*take nothing for granted!
Unless otherwise indicated all photos © Richard McKie 2005 - 2015

Who is Online

We have 49 guests and no members online

Translate to another language

The Chimera - also known as carbon capture and storage (CCS) or Carbon Sequestration

 

 

Carbon sequestration-2009-10-07
Carbon Sequestration Source: Wikimedia Commons

 

Whenever the prospect of increased carbon consumption is debated someone is sure to hold out the imminent availability of Clean Coal Technology; always just a few years away. 

I have discussed this at length in the article Carbon Sequestration (Carbon Capture and Storage) on this website. 

In that detailed analysis I dismissed CCS as a realistic solution to reducing carbon dioxide emissions for the following reasons:

  1. While each of the individual elements is technically achievable the scale that would be required, to make even a small difference, is breathtakingly vast.
  2. The projected capital costs are so large that they are likely to make coal sourced energy far more expensive than several low carbon alternatives; particularly nuclear power.
  3. The additional energy costs involved in gas compression, transport and injection are very significant and would involve the consumption of around a third more coal for the same energy delivered.
  4. There would thus be significant additional recurrent and mining costs in addition to faster resource depletion and environmental impacts; these too would be reflected in final energy and social costs.
  5. There will be significant safety and environmental issues that may well be insurmountable; and these impacts would extend for many thousands of years into the future.
  6. Present power stations; other points of carbon dioxide generation; the electricity grid; and transport infrastructure are not presently equipped, or located appropriately, to employ carbon capture and storage technology.

 

 

An Example

 

Here I use as an example the case of NSW Australia, for which I have current numbers in 2010.  But the same realities apply at any time, anywhere in the world.  

Around 70 Mt of black coal is consumed in NSW annually.  Major consumers are power stations, (85%), the steel industry  (6.5%) and the cement industry (1.6%). Other industry consumes the remainder.

While Australia is a major world coal exporter, the annual Australian domestic consumption of black coal is only around 1.2% of total world consumption.  Global hard coal consumption now exceeds 6,500 Mt pa; but Australian domestic consumption is less than 80 Mt pa. 

Australian exports have a far greater impact on global emissions than those at home.  Australia exported 274Mt of coal in 2009, comprising 135Mt metallurgical and 139Mt thermal coal, accounting for approximately one third of global coal exports. At current growth rates this is expected to exceed 390Mt by 2015. 

In addition to coal, every tonne of iron ore exported requires around 0.4 tonne of coal to be consumed (mainly in Asia) in its initial reduction to metal.  Similar or greater quantities of carbon are employed directly or indirectly in the reduction of most other metals from their ore.

Disposing of less than one percent of the world's carbon dioxide (CO2), just that produced in NSW, sounds pretty manageable doesn't it?  But let's put some numbers around this.

The coal burnt annually in NSW presently converts to around 200 Mt of CO2 (you can see how this is calculated in the extended paper).

 

Scale

 

So far this is just a number... so what does this mean in physical terms?

As a gas this is the vast volume; many trillions of cubic metres.  This is what presently 'goes up the stack' to threaten the climate.  So to store it it needs to be 'captured' and compressed into a liquid or solid. 

Separating the gas from the flue requires some less well proven technology but CO2 cooling and compression is an everyday, well understood, industrial activity. 

200 Mt of CO2 compresses to around 170,000 megalitres of liquid CO2.  Its weight and volume is far higher than that of the coal that went to producing it.  Transport to the storage site will be correspondingly far more difficult and costly.

 

To get a feel for this annual accumulation, it is the volume of about ten Guthega Dams, familiar to those who ski there;

 Guthega Dam  - near Jagungal Ski Lodge

 

or about a third of the volume of Sydney's annual water consumption.  But unlike water, this liquid must be kept at a high pressure otherwise it will become solid; dry ice.

I hope you are now imagining a lot of pipes - some very large and possibly very long.

 

The water supply pipes in this image are leaking, as they do from time-to-time, but CO2 needs to be pumped at around five times this pressure and must never leak.

If all this CO2 could, very optimistically, be injected into deep geological strata, to an interstitial equivalent depth of one metre, the liquid would underlie and area of 170 square kilometres; after just one year of operation. In less than a decade an area larger than the greater Sydney metropolitan area would be underlain by liquid CO2 that may remain in that state for thousands of years.

 

Energy

 

To compress this gas to a liquid requires energy; and to pump it around requires more energy; and to inject it into rock strata requires many drill holes the size of oil-wells and a great deal of pressure; more energy. 

Conservatively, this process would consume between a quarter to half of the energy generated by a power station employing the technology; and more than double the generator's capital cost.

The actual difficulties in injecting the liquid underground are not fully explored.  The technology is already in use in almost depleted oil basins on a very small scale; but it is not clear what other strata may be suitable. 

 

Carbon dioxide and the economy

 

Of course coal is not the only fossil fuel that produces CO2.  Petroleum and gas together produce more CO2 but the points of release, homes vehicles and smaller industrial sites, make capture and storage impractical. Thus no one talks of 'clean oil' or 'clean gas'.

In practice capturing all the coal sourced CO2 in NSW is technically impossible and the cost rises very rapidly with the percentage actually captured.  But if only a few percent is captured, for example from appropriately placed electricity generation, it will do little or nothing towards mitigating climate impacts and would certainly make electricity generation a lot more expensive.  These costs would be handed on to electricity consumers and industry.  Unless paid for by all CO2 producers and matched overseas, the inequitable impact of such technology has potential to seriously damage overall economic productivity.

 

Safety and the environment

 

Of additional and perhaps more significant concern is that burying CO2 may be very dangerous. If a large pocket of gas escaped, for example during an earthquake or future drilling or major earthworks it could kill every human and animal for miles around.  This has already happened as 'an act of God' on several occasions.  Most recently in 1986, at Lake Nyos in Cameroon when a sudden CO2 'belch' from the lake killed nearly 2,000 people; and all the animals in the region.

I have based this case on just 1% of the world's coal sourced CO2.  Globally coal consumption is two orders of magnitude greater and is growing on an exponential basis. 

 

Conclusion

 

Thus there is no prospect that Clean Coal technology can make a significant difference to world climate impacts from CO2; except to further accelerate resource depletion, impose higher costs through attempted 'pilot schemes' and pose unacceptable environmental and safety risks.

This, together with an analysis of the potential contribution of renewables (read more...) is why I continue to support the nuclear power as an increasing part of our energy mix.

To read about carbon sequestration in more depth click here...

 

The term chimera has come to describe any mythical animal with parts taken from various animals and, more generally, an impossible or foolish fantasy - Wikipedia.

 

Comments  

# Nodule 2017-02-04 02:00
I like nuclear power as an option with a single proviso. That the reactor and the waste be **within** the city that uses the power.
If the power production and waste storage is safe, then happy days.
I call this the "Zarra Street Solution" named for the Newcastle East NSW coal fired electricity generator.
The "Zarra Street Solution" provides many self interested eyes and hands to ensure that standards and procedures are preserved and maintained and that undesirable external influences are warded off.
Reply | Reply with quote | Quote
# Barry Cross 2017-02-11 06:19
Hello Richard. Your analysis of the "clean coal" option was very interesting. I agree nuclear seems a preferable option, one which the pollies lack the courage to even seriously discuss. The Greens in particular are blinkered on anything nuclear. With a bit more courage we might have even had a comprehensive study of the nuclear submarine option.
Cheers
Barry Cross
Reply | Reply with quote | Quote
# Chris 2017-03-16 03:34
is it necessary for emissions to reach zero before a thermal plant can be classified as clean? Stop setting up straw dogs. The challenges of CCS are undeniable. But it isn't necessary for a coal PS to reach zero emissions before qualifying as clean. Any emissions levels comparable to gas turbongenerator s- typically 400-500g/kWh - would, and should qualify as 'clean'. (or is gas also stigmatized as a dirty fuel?) If the solution of converting from coal to gas plants (as pursued in the UK to a point) got traction , then you could expect to cut CO2 emissions from the electricity sector by a good 50%. Siemens' latest turbines can do substantially better. But do not expect a plant burning much cheaper fuel- coal - to match a gas turbogen, Over-reaching is typical of political projects. If you could cut coal power station emissions by 20% for only a 20% increase in wholesale prices, it is worth pursuing. (and I suspect that is also technically achievable) But even if the local electricity sector actually achieved such a 20% reduction, would it make any perceptible difference to the global climate? Doubt it. If the entire OECD achieved a 20% reduction in emissions per kWh, it would amount to only a tenth of China's total, never mind other developing countries. If you take the problem seriously, first and foremost, talk zero population growth.

Chris
I have no argument with your final point. You will find plenty of support on this website.
Richard
Reply | Reply with quote | Quote

Add comment


Security code
Refresh


    Have you read this???     -  this content changes with each opening of a menu item


Travel

Denmark

 

 

  

 

 

In the seventies I spent some time travelling around Denmark visiting geographically diverse relatives but in a couple of days there was no time to repeat that, so this was to be a quick trip to two places that I remembered as standing out in 1970's: Copenhagen and Roskilde.

An increasing number of Danes are my progressively distant cousins by virtue of my great aunt marrying a Dane, thus contributing my mother's grandparent's DNA to the extended family in Denmark.  As a result, these Danes are my children's cousins too.

Denmark is a relatively small but wealthy country in which people share a common language and thus similar values, like an enthusiasm for subsidising wind power and shunning nuclear energy, except as an import from Germany, Sweden and France. 

They also like all things cultural and historical and to judge by the museums and cultural activities many take pride in the Danish Vikings who were amongst those who contributed to my aforementioned DNA, way back.  My Danish great uncle liked to listen to Geordies on the buses in Newcastle speaking Tyneside, as he discovered many words in common with Danish thanks to those Danes who had settled in the Tyne valley.

Nevertheless, compared to Australia or the US or even many other European countries, Denmark is remarkably monocultural. A social scientist I listened to last year made the point that the sense of community, that a single language and culture confers, creates a sense of extended family.  This allows the Scandinavian countries to maintain very generous social welfare, supported by some of the highest tax rates in the world, yet to be sufficiently productive and hence consumptive per capita, to maintain among the highest material standards of living in the world. 

Read more ...

Fiction, Recollections & News

Egyptian Mummies

 

 

 

 

Next to Dinosaurs mummies are the museum objects most fascinating to children of all ages. 

At the British Museum in London crowds squeeze between show cases to see them.  At the Egyptian Museum in Cairo they are, or were when we visited in October 2010 just prior to the Arab Spring, by far the most popular exhibits (follow this link to see my travel notes). Almost every large natural history museum in the world has one or two mummies; or at the very least a sarcophagus in which one was once entombed.

In the 19th century there was something of a 'mummy rush' in Egypt.  Wealthy young European men on their Grand Tour, ostensibly discovering the roots of Western Civilisation, became fascinated by all things 'Oriental'.  They would pay an Egyptian fortune for a mummy or sarcophagus.  The mummy trade quickly became a lucrative commercial opportunity for enterprising Egyptian grave-robbers.  

Read more ...

Opinions and Philosophy

A modern fairytale - in a Parallel Universe

 

I've dusted off this little satirical parable that I wrote in response to the The Garnaut Climate Change Review (2008).  It's not entirely fair but then satire never is.

 


 

 

In a parallel universe, in 1920† Sidney, the place where Sydney is in ours, had need of a harbour crossing.

An engineer, Dr Roadfield, was engaged to look at the practicalities; including the geology and geography and required property resumptions, in the context of contemporary technical options. 

After considering the options he reported that most advanced countries solve the harbour crossing problem with a bridge.  He proposed that they make the decision to have a bridge; call for tenders for an engineering design; raise the finance; and build it.  We'll call it the 'Sidney Harbour Bridge' he said; then less modestly: 'and the new crossing will be called the Roadfield Highway'. 

Read more ...

Terms of Use                                           Copyright