Author: Luxfer Cylinders

As the shift to greener, more sustainable fuels accelerates, John Carrigan, US Business Development Director for Alternative Fuels, highlights the vital role hydrogen cylinders play.  

The transition to cleaner energy is gaining momentum across the United States, and the transportation sector – one of the largest emitters of greenhouse gases (28%) in the country – is a primary focus of this transformation. Three key technologies are leading the charge in decarbonising mobility: hydrogen, renewable liquid fuels, and electric batteries, each presenting unique opportunities and challenges.

While renewable diesel and biofuels have gained attention for their compatibility with existing diesel engines, offering a cost-effective way for fleet operators to lower emissions without significant changes to infrastructure, electric vehicles are dominating the zero-emission market for passenger cars and light-duty vehicles. On the other hand, thanks to the potential to drastically reduce greenhouse gas emissions and provide an energy-dense, long-lasting fuel source, hydrogen is showing great promise, particularly for rail and road transport. As the market continues to expand, we are seeing growing demand for Luxfer’s technology and expertise.

Advancing short-line railroads with hydrogen

Freight rail remains one of the most efficient modes of transport in terms of emissions per ton-mile, yet it still relies heavily on diesel engines. Short-line railroads, which serve as vital connectors between rural areas and the larger rail network, are no exception. While these systems have long been powered by diesel locomotives, the push for global decarbonisation is driving the search for greener alternatives.

There are a number of reasons why hydrogen presents an attractive alternative to diesel for short-line railroads. First, hydrogen-powered trains have the potential to match the energy demands of these lines while producing zero emissions, making them environmentally favourable. Second, the lower-density routes typically served by short-line railroads make them an ideal testing ground for hydrogen technology and infrastructure. The ability to retrofit diesel-electric locomotives with modular hydrogen fuel cell systems is particularly advantageous for smaller rail operators. By integrating hydrogen technology, they can reduce emissions without sacrificing the operational performance needed for freight movement. There’s also no need to purchase entirely new fleets – a critical consideration for operators with limited budgets.

Breakthroughs in engine technology

Innovation plays a critical role in scaling hydrogen adoption in the transportation sector. One of the most noteworthy developments is the introduction of the X15 engine by Cummins, a global leader in power solutions. It is a fuel-agnostic internal combustion engine that can run on multiple types of fuels, including hydrogen. This technology offers a more versatile and scalable approach to hydrogen adoption.

The X15 provides a practical solution to operators looking to make the transition from fossil fuels to hydrogen. By offering a platform that can run on diesel, natural gas, and hydrogen, it allows fleets and railroads to begin incorporating hydrogen into their fuel mix without committing to an entirely new set of equipment. This versatility minimises costs and helps operators adapt as hydrogen infrastructure continues to expand. Additionally, its fuel-agnostic design enables mixed fleets to operate with both hydrogen and conventional fuels, ensuring seamless operations during the transition period.

Optimising storage with hydrogen cylinders

One of the technical challenges for hydrogen-powered vehicles and trains is efficient storage. Hydrogen has a lower energy density per volume than traditional fossil fuels, necessitating high-pressure storage solutions to ensure enough fuel is available for long-range operations. Generally, hydrogen is stored in either Type 3 or Type 4 cylinders, each of which offers distinct advantages.

In the North American market, Luxfer offers two hydrogen cylinders: the G-Stor™ Go H2 cylinder with Type 4 technology and the G-Stor™ Pro Type 3 cylinder. The former, available in three sizes from 14.5 to 19.1kg, is a high-pressure cylinder that delivers good storage volumes whilst remaining lightweight and is capable of pressures up to 350 bar (5,000 PSI). The latter is a fantastic solution if fast fill is critical.

The Type 3’s Luxfer-manufactured aluminium liner, fully wrapped with aerospace-grade carbon fibre, ensure no wastage as it allows all of the hydrogen involved in the system to be utilised.

Traditionally, operators would choose a single type of cylinder based on the application. However, in the push for maximising space and fuel efficiency, there is a growing trend towards combining Type 3 and Type 4 cylinders. For example, a Type 4 cylinder may be used in a spot where weight savings are critical, with a Type 3 cylinder fitted in an area where space is more constrained, within the same train or vehicle. This hybrid approach allows operators to optimise the available space for hydrogen storage. Since Luxfer’s range is technology neutral, with each product addressing different client needs and applications, we are fully able to support this.

Looking at the regulatory landscape

While hydrogen is gaining traction in the US, regulatory gaps remain a significant obstacle. Unlike Europe, where governments are heavily investing in hydrogen infrastructure, the US lacks a cohesive federal strategy. Progress is being made at the state level, with certain states leading the way with policies that support hydrogen refuelling stations and hydrogen-powered vehicles, but there is no unified federal framework for hydrogen infrastructure and usage. This regulatory gap is a key challenge that must be addressed if hydrogen is to play a significant role in the future of the US transportation sector. The development of hydrogen-specific safety codes, standards for refuelling stations, and incentives for operators to adopt hydrogen technologies will be crucial for the sector’s growth.

Pioneering hydrogen storage in the US

Hydrogen is increasingly becoming a viable fuel alternative for transportation in the US. While challenges remain – the biggest of which is competing with liquids – its potential to reduce emissions and improve operational efficiencies makes the gas an attractive option for rail and road applications. Luxfer is proud to be at the forefront of this green energy revolution, helping to widen access to hydrogen. As a 125-year-old company with an 80-year legacy in gas containment, we have spent more than two decades developing hydrogen fuel solutions to power buses, trucks, trains, marine vessels, refuse vehicles and more.

When it comes to gas storage solutions, innovation is at the heart of what we do. This ethos led us to explore how our multiple cylinder package (MCP) could enhance our own operations. The results have been remarkable, yielding significant time and cost savings, improved operational efficiency, and reduced gas wastage.

Pioneering innovation in gas storage

Since 1958, Luxfer has continuously innovated, introducing new products and exploring diverse markets. While in the development stages of our G-Stor® Hydrosphere offering, our design team identified a gap in the market for storing and transporting smaller quantities of gas. This insight led to the creation of the G-Stor® Pro Bundle – an MCP engineered to meet this demand.

The G-Stor® Pro Bundle consists of nine interconnected cylinders that are stacked horizontally. Due to the unique cylinder liner processing that reduces weight and increases volume, these bundles can store a larger volume of gas in a smaller footprint compared to other available options.

They incorporate Luxfer’s trusted Type 3 G-Stor® H2 cylinders, which are among the highest-capacity, lightest-weight Type 3 alternative fuel cylinders in the world. These cylinders offer:

- Capacity: Cylinders range from 150 to 322 litres, with storage capacities from 32.1kg to 84.3kg. 

- Efficiency: The Type 3 technology ensures zero gas wastage. 

- Durability: The cylinders are robust, designed for fast-filling, and provide zero permeation, increasing the asset value of the entire system. 

The system is set in a lightweight, durable, high-strength frame that can be seamlessly slotted into an existing structure and onto trucks and trailers, making it an ideal solution for transporting gases by road or rail. These bundles provide consistent flow rates and pressures, eliminate cylinder changeovers, and reduce gas wastage. They also offer a reliable onsite gas storage solution, ensuring continuous operations for critical applications such as industrial processes or backup power systems.

Putting our MCPs to work

To demonstrate the real-world advantages of the G-Stor® Pro Bundle, we integrated two MCPs into our Nottingham facility to supply nitrogen to our 3,500-ton extrusion press.

“Our press uses nitrogen to produce stored energy, delivering instantaneous power and constant speed during cylinder extrusion,” explains Alex Millward, Technical Engineering Manager. “Previously, we relied on nitrogen banks from a third-party supplier, but the system was inefficient, wasting significant amounts of gas and occupying excessive floor space.” 

Highlighting some of the challenges, Alex explains: “The system consisted of four banks of nitrogen used to charge the press, and another four banks ready to change over once the initial bundles, filled to 230 bar, reached a lower limit of approximately 100 bar. Trying to charge the press with less than 100 bar was extremely slow and inefficient. As we were essentially only using half the bundle, it meant there was a lot of wasted gas. Frequent hose connections also caused wear and tear, requiring regular replacements. Additionally, those bundles occupied precious floor space.

“Our G-Stor® Pro Bundle operates at 345 bar and holds a greater volume of nitrogen. Because of the increased pressure we can regulate down to 200 bar. Once it reaches 100 bar – the minimum pressure required to efficiently power the press – we can fill it up using our own liquid nitrogen stock, eliminating delivery wait times and gas wastage. Also, we don’t require as many cylinders occupying space on site. In theory we only ever need one bundle.”

Bundle benefits at a glance

- Cost savings: Nitrogen costs are ten times cheaper with the G-Stor® Pro Bundle compared to the previously used banks.

- Efficiency gains: The increased pressure halves press filling times, reducing each nitrogen shot from 20 to 10 minutes.

- Space optimisation: Luxfer’s own MCPs require seven times less floor space than the bundles they replaced.

- Improved reliability: Onsite refilling eliminates reliance on external deliveries.

- Simplified connections: A single hose connects directly to the MCP, reducing wear and tear and associated costs.

“The implementation of the G-Stor® Pro Bundles at our Nottingham site has not only enhanced our operational efficiency, but also exemplifies our commitment to innovation and sustainability. By leveraging our own products and showcasing the benefits they offer – cost savings, reduced wastage, and improved efficiency – we’ve demonstrated their transformative potential for organisations across various sectors,” concludes Alex.

By Keith Croysdale, European Business Development Manager – Alternative Fuels

The logistics sector has recognised that hydrogen fuel systems have the potential to play a pivotal role in meeting sustainability commitments and there is a great deal of innovation taking place.

When governments first began to set net zero targets, the focus for hydrogen was public transport and road freight, with some automotive design. This has burgeoned, with a growing interest in applying the technology to transport modes that would not have been considered a few years ago – huge leaps have been made to adopt cleaner fuel to power buses, trains, trucks, tractors and a range of off-road vehicles and plant machinery. There have also been increasing enquiries in recent years from marine, rail and aviation industry stakeholders keen to explore the fuel’s potential applications.

Suitability of hydrogen for various applications

As the investment in hydrogen continues to grow, it has become apparent that it is currently more suited to some applications than others. For example, hydrogen as fuel for the maritime and aviation sectors is currently a more complex proposition than for on-road as there are completely different regulatory landscapes, while rail presents operational, commercial and design concerns.

Embedding hydrogen in the aerospace sector also remains a challenge, although an area that should not be overlooked is the vehicles, equipment and plant around the aircraft itself. Collectively, they are an important part of the puzzle in reducing the carbon impact of aerospace.

This means targeting hydrogen to power the tug that brings the aircraft to the gate, the auxiliary generator keeping power to the plane while it's being fuelled, the buses that transport the passengers around terminals, the baggage vehicles that move luggage into the hold, and more. These are more common applications and can be implemented with far less development.

Hydrogen fuel systems safety and standards

High-pressure hydrogen cylinders are designed to meet strict performance requirements and are tested against major regulations and standards. Generally, these cylinders undergo a strict testing regime, for example: extreme temperature testing, drop and impact testing, gunfire testing, fatigue cycle, and burst testing.

While there are regulations in place – Luxfer was one of the first manufacturers to achieve approval for Regulation No R134, a global safety regulation which highlights that cylinders are safe for use in hydrogen-powered vehicles across a wide range of applications – it is important to note that not all hydrogen cylinders in the market meet the required standards.

Despite cylinders meeting regulatory requirements and undergoing rigorous testing, across the general public there can be a challenging rhetoric around the safety of hydrogen, with the general perception being that it presents a substantial risk.

Establishing clear guidelines and regulations across the entire supply chain and addressing concerns related to safety is vital for nurturing confidence in hydrogen systems among companies who may be looking to invest in greener, more sustainable solutions as part of their carbon reduction strategies.

With a growing hydrogen economy, we hope misplaced safety fears will be set aside and importantly, that there will be a proper infrastructure and regulations in place that will allow the potential of hydrogen to be fully realised.

Infrastructure and accessibility

A challenge preventing the wide-scale adoption of hydrogen is that there is still some way to go to make the fuel more accessible.

Widespread adoption of the gas, not just in the logistics sector, but across the wider industry, is hinged on the development of fuelling infrastructure, meaning that the development thereof is key. While some progress has been made, continued efforts are required to create a comprehensive and accessible hydrogen infrastructure.

One way to address the hydrogen infrastructure deficit by developing bulk gas transport systems (BGT). These ‘virtual gas pipelines’ can help connect the dots between hydrogen production and consumption by bridging the gap between the point of production and the point of use.

They allow operators to decarbonise transport while providing the means to move the gas in a scalable way. Crucially, they offer a stepping stone until dedicated pipeline infrastructure is established and can provide either temporary or permanent solutions to delivery or capacity difficulties. That said, the long-term future of hydrogen fuel systems for transportation will likely involve a combination of physical and virtual pipelines, with each solution utilised to meet different needs across the supply chain.

Once physical pipelines are established – according to National Gas Transmission, approximately 2,000km of the existing gas network is expected to be repurposed into a 100% hydrogen ‘backbone network’ by the early 2030s – it is unlikely to result in a retraction of virtual gas pipeline. Instead, the latter will likely be redeployed to best service the first and final miles of distribution.

Storage solutions

Modular solutions play a vital role in driving adoption of hydrogen fuel. Systems comprising interconnected, stacked cylinders, known as multiple cylinder packages (MCPs), can store gas in a smaller footprint compared to other available options.

A practical and efficient storage solution, MCPs are used where hydrogen is required to be fed at a regular flow rate and pressure without an interruption. They reduce the need to manage cylinder stocks and eliminate time lost in cylinder changeover and handling, as well as gas wastage.

These cylinder packages come into their own for mobility and portability – they can generally be seamlessly slotted into an existing structure and onto trucks and trailers – enabling hydrogen to be transported via trucks, ships, or rail to different locations. The technology especially suits marine applications, construction vehicles, running generators or even to fill test vehicles where a refueller or large storage may be deemed too costly for the small amount of gas required to check a fuel cell is working correctly.