The need to reduce reliance on fossil fuels has long been recognised, driving momentum toward lower-carbon energy sources. Among these, hydrogen has emerged as a promising enabler of the energy transition and global decarbonisation goals. In recent years, growing policy support, technological progress, and investment activity have accelerated the development of the hydrogen market.
Like any emerging sector, hydrogen faces growing pains. Supply constraints and infrastructure gaps have limited progress in some applications. Yet, despite these challenges, confidence in hydrogen’s long-term potential remains high. As demand continues to rise, so too will efficiencies across the hydrogen value chain, from production and distribution to end use, especially as infrastructure scales to meet market needs.
This article shows that hydrogen infrastructure, and especially hydrogen compression and liquefaction machinery, is ready for deployment today. It begins with recent developments that have made hydrogen an increasingly attractive proposition. It looks at small-scale, local production followed by the increasingly vital issue of scaling up production to enable more efficient hydrogen liquefaction and distribution. It briefly presents three production method scenarios, before finishing with a look at the proven reliability of hydrogen machinery, which is central to developing a successful hydrogen ecosystem.
Hydrogen compression or liquefaction?
In the absence of pipelines, hydrogen is typically transported by compressed gas tube trailers, which is suitable for short distances and small volumes. Liquefying hydrogen, however, can be more effective, especially for longer distances and higher capacities. While hydrogen liquefaction draws from lessons learned in LNG, particularly in cryogenic handling and compressor design, hydrogen’s lower molecular weight and lower boiling point require more specialised machinery, materials, and insulation systems.
Liquid hydrogen (LH2) is 800 times denser than gaseous hydrogen at atmospheric pressure, which allows for more hydrogen to be transported in a single trip, reducing the number of deliveries required. A single liquid hydrogen tanker, for example, holds approximately the same amount of hydrogen as eight standard gaseous hydrogen tube trailers. Liquid hydrogen is also preferred for onboard vehicle storage to enable longer ranges, especially for heavy duty applications like long-distance trucking, trains, ships, and eventually airplanes.
Hydrogen liquefaction requires refrigeration cycles to cool hydrogen gas to below -253°C. OEMs like Atlas Copco provide the proven, reliable turboexpanders and compressors to not only enable liquefaction but also to handle any boil-off. It is this extensive hydrogen experience that ensures hydrogen is ready for deployment. These machines are central to efficient plant design and help operators reduce energy consumption and lower the cost of hydrogen.
However, liquid hydrogen may not be the right solution for all hydrogen production and distribution systems. Beyond centralised infrastructure, distributed hydrogen production is emerging as a key contributor for the molecule’s availability, especially for regional refueling networks and smaller industrial users. High-pressure reciprocating and screw compressors allow these systems to operate at scale despite tight footprint and uptime demands — helping to bring hydrogen closer to where it's needed most. These smaller-scale sites are often quite demanding on the machinery, especially considering that intermittent operation may cause the compressors to cycle on and off multiple times throughout the day. This demanding operation warrants the use of proven and reliable machinery to ensure maximum availability for the refuelling station.
Scaling production for mobility
Fundamental to the future success of the hydrogen market is the requirement to scale production to help drive down costs. Of course, liquefaction technology also needs to be scaled as production capacities increase. Despite technological advancements, hydrogen liquefaction trains remain at around a capacity range of 30 tpd. Though still low, this represents growth compared to the legacy 5-10 tpd liquefiers. Larger-scale liquefaction is clearly needed to transport the large volumes of hydrogen required to support the demand from an expanding hydrogen mobility market. On the one hand, a single 30 tpd liquefier distributes enough hydrogen for approximately 300 heavy duty trucks per day (with an average fuel-tank capacity of 100 kg per truck). On the other, the International Energy Agency’s ‘Energy Technology Perspectives 2023’ report says 400 000 heavy duty FCEV (fuel-cell electric vehicle) trucks are expected to be deployed globally by 2030. Most of these trucks will rely on liquid hydrogen distribution to refueling stations, which is why hydrogen liquefier capacities need to scale significantly – to capacities in the range of 60, 100, 200 tpd or more.
Reliable machinery
Turbomachinery is engineered to operate at high speeds and volumes, efficiently converting rotational energy into pressure while minimising energy loss. These machines scale well as capacity increases. In contrast, positive displacement technology like reciprocating or screw compressors reduce the volume of the gas to increase the pressure. These involve moving parts in contact with wear surfaces, or use fluids like oil for sealing. There are also positive displacement diaphragm or hydraulic compressors that do not use sliding surfaces or oil for compression.
Reliable machinery is essential to any project, no matter what the scale, but uptime becomes increasingly critical at scale. Considering large-scale hydrogen liquefaction cycles, the turboexpanders play a central role in refrigeration as they are used in precooling and primary liquefaction cycles. Radial inflow turbines expand a gas in a nearly isentropic process to produce refrigeration and shaft power. Because of the low mole weight and the high enthalpy drop of hydrogen, hydrogen expanders have high impeller tip speeds that often require multiple stages to expand the gas effectively. Cycle performance is improved by recovering the turboexpander shaft power to generate electricity or reduce the compressor duty. Active magnetic bearing (AMB) turboexpanders reliably handle the deep cryogenic temperatures and prevent any oil contamination of the heat exchanger. AMB turboexpanders also allow for a scalable, oil-free solution, which provides a hermetically sealed system with no loss or venting of the refrigerant.
These compression technologies are already deployed, from large-scale LH2 facilities supporting hydrogen refueling stations (HRS) in California, US, to high-pressure compressors installed at localized hydrogen production facilities in Europe.
Three hydrogen production scenarios
The following are three realistic scenarios for the production of hydrogen for mobility applications. The different scenarios are matched by three different machinery solutions, scales and capacities. They highlight that each production and delivery method has unique requirements that directly influences machinery design. Moreover, it becomes evident that expertly tailored compressors improve uptime, reduce lifecycle costs, and de-risk projects:
Scenario 1: local hydrogen production at fueling station
One option for hydrogen production for mobility applications is on-site electrolysis. These small-scale systems eliminate the need to transport the hydrogen long distances and instead utilise the grid or local renewable electricity production to generate hundreds of kilograms (<1 t) of hydrogen per day. The system can be optimised for direct delivery to light-, medium, or heavy-duty vehicles. Fuel cell vehicles require hydrogen at 500 – 900 bar and 99.999% purity, demanding compact, robust compression solutions. Hydraulic compressors are well-suited for this task, offering high-pressure capabilities in a relatively small footprint. These systems are ideal for high-pressure, low-flow applications, where uptime, reliability, and footprint are critical factors. Their oil-free design helps ensure the high purity needed for fuel cell applications, while integrated cooling and automated control systems enable seamless integration into refueling infrastructure.
Scenario 2: medium-scale hydrogen production
Stepping up in size, medium-scale production facilities may range from 1 to 10 tpd. Facilities of this size may use one of a few different production methods, such as steam methane reforming, biomass gasification or even solid oxide electrolysis (SOEC), paired with renewable electricity. These systems often serve hydrogen refueling stations within a 50- to 100-mile radius. The machinery solution here combines crosshead piston compressors with screw compressors to manage both capacity and efficiency. Screw compressors handle the first stage, efficiently boosting volume and pressure. Crosshead piston compressors follow, delivering the durability and high pressures needed for continuous operation. This hybrid combination suits medium-pressure, medium-flow applications, especially where operational flexibility and serviceability are key.
Scenario 3: large-scale hydrogen production
At the larger scale (>15 tpd), hydrogen is produced at centralised production plants for regional distribution serving refueling stations up to 500 miles away. To effectively transport hydrogen to this larger network, liquid hydrogen is used to increase the delivery capacity per truckload. To liquefy the hydrogen, the feed gas is subcooled to -253°C via highly reliable turbomachinery. In this low-pressure, high-flow, and cryogenic scenario, integrally geared compressors and turboexpanders form the core of the refrigeration cycle. These centrifugal machines are engineered to handle high volumes efficiently while managing cryogenic conditions and minimising heat ingress. The scale of these operations demands machinery that can deliver not only performance and efficiency but also long-term reliability and scale – all essential for reducing liquefier specific energy consumption (SEC) and specific liquefaction cost (SLC).
Summary
Hydrogen mobility is no longer hypothetical as it is already being deployed in multiple applications. As hydrogen production scales and infrastructure expands, the coming decade could see a global network of hydrogen-powered heavy duty transport, decentralised fueling hubs, and widespread liquid hydrogen distribution ¬– all enabled by high-efficiency, field-proven machinery operating reliably across the value chain.
Each production and delivery scenario requires compression technology tailored to specific demands for pressure, flow, and purity. Properly engineered compressors not only improve uptime and performance but also reduce project risk. With a diverse portfolio of technologies available, Atlas Copco machinery can be precisely matched to the unique requirements of each application – from small-scale fuelling stations to large liquefaction plants.
Reliable, high-performance machinery has long been essential in energy infrastructure. It continues to be a critical enabler of hydrogen deployment and supporting global decarbonisation goals, including achieving net zero emissions by 2050.
Written by Daniel Patrick, Market Segment Manager – LNG & Hydrogen, Atlas Copco Gas and Process Division, and Alfonso Peschiera, VP, Business Line Manager, Atlas Copco. Alfonso manages the sales organization for the Atlas Copco High Pressure Business Line in the US. This includes a portfolio of high pressure compressors for a wide variety of gases and applications.