Technologies for Handling the CO2 for Power Plants
























                                                            June 2008

1          Introduction


Actual requirement leads to reduce de human-made carbon dioxide (CO2) emission into the atmosphere. This need, supported by the big business behind, allows developing several techniques to reduce the industrial CO2 emissions. 

New laws around the world supporting this requirement lead the birth of a very big market to address the CO2 emission reduction; As a result, there are several companies, government and universities developing solutions and improvements of the actual technology fighting for leading the solution and business. Carbon Capture and Storage (CCS) appears as one of the most important technology wide world supported; however, others technologies, which resemble less expensive and risky, are also being developed.


Emission in Canada and Alberta by 2005:

·            9 GtCO2e were emitted for Global Coal consumption.

·            Canada emitted 0.747 GtCO2e = 747 MtCO2e

·            Alberta emitted 0.233 GtCO2e = 233 MtCO2e

·            Alberta Electricity Generation emitted 0.053 GtCO2e = 53.3 MtCO2e

·            GHG emission definition involves several gases with different weights in the equation[1].

·            In Alberta, the 77% of GHG emission is due to CO2.

·            In the electricity industry of Alberta, the 95.5% of GHG emission is due to CO2.


Federal Budget 2008:

·         $240 million to develop Carbon Capture and Storage (CCS) projects for SK projects. SaskPower will refit Boundary Dam Coal power plant with an inversion of $1 billion. It is expected to cut 1 MtCO2 per year, the 7% of SK emission.

·         $5 million for Nova Scotia for research examining the potential for carbon storage in the province.

·         $5 million to the Institute for Sustainable Energy, Environment and Economy at the University of Calgary, Alberta, to work with a broad range of stakeholders on CCS outstanding issues.

·         Capital cost allowance (CCA) rate for CO2 pipelines will be increased to 8 per cent from 4 per cent, and the CCA rate for pumping and compression equipment on CO2 pipelines will be set at 15 per cent.







2          Carbon Capture and Storage


Carbon dioxide capture and storage is a process for reducing GHG emissions into the atmosphere by first extracting CO2 from gas streams typically emitted during electricity production, fuel processing and other industrial process. Once captured and compressed, the CO2 is transported by pipeline or tanker to a storage site, often to be injected into an underground storage site, where it will be safely stored for the long-term. The technology for CCS is most efficient for a few large, concentrated and high pressure sources of CO2 such as Electricity Power Plant and oil sand facilities.  These three technologies (capture, transport and storage) could be summarised as:


2.1                     Carbon Capture (CC)

There are several technical variations depending on the technology of the facilities:

·   Pre-combustion: pre-combustion is a process where the fuel source is gasified to create syngas.  The CO2 can be easily captured prior to combusting the gas mixture (syngas) with high efficiency (around 90%). Integrated Gasification Combined Cycle (IGCC) is a pre-combustion typical technology.

·   Post-combustion: typical air-fired combustion unit after the burning process has taken place. Most of Coal Power Plants in Alberta use this technology (Pulverized Coal technology or PC). Also, it is the more worldwide technology used for Coal Plant Units.

·   Oxyfuel combustion: oxy-fuel is an emerging approach to post-combustion capture, whereby the combustion process takes place in an oxygen enriched setting which results in low-emissions fossil fuel combustion.


Main issues for CC:

·   PC Power Plants are not prepared efficiently for CC compared with IGCC technology. However, the technology for CC PC is improving quickly.

·   The Cost of Electricity (COE) for PC technology is lower than IGCC technology without considering CC. When CC is required, IGCC technology has better COE than PC technology.

·   Oxy-Fuel technology has similar performance and cost to IGCC technology.

·   Oxy-Fuel and IGCC technologies need more technological development while PC technology is very well known.

·   It is not necessary new regulation for capture in CCS.

·   Overall CC cost for all technologies is estimated in around 3.5 $/tCO2, and is expected to decrease to around 0.5 $/tCO2 by 2020 due to the technological improvement and cost reduction.


Many technologies are being developed and proven. These technologies address reducing the cost of CC, increasing the efficiency of the process and developing the technology for a widespread use (e.g.: Power Plants, Oil Sands). The more important developments are:


2.1.1  Chilling ammonia


Alstom and BP are developing this technology for CC PC Power Plants. It uses chilled ammonia to cool flue gas which increases the volume and rate at which CO2 can be isolated in a highly concentrated form. Chilling Ammonia technology helps to reduce the cost in CC and does more competitive PC technology in relationship with IGCC technology. The process is very well known in petrochemical plants, but it needs to be improved for CC requirements in Power Plants.

Alstom has six pilot plants around the world, and it will start with commercial installation around 2011. On April 3, 2008, TransAlta signed an agreement with Alstom to develop CC project based on Chilled ammonia technology in Wabamun area, Alberta. The Coal-fired project requires spending 12 million for next five years.


2.1.2  Controlled Freeze Zone (CFZ)


ExxonMobil are developing this technology. The company plans to build a commercial demonstration plant in Wyoming. CFZ is a single-step cryogenic separation process that freezes out and then melts the CO2 and removes other components including hydrogen sulfide, which is found in so-called sour gas. The CFZ process is designed to discharge the CO2 and other components as a high-pressure liquid stream. Besides reducing the cost of separation and manipulation, the CFZ process can eliminate the use of solvents, sulfur plants and CO2 venting in processing of the natural gas.


2.2                     Transport


With the CO2 captured by CC, the transport to storage sites should be considered. The main issues for CO2 transport are:

·   The transportation technology is known for both onshore and offshore pipeline.

·   CO2 pipelines have been safely operated in North America since the middle 1970’s; the biggest operative CO2 pipeline network is located in West Texas with an extension of 3700 km.

·   The transport of CO2 is a dangerous process because the CO2 needs to be transported at high pressure (from 70 to 200 atm) and with high purity.

·   There is general regulation for liquid pipeline transportation, but it is necessary to develop a more specific framework for CO2 transportation in AB.

·   The cost is estimated from 5 to 15 $/tCO2, for common extension in West Canada.


2.3                     Storage


Storage is not a completely known technology. It consists of depositions of CO2, in supercritical state, trapped in a geological formation (Deep Saline Aquifers) or in association with other industries as Coal Beds, EOR[2] and EGR; however these three last technologies do not offer a huge potential storage. There are some studies driven to store the CO2 in deep ocean, but it was proven that the ocean salinity increase and become other environmental problem. The main concerns are:

·   the capacity to store CO2. Different studies reveal there is enough capacity and western Canadian Sedimentary Basin is one of the best locations in the world to implement CCS.

·   the knowledge of storage mechanism. Several researches allow understanding these mechanisms but they still remain unknown for huge storage facilities.

·   the establishment of a process to certify well injection sites.

·   the continuous monitor of CO2 underground injected.

·   the leak probability that CO2 has from injection sites.

·   the complete knowledge of risks. It is suspected they are small, but it is necessary several big storage projects to have the complete control of the risk.

·   the leakage detection. There is not security about leak detection of CO2.


At present, there is no institutional framework to govern geological sequestration of CO2 at large scale for a very long period of time.

The lack of a framework makes it more difficult and costly to initiate large-scale projects and will result in delaying large-scale deployment.


2.4                     Cost and CCS projects in west Canada


All the provinces affected by high CO2 emissions from Power Plants and other facilities are developing CCS projects for research.

CCS cost has a range from 25 to 110 $/tCO2.

There are 131 different projects around the world, seven of them as integrated CCS; In Canada there are more than 12 projects reported. Different governments constantly announce new projects. The main projects in west Canada are:

·         Weyburn CO2 Storage project, SK, operate like an EOR facility (the biggest in the world) driving 1.1 MtCO2e per year.

·         Boundary Dam Coal Power Plant project, SK, a complete CCS project. It is expected to storage 1 MtCO2 per year.

·         The Heartland Area Redwater Project, SK, a complete CCS project. The first phase, consist in the evaluation in detail the size and suitability of the site for CO2 capture and storage, will be completed in spring 2009.

·         CO2 Geological Storage Demonstration Project (Acid Gas Re-injection) in Western Canada


Start Date

Sulphur disposed of [t/d]

CO2 disposed [t/d]

Well depth [m]

Acheson Blairmore T

June 1989




Zama Keg River

May 1995




Gordond K Halfway

April 1996




Paddle River Nordegg

May 1996




Puskwaska Leduc

Nov 1996




Dunvegan Kiskatinaw

Dec 1996




Jedney Baldonell

Dec 1996





Mar 1997




·          CO2 Geological Storage R&D Project. Several projects were and are developing in West Canada. The more important are:

o   Canadian Clean Power Coalition (CCPC, $5 million project),

o   CANMET Energy Technology Centre (CETC) R&D Oxyfuel Combustion for CO2 Capture,

o   Sequestration of Carbon Dioxide in Oil Sands Tailings Streams ($1 million project),

o   CO2-Enhanced Coal Bed Methane Recovery Project (Alberta ECBM, $3.4 million project),

o   CO2 Sequestration Capacity in Hydrocarbon Reservoirs in Alberta ($0.48 million), and

o   Review of Acid Gas Injection in Alberta ($0.14 million).

o   Fort Nelson NG plant in BC, Large-scale CCS Project in collaboration with the National Energy Technology Laboratory (NETL), Spectra Energy Transmission and the Energy & Environmental Research Center (EERC)

3             Underground Coal Gasification (UCG)

UCG is a process through which coal is converted in-situ in syngas. The gas can be processed to remove its COcontent, thereby providing a source of clean energy with minimal GHG emissions. This syngas is produced at a lower cost than by IGCC technology.

The process is known since 1868 in the Former Soviet Union. Ten years ago started the studies to apply in commercial scale in Australia, China, UK, Spain and others countries.


Advantages:   Increase the economically recoverable reserves.

                        Low cost operation in mines.

                        Low cost in comparison with IGCC technology to obtain Syngas.

Disadvantages:   The technology is being developed.

                             Not focalized for Power Generation.

     It is a technology for CC, the technically most known in CCS.


4             Serpentinization


This technique is led by the Centre for Innovation in Carbon Capture and Storage (CICCS) in UK. It is based on using a natural process in conjunction with silicate-based rocks such as serpentine to store all the CO2 produced. The CO2 extracted from burning coal is put into a reactor with the rocks and is located in through a chemical reaction. Once the process is fully developed, it is estimated that the locking of CO2 will take place within minutes. The end product is a mineral such as magnesite, which can be used as aggregates for road-building or shaped into bricks for construction.


Advantages:   It is not necessary to build pipelines and storage facilities.

                        Huge cost reduction for CO2 emission reduction.

Disadvantages:   The technology is being developed.

     It will be necessary agreements with the construction industry to apply the products.


5             Bacteria and Enzymes


CO2 Solution, a Canadian company, developed a method based on an enzymatic catalyst to convert the carbon dioxide in bicarbonate; then, in carbonic mineral.

The solution provided could be use to obtain pure CO2 as well as it can regenerate the capturing solution by precipitating out the bicarbonate with hydrated lime. The first method is used in combination of storage facilities and it will compete in the market of this kind of solutions. The second method, obtain hydrated lime, looks more interesting because it is not necessary the CO2 transportation and storage.

CO2 Solution is evaluating their technology and there is not cost and capacity numbers to compare this technology with others.

Advantages:   could reduce the cost for PC Power Plant developing the competence between technologies.

                        Support the thousands of post-combustion plants installed around the world.

                        With hydrated lime could be not necessary to build pipelines and storage plants.

Disadvantages:   The technology is being developed.

     The main technological effort is developed for CO2 capture, the technically most known in CCS


6             Green Freedom


Los Alamos National Laboratory has developed a low-risk, transformational concept, called Green Freedom, for large-scale production of carbon-neutral. The technology is a new process for extracting CO2 from the atmosphere and making it available for fuel production using a new form of electrochemical separation. Currently, the principal market for the Green Freedom production concept is fuel for vehicles and aircraft; in addition to the new electrochemical separation process, the Green Freedom system can use existing cooling towers, such as those of power plants.


Advantages:   Reduce the cost for PC Power Plant developing the competence between technologies.

                        Support the thousands of post-combustion plants installed around the world.

Disadvantages:   It is a technology for CC, the technically most known in CCS.

     The technology is being developed.


7             Nature’s Carbon Handling Mechanism


A team of researchers of Harvard University developed a method to enhance removal of CO2 from the atmosphere and place it in the Earth's oceans for storage. The new technology does not make the oceans more acidic and may be beneficial to coral reefs. The researchers minimize the potential for environmental problems by combining the acid removal with silicate rock weathering mimicking the natural process. This process would allow removal of excess CO2 from the atmosphere in a matter of decades rather than millennia.

Advantages:   It is not necessary to build pipelines and storage plants.

Disadvantages:  implementation would be ambitious, costly and would carry some environmental risks that require further study.

This technique needs more work is be needed to bring down the cost and minimize other environmental effects.




CCS is a bridging technology that should be broadly implemented as part of a portfolio of GHG emissions reduction measures.


CCS is technically feasible but many challenges remain that must be overcome for full scale commercial deployment.


There are several projects around the world testing, knowing the process and measuring the risk for CO2 storage. There is significant potential capacity for CO2 storage in western Canada


The technology for CO2 capture is improving quickly, reducing the cost for PC Power Plants.


The storage technology is known, but there are not experiences in long term effects. Many countries are developing knowledge and R&D projects. Different groups speak about from eight to twelve years for having the first full scale commercial project. Regulation is necessary to support these large scale / long term developments.


Other technological alternatives are being developed which is not necessary the CO2 storage. If these technologies reach to develop for large scale projects, it would be a very important alternative solution for the CO2 emission problem.



[1] GHG = CO2e = CO2 + 21*CH4 + 310*N2O + ….



- CO2: Carbon Dioxide (Fossil-fuel combustion, Land-use conversion, Cement Production)

- CH4: Methane (Fossil fuel production and combustion, Agriculture, Waste decomposition)

- NOx: Nitrous Oxide (Fertilizer, Industrial processes, Fossil fuel combustion)

[2] Enhanced Oil Recovery (EOR) uses CO2 in secondary oil recovery to trap the oil over the reservoir. Approximately 40 to 50% of the injected CO2 remain in the ground.

Enhanced Gas Recovery (EGR) is being study as a possible use for CO2 storage, but until now it presents important limitations.