Mitsubishi Heavy Industries Technical Review Vol. 60 No. 3 (September 2023)
1“Hydrogen Park Takasago” and“Carbon Neutral Park Nagasaki”
Initiative to Create Decarbonized WorldJUNICHIRO MASADA*1

MASASHI TERAUCHI*2

HIROMI ISHII*3

KAZUHIRO DOMOTO*4YASUHARU CHUMAN*5 KENICHIRO KOSAKA*6

Gas turbine combined cycle (GTCC) and steam power generation systems are among the main
products of Mitsubishi Heavy Industries, Ltd. (MHI). Looking at the accelerating global trend ofenergy transition, there is an urgent need to make these products carbon neutrality as well. The
development of the key decarbonization technologies for thermal power generation is carried out in
the Takasago and Nagasaki districts in Japan where our corporate machinery works andlaboratories are located. In the former district’s Hydrogen Park Takasago, we are working on thecreation of an environment for long-term integrated demonstration of elemental technologies under
actual operation conditions. On the other hand, the latter district, the Carbon Neutral Park
Nagasaki, functions as the important area of our elemental technology development activities. This
report introduces these parks, together with the summary of the technologies being developed thereinsuch as hydrogen production.

|1. Introduction
Addressing the issues of global warming is critical for the world. In October 2020, the Japanese
government announced its intention of achieving carbon neutrality by reducing greenhouse gas
emissions to net zero by 2050. The term “reducing emissions to net zero” means that the total amountof greenhouse gases including carbon dioxide (CO2) becomes practically zero, when calculating theamount of “their (artificial) emissions” minus the amount of “their (artificial) absorption” throughmeans such as afforestation and forest management, etc. To achieve such carbon neutrality, it isindispensable to significantly expand the use of renewable energy. Simultaneously, it is also
important to maintain economic efficiency and stable energy supply. MHI aims to achieve a carbonneutral society in a realistic and speedy manner, while minimizing social costs by promoting energy
transition of existing thermal power generation facilities.
Renewable energies such as solar and wind greatly contribute to the achievement of a carbon
neutral society. However, because of their weather-dependent nature, the output is quite variable,
making it difficult to respond to the demand that changes every minute. As a means of absorbing
such variability and dealing with the changing demand, natural gas-fired GTCCs, which emit theleast amount of CO2 among thermal power generation systems, are high in flexibility and reliability
and are therefore expected to remain an important power source. Furthermore, by blending natural
gas fuel with hydrogen and eventually substituting it with hydrogen or ammonia, neither of whichemits CO2, it becomes possible to ensure power grid stability and, at the same time, significantly
reduce CO2 emissions from thermal power plants.

*1

Vice President, Energy Systems, Mitsubishi Heavy Industries, Ltd.

*2

Director, Hydrogen Technology Promotion Department, GTCC Business Division, Energy Systems, Mitsubishi Heavy*3

General Manager, Project Engineering Department, Steam Power Maintenance Innovation Business Division, Energy Systems,*4

Senior Engineer, Business Planning Department, Steam Power Maintenance Innovation Business Division, Energy Systems,*5

Senior Researcher, Research & Innovation Center, Mitsubishi Heavy Industries, Ltd.

*6

Chief Engineer, Senior Manager, Technology Strategy Department, Energy Systems, Mitsubishi Heavy Industries, Ltd.

Industries, Ltd.
Mitsubishi Heavy Industries, Ltd.
Mitsubishi Heavy Industries, Ltd.

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Figure 1 shows the background for hydrogen/ammonia utilization. When looking worldwide,
the use of renewable energies such as solar and wind is getting increasingly widespread. As thesepower sources fluctuate greatly with time, weather and season, the expansion of their use requires
the introduction of energy storage technologies. The left side of Figure 1 shows the gains/losses ofenergy storage technologies in terms of the number of electrical discharges and discharge hours per
year. For short-time storage, lithium batteries are advantageous. However, for several-day storage or
dozens of times of discharges per year, conversion to chemical energy such as hydrogen has anadvantage.
The right side of Figure 1 shows the regional characteristics of renewable energy endowment.
The use of renewable energies is expected to further progress in many regions of the world, thus
enabling water electrolysis to be powered by surplus renewable electricity and this type of hydrogenproduct will be used more widely. On the other hand, in regions that are not rich in renewable energy
resources such as Japan and South Korea, the application of ammonia with a high transportation
efficiency will progress. There are also high expectations for turquoise hydrogen, which is producedby pyrolysis of methane to hydrogen and solid carbon, using existing LNG infrastructure. In theregions that have become unavoidably dependent on inexpensive fossil fuel resources such as
Southeast Asia, turquoise hydrogen is also drawing attention, because the introduction of carbon
capture utilization and storage (CCUS) entails issues such as cost. Therefore, the decarbonization
technologies that can meet these respective needs should be urgently verified and implemented insociety.
This report provides an overview of the progress in the development of hydrogen-fired gas
turbines at the Hydrogen Park Takasago, and describes the development of decarbonization
technologies including hydrogen production at the Carbon Neutral Park Nagasaki.

Figure 1

Background for hydrogen and ammonia utilization|2. MHI’s road map for zero-emission power generation
MHI Group has declared “MISSION NET ZERO”, we aim to achieve carbon neutrality by
2040. We offer products and technologies that enable customers to achieve carbon neutrality viable
by 2050. Our major undertakings include the energy transition for low-carbonization anddecarbonization of businesses/products, and the expansion of CCUS business including CO2 capture.
Among these, this report focuses on those in relation to power producers and industrial applications.
The more specific goals that MHI’s Energy Systems has set for itself toward carbon neutrality
by 2040 are as follows: “energy transition of thermal power generation”, “efficient utilization ofindustrial energy” and “establishment of a hydrogen value chain”. Extremely important among theseis the promotion of carbon neutrality in thermal power generation by switching to non-fossil fuels.
Figure 2 shows the roadmap for the development of power generation technologies.

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Thermal power generation can be mainly divided into two types: steam power generation and
GTCC. The mainstream of the former is the coal-fired thermal power generation system consistingof the boiler and the turbine, in which CO2 reduction is under way through the already-establishedtechnology of high-ratio biomass co-firing. Further reduction of CO2 emissions will be attempted byco-firing ammonia and increasing ammonia co-firing rate, the technology for which is being rapidly
developed and demonstrated. The co-firing ratio of ammonia is expected to increase at later stages.
Moreover, if coal-fired thermal power plants are replaced by high-efficiency GTCCs, CO2 emissions
can be reduced by about 65%. Even so, these thermal power generation systems are still in need ofachieving further reduction of CO2 emissions, which will be tried by co-firing hydrogen or ammonia.
Our goal will be about a 90% reduction by CO2 capture, and eventual zero emissions by single-fuelfiring of non-fossil fuel such as hydrogen and ammonia.

Figure 2

Road map for development of power generation technologies|3. Development status of hydrogen-fired gas turbines
Gas turbines, which are our flagship products, are being developed to meet European CO2emission standards – the strictest in the world. Figure 3 gives the timeline and schedule of gas turbine
development, together with the European CO2 emission standards. Shown on the left side of the
figure is the development status of hydrogen-fired gas turbines. For large gas turbines, with a viewto making the co-firing system available commercially in 2025, a combustion test using a
conventional combustor was performed, and stable combustion at the hydrogen co-firing ratio of
50% was confirmed. This indicates that the EU taxonomy’s CO2 emission standard of 270 g/kWh
has been satisfied. We will develop a new combustor to realize 100% hydrogen firing in large gas
turbines in 2030.
When it comes to the technological development for use of decarbonized fuel (such ashydrogen and ammonia) in small and medium-sized gas turbines, we have succeeded in testing 100%hydrogen firing in the combustor alone in 2022. The demonstration of these combustion technologies
will be started this year at the Hydrogen Park Takasago, which is a full-scale power generation
facility.
Furthermore, at the Hydrogen Park Takasago, the demonstration tests on our hydrogenproduction technologies under development will also be started one by one using the actual units,
including alkaline water electrolysis, our originally developed solid oxide electrolysis cell (SOEC)
and turquoise hydrogen by methane pyrolysis.
Figure 4 is a road map for ammonia power generation technology. As in the case of hydrogen,ammonia is expected to be a clean fuel that emits no CO2 when burned. Furthermore, while gaseoushydrogen needs to be cooled to -253°C for liquefaction, ammonia can be transported as a liquid at 33.4°C. It is therefore expected to serve as a hydrogen carrier and energy source suitable fortransportation and storage. With regard to 100% firing of ammonia in gas turbines, a combustor is indevelopment with a view to conducting the demonstration test in 2025 or after. As for boilers, ourMitsubishi Heavy Industries Technical Review Vol. 60 No. 3 (September 2023)
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plan is to conduct a demonstration test using the actual facility for co-firing of 50% or higher in thelatter half of 2020.

Figure 3

European CO2 emission standards and schedule for gas turbine development

Figure 4

Road map for ammonia power generation technology|4. “Hydrogen Park Takasago” for demonstration of hydrogen power
generation
Toward early commercialization of hydrogen gas turbines with hydrogen fuel, the Hydrogen
Park Takasago is under construction to make it possible to perform the world’s first integrated
technological validation from hydrogen production to power generation on the premises of Takasago
Machinery Works, which is our base for development, design, manufacturing and demonstration.
Partial operation started in the Hydrogen Park Takasago in May 2023; preparation for full-scale
operation is under way.
Besides the adoption of water electrolyzers, the next-generation hydrogen production
technologies such as the production of turquoise hydrogen by pyrolysis of methane to hydrogen andsolid carbon are planned to be tested and verified one by one. Overall concept of Hydrogen Park
Takasago and its major facilities are shown in Figure 5. Regarding the gas turbine facility, the smalland-medium H-25 unit and the large M501JAC unit are already in operation. With the alkaline
electrolyzer having been installed this spring, the installation of other facilities such as SOEC will
start.

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Figure 5Overall concept of Hydrogen Park Takasago

Figure 6 is a configuration diagram of the Hydrogen Park Takasago. For hydrogen production,
the electrolyzer is expected to be used for water or steam electrolysis with renewable energy, while
the methane pyrolysis system involves thermal decomposition of natural gas (methane). Electrolytichydrogen and turquoise hydrogen produced respectively are stored in the hydrogen storage facility.
The stored hydrogen is used as fuel in the demonstration test facilities to generate electricity, whichis then fed into the local power grid. The Hydrogen Park Takasago is not only a facility to conduct
the integrated demonstration from hydrogen production to hydrogen power generation, but is also
intended to become a facility by which the integrated demonstration of advanced energy management
can be performed. Specifically, it means that, by combining with the secondary battery-based power
storage system, surplus power is stored with electrolytic hydrogen and second batteries, andelectricity can be supplied from the hydrogen gas turbines and the secondary batteries, when demandis high.

Figure 6

Configuration diagram of Hydrogen Park Takasago

Figure 7 is the latest construction status of the Hydrogen Park Takasago (taken in May 2023).
With the installation of the hydrogen storage facility completed, the operation has partially started in
the facility. The use of this demonstration facility is expected to greatly contribute to the widespread
introduction of hydrogen and the implementation of hydrogen power generation into society.
Figure 8 shows an example of hydrogen projects in which we are taking part. The Advanced
Clean Energy Storage is a US project to realize hydrogen production, storage and utilization, forwhich the demonstration test of a water electrolyzer will be conducted at the Hydrogen Park
Takasago before being introduced to the actual units. As renewable sources of energy have been
widely introduced in western US, there is a surplus of renewable electricity during spring when the
demand is low. This project aims to level out the supply and demand of power across seasons, byutilizing the renewable electricity surplus.
Renewable electricity from the grid is used to produce green hydrogen by electrolysis. The
produced hydrogen is stored as a gas in the underground rock salt cavern. The hydrogen is then sent

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in the pipeline to the power generation plant where it fuels our 840-MW hydrogen-fired GTCC. This
GTCC power plant is planned to start operation with 30% co-firing of green hydrogen in 2025, andgradually increase the hydrogen ratio until finally reaching 100% by 2024.

Figure 7

Construction status of Hydrogen Park Takasago(taken in May 2023)

Figure 8

Example of hydrogen storage and gas turbine project in US|5. “Carbon Neutral Park Nagasaki” – main area of key technology
development
In the Nagasaki District (the Nagasaki Shipyard & Machinery Works, and the Research andInnovation Center), the departments of design, manufacturing and development are united in working
toward realizing the practical application of the latest product technologies for decarbonization. This
district is called “Carbon Neutral Park Nagasaki” as shown in Figure 9, focuses on the developmentof key technologies to be tested for demonstration in the Takasago District. The Research andInnovation Center in Nagasaki, as shown in Figure 10, especially has the facilities for thedevelopment of key technologies that are closely related to the energy transition strategy of MHI
Energy Systems. It has become the icon of aforementioned “Carbon Neutral Park Nagasaki”.

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Figure 9

Carbon Neural Park Nagasaki

Figure 10 Our base for technological development at Carbon Neutral Park Nagasaki(Research and Innovation Center in Nagasaki)

The ongoing projects at the laboratories of the Research and Innovation Center in Nagasaki
include the hydrogen production technologies such as turquoise hydrogen, SOEC and anion
exchange membrane (AEM), the ammonia combustion technology for gas turbines, boilers andengines, and the production of sustainable aviation fuel (SAF) from biomass. The underlying
technologies for CO2 capture are also in development here.
Figure 11 shows some of the evaluation facilities related to hydrogen production. Methaneand hydrogen can be readily used in the test environments created by these facilities, thanks to past
projects such as long-term development of solid oxide fuel cell (SOFC). As the needs of society
rapidly increase, more facilities become usable for carbon neutral technologies. Combustion testing,whose main test fuel was natural gas or coal, is now likewise able to be conducted for carbon neutral
technologies, because an ammonia supply system has been installed while taking safety into
consideration.

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Figure 11

SOEC and turquoise H2 test facilities|6. Development of elemental technologies at Carbon Neutral Park
NagasakiThis chapter presents some of the developments in carbon neutral technology related to MHI
Energy Systems.
(1) Turquoise hydrogen production technology
Turquoise hydrogen is produced using the pyrolysis reaction of methane, which is atechnology of decomposing methane (one of the major components of natural gas) into solidcarbon and hydrogen at a high temperature. It has conventionally been used to produce carbon
materials such as carbon black for industrial application. Focusing on this by-product hydrogen,we found a reaction mechanism that enables efficient production of hydrogen.
Figure 12 summarizes the technology for turquoise hydrogen production and roughdevelopment road map. As the natural gas infrastructure has already been established, there aremany natural gas-fired thermal power plants. These existing thermal power plants can achieve a
considerable degree of low-carbonization or even decarbonization (zero CO2 emissions), simply
by replacing the gas turbine combustor with one for hydrogen firing in addition to the installationof a turquoise hydrogen plant between the supply line of natural gas infrastructure and the thermal
power plant, or upstream of the power generation facilities of other natural gas power producers.
As the by-product carbon is solid, it is easier to perform fixation and storage than for CO2, whichis gaseous at normal pressure and temperature. The element testing is under way to take it to thenext step of verifying the developed technologies at the Hydrogen Park Takasago.

Figure 12

Turquoise hydrogen development status

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Hydrogen production technology using SOECSOEC is considered to be suitable for application to large-scale plants, because of its
applicability for SOFC (which we already developed), advantageously high efficiency andrelevance to our experience in high-pressure SOFC. Figure 13 provides an outline of the SOEC
development. Currently, we are determining the suitable SOEC operation conditions and are
improving the specifications. As shown in the figure, we plan to start verifying the developed
technologies using a several-hundred-kW-class SOEC module in 2024.

Figure 13

SOEC development status

Figure 14 shows our plan for SOEC development. In past projects, we developed andmass-produced SOFCs in which the reaction occurs backward, and combined many of these cells
together to build a 200-kW-class module. Through further combining with high-temperature andhigh-pressure steam/gas handling technology in steam power generation, we aim for a large
SOEC plant.

Figure 14(3)

SOEC development plan

Hydrogen production technology by AEM water electrolysis
The widely used electrolysis technology using a solid polymer electrolyte membrane isproton exchange membrane (PEM) water electrolysis using a hydrogen ion permeable
membrane. When compared with the widely used alkaline electrolysis, PEM water electrolysis
can be operated at higher current density with a smaller electrolytic cell. However, as the PEM
containing many hydrogen ions is highly acidic, noble metals and Ti-based materials need to beextensively used for the adjacent catalysts and other liquid contact parts. It is also necessary to
prevent impurities in the feed water from causing performance degradation, by controlling thepurity by removing metal ions. When it comes to AEM water electrolysis, however, high current
density operation similar to PEM water electrolysis is possible. It can also be expected to have
low cost, because the electrolysis can take place in an alkaline aqueous solution in whichmaterials such as stainless steel are usable.

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Figure 15 shows the development status of AEM water electrolysis. At present, whileobserving properties using small element cells, we have prototyped a stack with an electrode areaof several hundred cm2, determining the appropriate manufacturing process and optimizing theoperation conditions. As indicated by the results of the evaluation using small element cells, amarked increase in current density can be expected, when compared with alkaline waterelectrolysis in general. Further proceeding with the development as shown in Figure 16, we willconduct a demonstration test on a several-MW-class unit at the Hydrogen Park Takasago before
applying it to the commercial units.

Figure 15

Development status of AEM water electrolysis

Figure 16

Road map for AEM water electrolysis(4)

SAF production technology by biomass gasification
SAF is an alternative aircraft fuel made from sustainable material such as biomass, whose
introduction is under consideration to reduce CO2 emissions. We have worked on the productionof liquid fuel from biomass since around 2000. The production of SAF by biomass gasification
was commenced in 2012. Under the sponsorship of the New Energy and Industrial Technology
Development Organization (NEDO), a pilot plant was operated from 2016 to 2020 in cooperation
with JERA Co., Inc., Toyo Engineering Corporation, and Japan Aerospace Exploration Agency(JAXA). The SAF produced at the pilot plant, which was built on the premises of JERA Co.,
Inc.’s Shin-Nagoya Thermal Power Station, was used in commercial flights by Japan Airlines
Co., Ltd. in June 2021. Figure 17 shows the situation in the development. In addition to scaling
up for commercialization, we are working to improve SAF production by adding further value.
This result was obtained as a result of the consignment business (JPNP17005) of NEDO.

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Figure 17

Technology of SAF production by biomass gasification(5) Ammonia co-firing technology in coal-fired boilers
With regard to the use of ammonia in boiler/turbine plants, we are developing a burner thatenables high-ratio co-firing of ammonia in pulverized coal-fired boilers. When compared withhydrocarbon fuels such as LPG, ammonia burns at a slower rate making it difficult to maintainthe flame in the burner. Another issue is that, because of its high nitrogen (N) content, ammonia
generates a large amount of NOx if the fuel concentration during combustion is not appropriate.
In 2021, a small combustion test furnace was used to conduct the testing for co-firing andsingle-fuel firing of ammonia. It was conducted on multiple burner types, based on our
accumulated experience in burner design for various fuels and the results of basic combustion
tests, with a view to providing burners for ammonia single-fuel firing in commercial andindustrial boilers in Japan and overseas. While confirming that the flame was extremely stable
during combustion, we also verified that NOx emissions were in line with the results of the basic
combustion tests carried out in advance, and that there was no residual ammonia. With the aimof co-firing ammonia at a higher ratio, we are working to develop and demonstrate high-ratio cofiring of ammonia in coal-fired boilers as part of NEDO’s Green Innovation Fund Project/FuelAmmonia Supply Chain Establishment. As shown in Figure 18, we plan to develop a burner forammonia single-fuel firing through combustion tests using a full-scale burner by 2024. Figure 18(b) is an exterior view of our 0.5 t/h furnace with which we started the combustion testing, while
Figure 18 (c) is the ammonia supply facility introduced in a project commissioned by NEDO.
Together with JERA Co., Inc., we are also formulating a basic facility plan to demonstrate anammonia co-fired boiler in an actual unit, and are conducting a feasibility study. During thisdemonstration operation in an actual unit, we will verify 50% or more ammonia co-firing withtwo different firing systems (circular and opposed firing).
Figure 18 (c) is the ammonia supply facility introduced in a project commissioned by
NEDO. Together with JERA Co., Inc., we are also making the basic facility plan for
demonstration of an ammonia co-fired boiler in an actual unit and are conducting the feasibility
study. During this demonstration operation in an actual unit, we will verify 50% or moreammonia co-firing with two different firing systems (circular firing and opposed firing).
The development described in this section is being carried out as part of NEDO’s “JPNP
21020 Green Innovation Fund Projects: Fuel Ammonia Supply Chain Establishment /High-ratio
co-firing and single-fuel firing needed for ammonia power generation/ Development anddemonstration of high-ratio ammonia co-firing technology (including single-fuel firing
technology) in coal-fired boilers/Demonstration project of high-ratio ammonia co-firing in thecommercial coal-fired power plants utilizing ammonia single-fuel burners”.

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Figure 18 Overview of development of high-ratio ammonia co-firing
technology funded by Green Innovation Fund

|7. Conclusion
Centering on the technologies to be demonstrated at the Hydrogen Park Takasago whose
operation partially started in the park in 2023, this report presents our initiatives toward achievingcarbon neutrality in the thermal power generation industry. While these technologies have yet to beverified, the development of MHI’s elemental technologies at the Carbon Neutral Park Nagasaki wassummarized.
Making use of the technologies for energy transition in this report, we contribute to theachievement of a carbon-neutral society, while aiming to fulfil MHI Group’s declared “MISSIONNET ZERO” for 2040.
“Hydrogen is Not the Future, This is Real.”