Emission inventory research of typical agricultural machinery in Beijing, China

Abstract

Non-road mobile machinery, especially agricultural machinery, has increasingly become an important source of air pollution in China. Hence, it is important to study these emissions. In this study, Beijing is used as an example, and the emission characteristics of 22 types of agricultural machinery (tractors, combine harvesters, and micro-tillers) in idling mode, moving mode, and working mode were tested using a portable emission measurement system (PEMS). The results indicate that the net power-based emission factor in working mode was larger than that in the idling and moving modes. Based on information from actual emission factors, ownership and activity levels, a typical agricultural machinery emission inventory for Beijing from 2006 to 2016 is established using the complex method from the Technical Guidelines for Compiling Non-Road Mobile Source Emission Inventory. In addition, the spatial distribution of the emission inventory is analyzed using Geographic Information System (GIS). Typical agricultural machinery in Beijing emitted carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM), and the total, and these decreased by 63.11%, 62.93%, 72.07%, 74.67%, and 68.66%, respectively, from 2006 to 2016, which proved the validity of emission control technologies and relevant regulations in China. In addition, the emission intensities of the different agricultural machines and different regions differed significantly. In 2016, the overall contribution of tractor emissions accounted for more than 80%. In the Yanqing District, Shunyi District, and Miyun District, the total emissions reached nearly 50%. The Chaoyang District was less than 1%. Therefore, in the future, government should pay more attention to high emission intensity agricultural machinery and its regional impacts.