOCs;The difference of concentration of VOCs emitted by different ships is obvious.but ranged from 1.57 mg/m3 to 38.40 mg/m3.The concentration of VOCs emitted by sand ships#5 was the highest and that of sand ships#4 was the lowest.Compared with the three sand ships,sand ships#5 emits the highest concentration of VOCs,which may be related to the small engine power and long age of ships.(2)Different ship types(sand ships,passenger ships,offshore ships)have different emission characteristics of VOCs.From the perspective of emission concentration,VOCs emission concentration of offshore ships is the highest at 23.94 mg/m3,followed by passenger ships at 23.09mg/m3,and sand ships#4 is the lowest at only 1.57 mg/m3.From the perspective of emissions ratio,sand ships#4 is dominated by alkanes,oxygenated VOCs and alkenes,accounting for 24.96%,23.80%,and 21.96% respectively,of which ethane,propylene,and benzene are the main components of VOCs;Passenger ships are dominated by oxygenated VOCs,aromatic hydrocarbons and alkenes,accounting for 33.11%,31.95%,and 25.38%respectively,of which benzene,propionaldehyde,3-methyl-1-butene,1-butene are the main VOCs Components;offshore ships are dominated by oxygenated VOCs,alkenes and aromatic hydrocarbons,accounting for 33.01%,28.51% and 28.11% respectively,of which benzene,propionaldehyde and 3-methyl-1-butene are the main components of VOCs.(3)VOCs emission characteristics of sand ships are different with different load states.From the perspective of emission concentration,VOCs emission concentration of sand ships#3 and sand ships#5 in the no-load state are 3.00mg/m3,37.78mg/m3,respectively.and4.72mg/m3,38.40mg/m3,respectively in the full-load state.the full-load is higher than the no-load emission concentration.From the perspective of emission ratio,under the no-load state,sand ships#3 is dominated by aromatic hydrocarbons,oxygenated VOCs and alkanes,accounting for 31.00%,26.18% and 22.36%,respectively.of which benzene is the main component;sand ships#5 is dominated by alkenes,aromatic hydrocarbons and oxygenated VOCs,accounting for 37.00%,32.83% and 18.50% respectively,and benzene and 1-butene are the main components of VOCs.Under the full-load state,sand ships#3 is dominated by aromatic hydrocarbons,oxygenated VOCs and alkenes,accounting for 35.04%,27.71% and20.03%,respectively.Of which benzene,n-decane and 1-butene are the main components of VOCs.sand ships#5 is dominated by alkenes,aromatic hydrocarbons and oxygenated VOCs,accounting for 49.11%,24.76%,and 16.96% respectively.of which benzene and 1-butene are the main components of VOCs.