Onshore-bunker-systems

Onshore bunker system

A high degree of standardisation and flexibility in the different operational modes allows for speedy project execution and safe installation on-site. The installation of the process equipment is facilitated by modules prefabricated in our own production facility in Gothenburg.

The basic design is a two-mode system, including LNG import by LNG truck, storage in vacuum-insulated storage tanks and export to the LNG-fuelled ship. 

In addition to a basic version, the onshore bunker system can be adjusted to handle:

  • LNG import from an LNG tanker
  • LNG import from a train
  • LNG import from an LNG-fuelled ship
  • LNG export to LNG containers
  • LNG export to a bunker ship

The standard concept of the onshore bunker system includes:

  • High-flexibility hose
  • Safety break-away coupling ensuring a safe and quick disconnection of the hose in case of unexpected movement of the vehicle
  • A reliable and fast connection of the vehicle with the system
  • Ship-to-shore safety system

After proper connection of the hose to the LNG vehicle, the transfer of LNG takes place with a flow rate of up to typically 35 m³ per hour, with a pressure of up to nine bar.

The LNG will be stored in pressurised and vacuum-­insulated storage tanks in order to control the boil-off gas. Larger storage tanks of up to 2,000 m³ provide a cost-effective storage solution compared to smaller tanks. Therefore, a modular increase of the storage capacity allows for a moderate investment in the early stage of the onshore bunker terminal.

The possibility to increase or even decrease the LNG storage capacity according to the client’s demand is an advantage compared to fixed installations such as flat-bottom tanks, thereby reducing the overall investment risk.

Expample of Process Gas Flow

Process-gas-flow

For safe operation of the onshore bunker system, a cost-effective boil-off gas handling system is required. Such boil-off gas is normally generated during loading in the idle period of the bunker terminal. 

The pressurisation of LNG allows heat increase to the system for a certain time without outake. The saturated pressure of the stored LNG will increase if no LNG send-out takes place to the client. Safe control of the energy input to the system can be realised by the external cooling source liquefied nitrogen (LIN, -194 °C).

The heat and cold transfer, respectively, from LIN to the medium takes place in the vacuum-insulated pressurised storage tanks. Two different methods have been developed: The installations can either sub-cool LNG directly in order to lower the saturated pressure and reduce the flash gas significantly, or the gas will be recondensed directly in the gas phase of the vacuum-insulated storage tank. 

The export of LNG to the end customer takes place at the quay, pontoon or jetty. The system includes a skid unit that contains: 

  • Valves
  • Instruments
  • Loading hose system 
  • Drop-free couplings
  • Breakaway couplings

A manually operated crane, supplied with a breakaway coupling, can be optionally installed to safely handle the hose.  The loading rate from the onshore bunker system is typically in the range from 50 to 500 m³/hour. The export pumps are situated in a pump skid unit near or below the tanks. The onshore bunker system is designed according to the standards EN 13645, EN 13648, EN 1160 and also the latest developed ship/shore standards created by SIGGTO.