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Clean Jacksonville,
owned by Tote Maritime, was the first-in-North America LNG bunker barge. It has a total capacity of 2,200 m3 of LNG.

The State of LNG in the U.S.

USCG and industry players work toward widespread use

By LCDR William J. Hickey and Aditya Aggarwal


More than a decade ago, the United States Coast Guard (USCG) began working in partnership with industry and the International Maritime Organization (IMO) to leverage provisions within regulations to allow for equivalencies and to develop a set of standards that are uniform for liquefied natural gas (LNG) as a fuel.


Because U.S. regulations do not directly address LNG as a fuel, national policy was developed by the Office of Design and Engineering Standards (CG-ENG) in April 2012 via CG-ENG Policy Letter 01-12, “Equivalency Determination – Design Criteria for Natural Gas Fuel Systems,” which provided initial design criteria for U.S. flagged vessels that intend to use natural gas as a fuel. This policy letter was later superseded with CG-ENG Policy Letter 01-12 Change-1 in July 2017, which was updated to reflect the January 1, 2017 effective date of the International Code of Safety for Ships Using Gases or Other Low-Flashpoint Fuels (IGF Code).


Further, due to increasing industry demand to supply LNG bunkers within the U.S. marine transportation system via barge, design standards for barges were developed by CG-ENG in April 2015 via CG-ENG Policy Letter 02-15, “Design Standards for U.S. Barges Intending to Carry Liquefied Natural Gas in Bulk.” Subsequently, guidance related to LNG bunkering operations, fuel transfer operations, and training of personnel on vessels using natural gas as a fuel was published in February 2015 by the Office of Operating and Environmental Standards (CG-OES). These policies helped guide the industry to develop safe and reliable LNG assets and infrastructure across the LNG fuel value chain while promoting reductions in harmful air pollutants from ships.


Today, our nation’s LNG marine fuel value chain continues to grow geographically and in capacity, as well as to evolve with advancements in optimization and operations. The industry has proved its ability to deliver the fuel via several modes, which include small-scale onshore facilities, mobile bunkering facilities, and ship-to-ship operations, both within port and offshore. Further, LNG future fuels such as liquefied bio-methane and liquefied renewable synthetic methane offer “drop-in” alternatives, providing the opportunity for the industry to leverage this growing infrastructure to reduce global emissions of greenhouse gases (GHG) with IMO milestones set for 2030 and 2050.


Our purpose here is to examine ongoing workforce initiatives established by USCG to maintain pace with this industry. We also will explore how industry expects natural gas to meet emission reduction targets by critical dates set by the IMO, securing it’s long term future in the mix of other alternative fuels being considered by the industry.


Governance, infrastructure, fleet growth

IMO addressed the safety challenges presented by natural gas-fueled ships by adopting the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code), which came into force January 1, 2017. The IGF Code is applicable to any ship subject to The International Convention for the Safety of Life at Sea and which uses a low-flashpoint fuel, other than liquefied gas carriers that are subjected to the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk. The IGF code considers a goal-based approach and provides functional requirements for the design, construction, and operation of ships and installations of systems using gas or other low-flashpoint fuels, as well as prescriptive requirements for ships using natural gas as a fuel.


USCG’s Office of Design and Engineering Standards policy letter CG-ENG 01-12 Change 1 provides design criteria for natural gas fuel systems on ships. The policy provides a level of safety at least equivalent to that provided for traditional fuel systems, as required by existing regulations, while recognizing the IGF code as the baseline standard. This national policy continues to provide industry with an avenue to obtain administration approval. Another avenue is via a concept review and design basis approval from USCG.


In addition to system design standards, several national policies were developed by the USCG Office of Environmental Standards to facilitate LNG infrastructure and operations. These policies served to provide appropriate maritime governance across the maritime transportation system including LNG bunkering facilities, LNG bunker barges, LNG bunkering operations, crew training, and simultaneous operations.


Domestic LNG bunkering

Both domestic and international consumers of natural gas as a fuel may receive LNG from several sources and locations within the U.S. Currently, there are three U.S. flagged LNG bunker barges that operate in the U.S. Owners and operators of LNG barges may obtain design approval via CG-ENG policy 02-15 or by concept review and approval with a design basis letter from USCG.


Clean Jacksonville was delivered in 2018 and was the first-in-North America LNG bunker barge built by Conrad Shipyard in Orange, TX and owned by Tote Maritime. The barge is equipped with one LNG tank using the MARK III flex cargo containment technology from Gaztransport and Technigaz, with a total capacity of 2,200 m3 of LNG.


Q-LNG 4000 was delivered in 2020 and was the first U.S. LNG articulated tug/barge (ATB) unit in operation. The barge was built by VT Halter in Mississippi and delivered to Shell Trading (U.S.) on a long-term contract. The barge was designed with type-C LNG tanks with a total capacity of 4,000 m3.

Q-LNG 4000 was delivered in 2020 and was the first U.S. LNG articulated tug/barge unit in operation, with a total capacity of 4,000 m3.

Clean Canaveral is the second ATB in operation in the U.S. and was delivered in December 2021 to Polaris New Energy by U.S. shipyard Fincantieri Bay Shipbuilding in Wisconsin. The barge is currently the largest LNG bunker barge built and in operation within the U.S. with a total capacity of 5,500 m3.


In addition to the barges already in operation, two additional U.S. LNG bunker barges are in the early stages of construction, to be built at Fincantieri Bay Shipbuilding. These include the sister to Clean Canaveral, as well as a 12,000 m3 LNG bunker barge for Crowley, which will be the largest LNG bunker barge in the nation once delivered. Crowley will operate the vessel on a long-term charter with Shell, and it is expected to be delivered in late 2023.


In addition to the growth of Jones Act-compliant LNG bunker barges, small-scale fixed facilities have been developed in Port Fourchon, LA for Harvey Gulf International Marine; two in Jacksonville, FL to include JAX LNG and Eagle LNG; and Puget LNG in Tacoma, WA. In addition, substantial interest exists to develop temporary solutions with mobile bunkering facilities (MBF) using LNG tank trucks, which are currently proposed along the Gulf, West, and East coasts. The success of an interim MBF solution via LNG tank trucks in the U.S. was evident with the LNG bunkering of TOTE’s LNG-fueled containerships while the company waited for their long-term LNG supply solution, Clean Jacksonville, to be delivered from Conrad shipyard.


The 33 Code of Federal Regulations (CFR) 127 is applicable to any transfer of LNG at a waterfront facility from shore to ship. As 33 CFR 127 was intended for large-scale LNG import and export terminals, USCG’s OES Policy 02-15 helps provide guidance on acceptable alternatives that the captain of the port can consider to ensure the governance over these facilities and operations is appropriate in nature.


By April 2022, there were 281 LNG vessels in operation using natural gas as a fuel worldwide with another 468 LNG fueled and bunker vessels on order. These numbers indicate that the natural gas-fueled fleet will nearly triple in the immediate future. Most orders are for large vessels operating in worldwide deep-sea trades to include cruise ships, oil tankers, containerships, and pure car and truck carriers, many of which will operate within U.S. waters. The high energy demand for these vessels will greatly increase natural gas consumption and drives the need for additional and more geographically dispersed LNG bunkering assets in the U.S.


Today, there are nine Jones Act-compliant natural gas-fueled vessels in operation, spearheaded by Harvey Gulf International Marine, Tote, and Crowley Maritime. LNG fuel operations on U.S.-flagged vessels so far have been centralized within Port Fourchon and Jacksonville. However, with the two new construction vessels being built in Brownsville, TX for PASHA to support the maritime trade between Los Angeles and Hawaii, as well as two retrofits of Totes Marlin Class containerships to operate between Seattle and Alaska, we expect to see this extend to the U.S. West coast. Recently, Matson Shipping also announced its plans to transform one of its containerships to LNG-power.


Fincantieri Bay Shipbuilding is building a 12,000 m3 LNG bunker barge for Crowley, which will be the largest LNG bunker barge in the nation when delivered in late 2023.

Low-flashpoint fuel

USCG’s Liquefied Gas Carrier National Center of Expertise (LGC NCOE) was established to serve as the organization’s subject matter experts on liquefied gas in support of the import and export industry, as well as on low-flashpoint fuels that fall within the scope of the IGF code. The center’s primary lines of effort include conducting operations as a force multiplier for field units, conducting training as Coast Guard National Verifying Officers, and providing technical advice both internal and external to USCG and building partnerships.


In 2021, the LGC NCOE made it a top priority to enhance training efforts across the USCG workforce to increase proficiency of marine inspectors on low-flashpoint fuel systems. In collaboration with the Office of Commercial Vessel Compliance, Coast Guard field unit Sector Jacksonville, Training Center Yorktown, and the Office of Engineering and Design Standards, the LGC NCOE developed a performance qualification standard for foreign vessels operating on low-flashpoint fuels. In September 2021, LGC NCOE National Verifying Officers led two verifying officer workshops in Jacksonville, FL to train more than 20 marine inspectors from across 15 units as USCG’s first-wave of low-flashpoint fuels (LFF) examiners. These efforts established the baseline competency needed for the organization to maintain pace with this growing and evolving industry.


Emissions and LNG

Since the introduction by the IMO of the global sulfur cap in 2020 limiting the sulfur in the fuel oil used onboard ships to 0.50% m/m (mass by mass) via an Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL), the environmental focus has shifted to carbon dioxide (CO2) and other greenhouse gases (GHG). LNG provides the industry with a low-carbon fuel comprised primarily of methane. IMO’s initial strategy is aimed at GHG emission reduction; however, it only refers to CO2. Other GHGs—methane and nitrous oxides—are currently outside the strategy’s scope, but future updates to the strategy are expected to incorporate them.


The IMO’s initial strategy on the reduction of GHG emissions from shipping sets key ambitions, but the main goals include cutting annual GHG emissions from international shipping by 50% of the 2008 totals by 2050, and working toward phasing out GHG emissions from shipping entirely as soon as possible in this century. Another goal is reducing the carbon intensity of international shipping, as an average across international shipping, at least 40% by 2030, and pursuing efforts toward 70% by 2050 as compared to 2008 levels.

LNG offers a 23% reduction in GHG emissions on a full lifecycle basis, inclusive of methane emissions, compared to heavy fuel oils.

The IMO’s Marine Environment Protection Committee is developing short-, mid-, and long-term measures to realize these goals. The IMO and member states are under increasing pressure to reduce GHG emissions further and faster to bring the industry’s emissions in line with the COP-21 Paris climate agreement, and IMO is planning a revision of its initial strategy in 2023.


The lifecycle of fuel classifications may include well-to-tank or tank-to-wake. However, a well-to-wake approach is recommended. A well-to-wake basis refers to the full lifecycle assessment of GHG from production through downstream emissions. Other alternative fuels, such as grey hydrogen or ammonia, emit no CO2 on a tank-to-wake basis, but have significantly higher emissions than natural gas (from which they are produced) on a full lifecycle or well-to-wake basis. LNG can provide a 23% reduction in GHG emissions on a well-to-wake basis right now.


The IMO regulates emissions on a tank-to-wake basis, which considers GHG emissions from the ship’s fuel tank to its exhaust, or the downstream emissions, but currently does not take into consideration emissions from the production and transportation of the fuel, also known as upstream emissions. The IMO is aware of the urgency in this matter and work is underway to develop the full lifecycle GHG guidelines that will address well-to-wake, including well-to-tank and tank-to-wake, lifecycle emissions.

Methane slip

Methane slip is a phenomenon associated with the use of LNG as a marine fuel. It describes what happens when part of the gaseous fuel injected into an engine’s cylinders is not combusted and leaves the stack as methane. Although methane is considered a potent GHG and currently an unregulated gaseous emission, it may be introduced as part of the IMOs GHG reduction strategy.


Currently, significant effort is being made to address methane slip as engine manufacturers are commercially incentivized to reduce slip and improve overall efficiency. As such, engine manufacturers have been able to reduce methane slip to minimum levels in recent years through significant improvements in engine designs. Current technologies in research and development, such as combustion enhancement and exhaust gas after-treatment catalyst systems, will continue to play a critical role in addressing methane slip. By 2030, engine manufacturers expect LNG-fueled engine technologies to have minimal levels of methane slip.


Additionally, supply chain-related methane emissions on a well-to-wake basis is approximately 6% of total GHG emissions. LNG suppliers continue to make progress in reducing upstream methane emissions resulting from the production and transportation. Various methane abatement measures are being implemented in the oil and gas subsector to significantly reduce methane emissions before the end of this decade.


Though the conversation surrounding the path to a zero-carbon future tends to revolve around fuel performance and assets, we must also consider human element issues. Mariners, management, and regulators continue to grow their knowledge and experience with the increased use of natural gas as a fuel. Many lessons learned during system design, construction, operations, infrastructure, and governance continue to shape and improve safety management systems, procedures, and industry guidance that promotes a positive safety culture. Experience from the LNG carrier industry was leveraged among regulators, classification societies, and industry to help facilitate the initial use of natural gas as a fuel. These human element issues may pose a significant challenge when considering other alternative fuels that may lack that same level of experience from top to bottom as compared to LNG.


Foreign-flagged vessels operating within U.S. navigable waters are subject to the Coast Guard Port State Control program, including vessel examinations. Those using low-flashpoint fuels are examined for compliance with the IGF Code as part of the vessels’ routine Port State Control exams.


Future of LNG

Marine fuels offer the most powerful tool in addressing the emissions challenge for the shipping industry and there is little doubt that the maritime energy transition requires more than one solution. However, in the absence of compatibility and interoperability of multi-fuel solutions, the industry would be subjected to risks arising from accessibility, affordability, and availability of marine bunkers. While sustainably produced ammonia, methanol, and hydrogen may offer future emissions benefits, significant environmental benefits are available today through the use of LNG, which offers operators a 23% reduction in GHG emissions on a full lifecycle (well-to-wake) basis, inclusive of methane emissions, compared to heavy fuel oils.


Based on Sphera’s emission study, “Definitive Study on Lifecycle Analysis for LNG as a Marine Fuel,” the 23% reduction in GHG emissions is based on a comparative analysis of engine technology between fossil LNG to heavy fuel oils. Sphera’s study showed that the absolute well-to-wake emissions reduction benefits for gas-fueled engines compared to very low sulfur fuel oil-fueled ships are between 14% and 23% for 2-stroke slow-speed engines, and between 6% and 14% for 4-stroke medium-speed engines.


The LNG pathway offers a viable route toward a zero-carbon future for the maritime sector through its BioLNG and renewable synthetic LNG variants. The U.S. Environmental Protection Agency (EPA) refers to liquefied biomethane (LBM), or BioLNG, as renewable natural gas (RNG), and liquefied synthetic methane (LSM) as renewable synthetic LNG, or e-LNG.


LBM is a non-fossil, renewable green energy that may be derived from a variety of sources, including landfills, digesters at waste treatment plants, agricultural and forestry residues, and organic waste management operations. There are two main ways of producing biomethane from biomass, namely anaerobic digestion and gasification. According to the International Energy Agency, anaerobic digestion of biomass produces biogas, which is then treated to remove moisture, particulates, contaminants, and other non-methane gases, which increases methane content and overall quality for injection into the pipeline. Gasification is a process in which biomass feedstocks are reacted with oxygen and/or steam at high temperatures to produce syngas, which is then fed into a methanation process. The biomethane produced from anaerobic digestion or gasification must then be liquefied to become LBM.


The use of LBM, or RNG, as a marine fuel offers net-zero carbon potential as it significantly reduces emissions that would have otherwise been released into the atmosphere and displaces fossil fuels in the combustion cycle. Farm-based RNG production sourced from dairy or swine manure has the potential to offer negative GHG emissions on a full lifecycle basis due to capturing methane emissions that would otherwise be naturally released into the atmosphere.


The U.S. is seeing growth in LBM projects with more than 150 agriculture and landfill projects currently in operation. According to the U.S. EPA, the use of LBM can provide benefits toward fuel security, economic revenues, local air quality, and greenhouse gas emission reductions. Additionally, policy development has allowed incentives for some transportation sectors, except for marine, under the Federal Renewable Fuel Standard (RFS) program. Future amendments to the RFS program that include the marine transportation sector would benefit the industry, as well as the LBM producers.


CMA CGM has announced their commitment to the energy transition through the use of LBM. They state that a 67% reduction in GHG emissions on a well-to-wake basis and an 88% reduction in GHG emissions on a tank-to-wake basis can be achieved by using LBM combined with their dual-fuel gas technology, paving a path toward achieving carbon neutrality. In December 2021, CMA CGM in partnership with Shell performed the first LBM bunkering in the port of Rotterdam. The containership Aurora received a 10% blend of LBM. In September 2021, the first LBM bunkering in the U.S. was delivered by JAX LNG to the M/V Isla Bella, demonstrating the ability to capitalize on LBM‘s environmental benefits today in the U.S. In February 2022, Pivotal LNG announced that they had completed the first delivery of bio-LNG to Harvey Gulf International Marine’s platform supply vessel. The bio-LNG was sourced from its LNG production facility in Trussville, AL.


Liquefied synthetic methane

LSM, or renewable synthetic methane, is methane derived from synthesis of CO2 and hydrogen produced by the electrolysis of water using renewable energy. Similar to LBM, LSM offers an advantage over other synthetic fuels as a carbon-free drop-in fuel in that it could be used interchangeably with existing LNG infrastructure.


The production process for LSM is also known as power-to-gas. MAN Energy Solutions developed a pilot facility in Werlte, Germany and they say that they use carbon neutral renewable energy to operate an electrolysis plant that serves to separate the hydrogen and oxygen in water. CO2 obtained as a waste gas from anaerobic digestion is then added to the hydrogen in a methanation reactor, resulting in synthetic methane. After a final cleaning process, the gas can be injected into existing natural gas infrastructure and distributed for liquefaction to create LSM. Two main factors exist when considering LSM’s GHG impact: the feedstock used to create synthetic gas, and the fuel replaced by the gas in its final application.


According to MAN Energy Solutions, replacing heavy fuel oils with LSM from a power-to-gas reactor, which uses biogenic CO2 or captures it directly from the atmosphere using direct air capture, may cut emissions 100% along the value chain. According to environmental consultant CE Delft, the use of LSM puts carbon neutrality by 2050 within reach. However, several factors would need to be addressed, including renewable electricity capacity, technology readiness, and costs.


Ongoing technological developments, combined with the growing infrastructure to support LNG in more locations throughout the U.S., public and private stakeholder familiarity, and increased mariner competence, LNG remains a viable fuel to meet the maritime global emission targets in the near, mid, and long terms.


LCDR William J. Hickey is detachment chief, Liquefied Gas Carrier National Center of Expertise with the United States Coast Guard. Aditya Aggarwal is general manager of SEA-LNG Limited, a multi-sector industry coalition focusing on LNG as marine fuel.