Overview of CO2 Capture andStorage Technology;
An Introduction of MHI’s CO2
Recovery Process
MASAKI IIJIMA*1TORU TAKASHINA*2

KEIJI FUJIKAWA*2

TSUYOSHI OHISHI*1

Climate change is one of the most significant issues facing humanity and the global society needs to deploy immediate
countermeasures against the threat posed by global warming. Yet with the current global energy structure, there are no viable energy
alternatives to fossil fuels. Thus, CO2 capture and storage (CCS) is considered as a critical and indispensable countermeasure toreduce the potentially catastrophic environmental impacts associated with this phenomenon. To improve the economic viability of CO2capture, power producers will need to help facilitate the practical deployment of CO2 capture from coal-ﬁred power plants and thus
reduce the CO2 capture cost. Mitsubishi Heavy Industries, Ltd. (MHI) has realized the signiﬁcant and important role of CO2 capture
technology and is continuing research and development of effective countermeasure technologies against global warming.

further, conversely with CO2 emissions.
(2) Large amounts of energy are required for CO 2 captureand storage. The energy required for CO 2 capture andstorage is highest for coal-ﬁred power plants, due to thelarge CO 2 emission per kW of generated power and oneof the most important challenge will be to further reduce
this additional energy.
(3) Underground, geological storage of CO 2 is seen as
a n i mpor t a nt mea ns of reduci ng at mospher ic CO 2
concentrations well into the future. The values describedin Table 1 show the potential for underground of CO 2
according to the “Special Report on Carbon Dioxide1. Outline of CO 2 capture and storage(1) Extensive climatic simulations of global warming predicta geometric increase in the number of natural disasters
attributed to an average temperature rise of 2°C or more.
The average global air temperature is expected to riseby 2°C if the CO 2 concentration in the air rises from its
current level of 375 ppm to 450 - 475 ppm.
According to the “ Special Repor t on Ca rbon
Dioxide Capture and Storage” 1 produced by the IPCC
( Intergovernmental Panel on Climate Change), CO 2emissions from fossil fuel cannot effectively be reduced
without CCS from stationary sources. Some 13.5 billion
tons of CO 2 per year, about 60% of worldwide emissions,is generated from stationary sources (excluding thosesources which produce less than 100,000 tons per year).
Some 78% of the CO2 emission from stationary sources isgenerated from thermal power generation facilities, and
60% of this ﬁgure originates from coal-ﬁred power plants.
Coal reserves are widely distributed and source locations
are abundant. Furthermore coal is significantly cheaper
than oil and natural gas. For these reasons, the quantity ofcoal consumed for power generation is expected to increase

Fig. 1 Areas with potential for CO2 underground storage

Table 1 Potential amount of underground CO2 storage
Storage geological formations

Low CO2 storage potential(GtCO2)High CO2 storage potential(GtCO2)

Oil and gas fields
Coal bed that cannot be excavatedDeep saline water aquifer

675*
3 - 15
1000

900*
200
104

Note * If a new oil and gas field is found, this value is expected to increase by 25%.

*1 Plant and Transportation Systems Engineering & Construction Center*2 Hiroshima Research & Development Center, Technical Headquarters

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Technical Review Vol. 45 No. 1 (Mar. 2008)

Capture and Storage” published by the IPCC. The CO 2
emitted from stationary sources can be captured andstored for an additional 100 years, or longer, if deep
saline aquifers are included in this assessment. If weconsider the geographical pairing bet ween the CO 2emission source and storage location, aquifers in Europeand America can serve as sufﬁcient, long term, sites for
CO 2 storage (see Fig. 1). Japan, however, has limited
storage potential due to the geological instability of theregion. The experience with CO 2 capture and storage
is now expanding with several commercial scale CCS
projects underway. These include; Sleipner (Norway),Snohvit ( Nor way), In Salah (A lgeria) and Weyburn(Canada).

such as storage potential sur veys, further definition
and regulatory certainty relating to relevant laws andordinances, international rules, and social acceptance ofCCS.
In the United States, a partnership in seven districts
f unded w it h g ra nts f rom t he DOE ( Depa r t ment ofEnergy) has led to the commencement of CO 2 -injection
experiments at a range of sites. More incentives, such asthese, to promote the CO 2 capture and storage concept
will be necessary in the future. Currently the revenue
generating activity of EOR is expected to facilitate someearly stage opportunities for CCS in key oil producing
regions. T herefore, MHI has deployed a businessmodel strategy focusing on CO2 EOR opportunities. The
following items have been identiﬁed as key areas of focus
to enhance the feasibility of CO 2 capture, and MHI isfurther promoting research and development in theseareas.
• Reduced CO2 capture/compression energy• Commercialization of CO 2 capture from coal-fired
thermal power generation plants• Economy of scale owing with large - capacit y CO 2capture

2. Why aren’t CO 2 capture and storage projects
widely implemented?
As mentioned above, there are a few commercial scale
CCS projects currently operating but the widespread global
implementation of CCS faces several hurdles.
The CCS projects now underway seek to reduce current
CO 2 emissions or to reduce future emissions. Most ofthese projects operate at relatively low cost. Some havebeen established through the provision of incentives ordisincentives, such as the CO 2 ta x in Nor way, the useof recovered CO 2 for EOR ( Enhanced Oil Recover y) in
Weyburn (Canada), and so on.
To implement CO2 capture and storage on a wide scale in
the future, two issues must ﬁrst be resolved.
(1) Burden of cost of CO2 capture and storage
To i m p l e m e n t C O 2 c a p t u r e a n d s t o r a g e a s acountermeasure against global warming, incentive based
mechanisms such as CO2 emission trading and funding/
subsidy instruments by central government are required.
( 2 ) I mproved k nowledge of busi nes s c i rc u mst a nc es

3. MHI’s CO 2 capture technology(1) Experiences of MHIMHI has already delivered four commercial plants torecover CO 2 from flue gas in the chemical and fertilizer
industries, with another four plants on the drawing board(3 of which are currently under construction). Figure 2shows a CO2 recovery plant for a urea production facility
with a CO2 recovery capacity of 200 tonnes/day, deliveredin 1999 in Malaysia. Figure 3 shows a general-use (dryice, beverage carbonation, welding, etc.) CO 2 recovery
plant with a capacity of 330 tonnes/day, delivered in 2005

Fig. 2 Malaysia CO 2 recovery plant for
urea production facility

Fig. 3 Japan CO2 recovery plant for
general use

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Fig. 4 India CO2 recovery plant for
urea production

Fig. 6 Japan CO2 recovery
demonstration plant at acoal-ﬁred power plantFig. 5 India CO2 recovery plant for urea productionin Japan. Figures 4 and 5 show CO 2 recovery plants
used at urea production facilities with a capacity of 450
tonnes/day, delivered in 2006 at two separate locations inIndia.
(2) Strategies to reduce CO2 capture energy
MHI began researching and developing CO 2 capture
technology from the flue gas of power plants in 1990.
This was undertaken jointly together with Kansai ElectricPower Co., Inc. As a result of this extensive R&D, MHI
has developed many proprietar y items including; anenergy saving absorption solution (KS -1), an energysaving regeneration system for practical use, and asystem for the optimal integration of steam between apower-generation facility and a CO2 capture facility.
(3) CO2 capture from coal-ﬁred power plants
MHI has already gained considerable experiencein CO 2 capture from natural gas-fired boilers. Yet themore urgent challenge today, with the advent of global
warming, will be CO 2 capture from coal-fired power
plants, the largest source of global CO 2 emissions. Itis expected that CO 2 capture systems will be crucial inareas such as Europe and the US.
M H I responded to t his cha llenge in 2 0 0 0 by
const r uct ing and test ing a CO 2 capt ure pilot plantwith a capacity of 1 tonne/day from coal-fired flue gas
at its Hiroshima Research and Development Center.
Furthermore with grant funding (50% of project cost)from the Research Institute of Innovative Technology
for the Earth (RITE) and cooperation from the ElectricPower Development Co., L td., M H I const r ucted ademonstration plant of 10 tonnes/day at the Matsushima
Power Plant of Electric Power Development Co., Ltd.
T he plant was constructed in 20 04 and commenced
demonstration testing in 20 06 ( Fig. 6). T he plant
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Technical Review Vol. 45 No. 1 (Mar. 2008)42

successfully completed stable operation for over 4,000
hours and proved that MHI’s CO 2 recovery process canbe successfully applied to a coal-ﬁred power plant.
(4) Approach for large capacity CCS implementation
T he CO 2 recover y pla nts t hat M H I has a l readydelivered for the chemical and fertilizer industries range
in capacit y between 200 - 450 tonnes/day. If CO 2 iscaptured for EOR all the ﬂue gas from the boiler and/orgas turbines of the power plants must be treated. Tocapture CO2 from a 1000 MW coal-ﬁred power plant, forexample, a large-capacity, multi-train CO2 recovery plantof 17,000 tonnes/day will be required.
MHI has already standardized a CO2 recovery plant of
3,000 tonnes/day and completed basic design. Further,
MHI is working to realize a large-capacity plant on a scaleof 5,000 - 6,000 tonnes/day.

generation industry, operators will need to reduce the energy
required for CO 2 capture, develop economically viable
commercial technologies to capture CO 2 emitted by coalﬁred power plants, and aim to further reduce the CO2 capturecost. MHI continues its efforts on a range of research anddevelopment initiatives technologies to meet these needs
and develop countermeasures against global warming, toultimately ensure humanity has a sustainable future.
Reference
1. Published 2005, IPCC Special Report on Carbon Dioxide Captureand Storage

4. Conclusion
Masaki Iijima

It is not possible, with the global energy structure, to rely
signiﬁcantly on non-fossil fuels for energy in the foreseeable
future. Thus, countermeasures for the current and future
fossil fuel power generation ﬂeet, against global warming arerequired urgently throughout the world. CO 2 capture andstorage systems are therefore indispensable. To promotewidespread, viable CO 2 capture and storage in the power

Toru Takashina

Keiji Fujikawa

Tsuyoshi Ohishi

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Technical Review Vol. 45 No. 1 (Mar. 2008)43