Microscopic characteristics and influencing factors of ship emissions based on onboard measurements

The sailing environment has a significant impact on the microscopic characteristics of ship emissions. A portable emission measurement system was used to measure and quantify the emission characteristics of two ships using different energy types in the Yangtze River. The effects of the key influencing factors, waterway environment, operating conditions, and fuel type on ship emissions were investigated. The reasonable control of ship speed, acceleration and engine revolution speed and torque can reduce ship exhaust emissions. The use of liquefied natural gas (LNG) can substantially increase CO emissions. The emission levels of the ship during departure and berthing were higher than that during cruising. As an alternative fuel, LNG may increase CO emissions; hence fuel selection requires careful consideration. This study provides key information for the development of effective emission reduction measures and can facilitate the adaptation of inland waterway shipping to low-carbon policies and the mitigation of the associated environmental impacts.