Innovating Dry Gas Seals for the New Hydrogen Economy | 2024 | Blog | Resources | John Crane

Innovating Dry Gas Seals for the New Hydrogen Economy

January 29, 2024

5 Minute Read

As nations intensify their efforts to cut carbon emissions, hydrogen is gaining attention as a cleaner way to power the world. It’s predicted to play a key role as an energy carrier and could become the fuel of choice for the future energy transition.

Some petrochemical and process industries are already utilizing hydrogen in their processes but also investigating ways to utilize hydrogen in their applications. Routinely installed in centrifugal compressors used for gas transfer and distribution networks, dry gas seals are critical to these initiatives. And while the principles of dry gas sealing do not change in the presence of hydrogen, renewable hydrogen presents certain dynamics that demand innovative solutions. Understanding the challenges of hydrogen and intermittent production is fundamental to harnessing the potential of dry gas seals in the evolving field of hydrogen technology.

Seals for High-Speed Hydrogen Gas Compression

Designers look at various process parameters when selecting a dry gas seal for a centrifugal compressor. Operating speed is particularly pertinent for hydrogen service.

At its most basic, a centrifugal compressor uses rotating impellers to compress process gas. The lighter a gas, the faster the rotational speed necessary to achieve the desired compression (as long as the compressor design is maintained). Most compressors are compatible with natural gas, which is composed mainly of methane. Hydrogen has a molecular weight significantly lighter than methane and requires extreme impeller-tip speeds to reach usable output pressures. This “need for speed” challenges the material-strength limitations of many components, including dry gas seals.

A possible solution is to limit rotational speeds by implementing additional compressor stages. However, this often isn’t feasible due to rotor dynamic issues.

John Crane has a robust portfolio of market-ready dry gas seals. We also have experience with dry gas seal designs for high impeller-speed service.

As a member of Hydrogen Europe, one of the world’s leading hydrogen industry associations, John Crane is committed to accelerating the scale up and deployment of the new hydrogen economy. We’re constantly innovating materials and testing new sealing and support system technologies, including those that address hydrogen gas compression. In doing so, we equip our customers to meet the challenges of hydrogen both today and as the ecosystem evolves.

Seals for Intermittent Hydrogen Production

Most hydrogen production taking place today is powered by fossil fuels, often natural gas. Although emissions-free hydrogen production is possible with renewable power sources like wind and solar, renewable inputs are notoriously inconsistent. If it’s not windy or the sun isn’t shining, compressors may have to start and stop multiple times daily — significantly impacting seal longevity.

At rest, a dry gas seal has two rings touching. They push off during operation as a thin layer of gas forms between the two rings, letting them run without contact. The more a compressor starts and stops, the more often the ring faces briefly touch, causing friction.

The actual duration of ring contact depends on the application. During start or stop, a single-shaft compressor may need up to five minutes of coast time, whereas an integrally geared compressor may only require 30 seconds.

Materials selection for dry gas seals is critical to resisting the effects of friction. For example, a carbon-based primary ring can be relatively friction-tolerant due to carbon’s self-lubricating properties. However, a mating ring of silicon carbide or tungsten carbide may benefit from a specialized coating to increase durability when put into intermittent service.

John Crane has a legacy of pioneering dry gas seal technology. Our engineers are assessing the effectiveness of various ring material pairings by using a test loop to reproduce the conditions of intermittent service and investigating the effects of hard-soft or hard-hard dry gas seal ring combinations. For cases with contact as a concern, John Crane can directly integrate a coating into manufacturing to extend seal life, which in turn increases reliability.

We also provide John Crane Sense, which provides visibility to the remaining lifespan of a seal. Sensors embedded directly into the dry gas seal itself provide real-time data for a comprehensive understanding of seal health. Data-driven insights into the current condition of a dry gas seal aid with maintenance planning, downtime prevention and, ultimately, enhanced visibility into a dry gas seal’s remaining lifespan.

Partner with the Dry Gas Seal Experts

Every day, a growing number of new players and projects are emerging in the low-carbon hydrogen space. There’s no standardized path forward, and the industry is exploring all creative solutions to power the new energy transition.

At John Crane, we have extensive experience with hydrogen and more than 5,000 seals, filters, couplings and systems in service, enabling some of the world’s most innovative clean hydrogen facilities. As we progress toward a net zero future, we are investing heavily in dry gas seal technology that supports a scalable renewable hydrogen economy.

Let us accelerate your energy transition through our legacy of technology leadership, innovative solutions and service excellence. Contact John Crane today to learn how our dry gas seals can support your renewable hydrogen initiative.

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