This study aims to accurately estimate the emissions of seven air pollutants (NO_X, SO_X, CO₂, CO, PM_2.5, PM₁₀, and NMVOC) from ships for one year (2020) in the busiest port in Korea, Busan Port. To achieve this, a more detailed method for calculating emissions was developed, taking into account factors such as the type of fuel used, mode of operation, and engine output of each ship that entered and left the port. In cases where information on the ship’s main engine was not available, a regression analysis was performed to estimate the engine output based on the ship’s tonnage. In addition, the output of auxiliary engines was estimated based on the ratio of the output of the main engine to that of the auxiliary engine for recently built ships. Finally, emissions from fishing vessels were also included in the calculations. Thus, in Busan port, the total estimated fuel consumption from 44,315 cases in 2020 was 252,519 t; the consumption during hoteling accounted for 87%. In detail, the emissions of seven air pollutants reflecting the emission factors were analyzed as follows: NO_X, 18,323 t; SO_X, 16,924 t; CO_2, 790.383 t; CO, 714 t; PM_2.5, 1484 t, PM_10, 1614 t; and NMVOC, 772 t. In addition, this study provides an estimation equation to estimate engine output based on a ship’s tonnage, which showed the highest fitness when compared to actual engine output. This methodology can be useful for calculating emissions of air pollutants at the port in detail and promoting marine environment policies.

This work studied the effect of the injector spray angle (SA) on the combustion and emissions of a 4-stroke port-injection natural gas-diesel dual-fuel (NG-Diesel DF) marine engine to determine the optimal SA for the fuel injector, aiming to reduce exhaust gas emissions while keeping the engine performance. Three-dimensional (3D) simulations of the combustion process and emission formations occurring in the engine cylinder in both diesel and DF modes were carried out using the AVL FIRE R2018a code. The engine’s in-cylinder temperature, pressure, and emission characteristics were analyzed. To clarify the effect of the injector SA on the combustion and emission characteristics of the engine, only the injector SA has been varied from 145 to 160°. Meanwhile, all other boundary conditions for the simulations and operating conditions of the engine have remained unchanged. The simulation results have been compared and showed a good agreement with the engine experimental results. The study has successfully investigated the effects of the injector SA on the combustion and emission characteristics of the engine. A better SA for the fuel injector, to reduce the NO emissions (145°) or soot and CO₂ emissions (150°), while keeping the engine power almost unchanged, without the use of any exhaust gas post-treatment equipment, has also been suggested.