Design and optimization of a zero carbon emission system integrated with the utilization of marine engine waste heat and LNG cold energy for LNG-powered ships

•The oxygen-enriched combustion system is built and host power is calibrated.•The composition of the circulating flue gas is CO2: H2O: Ar = 94.31: 2.97: 2.82.•The system can recover both high and low temperature waste heat from flue gas.•The system achieves zero carbon emission and the CO2 capturing purity is 97.09%.•The optimized system is cost-effective and has an exergy efficiency of 51.78%.