Transitioning to the Liquid Hydrogen Era

NASA KSC 24-meter outer diameter liquid hydrogen dewar under construction in 2020 (left) and internal design (right)*

I co-founded my sixth technology based startup in early 2016 after ending a thirty-one year career at NASA. The new company was focused on hydrogen as the sustainable solution to our global challenges in the energy, mobility, food, and water nexus. This was a natural fit for my expertise and experience developing liquid, slush, and gaseous hydrogen systems since the mid-1980s.

My business partner and I spent several years developing hydrogen system designs for various applications in the energy, agriculture, aerospace, and transportation market sectors. It was the classic Venn diagram overlap of our personal passions, unique capabilities, and the most urgent global needs. However, the general feedback at the time was that despite our unique expertise with these systems there was insufficient impetus to transition to widespread hydrogen use.

Historically, the hydrogen community has been small and concentrated. Early work with liquid hydrogen systems and applications was well underway in the U.S. in the 1950s at NBS (now NIST) and NACA (the precursor to NASA). The space industry has been the largest user of liquid hydrogen since the 1960s; supported by the cryogenic liquiefied gas production companies and prime aerospace contractors; and largely funded by the space and defense agencies of a few countries. Over time, an established supply chain of hydrogen technology, component and subsystem providers has developed. Other commodity users of hydrogen also emerged in steel making, food processing, semiconductor fabrication, and various research facilities.

This state of affairs changed dramatically in the past few years with an unprecedented growth in interest and investments in hydrogen systems for transitioning the global economy away from greenhouse gas emitting fuels. Unfortunately, the newfound interest in hydrogen has brought with it newly self-proclaimed experts. Organizations and individuals with little or no hydrogen experience - and who in some cases openly dismissed hydrogen just a few years ago - are now clamoring for related government funding. Startups are attracting large capital investments for hydrogen applications despite often lacking personnel with any significant relevant experience.

As a result, conversations around the transition to hydrogen frequently become mired in strongly held opinions rather than evidence-based reality. Some factions are hyping their own hydrogen system concepts without the requisite knowledge to assess the associated technical and economic feasibility, let alone the risks. At the other end of the spectrum are vehement hydrogen detractors who make hand waving arguments rooted in misinformation. They also often have a vested interest in legacy systems or competing technologies that are threatened by hydrogen.

In upcoming posts, I'll attempt to separate the signal from the noise based on more than 35 years of designing, developing, and deploying hydrogen systems as large as 4732 cubic meters of usable liquid hydrogen with zero boil-off losses*. The goal is to provide a clear-eyed perspective on transitioning to the liquid hydrogen era, and demonstrate that there are no true technology gaps preventing the widespread use of liquid hydrogen. Rather, the remaining challenges relate to experienced systems engineering, capital investments, competitive business models, market acceptance, public policy, and regulatory maturation.

*References:

1. Fesmire and Swanger, "Overview of the New LH2 Sphere at NASA Kennedy Space Center", DOE/NASA Advances in Liquid Hydrogen Storage Workshop, Aug, 2021.
2. Moran, "No-Loss Liquid Hydrogen and LNG Systems (Zero Boil-Off)", May 12, 2018. (https://blog.matthewemoran.com/2018/05/no-loss-liquid-hydrogen-and-lng-systems.html)

Matt Moran is the Managing Member at Moran Innovation LLC, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems for more than 40 years; and first-of-a-kind liquid, slush and gaseous hydrogen systems since the mid-1980s. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been a cofounder in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations. Matt has three patents and more than 50 publications including the Cryogenic Fluid Management report series. More about him can be found here.

Cryogenic Fluid Management of Liquid Hydrogen...

Executive Summary

This report provides passive cryogenic fluid management (CFM) insights, methods, equations, and algorithms suitable for performing system designs and trades. The content is intended for engineers, designers, analysts, managers and others who are developing or operating passive CFM systems.

Topics covered are based on cryogenic systems subject matter expertise at Moran Innovation LLC that has been developed over the past 35 years. Each main section concludes with calculation examples to demonstrate how to use the equations presented and interpret the results.

Main sections and subsections include:

• Introduction to mission and vehicle drivers, thermophysical properties, thermodynamic behavior, fluid dynamics and heat transfer.
• Acceleration and thermal environments, and how these environments vary based on mission segment.
• Tankage for the storage of cryogenic propellants including: material properties; design and sizing; heat loads and insulation; and packaging and integration.
• Venting of cryogenic tanks and associated implications such as: cryogen losses; liquid level rise in low gravity; and utilization of vent gas for propulsive settling and/or structural cooling.
• Pressurization and pressure response of tanks including: active pressurization, interfacial heat and mass transfer, self-pressurization, and ullage collapse.
• Other passive CFM topics including: chilldown and tank filling; tank internal insulation and structures; tank external structures and components; mass and energy balance; and propellant tracking.
• References section with all sources cited in the footnotes; and an Appendix with instructions on how to access additional online content, and information on Moran Innovation LLC.

Online Access

The report is available online and can be accessed at: www.moraninnovation.com

The online version is a shared document in pdf format with viewer permission granted. Download and print functions are disabled. If you are having difficulty accessing the document, check with the IT department at your organization to ensure online access to shared Google Docs is permitted.

Matt Moran is the Managing Member at Moran Innovation LLC, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems for more than 40 years; and first-of-a-kind liquid, slush and gaseous hydrogen systems since the mid-1980s. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been a cofounder in seven technology based start-ups; and provided R&D and engineering support to many industrial, government and research organizations. Matt has three patents and more than 50 publications including the Cryogenic Fluid Management report series. More about him can be found here.