A liquefied energy chain for transport and utilization of natural gas for power production with CO2 capture and storage - Part 3: The combined carrier and onshore storage

A novel energy and cost effective transport chain for stranded natural gas utilized for power production with CO2 capture and storage is developed. It includes an offshore section, a combined gas carrier and an integrated receiving terminal. The combined carrier will transport liquid carbon dioxide (LCO2) and liquid nitrogen (LIN) outbound, where natural gas (NG) is cooled and liquefied to LNG by vaporization of LIN and LCO2 onboard the carrier. The same carrier is used to transport the LNG onshore, where the NG can be used for power production with CO2 capture. The combined carrier consists of 10 cylindrical tanks with a diameter of 9.2 m and varying lengths from 14 to 40 m. The total ship volume is 13,000 m3. Assuming 85% capture rate of the CO2, the maximum ship utilization factor (SUF) is 63.4%. Due to the combined use of the storage tanks, the SUF is decreased with 1.4% points to 62%. The ship is equipped with a bi-directional submerged turret loading for anchoring and loading of NG and unloading of CO2. Two ships can deliver NG to and remove CO2 from a 400 MWnet power plant, and still obtain continuous production of LNG offshore without intermediate storage. The investment cost for each gas carrier is 40 million EUR giving total transport cost of 16.9 EUR/tonne LNG. The cost for the offshore transfer system is 6.6 million EUR per tonne LNG, whereas the cost for onshore storage and loading system is 3.1 and 0.8 million EUR per tonne LNG, respectively. The total specific costs for the ship transport, including onshore storage, loading shipping and offshore unloading are 27.5 EUR per tonne LNG for a roundtrip of 5 days, including voyage, production of LNG, unloading, connecting and berthing.