Shanghai has achieved a significant global milestone in maritime decarbonisation, successfully completing the world’s first ship-to-ship transfer of captured carbon dioxide (CO2) at sea. The groundbreaking operation took place on June 19, 2025, at the Yangshan Deepwater Port’s Shengdong Terminal, marking a pivotal step towards a more sustainable shipping industry.
This unprecedented transfer involved the Ever Top, a large Panamanian-flagged Evergreen containership, and the barge De Jin. The Ever Top, a 152,300 deadweight tonnage (dwt) vessel with a capacity of 14,000 to 18,000 twenty-foot equivalent units (TEU), is notable as the world’s first container ship to be retrofitted with an onboard carbon capture and storage (OCCS) system.
The Technology Driving Decarbonisation
The innovative OCCS system integrated into the Ever Top was developed by the Shanghai Marine Diesel Engine Research Institute, an entity affiliated with the China State Shipbuilding Corporation (CSSC). This full-process system, which includes absorption, regeneration, compression, refrigeration, and storage modules, is capable of capturing over 80 percent of CO2 emissions from the vessel’s exhaust, with the captured CO2 achieving a remarkable purity of 99.9 percent. The installation of this advanced system on the Ever Top was completed in 2024.
Prior to this ship-to-ship transfer, the Ever Top had already made history in 2023 by completing the world’s first full-process ship-to-shore unloading of captured CO2 at the same Shanghai port, demonstrating its pioneering role in maritime carbon capture.
Overcoming Logistical Hurdles in Carbon Management
The successful ship-to-ship CO2 transfer addresses a critical bottleneck in the wider adoption of onboard carbon capture technology: the efficient and economical offloading of captured CO2. Previously, captured CO2 was offloaded to trucks or tanks, a process that was slow, cumbersome, and limited by port infrastructure.
The newly demonstrated ship-to-ship method offers significant advantages. It provides greater capacity for CO2 offloading compared to land-based transport and offers enhanced flexibility, allowing transfers to occur even at anchorages without requiring dedicated port infrastructure. Du Mingsai, the project manager for the transfer operation, highlighted that a single CO2 carrier can transport dozens or even hundreds of times more gas than a standard tanker truck, making the process far more efficient and significantly cheaper than land transport.
This innovative approach streamlines the carbon capture value chain, enabling captured CO2 to be transferred directly to a specialized barge like the De Jin and then transported for reuse in various industrial applications.
Economic and Environmental Implications
The development of practical shipboard carbon capture and efficient transfer mechanisms like the one demonstrated in Shanghai carries profound economic and environmental implications for the global shipping sector. The International Maritime Organization (IMO) estimates that the shipping industry annually emits approximately 1 billion tons of CO2, accounting for nearly 3% of global emissions. Addressing these emissions is crucial for global climate goals.
The OCCS system provides a compelling and cost-effective alternative for shipowners facing stringent emissions regulations. Retrofitting a large container ship like the Ever Top with this carbon capture system costs around $10 million, which is less than half the price of converting vessels to run on alternative fuels such as methanol or ammonia. This makes it an economically viable option for extending the service life of existing vessels in compliance with new environmental standards.
Furthermore, the captured liquid CO2 is not merely waste but a valuable resource. It can be sold for various industrial purposes, with Chinese authorities suggesting the potential for vessels to generate up to $8 million in annual revenue from the sale of the captured CO2. This transforms emissions from a liability into a commercial asset, creating a new economic incentive for decarbonisation.
A “Shanghai Solution” for Global Shipping
Shanghai’s successful demonstration of a complete, closed-loop ecosystem for vessel-emitted CO2—encompassing capture, storage, ship-to-ship transfer, transport, and reuse—is being hailed as a replicable “Shanghai Solution” for international shipping emissions reduction.
The expertise gained from this pioneering effort is already contributing to global standard-setting. Experts from the Shanghai Marine Diesel Engine Research Institute are actively participating in the IMO’s newly formed working group on OCCS systems, sharing their experience to help shape future global regulations and standards for maritime carbon capture and transfer. This collaborative approach is vital for the widespread adoption of such critical technologies.
The successful completion of this world-first ship-to-ship CO2 transfer by Shanghai marks a monumental stride in the maritime industry’s journey towards a sustainable and decarbonised future. By demonstrating practical, efficient, and economically viable solutions for handling onboard captured carbon, Shanghai is not only setting a new global benchmark but also offering a tangible pathway for the shipping sector to significantly reduce its environmental footprint.
