Australia-based Provaris Energy has received class approval from the American Bureau of Shipping (ABS) for the design of Provaris’ 26,000 m³ H2Neo compressed hydrogen carrier, the first of its kind to receive this level of approval. This milestone approval follows the completion of extensive Front End Engineering Design (FEED) work and ABS review activities.

Illustration of the H2Neo 26,000m3 compressed H2 carrier

It confirms that the innovative and cost-effective multi-layered hydrogen tank can be incorporated into the H2Neo Carrier and meets the requirements for Ship Classification.

Next steps for the company are to construct and test a prototype hydrogen tank, and to prepare for ship construction with a selected shipyard(s). Provaris has appointed Clarksons’ newbuild team in London to work with Provaris to undertake a shipyard selection.

Provaris launched a program to develop a compressed hydrogen carrier in October 2020; in 2021 ABS awarded Provaris with an Approval in Principle (AiP) for two classes of green compressed hydrogen (GH2) carriers—the H2Neo (26,000 m³) and the H2Max (120,000 m³ capacity). Provaris is taking the H2Neo through to construction-ready status in 2023, with the H2Max to follow 2026.

ABS Consulting has carried out risk and safety workshops (HAZID) and specialist studies concerning gas dispersion, explosion and fire analysis to help assess and mitigate the risks associated with the storage and transportation of hydrogen. This is the first time that an extensive HAZID and FEED level design for a novel hydrogen carrier has been concluded.

The H2Neo design is characterized by two large-diameter cylindrical tanks, one in each of the port and starboard cargo holds with a maximum allowable operating pressure (MAOP) of 250 bar.

The advantage of the patented design, and Provaris’ Intellectual Property, is evident in the ABS-approved solution of integrating a relatively thick steel layered tank (as required for 250 bar) into the hull of a relatively conventional ship-sized hull with low operating drafts.

Illustration of Provaris’ Proprietary Compressed H2 Cargo Tank.

Leveraging its experience with gas and compression, Provaris has assessed various compressed cargo containment solution options, duly taking into account the characteristics of hydrogen, including MAOP and temperature levels, and hydrogen embrittlement. These key parameters were considered in detail concerning safety, construction methodology / CAPEX and operations / OPEX.

The tanks are designed so that they cannot suddenly rupture and release a catastrophic amount of energy. This is achieved by a cargo tank construction that is composed of layers of steel, nested together, including a stainless-steel inner layer to protect the high-strength carbon steel from hydrogen embrittlement. This nesting ensures that sudden through-wall cracks are impossible. Moreover, the layered tank construction benefits the construction methodology of the cargo tanks.

Additional safety measures are applied through continuous monitoring of the cargo tanks integrity. By using components and software that are proven, and readily available, in the market, Provaris has developed a monitoring system that will be installed on the outermost layer of the cargo tanks.

Provaris argues that the loading of compressed hydrogen directly into the GH2 Carriers can be accomplished through existing, proven technology (compressors) eliminating the need for onshore hydrogen storage and/or facilities to convert the hydrogen into alternative forms at the loading port such as ammonia or liquefied hydrogen.

Similarly, the hydrogen will be delivered to customers directly through simple decompression from the ship’s cargo tanks, largely utilizing the energy stored in the cargo tanks, and there will be no need for facilities at the receiving terminal to store and/or crack, change, or regas the cargo before distribution.

The H2Neo design is a result of extensive hull optimization and assessments of new technologies that have been applied to reduce fuel consumption. The propulsion platform is electric, including batteries for a hybrid configuration that allows for further fuel savings.

The battery plant is scalable and allows for an effective integration of both existing and prime mover technologies under development (including alternative fuel engines and fuel cells) thereby allowing for future maritime operations without any greenhouse gas emissions.