Onboard carbon capture and storage (OCCS) is promising, but downstream CO2 conditioning and liquefaction dominate energy and operability constraints. An integrated OCCS onboard for CO2 conditioning, deep cooling, phase separation and liquid CO2 (LCO2) storage for a dual-fuel marine engine was introduced and investigated. In addition, the proposed system has been scrutinized under Aspen HYSYS V12.1 steady state mode and a comprehensive sensitivity sweep on deep-cooler temperature and separation pressure. Sensitivity sweeps reveal a sharp liquefaction threshold governed by the deep-cooler outlet temperature. For the engine load range from 50% to 110% and exhaust gas from 1.288 to 2.863 kg/s with CO2 from 3.65 to 6.67%, the model is validated at 90.3% capture. Near vent-free operation for TE105 190 kPa at −24.7 °C, while −22.45 °C is unattainable within 1600–2200 kPa. Increasing compressor discharge pressure from 1500 to 2500 kPa raises compression power from 34.8 to 80.23 kW at −21 °C without improving vent/yield under throttled control. By identifying threshold-based deep-cooling setpoints, creating a separator pressure-temperature feasibility envelope for near-vent-free operation, and clearly quantifying CO2-rich vent slip as a system-level loss term, this study offers an operability-driven design layer for onboard CO2 liquefaction.
Tô et al. (Fri,) studied this question.