CCS is a process of stripping carbon dioxide from fossil fuels before or after they are burned to justify the continued burning of coal. CCS is seen by the industry as essential in preventing CO2 emissions, but progress is seriously hampered both by cost and viability. Carbon capture and storage is hugely expense and technological difficulty. There are also questions about its safety – how long can it be stored underground without leaking? Globally, carbon capture has been stalled, eliminated or over-budget.
As of January 2017, there are 21 carbon capture projects worldwide on a large scale that are either operating or have been built, but relatively few of these are in the power generation sector.  
CCS does not eliminate other dangerous pollutants. In addition to carbon dioxide, coal plants all produce sulfur dioxide which leads to acid rain, nitrogen dioxide, a key contributor to ground-level ozone (smog), particulate matter (soot), mercury and hydrocarbons.  link   


Latest news:

March 2 2018: America’s clean coal dream unravels. Executives at the world’s most ambitious “clean coal” plant knew for years about serious design flaws and budget problems but sought to withhold key information from regulators before their plans collapsed. The Kemper plant in Mississippi, held up as the global model for a new generation of “clean coal” power plants, was the most expensive fossil fuel power plant in US history, with a $7.5bn price tag. However  documents uncovered evidence that the company knew that the project would blow through state-imposed budget limits five years before the company decided to reverse course and become an exclusively gas-fired energy plant.  link



  • Overview
  • Investing in carbon storage - the positive view
  • Problems and the case against CCS
  • Canada and the USA
  • Costs of CCS
  • Natural carbon sinks
  • How CCS would work

June 2012: Whatever happened to carbon capture? The process was patented back in the 1930s, and it is reckoned to be one of the most important technologies we have for tackling greenhouse gas emissions. The International Energy Agency (IEA) forecasts global energy demand increasing by at least one-third by 2035. The majority of that increase will come from burning fossil fuels; and without capturing and storing some of the CO2 emissions that result, this implies a significant addition to global warming. To meet the internationally agreed target of keeping the temperature rise since pre-industrial times below 2C, the IEA calculates there should be about 1,500 full-scale CCS plants in operation by 2035. Currently, there are just eight. CCS makes electricity more expensive. Extra fuel needs to be burned to drive the process of capturing CO2 from the power station's flue gas, and to pump it down to its resting place in rock deep underground. link

March 2013: Canada's Saskpower plant rebuilding. A recent study in Energy Policy concluded that challenges for CCS globally are "greater than often recognized," and that current policies will not allow the technology to be implemented in time for significant CO2 reductions. Some environmentalists further charge that CCS is a technology that will never work, and governments should instead funnel money toward renewables and natural gas to cut emissions, rather than boosting fossil fuels. One of the biggest economic challenges with CCS is that capture units require energy to run, sapping 20 to 30% of the juice from a power plant. link

December 2014: CCS globally would cost $17.6 trillion. Scientists know only two ways to prevent temperatures rising to dangerous levels. Stop burning fossil fuels or capture CO2 emissions and bury them. The problem the costs have proved stubbornly high. The Saskatchewan project, for instance, came with a price tag of $1.23 billion despite favorable geological conditions. At that rate, fitting all the world’s power stations with carbon-capture technology would cost about $17.6 trillion. link

Clean Coal

While the term 'Clean Coal' feels like an oxymoron, it’s used more often within the energy industry to refer to an expensive technology called carbon capture and storage (CCS) that once promised to keep coal power a dominant source of electricity for decades to come. Efforts to make clean coal technology affordable in the US have so far failed despite hundreds of millions of dollars in government and private funding. But public and private funding continue to pour in as proponents believe the technology will play an important role in many countries that have pledged to cut emissions and abide by the 2015 Paris climate agreement.
April 2014: Environmentalists say that clean coal is a myth.
Coal provides 40% of the world’s electricity. It produces 39% of global CO
emissions. It kills thousands a year in mines, many more with polluted air. link  

May 2012:
 Norway leads in CCS testing. Norway opens the world's largest and most advanced laboratory for testing carbon capture technologies hoping to prove that CO2 can be captured cost effectively and efficiently. The Norwegian government and Statoil agreed to start building it back in 2006.  link   (Update: September 2013: Norway ends project: Norway's outgoing center-left government dropped plans on Friday for a costly large-scale project to capture CO2 that it once compared in ambition to sending people to the Moon. link  

October 2012: Insufficient CCS projects to affect dangerous global warming.
 More than a hundred CCS projects must be built to avoid dangerous global warming, an international group said this week. The report revealed that only one new large-scale CCS plant was built in the past year, taking the total number to 75, while eight projects were cancelled. The number of operational projects would need to increase to about 130 by 2020, but this seems unlikely, with institute projections indicating that only 51 of the remaining 59 projects identified in our annual survey may be operational by then. link

Investing in carbon storage - the positive view

December 2017: New technique could make captured carbon more valuable. Carbon capture could help the nation's coal plants reduce greenhouse gas emissions, yet economic challenges are part of the reason the technology isn't widely used today. That could change if power plants could turn captured carbon into a useable product. Scientists at the U.S. Department of Energy's Idaho National Laboratory have developed an efficient process for turning captured CO2 into syngas, a mixture of H2 and CO that can be used to make fuels and chemicals. link

January 2017: Indian firm makes carbon capture breakthrough. A plant at the industrial port of Tuticorin is capturing CO2 from its own coal-powered boiler and using it to make soda ash - aka baking powder. Carbonclean, the firm behind the  process, says its chemicals will lock up 60,000 tonnes of CO2 a year and the technology is attracting interest from around the world. The inventors believes capturing usable CO2 can deal with perhaps 5-10% of the world’s emissions from coal. It’s no panacea, but it would be a valuable contribution because industrial steam-making boilers are hard to run on renewable energy.  link

August 2016: Shell-backed study identifies safe carbon storage zones. Geologists have resolved one great problem about the capture of carbon dioxide, The bigger problem is whether it can be made to work at all. Independent studies have decided that the technology is both costly and risky, and in any case the response by the energy industry suggests that the approach is not being prosecuted with any enthusiasm.  link

June 2016: Icelandic power plant turns CO2 into stone. In a move advancing CCS, Scientists and engineers working at a major power plant in Iceland have shown for the first time that CO2 emissions can be pumped into the earth and changed chemically to a solid within months - radically faster than anyone had predicted. At the Icelandic geothermal plant, the process involves mixing the gases with the water pumped from below and reinjecting the solution into the volcanic basalt below. But no one knew how fast this might happen if the process were harnessed for carbon storage. Previous studies have estimated that in most rocks, it would take hundreds or even thousands of years. In the basalt below the Hellisheidi power plant, 95% of the injected carbon was solidified within less than two years. The main stumbling block beyond the needed basalt, he said, is the water required - about 25 tons for every ton of CO2. link

June 2016: Ancient rocks yield hard facts on safe storage of greenhouse gas. In the most complete analysis of its kind, researchers from the two Scottish Universities studied data on 76 natural CO2 reservoirs in America, Europe, Asia and Australia. These gas pools, many more than a million years old, were formed as a result of geological changes, volcanic activity, or from decayed plants and animals. Researchers have identified geological conditions best suited to long-term CO2 storage such as optimum temperature, pressure, and type of rock. They found that sites deeper than 1200 metres, high density of gas and multiple, thick rocks to cap reservoirs were all beneficial.   link

May 2016: Carbon capture costs could halve. Carbon Clean Solutions Limited (CCSL) has announced breakthrough test results after a successful pilot campaign at the world’s largest and most advanced facility for testing and improving carbon dioxide capture. The trial, carried out at Technology Centre Mongstad (Norway) involved a drop-in solvent test using CCSL’s patented ‘APBS,’ which involves capturing CO2 using a re-generable solvent combined with a unique heat coupling method. The CO2 recovered can then be used as a raw material for downstream industries. During the test, which was designed to measure environmental emissions, corrosion and energy efficiency, CCSL successfully captured more than 25,000 tonnes of CO2 with plant availability levels reaching the maximum 100%. link

October 2009: First breakthrough. The world’s largest carbon capture facility at a coal  factory was introduced by French firm Alstom - the pilot facility catches and contains around 20MW of CO2 from West Virginia’s Mountaineer plant. Since the unit can handle only a portion of Mountaineer’s 1,300MW  capacity, the remaining captured CO2 is buried 7,200 feet underground. Philippe Joubert, the head of Alstom's power division, said "What we are able to prove now, for the people who want to hear, is that the technology is here, there is no longer any doubt." link

June 2009: Recent global action to fund carbon capture and storage (CCS) technology is unprecedented. New project funding announced last month in the European Union, Canada, Australia and the United States is building momentum for accelerating the use of CCS to reduce greenhouse gas emissions. The G8’s goal of 20 demonstrations announced by 2010 – a goal that once seemed insurmountable – could be within reach.  In Australia, the federal government allocated USD$2 billion to build between two and four coal-fired power plants, each generating up to 1,000 MW, that have CCS capabilities. This funding action came shortly after Prime Minister Kevin Rudd announced the formation of the $70 million, investor-backed Global Carbon Capture and Storage Institute. link    

Problems and the case against CCS

February 2016: CO2 stored underground can find multiple ways to escape. When carbon dioxide is stored underground in a process known as geological sequestration, it can find multiple escape pathways due to chemical reactions between carbon dioxide, water, rocks and cement from abandoned wells, according to Penn State researchers. The researchers investigated the properties of porous rocks into which carbon dioxide is injected. These rocks, known as host rocks, function like containers for the carbon dioxide. The team looked at two abundant host rocks, limestone and sandstone, which have different chemical properties. link

February 2014: CO2 capture could raise wholesale energy price 80%. Requiring the use of carbon capture and sequestration technologies at coal-fired power plants could increase the wholesale price of electricity between 70% and 80%, according to the Energy Dept. which said the first generation of CCS technologies have a captured cost of CO2 of between $70-90 per ton. Many lawmakers and utility groups say the technology isn't commercially feasible and would make it impossible to build a new coal power plant in the U.S. Between fiscal years 2005 and 2014, the Energy Department has received around $7.6 billion in funding for development of CCS technologies in hopes of commercialization.  link   

July 2012: CCS may be a waste of time. In order to be effective, CCS projects need to keep CO22 out of the atmosphere for thousands of years, and that earthquakes too small to endanger life or property could nevertheless create leaks that would make the whole thing a waste of time. The bottom line, according to Mark Zoback of Stanford University: “CCS is a risky proposition. Not that it’s impossible, or even inappropriate. It should be done. But at a global scale, it’s not likely to reduce CO2 emissions significantly.” link 

January 2012: Growing doubts in Europe on future of carbon storage. Two carbon capture and storage projects in Germany and Britain were canceled last quarter, and many of the remaining projects will probably share that fate this year, imperiled by a mix of regulatory objections, a lack of money, public opposition to the possible geological risks and broader uncertainty about strategies to slow climate change. link

September 2011: CCS floundering world-wide. In Beijing, delegates including the US energy secretary, Steven Chu, heard  that the global temperature is on course to rise by 3.5C, due to poor progress both on carbon capture and storage, and on acceptance of a carbon price and other carbon-cutting efforts. Projects to capture and bury a major chunk of that are behind schedule and finding it harder to secure funds. To reach the 2C goal, the IEA estimates there will have to be 1,500 large-scale CCS projects around the world by 2035. However, only 74 have been announced, and the trend is in the wrong direction. "We're seeing a decline in new projects due to a softening global economy and an uncertain carbon price," said Brad Page, head of the Australia-based Global CCS Institute. link

October 2011: 1bn flagship carbon capture scheme is cancelled. Britain's efforts to fight climate change suffered an embarrassing setback when the Government abandoned plans for the UK's first coal-fired power plant fitted with technology to capture and store carbon emissions. The flagship project at Longannet fell apart after the consortium planning to build it, headed by ScottishPower and including Shell and the National Grid, demanded considerably more investment than the 1bn which the Government had set aside for the scheme. link

May 2011: Why CCS viability is daunting. At the 10th annual Conference on Carbon Capture and Sequestration in Pittsburgh (PA)  it did not come as much of a surprise when the chief executive of one of the largest utility companies in the United States questioning the viability of carbon-storage ventures in the next few years. Michael Morris, chief executive of American Electric Power said that the energy industry needs a signal from politicians in Washington DC. He believes that with time, industry can surmount the technical issues, but it is not a cheap proposition. To keep CO2 emissions below 450 parts per million by 2050, an oft-cited target associated with a roughly 50% chance of keeping global warming below 2 degrees, would involve 3,200 projects sequestering some 150 gigatonnes of CO2, roughly 70 times the United States’ total carbon emissions from electricity generation in 2009.  link

September 2010: New study suggests CCS technology in Europe is doomed. Innovative carbon-trapping technology might barely get past the testing phase in Europe after the economic crisis and a shift to green power destroys incentives, a new study warns.  Massive European investment in renewable energy will reduce demand for carbon emissions permits in 2020, dragging down their price and undermining investment in CCS, says the report “EU Energy Trends to 2030: by the National Technical University of Athens. (Pictured CCS unit at American Electric Power Company's Mountaineer Plant near New Haven, West Virginia.) link

Around the world.

December 2010: Carbon capture project in Queensland, Australia ends. The $4.3bn coal-fired station was due to open in 2015, but concerns about its viability brought a close to the project as it was not seen as economically viable. link

July 2009: German carbon capture plan appears to be a victim of local opposition.
The spread of localised resistance is a force that some fear could sink Europe's attempts to build 10 to 12 demonstration projects for CCS by 2015. link  mm  

October 2010: Kingsnorth project in UK shelved  - E.On UK shelves plans to compete saying it is uneconomical to build.  link

April 2010: U.S. research paper questions viability of carbon capture and storage.
A new research paper from American academics is threatening to blow a hole in growing political support for carbon capture and storage as a weapon in the fight against global warming. The document claims that governments wanting to use CCS have overestimated its value and says it would take a reservoir the size of a small US state to hold the CO2 produced by one power station. The paper concludes that CCS "is not a practical means to provide any substantive reduction in CO2 emissions, although it has been repeatedly presented as such by others."
British geologists and engineers refute carbon capture doubts  - link

June 2010: Potential of "clean coal" to reduce emissions is overstated. Environmental advocates say they've poked a hole in the popularized belief that capturing and burying CO2 underground is an effective response to the threat of global climate change. Called carbon capture and sequestration (CCS), the CO2 burial process is also called "clean coal" in industry advertising campaigns. The paper concludes that "CCS cannot deliver significant reductions in time to play a role in the effort of keeping the global temperature increase below 2 degrees Celsius."  link    

Canada and the USA

Canada -  SaskPower’s Boundary Dam plant

July 2016: U.S. Model for ‘clean coal’ runs off the tracks. A first-of-its-kind power plant in Mississippi, that was supposed to prove that “clean coal” was not an oxymoron  - that it was possible to produce electricity from coal in a way that emits far less pollution, and to turn a profit while doing so. The plant was not only a central piece of the Obama administration’s climate plan, it was also supposed to be a model for future power plants to help slow the dangerous effects of global warming. It is more than two years behind schedule and more than $4 billion over its initial budget.  link

March  2016: $1.1 billion project now looking like a green dream. In the first large-scale project of its kind, the SaskPower’s Boundary Dam 3 plant was equipped with a technology that promised to pluck carbon out of the utility’s exhaust and bury it underground, transforming coal into a cleaner power source. In the months after opening, the utility and the provincial government declared the project an unqualified success. But the project has been plagued by multiple shutdowns, has fallen way short of its emissions targets, and faces an unresolved problem with its core technology. The costs, too, have soared, requiring tens of millions of dollars in new equipment and repairs. “At the outset, its economics were dubious,” said Cathy Sproule, a member of Saskatchewan’s legislature who released confidential internal documents about the project. “Now they’re a disaster. link  

October 2014: Canada’s first large-scale coal-fired CCS power plant switched on. The project, the first commercial-scale plant equipped with carbon capture and storage technology, was held up by the coal industry as a real life example that it is possible to go on burning the dirtiest of fossil fuels while avoiding dangerous global warming. The Boundary Dam power plant promises to cut CO2 emissions by 90% by trapping the greenhouse gas underground before it reaches the atmosphere. The company said the project would reduce emissions by about 1 million tons a year, or the equivalent of taking 250,000 cars off the road. CCS is viewed with deep suspicion by environmental campaigners because its economic viability, so far, depends on using the CO2 to increase oil production, and because it is more expensive than renewable sources of energy. link

April  2014: Putting “clean coal’ to the test.  When Unit 3 at the Boundary Dam Power Station in Saskatchewan, Canada, switches on later this year after a lengthy refit, it will mark a historic moment for dirty coal power. It will be the first time that a commercial-scale plant supplying electricity to the grid captures and stores a large fraction of its CO2 emissions. The firm plans to sell about 1 million tonnes of CO2 a year, up to 90% of Unit 3’s emissions, to oil company Cenovus Energy of Calgary, Canada, which will pipe the compressed gas deep underground to flush out stubborn oil reserves. link   (Note: Odd that reducing emissions will lead to extract fossil fuels which produce CO2 emissions – AB)

Canada's rules go beyond U.S. EPA regulations. The project is significant for being the first of its type, but it will not alone jump-start a new wave of carbon capture retrofits in the United States, several analysts said. Without a carbon price or similar EPA regulations on existing plants, there is not enough of a financial driver for Boundary Dam-style projects.


January 2017: America’s first ‘clean coal’ plant is now operational. The Petra Nova project near Houston, Texas, captured carbon dioxide from the process of coal combustion for the first time in September, and has now piped 100,000 tons of it from the plant to the West Ranch oil field 80 miles away, where the CO2 is used to force additional oil from the ground. The plant can capture over 90% of the carbon dioxide. The Energy Department provided grants totaling $ 190 million to the Petra Nova facility, which cost $1 billion overall. link  

June  2014: US plant prepared for operation. The nation's first coal-fired power plant aiming to capture the majority of its CO2 emissions rises from a vast, cleared plot of Mississippi pine forests. The Kemper County Energy Facility which envisions grabbing 65% of the CO2 from a 582MW gasification power plant is nearing completion. Southern Co. and its subsidiary Mississippi Power, the developers of the $5.5 billion plant, said they are on track for a May 2015 operation date and plan to begin capturing CO2 at the gasification plant this fall.  link

(May 2012) Of the 15 major CCS projects currently running or being built, which aren't attached to power stations, the USA has eight. The $3bn for CCS in the US stimulus bill in 2009 turbocharged the several billion the nation had already ploughed in. Another factor has put the US in pole position: the need for copious CO2 to pump out the last dregs of oil from drained reservoirs, so-called enhanced oil recovery. All but one of the 8 current US projects depend on selling CO2 for this, to make their finances add up. (Europe hosts none of the 15 frontline CCS plants, but has 21 of the 60 or so plants currently in planning.) Howard Herzog, a CCS expert at MIT, said: "The EU plan is totally on the rocks.”  Most CCS projects funded by the EC face delays, due to slow investment and the low carbon price. link

November 2013: More dollars thrown at CCS. The Obama Administration will invest a further $84 million to support 18 different CCS projects despite the fact that the technology hasn’t yet proven to be practical, affordable and scalable.  Since President Obama took office, DOE has invested $6 billion in clean coal technologies to mitigate the effects of fossil resources, according to the department’s release.  link  (The list of CCS projects that will be funded by the DOE’s investment can be found here.)  


December 2016: The cost of testing and building CCS projects remains high after more than a decade of significant investments. One of the most notable flops, called FutureGen, was a $1.7bn public-private project that began in 2003. FutureGen was killed twice, by both the Bush and Obama administrations, after it ballooned into an expensive undertaking that faced lawsuits and couldn’t line up the money necessary to complete it in Illinois. By its second demise, the government had spent about $116.5 million of the $1.1 billion it committed in 2010.  link

February 2015: Troubled Future-Gen CCS plant killed off. The Energy Department is walking away from FutureGen, a public-private effort to create a power plant that traps and stores carbon emissions, which began but faltered under President George W. Bush and was revived by the Obama administration. DOE is yanking funding for the project that was authorized to receive $1.1 billion in funding via the 2009 stimulus law, though the bulk was never spent. Bush, who proposed FutureGen in 2003, envisioned a pioneering plant that would demonstrate sophisticated technology that uses coal cleanly on a commercial scale. Large-scale carbon capture remains far from widespread commercial deployment in the electricity sector. link  

November 2011: FutureGen 2.0 – another setback. The leading American effort to capture CO2 from coal plants has hit a stumbling block that could imperil the project. The Midwestern power company that was to be the host for the project said because of its financial situation, it cannot take part as promised. The federal government promised the project $1 billion, or roughly 80% of its costs, on the condition that the money be spent by the end of 2015 - a time frame for developing a technology that has never been used on a commercial scale.  link   

April 2013: Carbon capture in USA may never come to fruition.  link

Costs of CCS

July 2012: CCS still too expensive to be commercially viable. Federal efforts to reduce the cost have not yet been fruitful according to a report released by the Congressional Budget Office June 28. Congress has provided $6.9 billion in funding to the Energy Department since 2005 to develop and demonstrate the commercial potential of carbon capture and storage, but the efforts have not brought the cost of the technology down significantly enough to make it economically viable, according to the report.  link

August 2010: EPA and DOE say "clean coal" not possible without carbon pricing.  
In a new report to President Obama, the agencies claim the main obstacle to deployment of CCS technology is political, not technical.
The findings reflect input from 14 federal agencies and departments, as well as hundreds of stakeholders and CCS experts, the report said. link 

The International Energy Agency warned in October 2008 that global CCS spending and activity levels are “nowhere near enough” to achieve an agreed G8 goal to begin developing 20 large-scale demonstration CCS projects by 2010. The IEA said several industrial-size pilot CCS projects planned for Europe, North America and Australia are making “slow progress” and if they fail to materialise soon, it will be at least 2030 before CCS can contribute meaningfully to greenhouse-gas reduction. However China is beginning to lead the way to explore CCS more aggressively and promising even to build cleaner plants at lower costs than conventional plants elsewhere in the world. link

February 2010: President Obama has called for the rapid national adoption of "clean coal" technology. Last week, shortly after his budget address, President Obama ordered a high-level task force to deliver a plan within 180 days determining how "to overcome barriers to the widespread, cost-effective deployment of CCS within 10 years, with the goal of bringing 5 to 10 commercial demonstration projects on line by 2016." Obama's executive office memorandum looks like a big victory for the coal industry, which was already handed $3.8 billion in last year's stimulus act for carbon capture and storage (CCS) research and development and deployment. He did not simultaneously order a similar plan for a big roll-out of solar or wind energy to level the playing field. However CCS technology is projected to be notoriously expensive. No full-scale demonstration plant has yet been built, and the pieces of technology that have to fit together add significant cost to operations. Capturing carbon is the first step, and still quite expensive. It also requires the plant to burn about 25% more coal to power the capture process. Special pipelines need to be built to carry the CO2 in a supercritical state to suitable underground injection sites; these must be monitored for leakage and insured against catastrophe; and perhaps royalties must be paid to landowners for the use of underground pore space. link  

July 2010: GAO: Current CCS technology plagued by high costs, uncertain results. .  link    

A Massachusetts Institute of Technology (MIT) study (see page 19 - table 3.1) estimated  that fitting carbon capture to an ultra-supercritical - the most efficient - coal plant would reduce the efficiency, meaning that 27% more coal would be needed. In April 2009, Britain’s Energy Secretary, Ed Miliband announced that 4 new coal-fired stations would be constructed, but only if they captured CO2. However he limited this capture to 20-25% only, insisting that "when the technology is proven [we will make a] commitment that CCS will be fitted on the entire plant." This means 75% or more of CO2 emissions will still pollute the air. [This still makes it dirtier than uncontrolled natural gas-fired stations.] Further, it admits that the technology does not as yet exist. Britain’s Alistair Darling (former Chancellor of the Exchequer) said in May 2007: “It is true to say that the technology to capture, transport and store the carbon exists, but it has not actually been joined up on a commercial basis yet … these things might never become available”. George Monbiot in the Guardian writes: “So here's the difficulty for the government. It will approve a new generation of coal-burning power stations, starting with Kingsnorth in Kent, on the basis that they will one day reduce their emissions by means of a technology that has not yet been demonstrated."  In Britain 31% of energy comes from coal-fired plants - in the USA it is currently 47%.

Natural carbon sinks

Forests: The world's forests and oceans are natural regulators of carbon dioxide content in the atmosphere. While forests are regarded as sinks, meaning they absorb carbon dioxide, forests are increasingly being cut down. Eighty percent of the forests that originally covered the earth have been cleared, fragmented, or otherwise degraded: over the past 150 years, deforestation has contributed an estimated 30% of the atmospheric build-up of CO2.  link  
See also
  Indonesia - Peat adds to problem 

Oceans:   Oceans' ability to sequester carbon diminishing. The globe's oceans are massive carbon sinks: more than a quarter of carbon emissions from humans have been sequestered by the oceans. According to a new study - the first of its kind - an annual accounting of the oceans' intake of carbon over the past 250 years suggests troubling news. According to the study, published in Nature, the oceans' ability to sequester carbon is struggling to keep-up with mankind's ever-growing emissions. link   But it's a complex system; it takes about a thousand years for the ocean to complete one mixing cycle. As a result the ocean simply cannot take up excess carbon fast enough to match the anthropogenic (human-caused) increase. Only 40-50% of the carbon added to the atmosphere since 1800 has dissolved in the ocean, with 28% still remaining in the atmosphere. In summary the oceans have only a limited capacity to absorb anthropogenic carbon dioxide increases (link removed).

Coastal habitats. Highly endangered coastal habitats are incredibly effective in sequestering carbon and locking it away in soil, according to a new paper in a report by the International Union for Conservation of Nature (IUCN). The paper attests that coastal habitats - such as mangroves, sea grasses, and salt marshes - sequester as much as 50 times the amount of carbon in their soil per hectare as tropical forest. The key difference between these coastal habitats and forests is that mangroves, seagrasses and the plants in salt marshes are extremely efficient at burying carbon in the sediment below them where it can stay for centuries or even millennia. link

How CCS would work

Pre-combustion CCS. Pre-combustion CO2 capture involves removing all or part of the carbon content before burning it. The fuel is processed to produce a gas stream that primarily consists of CO2 and hydrogen. The CO2 is then captured for storage and the hydrogen is combusted in a conventional gas turbine combined cycle to generate electricity, resulting in a flue gas that only consists of water vapor. But, so far, only a small pilot project (Vatenfalls) in northern Germany has connected all the different stages of the CCS chain together. The pilot is an oxyfuel boiler that can generate 30MW of heat and around 12MW of electricity. 

One disadvantage of the pre-combustion method is that it cannot be retro-fitted to the older pulversised coal power plants that make up much of the world's installed base of fossil fuel power. It could perhaps be used in natural gas stations, where a synthetic gas is first produced by reacting the methane with steam to produce carbon dioxide and hydrogen. But the economic advantage of this method over post-combustion is yet to be proven. link

How would carbon storage work? more 

October 2016: Anglo-Indian firm claims revolutionary CCS technique. A technique to capture carbon emissions from coal-fired power stations has been shown to work on a commercially viable basis for the first time by Carbon Clean Solutions Limited (CCSL). The 10-megawatt power station in Chennai, India, is currently using CCSL’s system to generate electricity on a commercial basis while capturing some 97% of carbon emissions. CCSL says it developed a new solvent that makes the carbon capture process up to 66% cheaper than traditional methods.  link

Of several alternatives, coal generation with CCS is the least promising as it has some major strikes against. However it does have some advantages as well. CCS technology already builds on the practice in the oil industry of pumping carbon dioxide into oil and gas wells to increase yield by forcing out more oil and natural gas.         


The Guardian Environment web pages has an exclusive page devoted to CCS - link

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