Potential energy recovery from LNG regasification in LNG-fueled ships

Recent regulatory initiatives regarding ships emissions raised the interest of maritime operators on cleaner fuels. The International Maritime Organization (IMO) with Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) set strict limits on SOx , NOx and CO2 emissions. Many studies have been carried out to increase engine efficiency based on waste heat recovery such as ORC or turbo-compounding. Using LNG as a fuel opens new opportunities in this prospect. In this study, an energy recovery from LNG regasification process, through a dedicated and optimized cycle, is investigated. The system is made of an open supercritical Rankine cycle performed before engine injection and exploiting LNG as a working fluid. Results showed the influence of the maximum temperature and pressure of the cycle on the system performance. A maximum power recovery up to 2.2% of main engine power was found.