The technology group Wärtsilä’s recently introduced Compact Reliq reliquefaction plant will be installed in two new LNG Carrier vessels being built for Norway-based Knutsen OAS Shipping. The ships are to be built at the Hyundai Heavy Industries shipyard in South Korea. The order, which includes an option for an additional two vessels, was placed in November 2020.

The Compact Reliq solution is based on the well-proven reversed nitrogen Brayton cycle refrigeration technology. The solution is designed to reliquefy the boil-off gas (BOG) from gas carriers and LNG bunker vessels, and for keeping the cargo cool under all operating conditions. It allows a portion of the BOG to be used as fuel for the ship’s engines, with the excess able to be sold as part of the LNG cargo.

“Wärtsilä is a trusted partner with whom we have worked in the past. The first generation nitrogen based re-liquefaction plants is highly reliable, efficient, and of good quality, so we had no hesitation in selecting the Compact Reliq for these new LNG Carriers,” said Jarle Østenstad, Newbuilding Director, Knutsen OAS Group.

“These will be the first installations for the Compact Reliq reliquefaction solution. We are very proud of this latest addition to our portfolio of gas value-chain products and systems, and this order provides a positive indication that the market is ready to embrace it,” commented Kjell Ove Ulstein, Director of Sales and Marketing at Wärtsilä.

The system will be instrumented for remote monitoring and online operational support as part of Wärtsilä’s Operational Performance Improvement and Monitoring (OPERIM) programme. The equipment is scheduled to be delivered to the yard commencing in February 2022, and the vessels are expected to begin commercial operations from late 2022. Wärtsilä has earlier supplied Knutsen OAS Shipping with earlier generation reliquefaction plants for six of the company’s vessels.

The compact design of the Wärtsilä Compact Reliq makes it easy to retrofit on existing ships without the need for extensive modifications. It features high reliability and a minimal maintenance requirement. The refrigeration process uses safe and easily obtainable commercial grade nitrogen.

Wärtsilä Gas Solutions is a market leader with innovative systems and lifecycle solutions for the gas value chain. Our main focus areas are handling of gas in seaborne transport (storage, fuel, transfer and BOG management), gas to power, liquefaction and biogas solutions. We help our customers on the journey towards a sustainable future through focus on lifecycle, innovation and digitalization.