An AIS-based emission inventory and the impact on air quality in Tianjin port based on localized emission factors.

Ship pollution has become a hot global issue. This study established a basic information database of Tianjin Port ship emissions and used it to screen representative ship types and perform real-world ship measurements by a portable emission measurement system (PEMS), which generated localized emission factors. The results show that the localized emission factors are significantly higher than those recommended in recommended in Chinese guidelines, which will lead to lower calculation results of the previous inventory. A high temporal-spatial ship emission inventory for Tianjin Port was developed using a "bottom-up" method based on automatic identification system (AIS) data by combining localized emission factors. The total estimated ship emissions for SO2, NOX, PM10, PM2.5, THC and CO in 2018 were 1.453 × 10 t, 2.861 × 10 t, 2.04 × 10 t, 1.82 × 10 t, 1.13 × 10 t, and 2.21 × 10 t, respectively. NOX was the primary pollutant, accounting for 56.9%, followed by SO2 (28.9%). The use of low-sulfur fuel in the port area has significantly reduced the discharge of SO and primary particles. The main channel and anchorage are the areas with the highest emission intensity. The intermonth ship emissions varied according to the ship activity, lowest in February and highest in May. The contribution of cargo transportation vessels to various pollutant emissions is more than 60%. Main engines (MEs) were the largest source of emissions, followed by auxiliary engines (AEs). NOX and SOX from ships have the greatest impact on the air quality in the surrounding area, especially in summer and autumn, as analyzed by the atmospheric dispersion modeling system (ADMS) model. Our research will update localized emission factors and inventories and evaluate the impact of ship emissions on air quality.