Earthquakes - Potential Side effect of CCS (CO2 sequestration)

There is no time like the present to educate yourself about earthquakes - this link was sent to me and so I am passing it on to our readers in hopes no one ever needs this information

http://quakequizsf.org/

More Issues with Supercritical CO2

The quotes below come from the comments section on web site - http://tinyurl.com/owgbts

"First off, CO2 has what is known in the industry as a "triple point". A point on the temperature/pressure curve at which all three phases (liquid, solid, and gas) can co-exist. This is a dangerous situation because solids can plug up pipelines, liquids are incompressible, and gasses at that pressure are bombs waiting to blow. It is not at all uncommon for a pipeline to plug up due to a solid dry ice plug, burst due to the sudden spike in pressure from the incompressible liquids pumped in behind it, then flash to gas and cause an explosion. That is one reason it is not often used for oil well fracturing/stimulation, liquid nitrogen is far safer to handle/pump."

"The other issue is one of metallurgy. CO2, in the presence of water turns into carbolic acid. Carbon steel as well as most higher strength stainless steels are subject to severe pitting corrosion from carbolic acid. I have a piece of pipe that was in an oil well for two weeks in wet CO2 environment. It quite literally looks like a piece of wood that termites have been eating. Pitting corrosion is the most dangerous kind of corrosion because it is random and unpredictable in how deep it will go. Therefore you cannot build in a "corrosion allowance" into your designs to compensate for it the way you can with general corrosion. A corrosion allowance is when you specify a thicker wall for a pressure vessel than needed to account for the lost thickness due to corrosion over the vessel's life. But since pitting is localized and can go very deep very quickly, you cannot compensate for it in that manner."

"Carbolic acid also attacks the cement used to plug and case wells as well.

The way to compensate for it is to use group IV corrosion resistant materials. These materials are invariably very high Chrome, Nickel, Cobalt, and Molybdenum content materials. These are as you can imagine not cheap or plentiful, and were generally not used to drill or case the original oil wells that are to be used as CO2 injection wells. They also tend to present operational issues due to their propensity to gall. You cannot inject CO2 into a reservoir that has carbon steel cased wells that intersect it for there is a high likelihood that those capped wells may blow out later due to corrosion. Therefore using old oil wells is extremely problematic. Sure, it will work for a short time, but long term, those wells are ticking time bombs."

"Another issue is the energy required to capture, purify, liquefy, transport and pump the CO2. That energy has both a carbon and a financial cost associated with it. What good does it serve to sequester 1 MMCF of CO2 if you generate 1.25 MMCF in the process?

For example, carbonic acid in groundwater can dissolve limestone to form natural caves. We don't know what type of effect pumping such a volume of CO2 into the ground would have, so saying there could be an off-the-shelf system in the near-term is not reasonable."

Below are excerpts from the web site -

http://tinyurl.com/ov9264

"Potential problems

Beside the problem of carbon dioxide leaking out of old abandoned wells, there are other concerns.

Forcing carbon dioxide under pressure into rock formations could force natural gas and salt water out of those formations in unpredictable and undesirable ways – into shallow water wells, for example or to the surface, spilling natural gas (a potent greenhouse gas) into the atmosphere, or pushing brine into fresh water aquifers.

And in an ironic reversal, pumping gas under pressure into some rock formations could cause the surface of the ground to actually rise – as opposed to land subsidence caused by deep mining coal – damaging structures and affecting streams and drinking water aquifers.

Leaking carbon dioxide could find its way into drinking water aquifers, and while this sounds like it could produce club soda from the kitchen faucet, it would make the water more acidic, dissolving calcium and other minerals and creating a hard water problem, or in some cases dissolving toxic metals, raising trace elements to dangerous levels."

General hazards of carbon dioxide

This information is from the following web site:
http://www.hse.gov.uk/carboncapture/carbondioxide.htm

"At room temperature and ambient pressure CO₂ is a colourless, odourless gas that will not support combustion or human life. CO₂ has been recognised as a workplace hazard for over a century. It is significantly heavier than air and many fatalities from asphyxiation have resulted from entry into pits, tanks, sumps or cellars where CO₂ has accumulated and displaced oxygen.

It is also possible for dangerous levels of CO₂ to form out-of-doors in trenches, depressions or valleys. This is particularly likely when the gas is colder than the surrounding air, which may occur following pressurised release.

In 2000, a US Environmental Projection Agency study on CO₂ related incidents in fire scenarios reported that since 1975 there were 51 recorded incidents involving the discharge of CO₂ fire extinguishing systems resulting in 72 deaths and 145 injuries.
There is no significant inherent human response to CO₂ that could be useful as a detection mechanism. Human response to hydrogen sulphide by smell occurs at very low (ppm) concentrations, similarly with ammonia and sulphur dioxide.

In contrast, CO₂ is present in the air we breath (0.037%). This may cause problems with instrumented detection because the 'background' CO₂ levels are so high. In addition, the cooling effects of a pressurised CO₂ leak may have an adverse effect on the accuracy and operability of CO₂ gas detection systems.

The recognition of the dangers of CO₂ has prompted much research into its toxicity in both human volunteers and animals. It is now known that, in addition to the problem of asphyxiation due to the displacement of oxygen, the inhalation of elevated concentrations of CO₂ can increase the acidity of the blood triggering adverse effects on the respiratory, cardiovascular and central nervous systems. Data from published research reports has been used by HSE to quantify the toxicity of CO₂ in the form of Dangerous Toxic Load (DTL)¹ values.

The DTLs have been used in calculations by the Health and Safety Laboratories (HSL) to demonstrate that CO₂ exhibits major accident potential, when transported by pipeline in large quantities at ambient temperature and at a pressure of 7 bar or more, well below the dense phase or supercritical region. It is not yet clear whether controls should be applied to the transport of CO₂ in this context but pending further research, it is possible that HSE will propose amending the Pipelines Safety Regulations to include CO₂ as a dangerous fluid.

Additional hazards of dense phase or supercritical carbon dioxide

For economic and technical reasons it is likely CO₂ will be handled close to or above its critical pressure (73.82 bar) where many of its properties are similar to that of a liquid. In this state it is often referred to as a dense phase fluid, whereas above critical temperature (31.04oC) and pressure it is referred to as supercritical. Most of the additional hazards associated with dense phase or supercritical CO₂ arise when this pressure suddenly falls or is lost completely.

Scale of the thermal cooling envelope

In the event pf a major pressure loss, e.g a pipe rupture or containment failure, the depressurisation will result in an increase in the volume occupied by the CO₂ of several hundred fold as the escaping fluid undergoes a rapid expansion (and phase change) as a proportion essentially 'boils' and becomes a gas while the remainder forms solid particles. This rapid, violent expansion causes the temperature of escaping CO₂ to fall very rapidly, frequently below -80°C. while the particles of solid CO₂ formed (dry ice) will result in projectiles expelled at very high velocities.

Cryogenic burns and impact injuries from extremely cold jet of gas and entrained missiles are serious hazards to personnel. Cryogenic embrittlement of structural steelwork and adverse effects from the impingement of extremely cold gas jets on safety-critical equipment are major threats to the structural and functional integrity of nearby plant unless appropriately designed or protected.

Toxic contamination effects

Supercritical CO₂ is a highly efficient solvent. When supercritical CO₂ undergoes a significant pressure reduction it moves from its supercritical state with super solvent properties to a gaseous state with virtually no solvent capability. In any environment where other substances are present with supercritical CO₂ their solvation will occur resulting in fluid medium or "solution" containing various compounds or elements many of which may be extremely toxic. Any toxic substance held in such a pressurised 'solution' will 'precipitate' out on loss of pressure or containment and is likely to result in harmful human exposure or environmental damage due to the contamination of the area of deposition unless appropriate measures are taken.

Dry Ice 'grit blasting effects'

Where captured CO₂ may be present with solid particles such as reservoir-derived sand and other solid debris, loss of containment may result in these combining with the dry ice formed to produce particles of a much greater abrasive capability than dry ice alone. This would enhance the erosion effects on process pipework and vessels adjacent to the leak which could lead to further damage to equipment and hence risk to people.

Specific challenges associated with dense phase or supercritical carbon dioxide

Whilst the processes that make up Carbon Capture and Storage (CCS) are not novel in themselves there is relatively little experience worldwide in managing the risks associated with CO₂, compared with oil and gas. The major accident hazards presented by handling high pressure CO₂ offshore or onshore need to be considered in the context of about 10,000 years' operating experience in managing hazards associated with hydrocarbon processing offshore alone, and probably much more if onshore processes are included². In comparison there are probably less than 100 operating years for handling CO₂ and significantly less in dealing with supercritical CO₂.

Modelling dense phase/supercritical CO₂ releases

The ability to anticipate foreseeable major accident scenarios and accurately predict the consequences of these hazardous events is a fundamental element in the assessment of the risk. A lack of substantial operation experience in a novel process or technology generally leads to significant difficulties in identifying accurately the hazards associated with that process or technology.

We do not yet fully understand the behaviour of CO₂ when released from dense phase. Industry is researching appropriate models which will need to be validated. There is a need for appropriate scale experimental work to provide HSE and duty holders with a thorough understanding of how CO₂ behaves during foreseeable large releases.

Containment and integrity

Whilst there are applicable general engineering standards, there is a lack of internationally recognised standards and codes of practice specifically for dense phase or supercritical CO₂ plant and equipment. When designing, fabricating and maintaining plant for handling and transporting CO₂ it is important that the full significance its physical properties, at the temperatures, pressures and inventories required are fully recognised and managed accordingly. Where applying standards developed for other substances including hydrocarbons, such as natural gas, extreme caution is advised as even the highest standards for many other substances may not be sufficient to ensure adequate containment for CO₂ under the expected, and unexpected operating envelope(s).

Deep-Sixing CO2 Emissions

http://articles.latimes.com/2006/sep/03/science/sci-northsea3?pg=2

"By Robert Lee Hotz
September 03, 2006

Until recently, however, few cared so much about how long the carbon dioxide stayed put.

That is starting to change. Since 2000, the North American energy company EnCana Corp. has boosted oil production 50% at Weyburn, Canada, by injecting millions of tons of surplus CO2 from North Dakota. Plans call for at least 20 million tons in all to be sequestered permanently there in coming decades -- an amount equal to the annual emissions of 6.8 million cars.

So far, monitoring indicates that most of it will stay underground but, by one report, about 2,500 tons a day bubble to the surface where it must be recaptured and re-injected.

Critics of the storage operations worry about the long-term safety of the reservoirs. No one knows whether excess carbon dioxide will remain stable underground for hundreds or thousands of years.

"If it can find any well, crack or conduit in the rock, it will escape," said Harvard carbon storage researcher Kurt Zenz House.

With more than 3.5 million oil wells drilled in the U.S. since petroleum exploration began in earnest 150 years ago, there is no shortage of potential leaks.

Experts also worry how so much carbon dioxide will alter the chemistry of the storage formations themselves. Bubbles composed of millions of tons of sequestered CO2 could form an acid that could etch away the confining rocks or erode the concrete caps on well heads.

To test the effects of carbon dioxide storage, researchers funded by the U.S. Department of Energy recently injected 2,000 tons -- about half a day's power plant emissions -- into a mile-deep well northeast of Houston.

After monitoring the site for two years, researchers at the U.S. Geological Survey found no leaks.

But in a study made public in July, they did discover that the buried CO2 increased the acidity of the saltwater in the rock enough to dissolve the surrounding minerals. Should enough minerals be eaten away, the gas could seep slowly into the atmosphere again, they reported. The acidic solution also could combine with trace metals and organic compounds to contaminate groundwater."

CO2 Sequestration - How Secure Does This Make You Feel?

I think this is frightening - 2 Articles

How safe is CO2 sequestration? How much do the experts really know?
Remember - the largest portion of these experiments are paid for by taxpayers!

Article #1) January 24, 2007 - "Participants were asked to formulate questions and identify research needs to be addressed as EPA prepares to develop a scientifically-sound management strategy for CO2 injection."
(they are listed in the article - several pages of questions) -


Article #2) THREE months later -An announcement saying the well was ready for CO2 sequestration in Shadyside, OH

At that time, there were already MORE "CO2 sequestration Demonstration" projects on the radar for Ohio....... and all over the world...with many more in progress.


"State Regulators Workshop on Geologic Sequestration of CO2
The Environmental Protection Agency (EPA), in coordination with the Department of Energy’s National Energy Technology Laboratory (NETL), and the Ground Water Protection Council (GWPC) held a workshop on geologic sequestration of carbon dioxide (CO2) on
January 24, 2007 in San Antonio, Texas. At the workshop, representatives of state governments, EPA Regions, DOE research laboratories and Regional Partnerships, industry, non-governmental organizations (NGOs), academia, and other interested parties met in small groups to discuss issues associated with CO2 injection for the purposes of geologic sequestration (GS).

Participants were asked to formulate questions and identify research needs to be addressed as EPA prepares to develop a scientifically-sound management strategy for CO2 injection. The participants were organized into groups of 8 to 10 people, with each group having a mix of representatives from EPA regions, states, industry, research institutions, academia, and NGOs, to allow for sharing various points of view. The group discussed the following topics: site characterization; modeling; area of review (AoR); injection well construction; mechanical integrity testing (MIT); measuring, monitoring, and verification (MMV); closure and post-closure care; and liability and financial responsibility."

Click here for the entire article You will WANT TO READ this article.



Then - just 3 months later -

Issued on: April 24, 2007

"Regional Partnership Completes 8,000-foot Well for Critical Carbon Sequestration Assessment

Midwest Regional Carbon Sequestration Partnership Prepares for Test of Geologic Carbon Sequestration in Appalachian Basin

Washington, DC - The Midwest Regional Carbon Sequestration Partnership (MRCSP) has completed an 8,000-foot well at FirstEnergy's R. E. Burger Plant near Shadyside, Ohio, in preparation for a geologic sequestration field test. Sponsored by the Office of Fossil Energy's National Energy Technology Laboratory, the field test will determine the feasibility of storing CO2 in deep saline formations in the Appalachian Basin.

"The carbon sequestration field test in the Appalachian Basin is an important step in turning the promise of carbon sequestration into a reality," said Acting Assistant Secretary for Fossil Energy Tom Shope. "By assessing carbon storage in an area of the country that produces 20 percent of the nation's electricity, the test helps pave the way toward a future in which America's abundant fossil resources can be used to produce energy without contributing to global climate change."

Read the rest of the article here

From the web site - http://www.counterpunch.org/blair01232007.html

January 23, 2007

King Coal's Latest Con Job

Clean Coal is Not Clean

By JOHN BLAIR

Proponents of Integrated Gasification Combined Cycle (IGCC) technology like that Duke and Vectren desire to use at Edwardsport, Indiana, loudly proclaim that IGCC is the answer to global warming since the technology makes its easier to capture carbon dioxide. Once captured, their pitch is that it can be "sequestered" for thousands of years in deep geological formations. Out of sight, out of mind.

In December 2006, the US Department of Energy finally admitted in a supplement to an Environmental Impact Statement (EIS) for an IGCC plant in Pennsylvania that, "DOE has considered the potential to reduce project CO2 emissions using geologic sequestration. This is not a reasonable option because sequestration technology is not sufficiently mature to be implemented at production scale during the demonstration period for the proposed facilities."

This admission is consistent with most recent research done by government and private sources as it relates to sequestration. In fact, most recent research tells a story that makes the whole idea of sequestration questionable, at best, and perhaps even dangerous for those who may live near the areas where CO2 is dumped underground.

Three areas of concern have emerged in recent studies.

1. CO2 injected near earthquake faults like the region of SW Indiana which is in the New Madrid fault zone, may actually increase the potential for earthquakes due to CO2's ability to lubricate geologic plates, making it easier for them to move when subjected to pressure from beneath the earth's surface.

2. Injection of CO2 can ultimately damage groundwater used for drinking by a chemical conversion when the CO2 is injected causing an increase in acidity which leaches dangerous chemicals like metals out of the formation. Those contaminants often find their way to groundwater. Such a chemical conversion could render entire aquifers unusable as drinking water which people depend upon.

3. Huge financial and energy investment in sequestration. Most of the debate about IGCC has evolved around whether it is possible to convert coal to a synthesis gas in a manner that can be used to generate electricity more cleanly than conventional technology called pulverized coal. The real reason utilities are seeking to build these plants is to capture enormous federal and state taxpayer funded subsidies. For instance, Duke and Vectren were recently awarded more than $133 million in federal tax credits to build their costly and dirty plant.

This wrongly labeled "clean coal" has proven to be somewhat cleaner from an air pollution standpoint than pulverized coal but missing from the debate has been a real assessment of what to do with the captured chemicals that are by-products of the process, what the cost of actually building and operating these facilities will be on a commercial scale, how much of the energy produced will be required to run the sophisticated chemical processes required thus reducing the overall efficiency of the plants and what is the actual cost of capturing the CO2 and permanently storing it in some underground geological formation.

As it currently stands, not a single one of these IGCC proposals addresses any of these issues in any great detail. Not only that, but most IGCC proposals are not even promising carbon capture, let alone sequestration.

Add to that the fact that the costs of building proposed IGCC plants has completely gone through the roof. In Minnesota, government documents have recently revealed the cost of Excelsior's Mesaba IGCC has gone to at least $2.155 billion for a 603 MW facility. That's a whopping $3.5 million per megawatt, higher than projected cost for nuclear plants these days. It is also true in Indiana where Duke Energy president, Jim Rogers told the media a couple of months ago that the cost of their Edwardsport IGCC plant had increased in cost to build from $1.3 billion in early 2006 to what is now in excess of "$2 billion" for 630 megawatts. That is a per MW cost of $3.17 million and rising. Neither of these facilities have projected the cost to capture and sequester carbon which most estimates suggest will be at least another 50% in construction costs and a big unknown as to what it will cost to actually capture and store the CO2 in operational costs.

Using the conservative 50% figure, the cost of the Edwardsport plant to construct could rise to $4.75 billion or more than $7.5 million/MW. Contrast that with the ill fated Marble Hill Nuclear plant which was forced to stop construction in 1984 due to its rising costs. PSI (now Duke) said originally in 1973 that Marble Hill would cost $700 million for 2,260 MW ($309,000/MW). When it finally went through hearings in 1977, the cost had doubled to $1.4 billion ($619,000/MW). When the state of Indiana forced PSI to stop construction by telling them they would not guarantee that they would allow the plant to be placed into PSI's rate base, the construction costs had risen to $10 billion ($ 4.4 million/MW).

The comparison with IGCC technology and nukes is valid. Both were risky ventures that required significant government support to be economically feasible at all. Both stood to make their sponsors extremely high profits since they are guaranteed a profit based on their level of investment. (With Marble Hill the allowed rate of return was about 8%, now Duke and Vectren seek a 12% rate of return.)

When the cost of building coal plants rises to a certain level, ALL alternatives should be on the table. Ecological destruction when mined, multiple health problems when burned and contaminating our drinking water when the waste is dumped into aquifers and streams are abundant reasons why alternatives to coal should be pursued.

Who can list a single "Coal community" as prosperous? Indeed, it is the opposite. Coal is the bane of those forced to live near coal, not our economic salvation.

John Blair is president of the environment health advocacy group, Valley Watch and earned a Pulitzer Prize for news Photography in 1978. He can be reached at: Ecoserve1@aol.com

Missouri utilities seek cap on liability from carbon sequestration

From an article by Chad Livengood • clivengood@news-leader.com • March 25, 2009

Jefferson City - Fearing the federal government may soon start taxing carbon emissions, Missouri utility companies are seeking caps on legal liability for injuries sustained from the process of carbon sequestration.

Carbon sequestration is the process of capturing carbon dioxide emissions from smoke stacks and injecting the harmful greenhouse gas into geological formations.

City Utilities of Springfield is currently leading a $3 million pilot project to test the viability of the emerging technology at its 1,000-acre power plan on the city's southwest side. "


"CU officials and lobbyists for municipal and investor-owned power companies testified Tuesday before a House committee in favor of a bill limiting liabilities for potential accidents resulting from this technology to $2 million per site and $300,000 per individual."

It goes on to say -

"Supporters of the legislation say there is no harm in the process of drilling down 2,000 and pumping carbon dioxide emissions into Missouri's sandstone deposits.

But critics of the legislation questioned why the utility companies need legal liability protection if there's no danger involved.

“If there's no risk, there's no harm. If there's no harm, then there's no liability. If there's no liability, then there's no need for a waiver of liability,” said David Klarich, a lobbyist for the Missouri Association of Trial Attorneys."

WARNING - CO2 Sequestration Danger - What goes into the ground is NOT bubbles or carbonation!

It is supercritical CO2 and carries a lot of risks -

The full article is here - some excerpts from the article are below

Health hazards from CO2

"At room temperature and ambient pressure, CO2 is a colourless, odourless gas that supports neither combustion nor life. It is not just an asphyxiant but also has toxicological effects and has been recognised as an occupational health hazard for more than a hundred years.

Dense phase and supercritical CO2 give rise to additional hazards particularly when the pressure suddenly falls or is lost completely."

Further information on the cryogenic, traumatic and toxicological effects



General hazards of carbon dioxide

At room temperature and ambient pressure CO2 is a colourless, odourless gas that will not support combustion or human life. CO2 has been recognised as a workplace hazard for over a century. It is significantly heavier than air and many fatalities from asphyxiation have resulted from entry into pits, tanks, sumps or cellars where CO2 has accumulated and displaced oxygen.

It is also possible for dangerous levels of CO2 to form out-of-doors in trenches, depressions or valleys. This is particularly likely when the gas is colder than the surrounding air, which may occur following pressurised release.

In 2000, a US Environmental Projection Agency study on CO2 related incidents in fire scenarios reported that since 1975 there were 51 recorded incidents involving the discharge of CO2 fire extinguishing systems resulting in 72 deaths and 145 injuries.

There is no significant inherent human response to CO2 that could be useful as a detection mechanism. Human response to hydrogen sulphide by smell occurs at very low (ppm) concentrations, similarly with ammonia and sulphur dioxide.

In contrast, CO2 is present in the air we breath (0.037%). This may cause problems with instrumented detection because the 'background' CO2 levels are so high. In addition, the cooling effects of a pressurised CO2 leak may have an adverse effect on the accuracy and operability of CO2 gas detection systems.

The recognition of the dangers of CO2 has prompted much research into its toxicity in both human volunteers and animals. It is now known that, in addition to the problem of asphyxiation due to the displacement of oxygen, the inhalation of elevated concentrations of CO2 can increase the acidity of the blood triggering adverse effects on the respiratory, cardiovascular and central nervous systems. Data from published research reports has been used by HSE to quantify the toxicity of CO2 in the form of Dangerous Toxic Load (DTL)1 values.

The DTLs have been used in calculations by the Health and Safety Laboratories (HSL) to demonstrate that CO2 exhibits major accident potential, when transported by pipeline in large quantities at ambient temperature and at a pressure of 7 bar or more, well below the dense phase or supercritical region. It is not yet clear whether controls should be applied to the transport of CO2 in this context but pending further research, it is possible that HSE will propose amending the Pipelines Safety Regulations to include CO2 as a dangerous fluid.

Additional hazards of dense phase or supercritical carbon dioxide

For economic and technical reasons it is likely CO2 will be handled close to or above its critical pressure (73.82 bar) where many of its properties are similar to that of a liquid. In this state it is often referred to as a dense phase fluid, whereas above critical temperature (31.04oC) and pressure it is referred to as supercritical. Most of the additional hazards associated with dense phase or supercritical CO2 arise when this pressure suddenly falls or is lost completely.

Scale of the thermal cooling envelope

In the event of a major pressure loss, e.g a pipe rupture or containment failure, the depressurisation will result in an increase in the volume occupied by the CO2 of several hundred fold as the escaping fluid undergoes a rapid expansion (and phase change) as a proportion essentially 'boils' and becomes a gas while the remainder forms solid particles. This rapid, violent expansion causes the temperature of escaping CO2 to fall very rapidly, frequently below -80°C. while the particles of solid CO2 formed (dry ice) will result in projectiles expelled at very high velocities.

Cryogenic burns and impact injuries from extremely cold jet of gas and entrained missiles are serious hazards to personnel. Cryogenic embrittlement of structural steelwork and adverse effects from the impingement of extremely cold gas jets on safety-critical equipment are major threats to the structural and functional integrity of nearby plant unless appropriately designed or protected.


Toxic contamination effects

Supercritical CO2 is a highly efficient solvent. When supercritical CO2 undergoes a significant pressure reduction it moves from its supercritical state with super solvent properties to a gaseous state with virtually no solvent capability. In any environment where other substances are present with supercritical CO2 their solvation will occur resulting in fluid medium or "solution" containing various compounds or elements many of which may be extremely toxic. Any toxic substance held in such a pressurised 'solution' will 'precipitate' out on loss of pressure or containment and is likely to result in harmful human exposure or environmental damage due to the contamination of the area of deposition unless appropriate measures are taken.


Dry Ice 'grit blasting effects'

Where captured CO2 may be present with solid particles such as reservoir-derived sand and other solid debris, loss of containment may result in these combining with the dry ice formed to produce particles of a much greater abrasive capability than dry ice alone. This would enhance the erosion effects on process pipework and vessels adjacent to the leak which could lead to further damage to equipment and hence risk to people.


Specific challenges associated with dense phase or supercritical carbon dioxide

Whilst the processes that make up Carbon Capture and Storage (CCS) are not novel in themselves there is relatively little experience worldwide in managing the risks associated with CO2, compared with oil and gas. The major accident hazards presented by handling high pressure CO2 offshore or onshore need to be considered in the context of about 10,000 years' operating experience in managing hazards associated with hydrocarbon processing offshore alone, and probably much more if onshore processes are included2. In comparison there are probably less than 100 operating years for handling CO2 and significantly less in dealing with supercritical CO2. For Example, the Sliepner CO2 disposal project has been operational since about 1996 while in the USA, CO2 injection into wells has only been carried out over the last ~40 years.


Modelling dense phase/supercritical CO2 releases

The ability to anticipate foreseeable major accident scenarios and accurately predict the consequences of these hazardous events is a fundamental element in the assessment of the risk. A lack of substantial operation experience in a novel process or technology generally leads to significant difficulties in identifying accurately the hazards associated with that process or technology.

We do not yet fully understand the behaviour of CO2 when released from dense phase. Industry is researching appropriate models which will need to be validated. There is a need for appropriate scale experimental work to provide HSE and duty holders with a thorough understanding of how CO2 behaves during foreseeable large releases.

Containment and integrity

Whilst there are applicable general engineering standards, there is a lack of internationally recognised standards and codes of practice specifically for dense phase or supercritical CO2 plant and equipment. When designing, fabricating and maintaining plant for handling and transporting CO2 it is important that the full significance its physical properties, at the temperatures, pressures and inventories required are fully recognised and managed accordingly. Where applying standards developed for other substances including hydrocarbons, such as natural gas, extreme caution is advised as even the highest standards for many other substances may not be sufficient to ensure adequate containment for CO2 under the expected, and unexpected operating envelope(s).

Unique Potential Hazards of Carbon Dioxide Injection

These excerpts are taken from the same, well-written article I referenced in the last two posts. I have broken this article into bite-size pieces for your convenience. Click here to read the entire article.


"While deepwell injection of liquids has occurred safely for over 20 years, there is less experience with injecting gasses like CO2. While most CO2 injections for enhanced oil recovery have occurred safely, problems that have occurred illustrate the unique hazards that utilities and regulators must consider. A few of these potential hazards include the following.

Blowout
Well blowouts occur when gas escapes through old or unknown wells. In January 2001,a natural gas leak from a cracked gas well casing leading to salt caverns and used as a natural gas storage facility resulted in an initial gas explosion below two stores in downtown Hutchinson, KS. The initial gas explosion was followed by an eruption of natural gas and water geysers two miles east of the initial explosion later that day and for several days thereafter. Two people residing in a trailer home were killed as a result of one of the explosions. The gas leak originated from a cracked well casing at a depth close to 600 feet and proceeded to migrate horizontally, traveling along abandoned brine wells and ultimately reaching the surface some distance away from the initial explosion.62

In another case involving CO2, a blowout occurred during drilling at a production well in March 1982 causing the free flow of CO2 at the well head and leakage from ground fractures directly above the site. The high rate of CO2 from the well caused containment not to occur until the following month.63

The report issued a number of recommendations including: determining the potential for CO2 migration along unsealed fault and fracture zones; the potential for magmatic or seismic activity to cause damage to sealing caps resulting in CO2 releases; the potential for wells to transport CO2 to the surface; and implementation of public education and CO2 monitoring programs to minimize impact to human health and the environment from releases.65

The risk of blowout is hard to quantify since there is little information on the number of abandoned wells in the United States. It is difficult to estimate the number of these wells since some do not have observable caps or metal casings that can be detected through sensors. Texas estimates that there are approximately 11,000 orphan abandoned wells that it is gradually closing through a state program.66

Operators of CCS injection wells will have to find, close, and cap abandoned wells within the Area of Review.62

Economic Damage
The saline formations in Texas produce some oil and gas in formations nearby or overlaying the potential injection formations. In addition to well blowout, less apparent seeps from the injection zone into oil and gas producing layers can dilute the value of these deposits and ultimately return the CO2 to the atmosphere.67

Corrosion
As CO2 rises to the top of the injection layer, it may contact closed wells or the cement casings of older wells. If the CO2 reacts with water to form acidic compounds, these acids could start to erode the concrete. As more is eroded, the process accelerates, creating a reinforcing-negative cycle that could allow the CO2 to rise up the abandoned well to drinking water layers. While this problem can be prevented through different well closure approaches, the potential problem will increase the cost of an applicant’s Area of Review study and demonstration.68

This paper does not outline the necessity to deal with other issues such as amending state drinking water laws or amending federal environmental laws such as the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); Endangered Species Act ESA), Resource Conservation and Recovery Act (RCRA), and CERCLA’s Natural Resource Damage Assessment Act (NRDA). These issues have been addressed by other APPA papers located at www.appanet.org/files/HTM/ccs.html"

CO2 leakage through existing wells: current technology and regulations

"Preexisting wells and well bores are high-permeability pathways through the crust, and as such present zones of elevated risk to CO2 storage projects."

Read the full article here - from MIT

Dangers of CO2 Sequestration in Sandstone Formation

From the New Scientist Print Edition, March 27, 2008 article by Fred Pearce -

"Coal produces around three times its own weight of CO₂. This will all have to be pressurised, liquefied and moved to a site where it can be interred at depths of a kilometre or more, where the pressure will ensure that it stays liquid.

How secure would these burial grounds be? Opponents of CCS schemes recall the disaster in 1986, when a million tonnes of CO₂ belched from the bottom of Lake Nyos in Cameroon. Being denser than air, the gas formed a blanket that asphyxiated some 1700 people. Though the event was entirely natural, it has left a potent image of what could go wrong. As Bert Metz, co-author of a 2005 report on CCS by the Intergovernmental Panel on Climate Change, says: "Public acceptance is a possible show-stopper if things are not done properly."

Geologists don't dismiss the possibility of a catastrophic release, after an earthquake perhaps. But they see slow seepage as at least as important a concern. To prevent climate change, CO₂ has to be stored safely for millennia. Even a leakage rate of 0.01 per cent a year - a suggested industry standard - would see almost two-thirds of the gas gone within 10,000 years. The legal question of who has long-term responsibility for stored carbon is also unresolved, and it could prove as convoluted a debate as that over nuclear waste. No surprise, then, that next to designing a capture plant, assessing the leakage threat is the major research focus for CCS."

Susan Hovorka of the University of Texas, Austin, the project's principal investigator,points out, " geologists will be under pressure to find burial sites close to power plants, where the rock formations may be less than perfect. "We know how to recognise an excellent site," she says. "But we need confidence about when to screen out sites that are too risky." She also admits there is no method yet for deciding how much CO₂ a particular rock formation can absorb before leaking, and how to spot if things are going wrong


The furthest-advanced project is a test site at which engineers have injected 1600 tonnes of CO₂ into a sandstone formation known as the Upper Frio on the Gulf coast of Texas. The rock, which once contained oil, is now flooded with salt water. An early report on the Frio project, published in the journal Geology by Yousif Kharaka of the US Geological Survey, points to a possible danger of storing CO₂ in formations like these. The CO₂ has acidified the brine, allowing it to dissolve metal-oxide minerals in the rock, and this, Kharaka says, might eventually create tunnels in the cap rock through which CO₂ might escape.

An article about the Greenville, Ohio project, can be found by clicking here........as you read it, make sure you note the words used over and over......"TEST" TESTING"
In their own words from that site -

"The Midwest Regional Carbon Sequestration Partnership (MRCSP)1 is one of seven partnerships established by the U.S. Department of Energy (DOE) to test the feasibility of geologic sequestration."

"The carbon dioxide would be stored permanently deep below the ground under the plant."

This statement suggests that it would all be contained right there, not migrate off their property.

"The site has geology that is likely to be suitable for carbon dioxide storage. The Mount Simon
Sandstone, which underlies the site, is the largest potential geologic reservoir for carbon
sequestration in the Midwest. The test will enable geologists to learn more about the capacity of this deep formation, which underlies parts of Ohio, Kentucky, Michigan, Indiana, and Illinois and is estimated to have the capacity to store a large fraction of carbon dioxide emissions from large coal fired power plants in the Midwest for many decades."

"By the completion of the project in 2018, the injection site will be closed and will be returned to near the original condition that existed prior to implementation of the geologic storage demonstration test."


I ask you, HOW can the site be returned to "near original condition" after 1 million metric tons of supercritical CO2 is permanently injected into the ground......... who monitors this site afterwards? Who has the legal liability should YOUR home be damaged or destroyed in an earthquake as a result of this 'TEST" "EXPERIMENT"?


"CO2 measurement and monitoring approaches for subsurface processes have yet to be proven at the temporal and spatial scales relevant to geologic sequestration. While the current capabilities are not an impediment to undertaking CCS, monitoring and verification approaches will likely benefit from lessons learned through demonstration and early projects."

(Benson S. and L. Myer, 2008, “PIER white paper on Monitoring to Ensure Safe and Effective Geologic Storage of Carbon Dioxide.,” Assessment of Geologic Carbon Sequestration in California, E. Burton and R.Myhre, Eds. PIER Energy‐Related Environmental Research, C‐500‐2008‐009.)


"the ability to assess carbon sequestration risks will improve with time and with experience. Especially in the early years, each sequestration site is not just a place to get rid of CO2; it is also an experiment that will provide valuable data for use in future sequestration efforts." (http://www.energy.ca.gov/2007publications/CEC-500-2007-100/CEC-500-2007-100-CMF.PDF)