Have you traveled in a modern, fuel-efficient midsize passenger plane lately? Given that these planes look rather conventional, you may wonder: Where does the fuel efficiency come from? There is a good possibility you were on a plane with a geared turbofan.

Turbofans with large bypass ratios have an issue. The large fan is difficult to speed match with the low-pressure turbine that drives it. That’s due to large differences in their diameters. The turbine wants to run at a much higher speed than the fan. The solution is to use a gearbox (rated between 16,000 and 32,000 hp with a ratio of 3:1) between the turbine and the fan. This allows both to operate at their optimal speeds, thereby increasing efficiency. It also allows an increase in fan diameter, improving propulsion efficiency.

New aircraft engines of this type can reduce fuel consumption by 15% compared to older engines. While the introduction of this engine, first used in commercial service in 2016, was a bit rocky, none of the teething problems were related to the gearbox.

Full disclosure: Neither author of this article works or has worked for the manufacturer of these aircraft engines. So why are we writing about them? Because there is proof a gearbox can be a good thing, allowing the match of aerodynamic components with different optimum speeds. Without a gearbox, the speed of the components—for example, a power turbine and a high-pressure gas compressor—is a compromise, reducing overall efficiency. Of course, this improvement is, to some extent, compromised by the fact that the gearbox itself creates losses.

We’re not advocating for a gearbox in every possible application. In many instances—for example, gas turbine-driven compressors in pipeline applications—there is no significant speed mismatch. The power turbine of the gas turbine and the pipeline compressor that’s sized to absorb the gas turbine power have their respective best efficiency at about the same speed.

On the other hand, consider the same gas turbine powering a high-pressure, gas-injection compressor. That is an example of a physically small compressor that absorbs a lot of power, and the compressor wants to run significantly faster than the power turbine. It may be possible to design a compressor for the same duty that works as a direct drive, but it would be bigger and most likely less efficient. In this situation, a gearbox may be a better solution.

Properly sized gearboxes rarely cause problems. Still, end users and turbomachinery experts often advocate against their use. This is interesting because gearboxes—either speed-reducing for generators or speed-increasing for electric compressor drives—are the norm rather than the exception for compressors driven by electric motors and generators driven by gas turbines. They operate to the satisfaction of most users.

In fact, the most challenging applications are not parallel shaft gearboxes used as speed increasers in gas compressor drive applications. The most challenging gearbox designs are used for integrally geared compressors where it’s often necessary to reach to the limits of possible pitch line velocity and where multiple pinions run off the same bull gear. Also, since gearboxes for industrial applications require oil lubrication, a properly designed oil supply and cooling system is imperative to achieve high system reliability and avoid forced outages.

There’s another non-intuitive gearbox preference. For compressor trains, parallel shaft gearboxes are the norm, in particular because API does not recognize epicyclic or planetary gearboxes for this duty. Interestingly, they are commonly used for gas turbine-driven generators, as well as in variable-speed hydraulic gearboxes.

For compressor applications, there are advantages to using epicyclic gears. They are more compact and often, especially for higher gearbox ratios, more efficient than parallel shaft gears. They also allow for an inline drive train, which helps significantly in offshore installations where space requirements, weight, and single-lift capability are important.

Rather than avoiding a gearbox on principle, it is a good strategy to consider if its use could lead to better performance, lower costs, and greater flexibility. Gearboxes are proven devices and, if sized and integrated properly, provide high reliability.

Klaus Brun is the Director of R&D at Elliott Group. He is also the past Chair of the Board of Directors of the ASME International Gas Turbine Institute and the IGTI Oil & Gas applications committee.

Rainer Kurz is the Manager of Gas Compressor Engineering at Solar Turbines Incorporated in San Diego, CA. He is an ASME Fellow since 2003 and the past chair of the IGTI Oil and Gas Applications Committee.

Any views or opinions presented in this article are solely those of the authors and do not necessarily represent those of Solar Turbines Incorporated, Elliott Group, or any of their affiliates.

Debunking the Myth: Embracing Gearboxes for Enhanced Efficiency in Compressor Applications

Myth: Avoid a Gearbox at All Costs for Compressor Applications

In certain operational and environmental scenarios, turbomachinery could be under dynamic loads such as earthquakes, impact/dynamic loadings, or blast loads (blast pressures). Although these might not be normal conditions and may only happen a few times during the life of equipment, they should be considered for overall safety and reliability. Machinery protection requires proper engineering safety and hazard assessment.

Earthquakes, water-hammer, dynamic forces due to the release of fluids, and similar transient cases could happen any time just as error in operation or malfunction could lead to such accidental loading cases. Blasts and explosions, too, must be considered, as well as accidents such as an item dropped from a crane during maintenance or a truck hitting machinery during an overhaul.

How machinery behaves under extreme loads depends on the quality of the design and the engineering/fabrication criteria met. This means going beyond code prescriptions and accurately predicting how equipment will respond during extreme events. Since experimental investigations are invariably limited, alternative approaches should be sought to evaluate the real behaviour and strength under dynamic/impact loads. This requires the use of realistic models or methods that, although may not be entirely accurate, provide some realistic estimates of load-carrying capacity.

The complexity of the response of machinery subjected to large dynamic loads involves many phenomena. These include elastic and plastic wave propagation, material properties, elastic and plastic buckling, fracture, and rupture. Involvements of different kinds of jointing techniques (welding, bolting, etc.) make simulation or assessment challenging. Another difficulty is the time dependency of dynamic loadings and responses.

Machinery protection requires proper engineering safety and hazard assessment.

It might be assumed that dynamic responses resemble corresponding static responses. This is not the case in many applications. For example, the dynamic elastic-plastic buckling of mechanical parts has been different from static cases and can lead to counterintuitive behavior.

Sometimes a simple energy balance using the rigid-plastic method provides guidance on the overall response of machinery and is helpful in selecting dimensions. For instance, a large explosion can be approximated as a uniformly distributed loading.

Piping loads are particularly vulnerable to different dynamic, impact, and blast loads, resulting in serious damage or leaks. Assessments, simulations, and estimates are required for the resistance of pressurized piping to all possible dynamic/impact loadings to ensure their safety and reliability. In many cases, proper protections and barriers should be in place to reduce risk to acceptable levels. Supports and their structures play a major role in the dynamic responses of piping systems.

There could also be different types and modes of failure when studying machinery under dynamic/impact loadings. As examples, three types of defined failures are mentioned here.

The first type is defined as permanent ductile deformation of machinery without any major incident such as leakage, fracture, or rupture. For instance, the thin shell of a machinery casing might be deformed or wrinkle due to an earthquake. This should be regarded as a failure and should be repaired even if there is no leakage or rupture.

A second type of failure is when rupture, tear, or disconnection happens. In other words, this is when the maximum strain reaches the rupture/tear value for the material, usually in a localized area of the machinery. An example is permanent leakage of a flange joint due to large, exerted loads.

The third type of failure is transverse shear failure. This more readily occurs at boundaries and other hard points (or supporting points) of dynamically loaded machinery. For example, anchor bolt(s) of a machinery might be cut due to dynamic loadings. ■

Amin Almasi is a Chartered Professional Engineer in Australia and U.K. (M.Sc. and B.Sc. in mechanical engineering). He is a senior consultant specializing in rotating equipment, condition monitoring and reliability.

Why simple models estimating impact, dynamic, and blast loads provide insight. 

How to Assess Turbomachinery Reliability and Strength

In this episode of the TurboTime podcast, sponsored by Rentech Boilers, Kevin Slepicka, the VP of Heat Recovery Boiler Systems at Rentech, discusses repair and maintenance requirements of heat recovery steam generator (HRSG) boiler systems. He reviews the technical challenges associated with integrating HRSG boilers into an existing facility, the role that HRSGs play in emissions reduction, and a unique installation case.



More about our sponsor: Rentech Boilers, a Texas-based industrial provider, covers the manufacturing, repair, and maintenance of boiler systems and provides solutions to a range of industries.

In this episode of the TurboTime podcast, sponsored by Rentech Boilers, Kevin Slepicka, the VP of Heat Recovery Boiler Systems at Rentech, shares a comprehensive perspective of HRSG boiler systems.

TurboTime: Insights on HRSG Boilers with Special Guest Rentech Boilers

The Baker Hughes Annual Meeting at the end of January 2023 gave voice to oil and gas executives calling for a reevaluation of decarbonization policies they say may be inadvertently worsening emissions while pushing consumer energy bills upwards.

Caption: Decarbonization isn't as black and white as many world governments have made it seem. Credit: Adobe Stock.

Sheikh Khalid Bin Khalifa Al-Thani, CEO of Qatargas, explained that coal consumption reached an all-time high in 2022. Why? A general shortage of oil and gas was in evidence even before the Russia-Ukraine war. That crisis only heightened the problem, especially in Europe. The Europeans gobbled up any available LNG supplies at top dollar. That left a shortfall in many other areas, and coal became the solution.

“The energy crisis in 2022 highlighted the fragility of global energy markets,” said Al-Thani. “We must balance climate and emissions reduction policy with energy security.”

He believes that while the role of renewables within the energy mix will increase, it is many years before any energy transition can realistically take place.

“Substituting natural gas for coal is the key as we cannot decarbonize immediately,” he said. “Natural gas is a necessary complement to renewables for a robust energy supply and as support for climate mitigation. Natural gas is reliable, affordable, available, and has a low carbon footprint compared to coal. This makes it a destination fuel, not a transition fuel.”

Standing in the way is a policy and financing puzzle that makes it difficult and sometimes impossible to receive investment for natural gas projects. Several speakers at the event laid out how funding for large-scale natural gas and LNG projects is often thwarted as the investment field has been told that natural gas won’t be around by 2030. This idea comes from policy makers who set decarbonization targets without regard to the realities of the situation. When disruption comes, short-term policies are rapidly adjusted to accommodate a sudden switch to LNG, as in Europe in 2022. But long-term work to develop new oil and gas fields and build the infrastructure to support them is in neglect and has been for many years.

Lorenzo Simonelli of Baker Hughes laid out the hard truths of the energy transition.

Accordingly, Qatargas plans to boost gas production significantly over the next decade. Al-Thani said the company would do so while reducing its carbon footprint. It has already cut greenhouse gas (GHG) emissions by 12% compared to 2013 and CO2 emissions by 70% via injection and reduction of flaring. Methane emissions, he said, are already less than 1% of the company’s GHG profile.

Nasir Al-Naimi, Executive Vice President Upstream of Saudi Aramco (the largest oil and gas producer in the world), called for a return to energy realism.

“The impractical reality that oil and gas must be replaced has fueled chronic underinvestment, down by more than half from 2014 to 2021,” he said. “We must shatter the misleading narrative that oil and gas can be easily and quickly replaced.”

He laid out the statistics: Fossil fuels supplied 82% of the world’s energy needs in 2021 compared to 7% for renewables. The energy transition, he stressed, will happen at different speeds in different regions as they are at varying stages of development and industrialization. With three-quarters of a billion people still without electricity, the priority in these places is to get power by whatever means necessary.

“Each country has its own unique situation, so we must develop more realistic plays for affordable, reliable, and sustainable energy,” Al-Naimi said.

Saudi Aramco plans to boost production from its current level of around 12 million barrels of oil per day (boe/day) to 13 boe/day by 2027 and increase gas production by 50% by the end of the decade. In parallel, the company is investing heavily in carbon capture, renewables, and hydrogen.

“We must convince the world that oil and gas will play a prominent role in our energy future,” said Al-Naimi.

“We must shatter the misleading narrative that oil and gas can be easily and quickly replaced,” said Nasir Al-Naimi, Saudi Aramco.

Lorenzo Simonelli, Chairman and CEO of Baker Hughes laid out the energy “trilemma”—how to balance sustainability with affordability and security.

“There is no future without hydrocarbons, just as there is no one climate savior,” said Simonelli. “Instead of focusing on the fuel source, we need to focus on emissions as reliance on hydrocarbons won’t disappear.”

He announced that the annual meeting was attended by more than 1,600 people, with more than 50% attending for the first time. Faced with surging energy bills for consumers and industry across the globe, he laid out three key points:

1) The need to accelerate the development and adoption of technologies to meet net-zero targets. On the turbomachinery side, that means such things as compressors and valves that don’t leak methane and other gases.

2) There is no future without hydrocarbons and there is no one climate savior.

3) There is no path to net zero without partnerships.

According to Baker Hughes surveys of oil and gas users, 57% said they are continuing with commitments to natural gas and LNG. “LNG and natural gas are not transition fuels, they are destination fuels that play a critical role in abundant, secure, and affordable energy,” said Simonelli.

Panelists explained the problems with current energy and decarbonization policies.

The harsh realities of global energy were driven home by a series of speakers from around the world. Nurul Ichwan, Deputy Minister for Investment Promotion for Indonesia, explained that most energy in Indonesia comes from coal. He dismissed the idea that tens of GW of coal generation can be transitioned to renewables overnight. His country’s plan is to transition gradually from coal to natural gas while adding more wind and solar.

He commented that some countries in the region are promoting their own environmental credentials by reducing coal mining in their own countries while ordering more coal from Indonesia on multi-decade contracts.

“We want help in exploring and exploiting our own natural gas resources to aid in the transition from coal,” said Ichwan.

Farid Al Awlaqi, Executive Director of Generation for TAQA of the United Arab Emirates (UAE) said his nation has a different approach. It has plenty of solar and baseload nuclear but needs a lot more natural gas to meet swings in demand. “We are removing coal slowly out of the system and replacing with gas,” he said. “Our grids are not ready to manage intermittency.”

Helima Croft, Global Head of Commodity Strategy at RBC Capital Markets, said energy security is back as an energy priority. She is deeply concerned about energy supply over the next year, and said nations needed a diversity of sources. She added that Europe got lucky this year due to a milder winter. She complained about policy makers making it so difficult to fund oil and gas projects.

“We need to avoid underinvestment in oil and gas,” said Croft. “A stable supply of hydrocarbons is vital.”

Kazutomo Irie, President of the Asia-Pacific Energy Research Centre, went a stage further. He noted that emerging and developing nations place more importance on the security and affordability of energy supply than they do on decarbonization.

“We need natural gas to carry out coal-to-gas switching while building up renewables,” said Irie.

Octavio Simoes, CEO, Tellurian, said that while the supply of energy from renewable sources will grow massively in the coming years, it is still a long way from replacing fossil fuels. According to International Energy Agency estimates, the world will need at least 20% more gas and 40% more oil by 2050.

“No energy source has gone down in last 200 years except whale oil,” said Simoes. “The EU still gets 81% of its energy from fossil fuels, so replacing it in ten years is a fool’s errand.”

Yet the environmental lobby and the media are constantly vilifying non-renewable fuel sources. Adding to the problem is a big rise in the cost of the materials used in renewable energy.

“We are on the wrong path to decarbonization as we need affordable energy without volatility,” said Simoes. “We have written the first few and last few chapters on the energy transition and forgotten about the rest of the book. There is a big gap between vision and reality that is wide and getting wider.”

Yet investment in oil and gas in certain countries and political sectors is tabu, he added. The EU, for example, resists investment in gas but is spending far more on decarbonization and not getting there.

“Current energy transition Ideas are not executable,” said Simoes.

Onursal Soyer, Deputy Chief Executive Officer, Lambert Energy Advisory, described how Russian sanctions led the EU to buy up all available LNG at inflated prices to get through the winter and keep the wheels of industry running. As a result, a great many countries were denied LNG. That caused them to turn to coal.

“There was a record level of coal burned worldwide in 2022,” said Soyer. “Coal demand is not going away so replacing it with natural gas should be applauded.”

Hardline decarbonization policies, he added, are a major impediment to oil and gas investment. “This is causing coal to be used more and gas to be penalized, which is only making the situation worse,” said Soyer. 

To further worsen a difficult global energy situation, oil and gas consumption this year will be highest ever and 2023 will be, too. But even with prices high, major oil and gas companies are not investing due to policy hurdles. This investment is vitally needed to maintain current supply and create the oil and gas resources needed to take the world through the next 30 years.

It isn’t just oil and gas that faces shortages and high prices. Other materials are in a real supply crunch, said Kathleen Kelley, Founder and CEO, Queen Anne’s Gate Capital.

To meet the decarbonization and renewable energy targets that have been set, nickel production worldwide will have to go from 100,000 tons to 3 million tons a year. That is unfeasible. It is the same story with rare earths. Some point to the fact that Sweden has found new deposits of rare earths that can be used in batteries and other renewable energy. But those mines will take 10 to 15 years to come online.

“There was a record level of coal burned worldwide in 2022,” said Onursal Soyer, Lambert Energy Advisory.

“Investors are not allocating money to mining due to the industry’s poor performance on environmental, social and governance (ESG) metrics,” said Kelley. “We can’t possibly get to any climate goals based on the timescale of mining alone.”

Jessica Roberts, Head of Forecasting at Benchmark Mineral Intelligence, gave further specifics. Lithium batteries provided 700 kWH of power in 2022. By 2035, they are supposed to provide 5.5 TWH. That requires 300 new mines. It takes five to 25 years to open a new mine.

“We went from 100,000 tons of lithium a few years ago to a million tons last year and will need at least 2 million within a few years,” said Roberts.

Energy industry executives flip the script on unrealistic decarbonization goals. 

The Decarbonization Pushback Has Begun

Rotoflow, an Air Products business, is known for technological innovation in the development and production of turbomachinery over the last 65 years. The first Air Products turboexpander was developed in 1952, and the first practical application of radial turboexpanders in hydrocarbon processes by Rotoflow took place shortly thereafter. Its product range encompasses rotating equipment, alongside after-market services and support.

The company’s work is involved in turboexpander technology for the hydrocarbon, LNG, petrochemical, and industrial gas markets. Phillip Schuepbach, Business Development Manager – New Products and Aftermarket at Rotoflow, said, “Rotoflow’s designs have millions of successful hours of operation with over 3,000 units currently worldwide. Our core products include compressor-loaded expanders (companders), generator-loaded expanders, energy dissipative expanders, and specialty turbomachinery.”

Its full-service aftermarket solutions include field service, shop and field repairs, spare parts inventory, upgrades and rerates, performance and reliability assessments, remote monitoring, and training. Rotoflow’s service technicians can service turbomachinery at all phases of equipment lifecycle and plant types.

“Rotoflow equipment is efficient and reliable, which is a huge factor for oil and gas industry customers tasked with maintaining plant onstream availability. Our power recovery expanders are utilized to recover electrical energy from the expansion of the process stream fluid.” Schuepbach said. This recovered power can be used to offset other electrical usage in the plant, increasing the sustainability of a facility. By eliminating the costly gearbox for low power applications under 500 hp (<370 kW), customers can increase the sustainability of their facilities and recover more power, according to Scheupbach.

Caption: The Rotoflow EC 40 turboexpander is available in two types: oil-bearing or mag-bearing. Rotoflow’s high-pressure compressor-loaded turboexpanders (companders) provide refrigeration for the most efficient air separation and liquefaction facilities in the world. Credit: Rotoflow.

As an OEM, Rotoflow can provide both machinery solutions and turnkey support. “With service centers and field service technicians around the globe, we can mobilize quickly to safely and efficiently repair your equipment no matter where you are,” said Schuepbach. Rotoflow’s field service technicians and engineers handle everything from expander overhaul and changeouts to pump and compressor work, in addition to construction assistance and start up/commissioning activities.

One example of Rotoflow’s global reach is the Shanghai Solution Center. Rotoflow opened the

Caption: Rotoflow’s full-service OEM capabilities enable local service, reliable spare parts inventory, and quick access to system upgrades for turbomachinery. Credit: Rotoflow.

new center in the Qingpu district of Shanghai, China to better serve the turbomachinery needs of customers throughout Asia, reported Schuepbach. In addition to servicing turboexpanders, centrifugal compressors, reciprocating compressors, cryogenic pumps, small steam turbines, gearboxes, fans, and blowers, the facility will also be used to build new expanders for small nitrogen generation plants. Finally, it will support Air Products equipment for the company’s Hydrogen for Mobility initiative.

Setting up inspection and service schedules can help preemptively identify repairs and overhauls. Onsite assessments serve as one of the best strategies for ensuring overall performance of rotating equipment, said Schuepbach. Rotoflow’s experience as an owner/operator can be leveraged to get the most out of equipment. Proper training alongside product and operating knowledge minimizes downtime, maximizing safety, productive operations, and reliability.

Rerates and rebuilds also provide an opportunity to improve the longevity of turbomachinery. Rotoflow can identify causes of damage, recommend performance upgrades that reduce wear and tear, and help prevent future problems. “We have immediate access to materials and equipment and can rapidly dispatch a technician to complete your maintenance needs or get you back online as soon as possible,” said Schuepbach. Routine maintenance involving dirt cleaning, dust, debris, relubrication, and others must be considered, even in the cleanest work environments.

Rotoflow delivers design, engineering and production, and custom solutions. The company’s turbomachinery capabilities service the gasification, air separation, helium, LNG, hydrocarbon, petrochemical, and energy market segments. “In addition to broadening our footprint across the United States, we are enlarging our presence in many previously under-served local markets abroad,” said Schuepbach. Turbomachinery operators demand higher levels of reliability and efficiency. OEMs like Rotoflow—with investments in product development, vertical integration, and skilled teams—will subsequently see further growth. Demand in underserved markets like China and India will also be a strong driver for aftermarket turbomachinery service and support. 

Rotoflow, a manufacturer and operator of turbomachinery, is comprehensive in its approach to support the industry and provide machinery solutions. 

Putting the Flow in Rotating Machinery

In Part 2 of this episode of the TurboTime podcast, we cap off our discussion on energy storage systems in the turbomachinery industry. Klaus Brun and Rainer Kurz lay out the details on how hydrogen plays into it all, outline the California duck curve, and give insight into the costs of running and operating traditional versus alternative energy sources. What incentives are there for providers to produce electricity if the costs of doing so are prohibitively expensive and there's no guarantee that you will be able to sell that electricity in a couple years? We face this difficult question and more on the final chapter of the energy storage conversation.

In this episoode of the TurboTime podcast, the Myth Busters close out their conversation on energy storage in the turbomachinery industry.

TurboTime: Part 2: Myth Busters Talk Energy Storage 

Hydrogen is the most abundant element in the universe. As a carbon-free energy source, it represents one of the paths to a decarbonized energy supply. Flipping the switch to a decarbonized, green tomorrow would be wonderful. The reality is that a number of considerations, technical advancements, socio-economic hurdles, and resource limitations need to be navigated first. This article explores the current state of hydrogen as a fuel supply; what can be accomplished within today’s installed base of power generation; identifies intermediate hydrogen-based carbon reduction solutions; and outlines the advancements necessary to realize the vision of an entirely hydrogen-fueled gas turbine power generation fleet.

When looking for carbon-free energy sources, the most apparent options are solar, wind, hydro, and nuclear. Yet each of these present unique constraints when asked to satisfy the world’s growing demand for electricity. With their fuel flexibility and high efficiencies, gas turbines have increasingly been relied upon to meet the growing global demand for power. Hydrogen represents a means to leverage this installed base to supply car-bon-free electricity in a less disruptive manner than a complete transformation to new power generating technologies. Fueling gas turbines with pure hydrogen produces only water vapor with zero CO

Hydrogen has been successfully blended with the fuel supply in gas turbines for decades. Recent field demonstration tests have shown successful operation at up to a 44% blend of H

 by volume for aeroderivative gas turbines, and up to 20% for large heavy-frame gas turbines. One concern with combusting hydrogen is increased NO

 emissions due to increased flame temperature. Studies have demonstrated negligible change to NO

Table 1: Hydrogen vs. natural gas properties

Gas turbine OEMs are projecting the capability to operate on 100% hydrogen without impacting NO

 formation, primarily through advancements in combustor design and minor if any changes to existing SCR reliance.

The key to unlocking the full potential of hydrogen as a carbon-free energy source is to convert unused solar, wind, hydro, and nuclear energy available during low-demand periods to hydrogen via water electrolysis. The stored hydrogen produced can then be utilized as an alternate fuel by gas turbines to generate carbon-free electricity during high-demand periods.

Today, the United States utilizes approximately 10 quadrillion BTU/yr of natural gas to produce electricity, according to the U.S. Energy Information Administration. Total hydrogen production is approximately 1 quadrillion BTU/yr. Of this, green hydrogen production capability is only 269 trillion BTU/yr. Note that the vast majority of hydrogen produced today is NOT used to generate electricity—nearly all in the United States is used in refining petroleum, treating metals, producing fertilizer, and processing foods. Petroleum refineries use it to lower the sulfur content of fuels. With the introduction of the Inflation Reduction Act (IRA), the hydrogen industry is poised to take the biggest steps seen to date toward closing this production gap, with a $3/kg tax credit available for green hydrogen production and lesser amounts for more carbon-intensive forms of hydrogen production.

Figure 1: The hydrogen color wheel. Courtesy of MHI.

As the availability of hydrogen continues to grow, opportunities will arise for power utilities to introduce it as a carbon-free fuel stream for their gas turbine fleets. Making the change from natural gas to 100% hydrogen in a single step may not be feasible in the near term given the required energy consumption and lack of availability of hydrogen. A reasonable approach may be to introduce it in increasing volume in blends aligned to availability in given geographic areas. The following factors should be considered when approaching these blending opportunities: hydro-gen supply and storage, fuel conditioning and blending skid design, gas turbine capability and period of use, and personnel safety and training.

Table 2 provides a mathematical model of a blending application for a 60Hz GE LMS100 PA+ gas turbine genset operating in simple cycle mode. Figures presented are based on published full-load, beginning-of-life performance for the LMS100 PA+, based on data from GE Gas Power. Based on the relative density and LHV differences between natural gas and hydrogen, one can see the total flow more than triples as you approach 100% hydrogen operation. (This model assumes the line pressure does not change across the range of blending %.) An important consideration for retrofit applications is accommodating this increase in volumetric flow once the 75% blending threshold is approached, where total flow is approximately doubled. Existing piping infrastructure supplying the genset, as well as the fuel delivery piping at the combustors, will need to be evaluated for the increased relative pipe velocities this will result in.

Table 2: Model of a hydrogen-blending application. Courtesy of CRDX.

Assuming the hydrogen delivered in the Table 2 example is green or pink hydrogen, another interesting point is the amount of water required. These figures represent the theoretic water necessary to produce hydrogen, which are significant in and of themselves, but do not take into consideration any losses encountered during the purification process of the water to meet a given electrolyzer application. For instance, if sea water is considered as the water source, a desalination process is necessary as well as a deionizing process. Considerations and technical advancements in this area will be necessary to introduce green or pink hydrogen at the scale necessary for power industry consumption.

Blue hydrogen, and turquoise hydrogen (further down the road) represent alternate sources of carbon-free hydrogen that are based on the conversion of natural gas with some form of carbon sequestration. For blue hydrogen, carbon capture and sequestration systems are added to the existing grey hydrogen reforming process to eliminate CO

 emissions. For turquoise hydrogen, a pyrolization process produces hydrogen and carbon in the form of carbon black versus CO

. The carbon is immediately sequestered and available for alternate usage points, replacing more carbon intensive sources.

Hydrogen represents a promising way to reduce the carbon footprint of the power industry. Growing advancements in hydrogen production technologies coupled with strong support from the federal government by way of the IRA bring the opportunity to deliver solutions to the forefront. State and local incentives likewise serve as a catalyst for adoption.

Figure 3: H-Cubed hydrogen blending by CRDX

Recent in-the-field hydrogen-blending demonstration projects on both aeroderivative and heavy-frame gas turbines indicate the power sector is ready to take the next step. Implementing a gradually increasing hydrogen-blending strategy for the gas turbine fleet represents an opportunity to realize these benefits today while laying the framework to support a carbon-free energy sector of the future. 

Gus Graham is Business Development Manager at Carbon Reduction Systems (CRDX), a technology-based manufacturing company developing products and services for reducing the use of carbon-based fuels and their emissions. Visit www.crdxs.com or call +1 518-765-8329.

Anthony Brough, P.E. provides business development support for CRDX. He can be reached at abrough@CRDXS.com.

Hydrogen plays a significant role in decarbonizing power generation.

Hydrogen Turbines in Power Generation

In this episode of the TurboTime podcast, we interview longtime 

columnists Klaus Brun and Rainer Kurz on the state of energy storage in the industry. Existing technologies such as the natural gas pipeline system are crucial compared to alternative energy storage solutions, such as batteries or wind. The intermittency of newer storage systems puts into question their reliability, especially in terms of meeting peak demand. Natural gas can be ramped up or down depending on demand and doesn't heavily rely on exterior factors such as wind, water availability, or sunshine to reach optimal efficiencies.

In this episode of the TurboTime podcast, longtime columnists Klaus Brun and Rainer Kurz discuss the state of energy storage in the industry. 

TurboTime: Part 1: Myth Busters Talk Energy Storage 

Matias is a turbine/project engineer at GASRE/GTUsers based in Finland.

Assistant Editor, Turbomachinery International Magazine

The long-anticipated Frame 6FA User Group Conference was recently convened in Budapest, Hungary, attracting a notable number of attendees who actively participated in comprehensive discussions and networked extensively. Participants were also offered a unique opportunity to visit the General Electric manufacturing and repair center in Veresegyhaz.

The GTUsers website provides information on the various webinars, conferences, and future meetings for those who were unable to attend this session.

The opening day was dedicated to end-users, showcasing engaging case studies and lessons learned, along with a dynamic Q&A session.

Two potential approaches to manage rotor life extension were presented: the first involves an analysis and overhaul of the original rotor, which may necessitate considerable downtime, whereas the second recommends a refurbished or new replacement rotor to minimize unit downtime.

Insights from users who operate a gas fuel DLN 2.6+ unit with backup Light Fuel Oil (LFO) were shared. The transition from gas to LFO and vice versa was successful, highlighting minor improvements needed for auxiliary systems, especially the flame detection and combustion dynamic monitoring system.

Details regarding compressor clashing during startup sequence and the condition of stator vanes and carrier rings as the fleet ages were also shared.

A discussion on the 6FA load gear, which is affected by various operating parameters like temperatures, speeds, oil quality and flow, load, and shaftline alignment, was presented. Proper inspections are important to determine and document the gear's condition.

Caption: 6FA Load gear barrelling issues were discussed. Credit: GTUsers.

Caption: There were many discussions about 6FA RLE and overhauled exchange rotor experiences. Credit: GTUsers.

In a dedicated session, GE addressed queries from end-users while providing updates on the latest technical developments, fleet status, and Technical Information Letters (TILs). Furthermore, GE arranged a visit to their workshop, including breakout sessions and a tour of the manufacturing and repair shop floor.

The conference covered multiple topics, including decarbonization and fuel flexibility for the 6FA DLN2.6, 2.6+, and new DLN EVO combustion systems, control system upgrades and cybersecurity, and Opflex opportunities.

A Q&A session, with questions collected from end-users in advance, concluded the event. GE experts addressed all inquiries, leading to comprehensive discussions and a deeper understanding of the topics presented.

The conference also welcomed presentations from several third-party service providers. MJB International highlighted the wide range of aftermarket maintenance, repair, and overhaul solutions it offers for the 6FA gas turbine fleet.

Mechanical Dynamics & Analysis presented on the repair and new manufacturing of DLN2.0 and DLN2.6 fuel nozzle assemblies with end covers. GTC Control Solutions discussed the role of an owner's engineer during a controls upgrade project.

Dekomte presented several case studies, including the transition of a 6FA gas turbine, where they efficiently installed a new expansion joint between the GT and HRSG, resulting in minimal outage duration and cost savings for the customer.

Additionally, several other third-party service providers, including Minimax, National Electric Coil, Trinity Turbine Technology, Emerson Controls, and Turbine Services Ltd., were present at the conference. During the Vendor Fair, end-users had the opportunity to interact with GE and third-party specialists.

Caption: End user day consisted of multiple end user presentations and discussions. Credit: GTUsers.

Caption: Vendor fair was running during breaks where vendors were able to present their services/solutions and answer end user’s questions. Credit: GTUsers.

Articles

The Conference held in Budapest, Hungary offered detailed insights on technical advancements, case studies and interactive sessions for participants.

Summary of the Frame 6FA User Group Conference 

The announcement of a Strategic Collaboration Agreement (SCA) was made by Kawasaki Heavy Industries, pairing with ADNOC, an Abu Dhabi-based firm known for its lower-carbon intensity energy offerings. The primary focus of the agreement is to probe the possibilities for the companies in setting up international liquefied hydrogen supply chains.

Given the growing global thrust towards decarbonization, hydrogen is increasingly perceived as a promising energy source for the future, as its combustion process releases zero carbon dioxide. Through the SCA, Kawasaki and ADNOC will jointly explore opportunities in large-scale hydrogen production, liquefaction, infrastructure development, and maritime transportation of hydrogen to potential receivers. The end goal is the creation of a commercially viable international hydrogen supply chain.

In line with Kawasaki's Group Vision 2030, which emphasizes "Energy and Environmental Solutions" as a crucial area for future growth, Kawasaki through the SCA, intends to contribute to global decarbonization initiatives by endorsing and employing clean hydrogen energy.

Kawaski and ADNOC will explore how to create a commercially viable hydrogen supply chain.

Kawasaki Heavy Industries, ADNOC Collaborating on Liquefied Hydrogen Supply Chain

In this Turbo Blast, we shine a spotlight on the importance and intricacies of dynamic load assessments. These assessments are essential in understanding how machinery can withstand and respond to extreme load conditions. From earthquakes to operational errors, the variety of dynamic loads that can affect our machinery is wide and unpredictable.

Then, we turn our attention to the latest happenings in the industry. In this section, we report on notable projects and events such as Bahrain's Al-Dur Project. This significant initiative in the field of water and power signifies Bahrain's continued commitment to energy efficiency and infrastructure development. Also in focus is the Frame 6FA User Group Conference. Adding to the industry news, we highlight GE Vernova's documentary on gas technology in the energy transition.

Finally, we round off our discussions by examining a commonly held myth in the industry: the use of gearboxes in compressors. This deep dive seeks to dispel misinformation and shed light on the effectiveness of gearboxes in compressor applications.

Podcasts

This Turbo Blast episode offers an informative examination of dynamic load assessments, debunking the myth of gearboxes in compressor applications, and the latest industry updates from Bahrain's Al-Dur Project, the Frame 6FA User Group Conference, and GE Vernova's new documentary.

TurboTime: A Deep Dive into Dynamic Loads, Compressor Gearboxes, Recent Industry Developments

In advancing their Low-CO₂ Iron Metallics Project, Kobe Steel and Mitsui & Co. have formalized a Memorandum of Understanding (MoU) with Oman's Public Authority for Special Economic Zones and Free Zones (OPAZ). The endeavor aims to put direct reduced iron (DRI) production and sales into operation, utilizing Kobe Steel's MIDREX Process. Additionally, a Land Reservation Agreement with the Port of Duqm Company S.A.O.C. (PODC) has been solidified.

Caption: Signatories to the agreement. Credit: Kobe Steel.

OPAZ administers all of Oman's special economic zones and free zones, while PODC manages the Port of Duqm. Kobe Steel and Mitsui have been in ongoing negotiations with the Ministry of Energy and Minerals of the Sultanate of Oman concerning the particulars of the natural gas supply. With the location and collaborative framework in the Special Economic Zone at Duqm now firmly established, the feasibility study is set to advance.

Oman, given its abundant natural gas reserves and commitment to renewable energy sources and green hydrogen as detailed in Oman Vision 2040, presents a fitting site for this initiative. The MIDREX process initially employs natural gas as a reducing agent, with a view to eventually substitute it with hydrogen and incorporate carbon capture, utilization, and storage to further decrease CO2 emissions.

The project's objective is to generate 5 million tons of DRI, with potential expansion plans under review. Kobe Steel Group has previously developed and brought to market low CO2 blast furnace steel products and novel DRI technologies such as MIDREX Flex and MIDREX H2. The partnership with Mitsui is intended to leverage their combined experience and technologies towards aiding the steel industry's decarbonization efforts and achieving carbon neutrality.

The partners have secured a land agreement and signed an MoU with Omani authorities for their collaborative project.

Kobe Steel, Mitsui & Co. Progress in Low-CO2 Iron Production Project in Oman

Atlas Copco became a silver sponsor of the Heroes MAKE America initiative, which is run by The Manufacturing Institute, the workforce development and education partner of the National Association of Manufacturers. The program, aimed at promoting manufacturing careers in the United States, establishes links between the manufacturing industry and the military and veteran communities. 

"Manufacturing careers are great opportunities for veterans to find their next calling and join a new mission," said Carolyn Lee, MI President and Executive Director. 

Aaron Prato, Atlas Copco North America Vice President, emphasized the company's commitment to serving American veterans and military members.

In addition to its sponsorship, Atlas Copco extended its market presence through the acquisition of three distributor companies across Italy, the United States, and the UK. In Italy, Atlas Copco acquired C.P. Service SRL, a Naples-based compressor distributor and service provider, aiming to strengthen its service and sales presence in southern Italy. 

"The company has built up a strong customer base in the area," noted Vagner Rego, Business Area President Compressor Technique at Atlas Copco.

The company also expanded its reach in the United States by acquiring the assets of James E. Watson & Co., a distributor of vacuum equipment and service solutions based in Georgia. The acquisition will enhance Atlas Copco's footprint in the Southeast region of the U.S. Geert Follens, Business Area President Vacuum Technique, highlighted the company's reputation and diverse market service.

In the UK, Atlas Copco acquired Maziak Compressor Services Ltd., a distributor of air compressors, nitrogen generators, and process cooling equipment based in Northamptonshire. The acquisition will increase Atlas Copco's presence and provide growth opportunities in the East of England and East Midlands regions, according to Rego.

This series of initiatives underscores Atlas Copco's dedication to workforce development and its strategic efforts to strengthen and expand its market presence globally. The terms for each acquisition were not disclosed, but all new businesses will become part of the respective divisions within Atlas Copco.

Atlas Copco announced its sponsorship of a military workforce training program, "Heroes MAKE America," while expanding its footprint in Italy, the United States, and the UK.

Atlas Copco Sponsors Heroes MAKE America Initiative, Acquires Distributors in Italy, US, UK

Consumers Energy has initiated operations at the Covert Generating Station in Van Buren County, Southwest Michigan, marking a key milestone in its Clean Energy Plan. This initiative aims to satisfy the state's increasing energy demands in an environmentally responsible manner.

“The Covert Generating Station will be an integral part of our energy generation assets, providing a cost-effective and reliable electricity supply to our customers in Michigan," said Tim Sparks, Vice President of Electric Supply at Consumers Energy. "The plant's operations will complement our clean energy resources, including solar and wind power, which are earmarked for further expansion."

Acquired by Consumers Energy, the natural gas-fueled Covert Generating Station boasts a generation capacity of 1,200 MW, capable of serving over a million homes in Michigan. Operational since 2004, the plant's integration into Consumers Energy's portfolio allows for an increase in affordable and reliable power generation without additional greenhouse gas emissions.

The Covert plant's workforce, comprising 29 employees, is anticipated to join Consumers Energy in the course of the transition.

As part of its summer energy projection, Consumers Energy ensures that Michigan's nearly two million homes and businesses will have a sufficient energy supply. The Covert station will work in conjunction with two other natural gas plants in Zeeland and Jackson, alongside coal, hydroelectric, pumped storage, wind, and solar energy sources.

Consumers Energy is committed to a cleaner and more cost-effective energy mix. The company plans to retire its remaining coal-fueled power plants by mid-2025. Over the next two decades, the company estimates that more than 60 percent of the power provided to customers will be generated from renewable energy sources, potentially saving customers around $600 million.

"Our commitment to our customers is to ensure consistent power supply. The addition of the Covert plant allows us to augment our renewable energy resources while reliably addressing the day-to-day energy requirements of our community," Sparks added.

Consumers Energy, the main subsidiary of CMS Energy, delivers natural gas and/or electricity to 6.7 million out of Michigan's 10 million residents across all 68 Lower Peninsula counties.

The Michigan-based power company bolsters state's energy capacity with 1,200 MW natural gas facility.

Covert Generating Station Joins Consumers Energy's Operational Fleet 

TPM, a provider of design and manufacturing solutions, has inaugurated its additive manufacturing lab in Greenville, South Carolina. This facility aims to be a regional showcase for additive and 3D printing technology and supply outsourced 3D printed parts throughout the Southeast, which helps promote the expansion of the industry.

Caption: TPM's Additive Manufacturing Lab in Greenville, SC. Credit: TPM.

The lab is outfitted with technology from manufacturers like Markforged, HP, 3D Systems, Artec 3D, and AMT. These components can help in increasing TPM's ability to offer services characterized by precision, quality, and efficiency.

"The establishment of our advanced additive lab represents a significant stride in TPM's growth strategy in the Southeastern manufacturing industry, providing the latest technology solutions to our clients," stated Chris Fay, President of TPM. 

This launch strengthens the region's manufacturing capabilities by offering local manufacturers the tools needed for rapid innovation, cost reduction, and faster product market entry.

The decision to create the additive manufacturing lab is a response to the escalating demand for 3D printing in the manufacturing industry, reflecting TPM's belief in additive manufacturing's transformative potential and its influence on future production methods.

This launch comes at a time when manufacturers are increasingly investigating new methods to improve their processes, enhance product quality, and retain a competitive advantage.

TPM aims to boost regional manufacturing through the demonstration of 3D printing technology and printed parts.

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