Conceptual design of the LNG dual-fuel system for harbour tug towards Indonesia Greenport

Declaration of several large ports as Greenport indicates that increasing the environmental concern of port operatio n in Indonesia. Harbour tug as one of the port's operational supports is also required to contribute low emissions. One method to reduce exhaust emissions from tugboats is to replace the use of fuel oil with natural gas. This study describes the conceptual design of a dual-fuel LNG system at the harbour tug vessel for operational needs at the Indonesian port. The 2x2500 HP Harbour Tug, which is the case in this study, uses a dual fuel diesel engine as a prime mover with a direct mechanical propulsion system. Study optimization considering the operational mode of a prime mover will determine the LNG storage capacity, due to harbour tug vessel operation and space capacity as well as of bunkering system. The design parameters for the main components of the fuel system, such as the Regasification Unit, Gas Valve Unit are essential considerations to support the system's operation optimally.