U.S. Energy Innovation: Closing the Loop on the Carbon Lifecycle with LCO2 Transport

First pioneered in the 1970s for enhanced oil recovery in the United States, carbon capture and storage (CCS) is a proven technology solution. It reached global scale with the world's first commercial CCS project launched offshore Norway in 1996. Now, CCS holds promise as a transformative process improvement solution to convert raw emissions into a valuable commodity for the maritime community—and effectively close the loop on carbon life cycle.

Both global and U.S. maritime companies are accelerating this energy innovation with strategic investments in industry-first vessel designs, including an innovative barge configuration that global ports could replicate as they build out infrastructure to support large-scale adoption. The maritime community is closer to utilizing CO₂ as a recoverable resource with a novel closed-loop system onboard.

At the Forefront of Maritime CCS

The U.S. is positioning itself at the forefront of maritime carbon capture infrastructure development with emerging projects along the Gulf Coast Corridor, from Corpus Christi, Texas to the Mississippi River and beyond. According to the National Energy Technology Laboratory, in 2024 there were more than 30 CCS-related projects either proposed or active in this region . One of the nation’s busiest industrial corridors, the U.S. Gulf Coast presents a high concentration of carbon dioxide (CO2) emissions, making it a prime hub deploying next-generation CCS technology infrastructure to use as a resource and “birth of a new industry,” according to ExxonMobil which is developing an expansive CCS network across its Texas, Louisiana and Mississippi operations.

Building on the momentum to transform a waste stream into future opportunity, Aptamus Carbon Solutions LLC, a subsidiary of Overseas Shipholding Group, Inc. (OSG), announced it will design and engineer a CO₂ discharge terminal at LBC Tank Terminals' facility in Baton Rouge, Louisiana. This development represents a critical link in an emerging supply chain that will connect emission sources with sequestration sites.

In collaboration with LBC and Port Tampa Bay, Aptamus aims to create an efficient, cost-effective waterborne supply chain for the temporary storage, processing and ocean shipment of captured CO₂ from Florida, the nation's third highest emitting state and where there is very limited potential for safe underground sequestration.

This strategic positioning of infrastructure supports large-scale CO₂ transport and storage operations. Additionally, Aptamus announced plans to design a CO₂ loading terminal at Port Tampa Bay, creating a comprehensive supply chain solution for the collection, processing and marine transportation of captured CO₂ from Florida's industrial emitters. This captured carbon will then be transported to permanent sequestration sites, with ABS's safety oversight as the leading maritime classification services provider overseeing the design verification and construction of Aptamus’ new innovative liquified CO2 barge.

First LCO₂ Vessel for U.S. Operations

For more than 160 years, classification societies like ABS have served as integral components of the maritime safety framework to ensure that technically sound and compliant standards are upheld throughout engineering, construction and operations. Receiving an Approval in Principle (AiP) represents a critical first step in vessel development; this designation serves as an independent verification that a design concept meets applicable class and statutory requirements before detailed construction begins.

ABS recently awarded AiP for the preliminary design of Aptamus’s LCO₂ barge designed for U.S. coastal operations to transport this future commodity. The vessel design features several innovations in maritime technology.

Significantly, this articulated tug and barge (ATB) design represents a first-of-its-kind solution to service carbon capture projects domestically. ATBs are common in the U.S. maritime sector, and the advantages for petroleum transport hold true for LCO₂ vessels as well. The cargo handling system design utilizes medium pressure LCO₂ Type-C tanks with a capacity for transporting 20,000 metric tons of cargo. The operating pressure was determined through comprehensive track record studies and market trend analysis, with careful consideration of loading capacity and holding time requirements.

ABS completed design reviews based on class and statutory requirements and incorporated the latest ABS requirements for building and classing liquefied gas tank barges. This rigorous review process ensures the vessel meets international safety standards while addressing the unique challenges associated with LCO₂ transport.

The development of this barge design also represents a core component of Aptamus’s Tampa Regional Intermodal Carbon Hub (T-RICH) project, an initiative designed to receive, store and process emissions from Florida industries for transport to northern Gulf Coast sequestration sites.

The greater Tampa region alone generates more than 30 million tons per year of CO₂ emissions, driven largely by regional electricity generation and industrial activities.

A critical part of the region’s CCS infrastructure buildout, the LBC discharge terminal's strategic location on the Mississippi River is adjacent to an existing CO₂ pipeline network which enables direct delivery to Class VI injection wells. This connection is key given that the northern Gulf Coast region, including the onshore areas of Texas and Louisiana, contains the largest confirmed capacity for safe, permanent underground sequestration of CO₂ in the United States.

A Global Blueprint for LCO₂ Carriers

LCO₂ carrier developments represent a rapidly evolving segment of the maritime industry, driven by global decarbonization efforts. Based on research from Rystad Energy, carbon capture capacity is poised to surge more than 10 times by 2030 , creating substantial demand for specialized vessels.

Liquefied CO₂ carriers are intentionally built to efficiently transport liquefied carbon dioxide at low temperatures and high pressures to the location of storage or usage, and work is currently underway to establish a global CCUS value chain that will entail the transportation of a projected 1 billion metric tons of CO₂ every year.

Current LCO₂ carriers primarily serve the food and beverage industry with small-scale vessels ranging from 800 to 1,000 cubic meters. However, the emerging CCS market demands significantly larger vessels. Capital Maritime has ordered two 22,000 cbm LCO₂ carriers from Hyundai Mipo Dockyard in South Korea, designed to transport up to 22,000 cubic meters of liquified CO₂ at -55 degrees Celsius, representing the world's largest dedicated CO₂ carriers contracted to date.

Northern Lights, a Norwegian project developed by TotalEnergies, Shell and Equinor, has three 7,500 cbm vessels on order at Dalian Shipbuilding Offshore Co. Ltd. in China, based on medium pressure (15 bara at −28°C), demonstrating the international momentum behind large-scale CO₂ transport infrastructure. The first vessel, Northern Pioneer, delivered in November 2024 and is fully operational.

Meanwhile, the transportation of liquefied CO₂ presents unique technical challenges that require specialized solutions. Sea-transport-based CO₂ is an attractive technology for early deployment of CCS, with advantages including cost-effectiveness for long distances and small volumes, low capital investment, flexibility and opportunities for co-utilization of infrastructure.

ABS has published the first industry guide dedicated to the design, construction and classification of LCO₂ carriers where liquefied CO₂ is carried as cargo, providing much needed guidance to minimize risks to the crew, vessel and marine environment. This comprehensive guidance addresses the unique properties of CO₂ and the specialized requirements for its safe maritime transport.

The choice of transport conditions significantly impacts vessel design and operational efficiency. Low pressure-based transport (7 bar and -50℃) and medium pressure-based transport (15 bar and -30℃) have been the two most discussed options, with recent work suggesting that lower pressure-based transport could be a better solution for future projects.

Environmental and Safety Considerations

Safety remains paramount in LCO₂ vessel design and operation. The safe transportation of CO₂ plays a vital role in the carbon value chain, and classification societies use their expertise to support this sector of the future energy landscape. ABS has developed comprehensive requirements that address vessel design and construction in addition to practical considerations specific to CO₂ transport.

The environmental benefits extend beyond simple carbon capture. Alternative fuels are being evaluated for adoption across various LCO2 carrier designs.

The emerging trend toward CCS technology adoption represents a convergence of U.S. industry stakeholders and government investment in an economically viable pathway for American Gulf Coast CCS development. This coordinated approach supports global decarbonization efforts while establishing the United States as a leader in carbon management technology.

A Catalyst for America’s Energy Future

The LCO₂ barge represents a step towards the future of maritime transportation infrastructure, enabling industries to capitalize on what was previously considered a waste byproduct of industrial processes. By capturing, transporting and permanently storing CO₂, this technology creates a true closed-loop system that contributes directly to emission reductions while generating economic value.

Additionally, the success of the Aptamus LCO₂ barge design approval demonstrates the maritime industry's readiness to embrace transformative technologies that support both environmental stewardship and economic growth. As the future energy landscape continues to evolve, critical infrastructure and transportation will enable the scaling of CCS technologies across multiple industries and geographic regions.

Through close collaboration between industry leaders, classification societies and government agencies, the United States is building a resilient future to support a thriving energy economy.