| Although railway has played a great role in transportation in china,there has been no any study on air pollutants emissions of locomotives until now. Based on the annual statistical data collected by the Chinese Railway Statistic Center,using the emission factor method derived from fuel consumption,the air pollutants emissions of locomotives during 1975-2007 were calculated,and their emission intensities and dynamic characteristics were analyzed. The results show that the emissions of soot,SO2,CO and CnHm from steam and diesel locomotives in china decreased from 3510.6 thousand,399.7 thousand,846.0 thousand and 845.3 thousand ton in 1975 to 78.7 thousand,11.4 thousand,36.7 thousand and 26.4 thousand ton in 2007,indicating a decrease of 107.0 thousand,12.1 thousand,25.3 thousand and 25.6 thousand ton per year,respectively. However,the emissions of NOxshowed an increase trend from 34.8 thousand ton in 1975 to 98.3 thousand ton in 2007 with an increase rate of 2.0 thousand ton per year. The emission intensities of soot,SO2,CO and CnHm decreased significantly from 686.2,78.1,165.4 and 165.2 g/(hundred converted ton-km) in 1975 to 5.4,0.8,2.5 and 1.8 g/(hundred converted ton-km) in 2007,respectively. The emission intensity of NOxfluctuated in the range of 5.0-8.0 g/(hundred converted ton-km). Air pollutants emissions of locomotives accounted for very little of the total emissions in China,and the emission intensities decreased persistently. It shows that railway transportation is a perfect way of saving energy and reducing emission in the sector of transportation. |
