The Finnish company Wärtsilä has designed a new system for recovering evaporation gases, also known as boil-off gas (BOG), which reuses them as fuel. This system will be implemented in two LNG tankers of the Knutsen OAS shipping company that are being built at the Hyundai Heavy Industries shipyard (South Korea).
Wärtsilä’s new solution is based on reverse nitrogen Brayton cycle refrigeration technology, which constantly liquefies the BOG produced on ships and reuses it as fuel or restocked as cargo. In fact, the plant will integrate a remote system both for its supervision and for its operation. This team will be part of Wartsila’s operational performance monitoring and improvement program.
Regarding this novelty, the director of new constructions at Knutsen OAS, Jarle Østenstad, highlighted that “first generation nitrogen-based re-liquefaction plants have a high level of reliability, efficiency and quality”.
It is estimated that these compact re-liquefaction equipment will be delivered to the shipyard from February 2022, and that the new vessels will start operating at the end of that same year. Another example that the maritime sector is advancing increasingly sustainable solutions is that the first fully battery-powered, zero-emission container ship designed to operate autonomously made its maiden voyage successfully.
The “Yara Birkeland”, which was delivered to Yara Norge AS in November, completed its first route from its home port to the autonomous ship testing area in Horten, Norway, powered solely by its own batteries.