Life cycle analysis of a waste heat recovery for marine engines Organic Rankine Cycle

The Marine ORC prototype unit is based on a conventional low-temperature subcritical Organic Rankine Cycle and has been designed as a waste heat recovery system for the jacket water of marine diesel auxiliary internal combustion engines (ICEs). In the present work, the key remarks of the life cycle analysis on the experimental test rig, installed in Athens, Greece, are presented. The analysis of the impacts has been conducted using the ReCiPe 2016 method. The system was evaluated in coupling with the auxiliary ICE and was compared against an ICE of the same electrical energy output on annual basis. The ICE-marine ORC system enhanced the environmental performance up to 3% on many impact categories, apart from the mineral resources and the terrestrial ecotoxicity which is related to the extended use of copper-based materials. The working fluid was found to have a major impact on the ozone depletion and the global warming categories with a share of 95.9% and 91.6% over the total equivalent system emissions, respectively. On the other hand, the replacement of R134a with R1234ze was found to reduce the ORC's global warming impact down to less than 10% of its initial value. © 2022 Elsevier Ltd