Japan Is Capturing CO2 Straight From a Coal Plant's Exhaust
Japan Is Capturing CO2 Straight From a Coal Plant's Exhaust
Japan is moving carbon capture from the laboratory into the smokestack, testing systems designed to pull carbon dioxide directly from the exhaust gases of coal-fired power plants. At Kansai Electric Power's Maizuru Power Station, Kawasaki Heavy Industries is testing equipment that separates CO₂ from flue gas before it reaches the atmosphere, while other Japanese utilities are preparing larger-scale projects aimed at eventually connecting captured carbon with transportation and underground storage.
Rather than replacing every coal plant immediately, the approach seeks to capture a large portion of the CO₂ produced during combustion and then transport it for utilization or permanent geological storage.
Japan's Coal Plants Are Becoming Carbon-Capture Testbeds
One of the most closely watched projects is at the Maizuru Power Station in Kyoto Prefecture, operated by Kansai Electric Power.
Kawasaki Heavy Industries has installed specialized carbon-capture equipment at the coal-fired facility and has begun intermittent testing. The system is designed to separate CO₂ from the plant's exhaust gas, creating a concentrated carbon stream that can subsequently be transported and potentially stored underground.
The project is significant because it moves carbon capture into actual coal-plant operating conditions. Capturing CO₂ from combustion exhaust is technically different from removing carbon dioxide from a concentrated industrial process stream because the exhaust contains a mixture of gases that must be treated before the CO₂ can be separated.
Japan sees this type of technology as one component of its wider CCUS strategy.
How CO2 Is Pulled From the Exhaust
The basic concept is relatively straightforward.
Coal is burned to produce steam and electricity. The resulting flue gas contains CO₂ along with nitrogen, water vapor and other components. A capture system processes this exhaust and selectively removes the carbon dioxide.
Mitsubishi Heavy Industries, which has developed another major Japanese post-combustion capture technology, describes a process in which flue gas is cooled before entering an absorption tower. A solvent absorbs CO₂ from the gas, after which the solvent is heated in a regeneration tower to release the captured carbon dioxide.
Kawasaki Heavy Industries is taking a different approach at the Maizuru and Yokosuka projects. Its Kawasaki CO₂ Capture technology uses a solid sorbent to absorb CO₂ and low-temperature steam to release it. The company says waste heat can be used to generate the required steam, potentially lowering the energy requirements of capture.
That energy requirement is one of the biggest challenges facing carbon capture.
The Energy Penalty Is the Real Engineering Challenge
Capturing carbon is not simply a matter of attaching a filter to a smokestack.
The separation process requires equipment, heat, electricity, compression and additional infrastructure. A power plant therefore has to consume part of its energy output to operate the carbon-capture system.
This is why Japanese companies are focusing heavily on improving capture efficiency and reducing the amount of energy needed to regenerate solvents or sorbents.
Mitsubishi Heavy Industries says its Advanced KM CDR Process can capture more than 90% of the CO₂ in a target gas stream, while its newer solvent technologies are designed to reduce regeneration energy and solvent degradation.
The economics become particularly important when the technology is applied to large coal-fired units operating continuously.
Japan Is Building the Transport Link Too
Capturing CO₂ at the power plant is only the first stage.
The captured gas has to be compressed, liquefied or otherwise conditioned, temporarily stored and transported to a utilization site or geological storage location.
Japan is therefore developing an integrated CCUS supply chain rather than treating capture as a standalone technology.
J-POWER and Kyushu Electric Power, for example, are conducting front-end engineering design for shared CO₂ separation, capture, liquefaction, temporary storage and shipping facilities at coal-fired power stations in Matsuura, Nagasaki. The companies are targeting commercialization in the early 2030s and are studying facilities capable of handling approximately 1 million tonnes of liquefied CO₂ per year from each plant.
The scale shows where Japan ultimately wants the technology to go: from small demonstration equipment toward industrial-scale carbon-management infrastructure.
Maizuru Could Become Part of Japan's Offshore CCS Network
The Maizuru project is also important because Japan is preparing to move captured CO₂ beyond the power station itself.
Kansai Electric and Kawasaki Heavy Industries plan to develop experience in transporting captured CO₂ off-site, with the longer-term objective of connecting capture projects to underground storage projects. The initiative is expected to help establish the operational knowledge required for future CCS operations in locations such as Hokkaido.
This approach creates a new industrial chain:
Coal combustion → CO₂ capture → compression/liquefaction → transport → offshore storage
Japan has already been developing the transport and storage components of this chain. NEDO's CCUS program includes research into liquefied CO₂ transportation as well as geological storage beneath the seabed.
Yokosuka Is Another Major Demonstration
Japan's carbon-capture push is not limited to Maizuru.
JERA and Kawasaki Heavy Industries signed a memorandum of understanding in 2025 to study a CCUS value chain at JERA's Yokosuka Thermal Power Station in Kanagawa Prefecture.
The companies plan to conduct demonstration testing using Kawasaki's carbon-capture equipment at the coal-fired station by 2030. The project is intended to demonstrate the process from capturing CO₂ in power-plant exhaust through to its effective utilization.
The Yokosuka project is particularly notable because JERA describes it as the first planned test of CO₂ capture equipment at a coal-fired thermal power plant on Tokyo Bay.
Japan Is Betting on Carbon Capture Without Ignoring Coal Reduction
Japan's approach is more complicated than simply keeping coal plants running indefinitely with carbon capture.
JERA says it is simultaneously working to reduce the operation of inefficient coal-fired plants during periods of low demand and plans to decommission them entirely by fiscal 2030, while considering ammonia co-firing and CCUS for higher-efficiency plants.
That means carbon capture is being positioned as one part of a broader strategy involving renewables, thermal-power efficiency, alternative fuels and carbon storage.
For Japan, the argument is partly linked to energy security. The country relies heavily on imported energy and continues to use thermal generation to maintain electricity supply reliability.
Mitsubishi Heavy Industries Is Scaling Up Its Capture Equipment
Japan's carbon-capture equipment industry is also moving toward standardized systems.
Mitsubishi Heavy Industries announced in August 2026 that it had expanded its CO₂MPACT Full-Module product range with a new model capable of capturing up to 450,000 tonnes of CO₂ per year. Earlier models were designed for capacities of up to 70,000 tonnes per year.
The modular approach is intended to make carbon-capture installations easier to adapt to different industrial exhaust sources and potentially shorten project delivery times.
MHI's wider capture portfolio has already been deployed at commercial facilities around the world. The company says its KM CDR Process had been adopted at 18 commercial plants as of September 2024.
The Bigger Question Is What Happens to the Captured CO2
The most important part of Japan's strategy may not be the capture equipment itself.
Once CO₂ has been separated from the exhaust, it needs a destination.
Some projects can use carbon dioxide as a feedstock for chemicals, fuels or other products, but utilization markets are generally much smaller than the quantities emitted by large power stations.
For millions of tonnes of captured CO₂, permanent geological storage is therefore likely to be essential.
Japan has been studying offshore storage because the country's geography provides limited land availability for large-scale storage infrastructure. NEDO's existing Tomakomai demonstration has already involved injecting CO₂ into geological formations beneath the seabed at depths of approximately 1,000 metres or more.
This makes the emerging Japanese model more than a carbon-capture project. It is becoming a complete CO₂ management supply chain, linking power plants, capture technology, liquefaction facilities, shipping infrastructure and offshore storage.
Why the Coal-Plant Demonstrations Matter
The Maizuru and Yokosuka projects will help determine whether carbon capture can operate reliably on real coal-plant exhaust while keeping energy consumption and operating costs under control.
That matters beyond Japan.
If Japanese companies can demonstrate lower-energy capture systems, reliable operation and practical transportation and storage infrastructure, the technology could become relevant to other countries where coal and thermal power remain significant parts of the electricity system.
The challenge is now moving from “Can CO₂ be captured?” to “Can it be captured continuously, affordably and transported safely at million-tonne scale?”
Japan's latest projects are designed to answer exactly that question.
Sources:
Agar (E406)
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