Part 2 CCT Overview
Environmental Protection Technologies (CO2 Recovery Technologies)

5A4. Oxy-fuel Combustion (Oxygen-firing of Conventional PCF System)
Research and development: Japan Coal Energy Center; J-POWER; Ishikawajima-Harima Heavy Industries, Co., Ltd.;
Taiyo Nippon Sanso Corporation (Nippon Sanso Corp.); and Institute of Research and Innovation
Project type: Coal Production and Utilization Technology Promotion Grant
Period: 1992-2000 (8 years), 2004-2005 (2 years)

Technology overview

1. Background and the oxy-fuel combustion system
The Kyoto Protocol entered into force in February 2005, and now

and to easily recover CO2.(1) When this technology is applied tomany countries are working actively toward the second

power plants for the purpose of controlling the flame temperature,commitment period starting in 2013. From a global viewpoint,

flue gas (mostly CO2) is recirculated and mixed with O2. With thishowever, thermal power plants are releasing CO2 in large

technology, it has been confirmed that the process characteristics

quantities, which indicates the necessity for a power generation

help reduce NOx emissions. Expectations for this system are highsystem with CO2 recovery and storage capabilities. Among all thebecause it represents a direct CO2 recovery method that is better

fossil fuels used at thermal power plants, coal produces thethan other CO2 recovery systems in terms of economical efficiency

greatest amount of CO2 per calorific unit value.

and technological feasibility.

In the process of recovering CO2 through oxy-fuel combustion as

In the future, it will be increasingly necessary to establish a coal-shown in Figure 1, O2 is separated from combustion air and used

fired power plant with CCS (Carbon Dioxide Capture and Storage).

for burning coal. In this process, it is theoretically possible toIn this respect, it will be important to integrate the power generating

improve the CO2 concentration in the emissions to 90% or more,unit and the CO2 recovery and storage capabilities.

N2

Non-condensable gas

Coal
BoilerAir

Flue gas
treatment
CO2 storage

O2
Compression/cooling
Oxygenproduction unit

H 2O
Flue gas recirculation

Fig. 1 Concept of oxy-fuel combustion with CCS

2. Development results
An application study on an existing 1000MWe coal-fired power

oxygen production account for more than half of the total cost,plant was carried out to examine the system structure and theand thus it is hoped that innovative oxygen production technology

boiler furnace, as well as the operating and economic efficiency.

will be developed.

Table 1 and Figure 2 show the specifications of the existing 1,000
MWe power plant when the oxy-fuel combustion system was
Table 1 Specifications of a plant with oxy-fuel combustion system

introduced. In applying oxy-fuel combustion, motive power isSpecifications

Unit

Air combustion

Oxy-fuel combustionnecessary for oxygen production and CO2 recovery. The station

Rated output

MWe10501050

service power occupies up to 30% of the total electricity

Net efficiency%4030

Station service power

generated, and the net efficiency is 30%. The amount of CO2%

530

Availability%

8080

recovered is about 800 t/hr (or about 5 million tons per year.)

Coal consumption

t/h

330

330

(Australian coal)

According to our calculation, the cost for CO2 separation andOxygen supply

km3N/hCO2 recovery rate%

480 (in Air)
_430

recovery is approximately 3,000 yen per ton-CO2. In this process,the initial cost and the operational and maintenance costs forCO2 recoveryt/hr_8028395

Clean Coal Technologies in Japan

3. Demonstration project in Australia

CO2 recovery-type oxygen pulverized coal combustion power plant

On the basis of the study results described above, demonstrative
studies are now underway for applying oxy-fuel combustion to anexisting plant.(4) These studies include an Australia-Japan joint
project in which an oxy-fuel combustion demonstration plant will becompleted by the end of 2008. This project aims to recover andCO2 underground sequestration

Boilerstore CO2 from an existing power plant. The outline of the project isOxygen production facility

as follows:

CO2 tank

The project is being implemented at a power generation plant in theCallide-A power plant’s No. 4 unit owned by CS Energy on the east
coast of Australia. This unit was selected because it has adequate

CO2 ocean sequestration

capacity as a demonstration plant. Additionally, it is currently out ofFig. 2 Image of CO2 recovery-type power plant applying oxygen combust

service and thus is available for modifications.
The storage site is planned to be located in a depleted gas field,

feasibility study from FY2004 to FY2005. Based on its results,

about 250 km to the west of the power plant. This site was chosendetailed studies began in 2006, aiming at completing the plant by

because it is not far away from the power plant, the estimated CO2

the end of 2008. Demonstrative operation of the oxy-fuelstorage capacity is sufficient, and the reservoir characteristics suchcombustion system will be carried out for five years afteras permeability and porosity are adequate.

completion. Storage of captured CO2 will start in FY2011, and thus

The entire project schedule is shown in Table 2. For thisdemonstration and monitoring of CO2 storage will be carried out for

demonstration project, Australia and Japan jointly conducted athree years.

Table 4 Project schedule
2004

2005

Feasibility sudy

Boiler modification & demonstrationof CO2 recovery

Demonstration of CO2 storage

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

FSDesign,construction,commissioning

Demonstrative operation

Test
Testdrilling,drill, design,design,construction,construction,commissioning
commissioning

CO2 storage & monitoring

Summary

4. Issues and feasibility of practical application
As described above, the demonstration of a power plant using oxy-demonstration and further studies:

fuel combustion is now about to start. Hopefully by the year 2010, it(1) Stability and safety in the operation of a power plant using oxy-will be demonstrated that the system is reliable and economically

fuel combustion

efficient for CO2 recovery. It is necessary first and foremost to(2) Stable operation of a CO2 recovery system

ensure the steady implementation of the Australia-Japan(3) Efforts for reducing costs and enhancing efficiency

demonstration project, so that it will be the first step toward(4) Total system optimization for power generation and CO2commercialization. The following topics will be the subjects of therecovery/transportation/storage

References

1) K. Kimura et al., JSME-ASME Int. Conf. On Power Eng.-93, Tokyo, Sept. 1993.
2) NEDO, "Report on the Clean Coal Technology Promotion Project 2004: Study on the Application of Oxygen Combustion Technology
to an Existent Pulverized Coal-Fired Power Plant".
3) NEDO, "Report on the Clean Coal Technology Promotion Project 2005: Study on the Application of Oxygen Combustion Technology
to an Existent Pulverized Coal-Fired Power Plant".
4) C. Spero, Proc. Clean Coal Day in Japan 2004, Advanced Clean Coal Tech. Int. Symp. Tokyo, Sept. 2004.
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