Various posts on the list mention that House et al or APS have demonstrated 
that DAC costs 1000 or 600 $/tCO2. One might respond that other academic papers 
by folks like Lackner or Eisenberger have demonstrated that's its cheap.

Neither assertion seems true, and both go beyond the claims in the literature 
itself.  (E.g., the APS report was careful not to say that their cost was for 
all air capture, but rather that it was for a particular design they devised 
for the report and that other designs might be cheaper.)

It would be great if you could figure out the cost of some not-yet-commercial 
technology by just doing an academic study or holding a panel.

In fact, academic papers are often a poor source of information on the costs of 
technologies that are already commercial, let alone on technologies that are in 
early phase development.

If you want good cost estimates of a particular design one needs to go to 
industrial engineer from engineering firms with experience in the relevant area.

At Carbon Engineering we are trying to do just that working iteratively between 
design and costing, were we work with engineering firms to do our costing using 
standard methods. nuts-and-bolts engineering. We then try to reduce specific 
technical risks by building an operating prototypes.



Regarding the APS study and the recent Calgary meeting. For my part I think the 
interaction with the APS authors has driven home to me the fact that 
differences in our cost estimates arise from differences in design rather than 
from differences in cost mythology (e.g., capital charge factor, contingency, 
and scaling factor between bare equipment costs and installed costs.) I think 
the APS cost estimate for their system is sensible. But, no group developing 
air capture is proposing to build a system using the APS design.



For our design the big questions are: (a) is our costing reasonable and (b) can 
we manage the risks?



We have comments on the APS report at 
http://www.carbonengineering.com/?page_id=17, and we have a paper accepted at 
Philosophical Transactions A of the Royall Society that gives many more details 
of the engineering and costing of our contactor. It suggest that the cost of 
our contactor design (without a backend) would be about 60 $/tCO2. I will post 
a final version of that paper by Monday.



Finally, on a more personal note. Greg Rau has asked why folks like me work on 
DAC since other CDR technologies (e.g. Greg's clever Ca dissolution scheme) 
are, in his view, obviously better. In a post from October 09, 2011 Greg ended 
one of these posts with a dig saying, "perhaps we can borrow from (the amazing) 
marketing skills of the physicists [promoting DAC]" to push the technologies 
Greg views as more sensible.



In answering it's worth noting that I have worked technology assessments of 
many CDR technologies including some of the early work on biomass with capture 
and on project to assess geochemical carbon management and specifically the 
addition alkalinity to the ocean. As part of these efforts I have seen the 
details of some real business estimates of the cost of CO2 mitigation using 
biomass with CCS and biomass burial. I have spent time working with the 
engineers at Babcock and Wilcox who did the costing study of Greg and Kens very 
clever Ca dissolution method. More recently I have also been supervising the 
student whose work hard on a scheme to make MgO from magnesium silicates.



I am a technological agnostic. If I thought that one of these clearly dominated 
DAC on cost, scalability and environmental impact I would not waste any time on 
DAC. This is not a claim that air capture will necessarily be useful or that it 
necessarily trumps other methods. I think more hard-nosed research on all of 
these methods, their costs and environmental impacts is essential.


-- 
You received this message because you are subscribed to the Google Groups 
"geoengineering" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/geoengineering?hl=en.

Reply via email to