Small vessels make up a significant share of about 23% of the number of ships operating in the Baltic Sea basin and are responsible for about 8% of total harmful emissions of exhaust gases.
Established on seas Emission Control Areas (ECA) are regulated by international conventions, limiting the amount of pollutants emitted to the environment by vessels during their operation.
The way to reduce harmful emissions from marine engines is to use LNG or bio-gas as fuel. There is an analysis types of small ships in use for conversion to LNG usage -> document.
Small ships use mainly four-stroke, medium and highspeed engines with supplied almost exclusively by the distillate fuels. The use of gas supply for engines requires an analysis of the supply methods and operating conditions. There are three basic technologies used in natural gas engines – lean burn spark-ignition pure gas, dual fuel with diesel pilot and direct injection with diesel pilot. The engine technology can also be divided into which thermodynamic cycle is used by the engine, either the Otto cycle or the Diesel cycle.