Wärtsilä develops compact BOG reliquefaction system

The Finnish technology group Wärtsilä has unveiled its reliquefaction system designed to reliquefy boil-off gas (BOG) onboard gas carriers and LNG bunker vessels.

The solution named Compact Reliq reliquefaction plant is also designed to keep the cargo cool under all operational conditions. It can be installed on existing vessels without extensive modification work, Wärtsilä said in its statement.

“As the global market for LNG applications expands in response to increasing environmental regulations, greater flexibility in meeting these growing needs is required,” says Kjell Ove Ulstein, director sales & marketing, gas solutions, Wärtsilä Marine Systems.

As with previously delivered Wärtsilä reliquefaction systems, the Compact Reliq is based on Brayton technology. This allows a portion of the BOG to be utilised as fuel for the vessel, while the excess can be liquefied and sold with the LNG cargo.

Liquefying the BOG instead of burning it in a Gas Combustion Unit also has a positive environmental effect, as no gases are released into the atmosphere, Wärtsilä said.

The system is readily instrumented for remote monitoring and online operational support and requires minimal maintenance between 5-year interval docking.

The system is compatible with Wärtsilä’s Operational Performance Improvement and Monitoring (OPERIM) protocol, and can be fully integrated with the ship’s Planned Maintenance System (PMS).