The U.S. government has set out to fast-track technology development enabling hydrogen and ammonia combustion in power-generating gas turbines, furnishing six novel industry-led projects with a combined $24.9 million on May 19. Projects include development of hydrogen-ready combustion technologies for F-class retrofits, more efficient hydrogen and ammonia burners, and a potential demonstration of a rotating detonation combustor.
The funding is offered by the Department of Energy’s (DOE’s) Office of Fossil Energy and Carbon Management (FECM) to four entities—8 Rivers Capital, General Electric (GE), Raytheon Technologies Research Center, and the Gas Technology Institute (GTI). It seeks to “make hydrogen a more available and effective fuel” for power generation, the DOE said. The six projects will receive funding under Funding Opportunity Announcement (FOA) 2400: “Fossil Energy Based Production, Storage, Transport and Utilization of Hydrogen Approaching Net-Zero or Net-Negative Carbon Emissions,” a measure the agency rolled out in January 2021 that will dedicate up to $160 million to “help recalibrate the nation’s vast fossil-fuel and power infrastructure for decarbonized energy and commodity production.”
8 Rivers Developing Innovative 8RH2 Hydrogen Production Plant
The six projects the DOE chose represent an interesting array of technology applications.
North Carolina–based 8 Rivers Capital notably snagged $1.4 million in DOE funding to complete a pre-front-end engineering design study for a new hydrogen production plant equipped with its proprietary 8RH2 technology. 8 Rivers, a company whose development portfolio includes the Allam-Fetvedt Cycle (it partly owns NET Power, developer of supercritical carbon dioxide power plants), is spearheading several industrial decarbonization technologies, including the TarT sour-gas treatment system and net-zero solutions for steel production, direct air capture, and point-source carbon capture.
Its 8HR2 is a process that essentially reforms natural gas with natural gas and pure oxygen, combined with cryogenic CO2 capture. “It generates hydrogen at high pressure while capturing CO2 using a proprietary refrigeration-based CO2 separation system,” the company says. “This is cheaper and cleaner than traditional steam methane reforming approaches that also release all their carbon dioxide.”
8 Rivers says the technology uses commercially available equipment, making it ready for large-scale deployment today. “Full-scale projects using this combined reforming system are under development today,” it adds. One example is Pilot Energy’s May 19–commenced Mid West Integrated Renewables and Hydrogen Project in Western Australia, which is looking at incorporating 8HR2 to produce “blue hydrogen” to produce hydrogen at a cost of A$2/kg and potentially expand it to green ammonia for export.
DOE funding materials suggest 8RH2 can “cost-effectively” produce 100 million standard cubic feet per day of 99.97% pure hydrogen and capture 90.99% of CO2 emissions. The DOE-funded work will involve a study that will evaluate three design cases that will implement “varying processes” of the 8RH2 equipment and a CO2 separation unit. An estimated 600,000 tonnes/year of CO2 captured from the project is slated to be transported and stored at Painter Reservoir Gas Complex in Evanston, Wyoming, while the project’s hydrogen product will be converted to ammonia for rail export to California.
GE Developing Retrofittable H2-Ready F-Class Combustor Module, Rotating Detonation Combustor
GE, which kicked off hydrogen combustion technology development decades ago with support from the DOE’s High Hydrogen Turbine Program, will develop and test a retrofittable F-Class-staged combustor module with natural gas/hydrogen fuel mixtures ranging from 100% natural gas to levels of up to 100% hydrogen. The $12 million project ($6 million of which the DOE will fund) will be based on micromixer (MM) and axial fuel staging (AFS) technologies that are currently featured in GE’s DLN2.6e high-efficiency air-cooled combustion system.
GE, which in the 1990s pioneered the lean premix combustion system known as Dry Low NOx (DLN), has refined the technology and released advancements, including the DLN2.6+ combustion system for new and existing F-class gas turbines in 2015. DLN2.5e technology is already currently installed in GE’s larger 9HA machines, but its newest model, the 7HA.03 will introduce the technology for the first time on a 60-Hz machine later this year.
“The project will optimize the combustor, enabling operation in two or more ‘mixed’ modes to account for the dramatic changes in combustion behavior at higher hydrogen concentrations,” the DOE said on Thursday. “A combustor module will be sized specifically for retrofit on F-class engines and will test full-scale MM/AFS concepts at relevant conditions,” it added. Results will allow GE “to accelerate future full-scale pre-commercial F-class testing on hydrogen fuels and position these technologies for retrofit into the F-class installed fleet,” it said.
GE is currently slated to pilot an F-class dual-fuel gas and hydrogen plant at EnergyAustralia’s 316-MW Tallawarra B Power Station in New South Wales (NSW), Australia. As POWER has reported, that much-watched project will demonstrate what the next-generation DLN will bring to the F-class portfolio. The DOE project would provide another significant solution as a retrofit for F-class machines, which GE first put online in 1991. GE says it today has more than 1,100 installed units, which represents the world’s largest fleet of F-class gas turbines.
However, in a separate $8.7 million project, GE and GE Research will leverage $7 million in DOE funding to develop, design, fabricate, and demonstrate the operation of a rotating detonation combustor (RDC) “to substantially improve gas turbine efficiency for both simple- and combined-cycle power generation applications,” the DOE said.
According to experts, RDCs are at the forefront of pressure gain combustion (PGC) research, utilizing one or more “azimuthally spinning” detonation waves to effect a stagnation pressure rise across the device. “Internal combustion engines such as gas turbines are effective, but they suffer pressure and power output limitations. Rotating detonating engines create controlled, continuous detonation waves that rotate inside a modified gas turbine combustion chamber,” explains the National Energy Technology Laboratory. “This allows the engines to be able to avoid pressure losses and the subsequent decreases in efficiency that occur with conventional gas turbine engines. The rotating detonation process enables more of a fuel’s energy to be captured and utilized, resulting in higher power output, less fuel consumption, a smaller industrial footprint, and reduced environmental impact.”
GE’s DOE-funded RDC project has three goals. First, it will demonstrate the feasibility and operability of hydrogen-fueled or hydrogen-enriched RDC at 7FA cycle conditions. It will also develop “a low-loss thermal-steady-state RDC” and demonstrate at the 7FA cycle. Finally, it will “integrate the low-loss thermal-steady-state RDC with turbomachinery components at upstream and downstream locations to demonstrate the system at 7FA cycle conditions.” Project success “will achieve the final step in applying an RDC in an actual gas turbine for power generation,” the DOE said.
Research Groups GTI and Raytheon Spearheading Ammonia Combustion Projects
GTI, meanwhile, will get $3 million in DOE funding for its $4.2 million “investigation of ammonia combustion for turbines.” The project involves validating a technical foundation for ammonia-fueled gas turbines. The team is set to establish “the foundational aspects of the physics of combustion of ammonia and ammonia-hydrogen mixtures through literature search, analyses, modeling, and experiments under gas turbine operating conditions.”
GTI expects to use the resulting modeling data to design one or more gas turbine combustor prototypes, as well as complete fabrication and testing to confirm and validate combustion system performance and emissions estimates. “Results could provide supporting data, guidelines, and design support tools for use by the original gas turbine equipment manufacturers for subsequent combustor component development and gas turbine integration,” the DOE said.
Raytheon Technologies Research Center in East Hartford, Connecticut will separately leverage $3 million in DOE funding for its $3.7 million project to develop and demonstrate an ammonia combustor for power-generating turbines. A key aim of the project is to develop an ammonia combustor that can provide low nitrous oxide (NOx) emissions yet provide “robust operability and stability for greater than 99.99% combustion efficiency.” The DOE-funded project involves generating fundamental and engineering data for ammonia combustion at gas-turbine-relevant conditions and apply this learning to the low-NOx combustion of ammonia.
In another $5.6 million project for which Raytheon Technologies Research Center garnered $4.5 million in federal funding, the technology center will develop a retrofittable combustor module for the FT4000 aeroderivative power generation gas turbine engine “to enable efficient operation” using hydrogen as a fuel source. The FT4000 is a relatively new aeroderivative industrial gas turbine model developed by Pratt & Whitney. It is now marketed by Mitsubishi Power Aero.
Raytheon is expected to advance the FT4000 combustor components for operation with hydrogen, “starting with an experimental assessment of the current hardware with increasing hydrogen content in natural gas, and ending with 100% hydrogen at full baseload temperature and pressure conditions.” Design elements that will help separate the flame from the burner surface or provide sufficient cooling for full life operation will be tested in high-temperature rigs to evaluate their effectiveness.
U.S. Gas Technology Backing Echoes Measures by Other Governments
The DOE’s backing of these technologies is significant given recent efforts by several other countries to make hydrogen and ammonia power part of their generation portfolios.
Japan, notably, wants to use 0.3 million tons (Mt)/year of hydrogen—for up to 1 GW of hydrogen-fired power capacity—and 3 Mt/year of ammonia in the power sector by 2030. Japan in January furnished $500 million to several projects that will develop and demonstrate 100% fuel ammonia combustion technology for gas turbines and 50% co-firing at coal boilers. South Korea, which has a target of 1.5 GW installed fuel cell capacity in the power sector by 2022 and of 15 GW by 2040, is backing industry efforts to demonstrate hydrogen and ammonia-capable gas turbines. The European Union, which this week published its REPowerEU Plan response to global energy market disruptions prompted by Russia’s invasion of Ukraine, is mulling legislative proposals to decarbonize gas markets. Recent EU taxonomy regulation also targets power generation from unabated gas.
Along with GE, several original equipment manufacturers (OEMs) worldwide are looking to “future-proof” their technology portfolios, and many have already developed turbines and engines that can combust 100% hydrogen by volume. Some OEMs are now also developing gas turbines that can be fired with ammonia.
Bolstered by Japan’s roadmap for ammonia fuel, Mitsubishi Power, for example, is developing a 40-MW class gas turbine that could directly combust 100% ammonia, while Japanese firm IHI Corp. has demonstrated ammonia co-firing on a 2-MW aeroderivative gas turbine. Doosan Enerbility (formerly Doosan Heavy Industries & Construction), meanwhile, is actively working with a South Korean power generator to commercialize gas turbines that can run on ammonia extracted from hydrogen. Several companies around the world have also recently announced plans to convert large-scale plants for hydrogen or ammonia co-firing or operate dedicated hydrogen-fired power plants.
In the U.S., where a regulatory conversation about the impact of greenhouse gas (GHGs) emissions from stationary combustion turbines is emerging, funding priorities at the DOE are being driven by President Biden’s goal of having a zero-carbon American power sector by 2035, which is one reason for the agency’s fast-track focus. “Across the Department, we’re working to make clean energy sources—like hydrogen—more affordable and accessible to help decarbonize America’s electrical grid and directly combatting climate change,” U.S. Energy Secretary Jennifer Granholm said on Thursday.
The DOE’s support of hydrogen combustion, however, is nuanced. Hydrogen power may be directly considered a “clean fuel” if combined with oxygen in a fuel cell, it says, but combustion in a gas turbine isn’t necessarily pollutant-free. However, hydrogen “can be produced through a variety of low-carbon pathways, including domestic resources like natural gas and waste coal, coupled with carbon capture and storage; biomass; and renewable energy sources like solar and wind,” the agency said. “These qualities make it an attractive fuel option for electricity generation and industrial applications, such as in buildings and manufacturing.”
—Sonal Patel is a POWER senior associate editor (@sonalcpatel, @POWERmagazine).