Ejector subcooling reliquefaction unit

~37% less power

Thermally integrating ejector refrigeration and subcooling into the Linde–Hampson process to reliquefy boil-off gas on CO₂ carriers with lower energy use.

Zhang, Qiang · Hongye, Wang · Heng, Ma

Applied Thermal Engineering 2026

Specifications

Total power consumption reduction (vs MSRS)

{'zh': '14.7', 'en': '14.7'} %

Total power consumption reduction (vs BSRS)

{'zh': '19.1', 'en': '19.1'} %

Total power consumption reduction (vs BRS)

{'zh': '37.3', 'en': '37.3'} %

Unit cost reduction of liquefied CO2 (vs MSRS)

{'zh': '6.9', 'en': '6.9'} %

Unit cost reduction of liquefied CO2 (vs BSRS)

{'zh': '11.6', 'en': '11.6'} %

Unit cost reduction of liquefied CO2 (vs BRS)

{'zh': '27.8', 'en': '27.8'} %

Exergy efficiency improvement (vs MSRS)

{'zh': '15.8', 'en': '15.8'} %

Exergy efficiency improvement (vs BSRS)

{'zh': '22.0', 'en': '22.0'} %

Advantages

Much lower power draw

Compared with three conventional systems, total power consumption drops by 14.7%, 19.1% and 37.3%, with even larger benefits in hot climates, directly reducing the vessel's electrical load.

Lower unit cost

The unit cost of liquefied CO2 is 6.9% to 27.8% lower than reference systems, improving the overall economics of CO2 shipping.

Efficient and cleaner

Exergy efficiency improves by up to 56.5%, and the system achieves the maximal net CO2 reduction, balancing energy efficiency and environmental performance.

Applications

• CO₂ ship transport：Handles BOG on LCO2 carriers, cutting reliquefaction power and cost.
• Marine refrigeration：Provides an efficient onboard liquefaction process, recovering BOG and utilizing cold energy.
• Carbon capture and storage：Ensures low-energy CO2 marine transport, supporting emission reduction across the CCS chain.