Alissa Marrapodi

Rolls-Royce and easyJet—partners in developing hydrogen combustion engine technology for aircrafts— are working with Loughborough University in the United Kingdom and the German Aerospace Center, Deutsches Zentrum für Luft-und Raumfahrt (DLR), to test a full annular combustor of a Pearl 700 engine running on 100% hydrogen. The team has shown that 100% hydrogen fuel can be combusted at conditions representing maximum take-off thrust.

Hydrogen testing at DLR, Cologne. Credit: Rolls-Royce

“This is an incredible achievement in a short space of time,” said Grazia Vittadini, Chief Technology Rolls-Royce. “Controlling the combustion process is one of the key technology challenges the industry faces in making hydrogen a real aviation fuel of the future. We have achieved that, and it makes us eager to keep moving forward.”

Pivotal of this achievement was the design of fuel spray nozzles that control the combustion process. This involved overcoming engineering challenges, as hydrogen burns hotter and faster than kerosene. The new nozzles control the flame position using a new system that progressively mixes air with hydrogen to manage the fuel’s reactivity. The nozzles were initially tested at intermediate pressure before the final full-pressure combustor tests.

“We believe hydrogen is the future of short-haul aviation and the success of this test and progress being made demonstrates that this is becoming ever closer,” said Johan Lundgren, CEO of easyJet. “We remain optimistic that it will play a critical role in helping us achieve the ambitious goals we set out in our net zero roadmap.”

The technologies tested will be incorporated into the learning from the Boscombe Down tests as Rolls-Royce and easyJet prepare for a full gas hydrogen ground test on a Pearl engine followed by a full ground test on a Pearl engine using liquid hydrogen.

“This is an outstanding success story, and we are more than happy to have contributed our hydrogen testing capabilities,” said Markus Fischer, Divisional Board Member Aeronautics of DLR. “It was very exciting supporting this technology journey and seeing the burner technology mature in various rigs at our Institute of Propulsion Technology. This underlines again DLR’s capabilities in complex applied research and the achievement, at such a high pace, was supported by our experience in real-scale testing of ground-based gas turbines.”

Articles

Recent tests support the combustion element of Rolls-Royce’s hydrogen program after running an aircraft combustor on 100% hydrogen. 

Rolls-Royce’s Aero-Hydrogen Research Project Makes Headway 

On Wednesday morning at Turbomachinery & Pump Symposia (TPS) 2023, speakers from Siemens Energy—including Yuri Biba, Principal Aerodynamic Engineer at Dresser-Rand, Kurt Aikens, Aerodynamic Engineer at FoxRES, and Jim Sorokes, an aerodynamic independent consultant, presented a tutorial on 

Troubleshooting Aero-Performance Issues in Centrifugal Compressors

. The session provided guidance on how to resolve aero-performance-related issues both in the field and on an OEM production test stand.

The session outlined several key steps in the resolution process, including:

establishing effective communications between the parties involved in resolving the issue

understanding the scope and/or history of the problem

accumulating pertinent data, e.g., geometric, process, dates/times, etc.

applying advanced analytical tools to help identify possible root causes and assess solutions

Sorokes kicked off the discussion by asking the question, “Could we have avoided the problem in the first place? Did we do our due diligence in evaluating the technology that was used in the machine when it was being built?” He stressed that there must be open communication between the OEM and end user to define suitable levels of design verification. 

“It’s best to identify any issues before the machine leaves the test stand,” he said.

The first step when troubleshooting aero-performance issues is to gain an understanding of the scope of the problem: Is it a mechanical issue, an aero-performance issue, or both? Is it only happening at low- or high-flow? Have I seen this issue before or is it new?

Jim Sorokes, an aerodynamic independent consultant, speaks at TPS 2023. Credit: Turbomachinery International 

Ultimately, you want to determine whether the issue is specific to this type of compressor or this application. The OEM can help get this process started.

Next, determine who will be involved in this process—the OEM? Who from the client’s company? Is a third party involved? Who is in charge? Who’s leading the effort within each organization that’s involved?

Foundational in this process, however, is communication. “Communication is vital,” Sorokes said. “It must be open, honest, and thorough and a willingness to share data. Avoid back-channel communication!”

Establishing priority relative to ongoing activities

Gathering and understanding data: frequency, trends, and vibration data

Conduct a review of data and review operator logs

Plot raw data to look for “strange” trends

Waterfall diagrams (for example, a diagram from a rotating stall tutorial enabled them to see the sub-synchronous vibration and monitor how it changed as they were changing process flow to ID an impeller stall

Compare data to the original test stand results

Gather physical evidence: photographs of flow patterns

Biba discussed trends in performance testing, including excess internal leakage, discharge losses, compressor fouling corrosion, and the impact of various manufacturing assembly mistakes.

“Excess internal leakage can cause damage to the seals, which causes incorrect clearness, which causes more leakage—this could occur over time or suddenly,” Biba said. An example he used was leakage in a labyrinth seal—leakage caused performance curve shifts that led to lower efficiency.

Biba then discussed inlet losses, which could be caused by blockage, improper upstream, or piping. Inlet losses cause a drop in pressure from that inlet location to the first impeller I, which increases the flange-to-flange pressure ratio.

Another issue seen in the field is fouling/corrosion caused by deposits on the flow path, foreign material ingested into the machine, or chemical reactions during compression. As a result, performance is slowed over time as well as increased vibrations.

Biba said there are times a compressor is assembled incorrectly; for example, some stationary components are put on in the wrong direction. A mistake in compressor assembly may result in large pressure drops or unsteady flow. “Proper impeller rotation and diffuser valve alignment will avoid these issues,” he said.

Another factor to consider is manufacturing issues, which may also lead to performance problems.

Biba said there is some controversy over whether tool accuracy is sufficient for predicting absolute performance values. “The most common prediction and accuracy sources are uncertainties: operating conditions, geometric deviations, and insufficient tuning of the tools,” he said.

Aikens rounded out the discussion by diving into an analytical tool used to find the root cause analysis for performance issues: computational fluid dynamics (CFD).

“CFD is more time-intensive [than the new tools that Biba discussed], but in exchange for that we get significantly more detail about what may be going on,” Aikens said. “CFD resolves the full 3D characteristics of the flow field by approximating the solution to conservation of mass, momentum, and energy.”

It is based on fundamental fluid dynamics, but it’s up to the user to choose what 3D geometry is relevant to the problem at hand. “Simple CFD setups are reliable for reductions near the design point where losses are at a minimum,” Aikens said. “It’s also accurate for higher Mach number conditions.” CFD is also reliable for subtle changes in geometry.

The accuracy of CFD is, however, influenced by many factors, including mesh resolution, surface boundary conditions, steady versus unsteady state, turbulence models, and interface conditions. Complex issues may require more detail, such as including multiple stages, 360-degree analyses may be required, or switching to unsteady state analysis.

Some other challenges with CFD include predicting stall/surge in the context of a steady-state simulation. The biggest challenge is computational cost. Despite these issues, however, Aikens said CFD is widely popular for solving aero-performance issues.

On the second day of TPS 2023, speakers outlined resolution steps for aero-performance-related issues in the field and on a production test stand. 



TPS 2023: Steps to Resolving Aero-Performance Issues in Centrifugal Compressors

The 2023 Turbomachinery & Pump Symposia (TPS) in Houston, TX, kicked off with a welcome address delivered by Dr. Michael Webber, professor at the University of Texas at Austin and John J. McKetta Centennial Energy Chair in Engineering. The address set the stage for this year’s display of turbomachinery and pump technology and highlighted the latest trends in the energy landscape and turbomachinery.

Dr. Michael Webber gave the keynote address on opening day of TPS 2023. Credit: Turbomachinery International 

Dr. Eric Petersen, Director of the Turbomachinery Laboratory at Texas A&M University, opened the keynote address with some helpful notes for the audience: keeping up with TPS 2023 through the designated app, attending the end-of-conference banquet, and submitting abstracts for next year’s symposia. Dr. Petersen closed his brief introduction with an outline of the Asia Turbomachinery & Pump Symposia at the Kuala Lumpur Conference Center in Kuala Lumpur, Malaysia, May 13-16, 2024. This extension of TPS is expected to garner over 2,000 attendees and exhibitors, displaying an international focus on the development of turbomachinery for the future.

Dr. Petersen handed the role of lead keynote speaker to Dr. Webber, who discussed the importance of turbomachinery in the modern world, particularly in the energy generation sector. The history of rotating technology and the predecessors to modern gas/steam turbines were laid out by Dr. Webber, citing the efficiency of continuous rotating motion in power generation as superior to back-and-forth batch power generation. He said that the world of turbomachinery, including gas turbines, will remain relevant given the stability it offers to the grid.

Dr. Petersen highlighted a few trends he sees shaping the future:

New designs that include smaller (and simultaneously, larger) turbines

Turbines that support higher temperatures

Turbines that support a wider range of fuels

Fuel flexibility that can support newer fuels such as ammonia and hydrogen as well as blends: bio-methane + hydrogen, for example

Cooling channels inside the blades (difficult, but possible)

Although the industry is buzzing with talks of hydrogen because it burns clean, challenges with handling and leakage, to name a few, complicate matters. Dr. Petersen said using a 20% hydrogen blend is fine, but higher percentages create problems. He also mentioned ammonia, which reduces emissions but increases energy usage.

Dr. Webber detailed a future in which turbomachinery integrates clean-burning fuels at ever-increasing efficiencies, separating itself from antiquated technologies incapable of fuel flexibility and carbon minimization. Gases like hydrogen, ammonia, nitrogen, and methane will go hand-in-hand with carbon sequestration to develop a power generation sector that is cleaner and more efficient than technologies of decades past.

He closed the keynote address with words of encouragement for those in the field of turbomachinery, deconstructing notions of doubt from those who believe that turbines have no place in the future of energy. Dr. Webber advised those in the crowd to keep developing turbomachinery to counter issues in modern energy generation.

The 2023 Turbomachinery & Pump Symposia in Houston, TX, kicked off with the keynote address by Dr. Michael Webber.

TPS 2023 Keynote: Turbines Will Continue to Play a Role in Power Generation, New Energy Landscape

In the third and final part of our roundtable Q&A on the state of hydrogen in the turbomachinery industry, experts and OEMs talk about how, from a technical standpoint, different types of turbomachinery benefit or become challenged by the integration of hydrogen. And Mark Axford, founder of Axford Turbine Consultants, weighs in on the role ammonia can or does play in the incorporation of less carbon-intensive fuel sources. 

Mark Axford
Founder
Axford Turbine Consultants

Klaus Brun
Global Director of R&D 
Ebara-Elliott Energy Company

Alex Habeder
Head of Business Strategy
Sustainable Energy Systems 
Siemens Energy

Andreas Kramer 
Senior Manager Business Development 
MAN Energy Solutions

Daniel Patrick
Market Manager Hydrogen 
Atlas Copco Gas and Process

Q: HOW, FROM A TECHNICAL STANDPOINT, DO DIFFERENT TYPES OF TURBOMACHINERY BENEFIT OR BECOME CHALLENGED BY THE INTEGRATION OF HYDROGEN?

The turbomachinery types that are affected by the hydrogen discussion are pipeline compressors and combustion gas turbines. There is no benefit provided to these turbomachines by integrating hydrogen, but there are certainly challenges. 

For centrifugal compressors, the molecular weight of the gas being compressed is an essential design criterion for each impeller. Injecting more than a few percent of hydrogen (by volume) into the existing network of interstate pipelines would require replacement rotors for thousands of centrifugal compressors. Interstate pipelines are regulated by FERC, and the additional costs for the rotor rework would have to be passed along to customers.

For gas turbines, most existing makes and models could be operated with a 5-10% hydrogen fuel blend (by volume) without significant modification. But higher percentages create challenges, i.e., flame temperature and NOx emissions. Hydrogen burns at a hotter flame temperature and has a longer flame shape. Plus, more NOx will be produced for the same power output. This can be mitigated by redesigning the gas turbine combustor and/or spending more on the ammonia catalyst system installed on the gas turbine exhaust.

The two primary types of turbomachines that are affected by a conversion to a hydrogen economy are compressors and gas turbines—compressors, since they are used to gather and transport gas in a pipeline; gas turbines, since they are used to convert energy carrying gas into mechanical energy and electricity via a generator. Gas turbines have been utilized for the combustion of natural gas for many years, and although there are some challenges to maintain other criteria pollutants (such as NOx) low when burning hydrogen, the technology challenges to convert gas turbines to hydrogen operation are manageable. Similarly, compression of hydrogen has been demonstrated in refineries and other petrochemical applications for many years. However, for large-scale transport of hydrogen, different types of compressors will be required. Hydrogen is the lightest of all gasses, and to effectively compress hydrogen to the pressure ratios needed for transport and storage requires very high-speed turbomachines with impellers that operate at speeds well above that of conventional compressors. This technology is currently being developed but is not yet commercially available.

The application of hydrogen compression is not a novel concept. There are currently hundreds of centrifugal and positive displacement machines operating in this field, processing either "pure" hydrogen or a blend of gases with significant hydrogen content. Both compressor types can handle a broad range of application sce­narios, with the choice of technology largely coming down to eco­nomic tradeoffs and the facility’s specific requirements, includ­ing required flow rates, pressure ratios, foot­print limitations, use of dry or wet sealing, etc. Minor modifications usually suffice when the process gas contains smaller quantities of hydrogen; however, as this percentage increases, we must pay particular attention to factors such as power consumption, material compatibility, gas leakage, and operational flexibility.

Compressing hydrogen requires 2.5 - 3 times the compression power needed for an equivalent volume of natural gas.

Hydrogen can induce phenomena like hydrogen embrittlement in certain metals, potentially leading to premature failure of compressor components.

Hydrogen molecules are smaller than natural gas molecules, increasing their propensity to leak through seals and gaskets.

Green energy sources generate fluctuating loads and necessitate operational flexibility. Products should have the capability to operate over a more extensive flow range. There's an opportunity to optimize a hybrid solution comprising both centrifugal and positive displacement machines.

Different types of turbomachinery indeed have their advantages and challenges when it comes to integrating hydrogen. For example, when dealing with large effective volume flows, reciprocating compressors would become excessively large and costly. This is where process gas screw compressors, centrifugal inline compressors, and integrally geared compressors come into play. They can be used upstream of reciprocating compressors to reduce the effective volume flow. In cases requiring further compression, reciprocating compressors can be installed downstream, particularly for extremely high-pressure ratios and for pressure requirements beyond 250 bar. In such cases, centrifugal and integrally geared compressors face the challenge of achieving the necessary polytropic head with an acceptable number of stages. For moderate pressure ratios and below 250 bar, centrifugal inline compressors and integrally geared compressors may be the better solution, depending on the specified process data. For compression from low-pressure electrolysis, e.g., atmospheric, oil-free process gas screw compressors can achieve the required pressure ratio at volume flows not suitable for reciprocating compressors. Additionally, there have been advancements in gas turbines specifically designed for hydrogen, and further developments have been announced for use of green ammonia as fuel.

 Hydrogen is a notoriously difficult molecule for turbomachinery due to its low molecular weight. Turbomachinery designed for hydrogen applications requires high speeds and high stage counts to achieve most pressure ratios. This challenge can sometimes make turbomachinery less appealing for hydrogen when compared to other compression technology like positive displacement, especially for lower flow, high-head applications. However, turbomachinery lends itself well to certain hydrogen applications. For example, the cryogenic temperatures of liquid hydrogen applications result in increased gas density, making it favorable for centrifugal technology. This makes applications such as liquid hydrogen boil-off gas a good fit for integrally geared centrifugal compressors. Hydrogen liquefaction is another area where turbomachinery can shine. Cryogenic hydrogen turboexpanders play a crucial role in providing the necessary refrigeration duty to achieve liquid hydrogen temperatures.

Q: WHAT ROLE CAN/DOES AMMONIA PLAY IN THE INCORPORATION OF LESS CARBON-INTENSIVE FUEL SOURCES?

 Hydrogen is difficult to transport. Unlike natural gas, which can be liquefied and transported globally by ship, it is not economically feasible to liquefy hydrogen for bulk transport. An idea to address this problem is to manufacture green hydrogen and then convert it to ammonia by combining hydrogen and nitrogen. This requires additional capital investment to separate nitrogen from air to manufacture green ammonia. It is feasible to transport ammonia, and upon arrival at a power station, convert the ammonia to hydrogen, which can then be utilized as a turbine fuel. 

If you have excess electricity from wind and solar during peak hours, and you utilize this energy to make green ammonia, why not just stop there and use the subsidized green ammonia as fertilizer? Otherwise, an additional manufacturing step is needed to convert the green ammonia back into hydrogen. Each of these “conversion” processes requires capital investment and machinery that uses energy, thus creating additional cost and inefficiency all to address the hydrogen transportation problem. 

Let’s not forget that natural gas is a “less carbon-intensive fuel source” when compared to coal. It is likely less expensive to add carbon capture to natural gas combined-cycle plants than to pay for the extra infrastructure associated with hydrogen. To that point, hydrogen technology must compete not only with batteries but also with carbon capture.

Part 1: Roundtable Q&A: The State of Hydrogen in the Turbomachinery Industry

Part 2: Roundtable Q&A: Obstacles Preventing Large-scale Implementation of Hydrogen

In Part 3 of our roundtable Q&A on the state of hydrogen in the turbomachinery industry, experts and OEMs discuss how different types of turbomachinery are affected by the integration of hydrogen and the role of ammonia.

Part 3: Roundtable Q&A: The Roles of Hydrogen and Ammonia as Less Carbon-Intensive Fuel Sources

This week kicks off the 2023 Turbomachinery & Pump Symposia (TPS) in Houston, TX, held at the George R. Brown Convention Center from Sept. 25 – 28, with short courses starting today, Monday, and the exhibition floor and technical sessions kicking off on Tuesday. Topics for this year’s program include maintenance, new technologies, reliability, troubleshooting and instruction on emerging designs, and best practices supported by case studies.

TPS 2023 is host to more than 270 turbomachinery and pump companies that will be showcasing full-size equipment, new technology, and emerging industry trends. The symposium features a continuing education program that spans the oil and gas, petrochemical, power, aerospace, chemical, and water industries.

A few new events at this year’s show include a social media scavenger hunt, Women in TPS luncheon, a book signing with Dr. Dara Childs, author of 

Turbomachinery Rotordynamics with Case Studies

, and a tour of the Lab at Texas A&M University in College Station on Thursday—attendees can see how the lab is equipped and what research projects are in progress. The conference is also featuring the Innovation Presents Stage, located in the front corner of the exhibit hall, which gives exhibitors a platform to present 20-minute commercial presentations.

Michael Webber, Ph.D., a professor at the University of Texas at Austin and John J. McKetta Centennial Energy Chair in Engineering, will kick off the first day of technical sessions during the keynote address on Tuesday, Sept. 26 at 8 a.m.

Also on Tuesday, folks from the Elliott Group and Aramco are hosting a tutorial on 

Applications and Technology for Hydrogen Compression and Pumping

. On Wednesday, Sept. 27, speakers from Siemens Energy and two industry consultants are presenting a tutorial on 

, which will provide guidance on how to resolve aero-performance-related issues both in the field and on an OEM production test stand. The discussion includes:

application of advanced analytical tools to help identify possible root causes and assess solutions

Experts from Elliott Group and Solar Turbines are also presenting on 

Turbomachinery in Liquified Natural Gas Production Plants

. Given that the global demand for LNG has dramatically risen over the last 20 years, this trend is expected to continue in the foreseeable future. The tutorial will review major turbomachines, such as turbines, compressors, pumps, and expanders, in LNG plants, focusing on how compressors, pumps, and gas turbines fit into the various LNG plant cycles and their integration, operation, and application limits. Presenters will also discuss how to best match turbomachinery for optimal service in LNG plants based on the power, speed, and utility needs of the most common LNG cycles.

The Turbomachinery & Pump Symposia in Houston, TX, held at the George R. Brown Convention Center, runs Sept. 25 – 28, 2023. 

2023 Turbomachinery & Pump Symposia Kicks Off in Houston

In this episode of the TurboTime podcast, we talk to Carolyn Woeber, the Director of Application Engineering at Cadence Design Systems, about computational fluid dynamics (CFD). Woeber gives a crash course in CFD and how it relates to the turbomachinery industry. She then talks about how CFD streamlines and benefits pump and compressor design and performance, how it improves the design and analysis of aerospace machinery, and what areas CFD could improve in the aerospace industry and the challenges it faces in terms of the turbomachinery industry.

“Engineers use multiple analysis tools to predict the behavior of these fluids to identify the most optimum design for their needs,” Woeber said. “This can range from analytical empirical analyses all the way to experimental setups, to computational fluid dynamics (CFD),” she said, “Most engineers that you talk to are familiar with and they use the analytical and the empirical analyses. They also use experimental setups when they're evaluating potential designs. But increasingly, we see more and more organizations moving toward enhancing their design processes by also incorporating CFD. So how does that work? What does that look like?

“A CFD practitioner begins with a CAD model that serves as a foundation. On that CAD model, they then create a 2D mesh,” she continued. “This 2D mesh adheres to and resolves the model’s geometry to the level of fidelity that's required for numerical simulation. Then we construct a mesh in the 3D space around that model—this is the space you want to conduct the fluid flow analysis. This 3D space can be internal, it can be external, or it could be a combination of both depending on the configuration. Next, we'll make sure that the topology within the mesh.”

Podcasts

In this episode of the TurboTime podcast, we talk with Carolyn Woeber, the Director of Application Engineering at Cadence Design Systems, about 
computational fluid dynamics. 



TurboTime Podcast: Computational Fluid Dynamics with Cadence

In the second part of our three-part roundtable Q&A on the state of hydrogen in the turbomachinery industry, experts and OEMs discuss the various obstacles that are preventing the large-scale implementation of hydrogen, including the costs of manufacturing hydrogen, transporting it to a power station, and providing large-scale storage at the site.

Q: WHAT OBSTACLES ARE PREVENTING THE LARGE-SCALE IMPLEMENTATION OF HYDROGEN?

The main obstacles are the costs of physically manufacturing hydrogen, transporting it to a power station, and providing large-scale storage at the site. Modern gas turbine power plants utilize combined-cycle technology for high efficiency. These plants are designed to run at baseload and typically utilize building blocks of 300 – 600 MW of capacity. Continuous consumption of this much fuel requires an infrastructure of interconnected pipelines fed from numerous fuel sources. Because this infrastructure does not exist for hydrogen, a nearby storage cavern of substantial proportion must be located near the power plant. In terms of green hydrogen, the electrolyzer and renewable energy sources need to be located nearby. These obstacles can be overcome with government subsidies, but only if the cost of green electricity does
not matter.

The primary obstacle to the large-scale implementation of hydrogen as an energy carrier is the cost of hydrogen production, transport, and storage. It is difficult to utilize or convert the existing hydro-carbon transport infrastructure to hydrogen transport because of the challenging physical properties of hydrogen. As previously noted, hydrogen is not an easy gas to handle. Thus, to convert our industrial and domestic usage from fossil fuels to hydrogen requires an entirely new infrastructure, which could cost trillions of dollars. This is something that will take time, money, and commitment to implement.

The main obstacles [preventing large-scale implementation of hydrogen] are the costs of physically manufacturing hydrogen, transporting it to a power station, and providing large-scale storage at the site. - Mark Axford

Reasonably priced and affordable electrolyzers are the prerequisite for covering the growing demand and future hydrogen costs. Furthermore, generating green hydrogen requires a significant and accelerated expansion of renewable energy worldwide. This expansion can only accelerate if permitting becomes faster and less complicated. Automated factories for electrolysis on an industrial scale (including the GW scale) must be constructed, and the pipeline and industrial-scale hydrogen storage infrastructure must be implemented for storing and transporting the hydrogen.

If the preconditions described in the first question have not been achieved, and the necessary infrastructure has not been established, large-scale implementation of hydrogen is expected to face significant challenges and may ultimately fail.

 Supply and demand is one of the largest obstacles we face in hydrogen today. We are stuck in the classic “chicken-or-the-egg” situation. Hydrogen producers need confidence that there will be eager consumers, while consumers need reassurance there will be a consistent supply of hydrogen to suit their needs. Both sides of the supply chain seem to be looking at the other, waiting to see what will happen next. With the number of hydrogen projects on the horizon and the ever-growing demand sector, this seems to be a short-term issue. Once we get past the supply-and-demand hurdle, the next challenge will be bringing down the cost of hydrogen. Companies and consumers are generally willing to pay a “green” premium, but there are still significant economic gains to be made before hydrogen becomes adopted as a mainstream energy carrier.

Part 3: Roundtable Q&A: Turbomachinery and Hydrogen, Ammonia's Role as a Less Carbon-Intensive Fuel Source

In Part 2 of our roundtable on the state of hydrogen in the turbomachinery industry, experts and OEMs discuss the various obstacles that are preventing the large-scale implementation of hydrogen. 

Microsoft is purchasing up to 315,000 metric tons of CO

 removal over a multi-year period from Heirloom, a direct air capture (DAC) company, which follows Heirloom’s DAC Hub selection by the DOE for up to $600 million in matching funding.

“Microsoft’s agreement with Heirloom is another important step in helping build the market for carbon removal and supports our path to become carbon negative by 2030,” said Brian Marrs, Senior Director of Energy and Carbon at Microsoft. “As an investor in and customer of Heirloom, we believe that Heirloom’s technical approach and plan are designed for rapid iteration to help drive down the cost of large-scale DAC at the urgent pace needed to meet the goals of the Paris Agreement.”

The deal between Microsoft and Heirloom opens up a funding mechanism for Heirloom to finance future DAC facilities.

“Microsoft has been an incredible supporter of Heirloom, helping us scale one of the world’s most cost-effective DAC solutions,” said Shashank Samala, CEO of Heirloom. “Bankable agreements of this magnitude enable Heirloom to raise project finance for our rapid scale-up, fueling exponential growth like what we’ve seen in the renewable energy industry.”

This agreement provides additional predictable and durable cash flows needed to enable the project financing of upcoming Heirloom DAC facilities. Project financing involves the funding of capital-intensive projects with the future cash flows generated by those projects.

This contract unites domestic buyers and sellers to advance net-zero commitments under the First Movers Coalition, an initiative launched by the Biden Administration in which private companies use their purchasing power to create early markets for clean technologies that enable both reductions and removals. The CO

 removal credits purchased as part of this agreement will be generated at Heirloom’s next two commercial deployments in the United States.

“It is incredibly encouraging to see agreements of this magnitude because corporate buyers, like Microsoft, can unlock a significantly lower cost of capital for DAC companies that are seeking to finance infrastructure projects, such as future carbon dioxide removal facilities.” said Robert Keepers, Managing Director, J.P. Morgan Green Economy Banking.

Microsoft’s purchase will help scale and reduce the cost of Heirloom’s direct air capture facilities.

Microsoft, Heirloom Sign Agreement for CO2 Removal 

Sempra Infrastructure sold to KKR its 42% indirect, non-controlling interest in its Port Arthur LNG Phase 1 project. Sempra Infrastructure, according to the terms of the transaction, will retain a controlling 28% indirect interest in Phase 1 at the project level while ConocoPhillips will own the remaining 30% interest.

"The closing of this transaction continues the positive momentum of our Port Arthur LNG facility and highlights Sempra Infrastructure's ability to access capital to support the growth of its infrastructure business," said Justin Bird, CEO of Sempra Infrastructure. "We remain committed to developing energy infrastructure projects with strong partners to continue growing our portfolio while advancing global decarbonization and energy security."

In March 2023, Sempra Infrastructure reached a positive final investment decision for Port Arthur LNG Phase 1 and contracted Bechtel Energy Inc. to build the project.

Rendering of the Port Arthur Phase 1 LNG project; Image Credits: Port Arthur LNG

"We are pleased to close our investment in this critical energy infrastructure project led by the Sempra Infrastructure team," said James Cunningham, Partner at KKR. "Port Arthur LNG Phase 1 has continued its strong momentum and is on track to meet its objectives of helping to deliver energy security, economic growth and a near-term supply of reliable and cleaner energy."

Since construction began in spring 2023, more than 2.8 million hours of work have been completed. The expected commercial operation dates for Train 1 and Train 2 are 2027 and 2028, respectively.

The company sold its 42% non-controlling interest to KKR. 

Sempra Infrastructure Sells its Interest in Port Arthur LNG Phase 1 Project

As hydrogen continues to dominate discussions about energy security and decarbonization, conference agendas, and government climate goals, its role and capacity are often misrepresented and overhyped. According to the International Energy Agency’s (IEA) Global Hydrogen Review 2022, more than 80% of hydrogen is derived from fossil fuels, with some experts placing it higher. Further, the main uses of hydrogen in the industry are to produce ammonia—which accounts for 34 Mt of hydrogen demand—methanol (15 Mt), and direct reduced iron in the steel industry (5 Mt). Most importantly, almost all hydrogen used in the industrial sector is produced from unabated natural gas or coal, which translates to 630 Mt of direct CO

 emissions. These numbers complicate the carbon-neutral image of hydrogen.

While the technology is proven, hydrogen still plays an insignificant role in the power generation sector, accounting for 0.2% of the total generation, according to IEA. Solutions are underway, but most say it will be at least 10 years for green hydrogen to make deep headway in power generation. IEA reported that 2021 was a record year in electrolysis deployment, with more than 200 MW of additional installed capacity, three times more than 2020, bringing the total operational capacity above 500 MW. But carbon capture, utilization, and storage (CCUS) associated with hydrogen production has been largely stagnant. IEA reported in 2021, 0.6 Mt of hydrogen were produced from fossil fuels with CCUS, capturing roughly 10 Mt—the same production and capture level as in 2020, as no new projects started operation.

To elaborate on these numbers, facts, and technologies, Turbomachinery International put together this roundtable of industry insiders to offer their points of view and insights into hydrogen’s current and projected role in the energy sector.

Q: HOW REALISTIC IS IT TO COUNT ON HYDROGEN AS THE “GOLDEN TICKET” TO NET-ZERO EMISSIONS IN TERMS OF COST, SUPPLY, AND IMPLEMENTATION?

Net-zero emissions are normally discussed to be achieved within a timetable—often 2050. I do not see hydrogen as the golden ticket primarily because green hydrogen is far too expensive compared to other competing technologies. In 2022, the worldwide industrial demand for hydrogen was 95 million metric tonnes—almost half of the demand was fulfilled by manufacturing hydrogen by reforming methane gas, i.e., grey hydrogen. 

In the United States, the industrial price of grey hydrogen is $1 per kg delivered. The cost to make green hydrogen utilizing an electrolyzer is $5 per Kg. To encourage the production of green hydrogen, the United States and the European Union have passed legislation to subsidize its production. The U.S. subsidy is a “double dip”. First, $3 per Kg for all the green hydrogen produced plus an additional guaranteed payment for the electricity produced from it as it is put into fuel cells or gas turbines. There is no market for green hydrogen without huge government subsidies. Moreover, there is no way to discern $5 green hydrogen from $1 grey hydrogen; they are physically identical. Safeguards must be put in place to prevent large-scale fraud.

There are also technical issues with hydrogen relating to the cost of storing and transporting it. Most of the large U.S. interstate pipelines could safely transport hydrogen or a blend of hydrogen and natural gas. However, the pipeline compressor stations would require major rework to handle the volumetric changes due to mole weight. A bigger problem exists in the gas distribution pipelines networks and end-user appliances like stoves and furnaces. Much of the smaller diameter piping could suffer embrittlement if exposed to hydrogen. Also, most end-user devices would not operate if the hydrogen component of the fuel was more than a few percent.

Hydrogen is not a golden ticket to net zero. It is one of many enabling technologies that can, if properly applied and deployed, provide a positive contribution toward a net-zero or decarbonized energy economy. Hydrogen is not a fuel source. It is a basic chemical element that can be utilized for energy storage and transport. Since it does not release CO

 in a net-positive energy exothermic reaction, it is a viable energy carrier. However, hydrogen does not occur naturally and, thus, it needs to be produced either through electrolysis or partial oxidation reactions. Both processes are energy-intensive and require expensive equipment and new infrastructure. Hydrogen is not an easy gas to handle in that it is highly explosive, has a wide flammability range, leaks easily, causes embrittlement in many metals, and is hard to compress since it is a very light gas. Thus, the practical usage of hydrogen is limited to those applications where an industrial process requires hydrogen as a precursor product (such as refining or fertilizer production) or to an application where energy cannot be viably stored or transported by other cheaper and safer means, i.e., hydrogen as an energy carrier is only practical when energy that is produced cannot otherwise be transported easily (via an electrical grid), stored in batteries or other energy storage devices, or locally consumed.

While hydrogen holds promise for achieving net-zero emissions, relying solely on it as the “golden ticket” for cost-effective and scalable implementation creates challenges. The two most significant challenges are (1) hydrogen must become a closed commercial business model that enables worthwhile private commercial investments, and (2) at the same time, we must enter series production with supply chains and suppliers—the majority of whom are still manufacturers.

The cost of hydrogen production today, particularly from renewable sources, remains relatively high compared to traditional fossil-fuel alternatives. While new technologies and economies of scale are emerging and expected to drive down costs over time, achieving cost competitiveness with fossil fuels will require substantial investment and innovation. The development of fossil fuel prices also plays a role, especially with regard to the price of CO

Scaling up hydrogen production and ensuring a reliable supply pose logistical challenges and require substantial infrastructure development. Although hydrogen is an established chemical feedstock in the industrial sector, using green hydrogen in the energy sector is relatively new; thus, there’s no established infrastructure for green hydrogen. We will need robust supply chains, production capacities, or transportation networks to promote the use of green hydrogen on a large scale. All of this must be created at a speed that can keep pace with an announced market ramp-up.

"The cost of hydrogen production today remains relatively high compared to traditional fossil-fuel alternatives. While new technologies and economies of scale are expected to drive down costs over time, achieving cost competitiveness with fossil fuels will require substantial investment and innovation."  - Alex Habeder

Transitioning to a hydrogen-based economy necessitates extensive changes across sectors and the widespread adoption of hydrogen technologies. A comprehensive approach integrating it with other decarbonization solutions is crucial to leverage hydrogen effectively. We need large-scale kick-start projects to test the technologies and progress from talking to acting. Speed is also of the essence.

In these areas, there is no doubt that low-carbon hydrogen is the path to decarbonization: replacing grey hydrogen as feedstock in the chemical and fertilizer industry and changing steel production to the direct reduction pathway with low-carbon hydrogen. On the other hand, in terms of mobility, shipping and aviation cannot be easily electrified and need fuels synthesized from clean hydrogen and carbon, such as CO

To produce green hydrogen, there is a need for renewable energy in large and sufficient quantities. Without the establishment of regulatory frameworks, the feasibility of implementation becomes questionable. Moreover, industries require investment security to proceed. Additionally, cost reduction through economies of scale must be achieved. Without meeting these prerequisites, relying on hydrogen as the ultimate solution may not be realistic.

 Hydrogen is an excellent choice to decarbonize certain industries. However, it is just one of the many strategies we will need to deploy to reach net-zero targets. Industries such as material handling, heavy-duty transportation, long-duration energy storage, stationary power generation, and combustion applications (such as green steel) all seem to be attractive sectors for the early implementation of hydrogen.

Q: WHAT ARE SOME OPPORTUNITIES CREATED BY HYDROGEN UTILIZATION IN THE ENERGY INDUSTRY?

Utilizing hydrogen as an energy storage technology requires substantial economic subsidy. Today, the most economical forms of energy storage are coal piles, oil tanks, and LNG tanks. Of course, these are all hydrocarbons and out of favor politically. So, what are the least expensive non-hydrocarbon forms of energy storage? Pumped storage on rivers and lakes has been utilized for decades, but most of the good sites have already been built out. More recently, lithium-ion batteries, similar to automotive battery packs, have become a favorite. Batteries can soak up the excessive quantities of electricity produced by wind turbines and solar panels during peak production hours. Subsidies for battery storage have been generous and batteries can provide instantaneous injection of KW into the grid when needed—a valuable technical feature. 

As I see it, if we set aside hydrocarbon energy storage, hydrogen must compete with battery storage. However, lithium-ion battery technology is expensive and not necessarily the best battery technology for long-term bulk storage. Several other battery technologies that are now being tested could bring about a sharp reduction in the installed cost per MWh of battery storage—companies such as Form Energy, EOS, and Zinc8. Toyota has also recently announced a solid-state battery breakthrough. I anticipate a disruptive battery technology will emerge for bulk-energy storage over the next two years that will cause severe damage to hydrogen storage's economic viability.

 The primary opportunities for hydrogen utilization, with the aim to decarbonize the total energy supply, are in the areas of petrochemical production—the replacement of blue/brown/black hydrogen with green hydrogen—as a transportation fuel, for fertilizer and ammonia production, and for other industrial chemical processes that require hydrogen as a precursor supply. The usage of hydrogen for power generation makes less sense since the cost of converting green electricity to hydrogen and then back to electric power is expensive, and the roundtrip efficiency of this process is well below 40%. It is not logical to use a process that wastes well over 60% of the produced energy to reduce carbon emissions. For curtailed green electricity it makes more sense to try to improve the distribution system to find off-takers for the electricity or to utilize energy storage technologies with higher roundtrip efficiencies, such as pumped hydro, pumped heat, compressed air, liquid air, etc.

Switching from coal to natural gas for power generation and improving efficiency are the first steps to reducing CO

 emissions. Next is substituting sustainable hydrogen for natural gas to enable carbon-neutral power plant operation, since hydrogen combustion does not produce CO

. Combined- and simple-cycle plants provide residual load for periods of low renewable generation and enable large-scale, seasonal storage of renewable electricity. In the long term, hydrogen-fueled gas turbines and combined-cycle plants will enable a fully decarbonized energy system in which renewables form the backbone of all energy consumed.

Currently, hydrogen is predominantly used in refineries and ammonia production via the steam methane reforming process where 1 ton of hydrogen causes 10 tons of CO

 emission. Future advancements aim to replace fossil-fueled power plants with hydrogen-based alternatives, such as power plants utilizing hydrogen, ammonia (produced with green hydrogen), or synthetic fuels (produced with green or blue hydrogen and CO

 from emitting industries like cement). Co-firing of ammonia or methanol in coal-based or combined-cycle gas turbine power plants is also planned. The same applies to large ship engines for ocean-going vessels, which can be fueled by methanol or, in the future, by ammonia (Power-to-X).

The most obvious opportunity for the energy industry is the chance to reduce the carbon footprint of a traditionally carbon-intensive sector and do so by enabling a low-carbon hydrogen economy. Also, the hydrogen economy will create a variety of new jobs, all while leveraging the wealth of knowledge and experience the energy industry has acquired over the decades from working with traditional energy sources.

A roundtable of experts and OEMs addresses hydrogen’s role in the energy landscape, including supply and demand, opportunities, and obstacles. 