Sunday, November 26, 2023

Carbon Capture & Storage (CCS) Is Problematic

 In my travels on Twitter (sorry, X) this morning, I saw this, and it raises more questions than it answers:

This is a “look, it works!” statement. We had already proven that CCS was possible a decade earlier.  8,000,000 tonnes sounds like a very large number - but that works out to barely 1 Mt annually.  Alberta alone produces some 260 Mt annually just from its oil production.

There’s a red flag here.  This is a technology still very much in its infancy.  Then in October, it was announced that Oxy had sold off its plant in Texas, after never running it up over 1/3 of its stated capacity.   Even if that was a means to offset the cost of acquiring Carbon Engineering earlier in the year, something still doesn’t add up.

I don’t have access to the numbers and engineering analyses involved here, but I do have some suspicions as to what is going on: 

First, Carbon Engineering has a significant patent portfolio around CCS technologies.  That’s worth quite a bit of long term revenue to whoever owns them.  Oxy cannot be blind to that potential future revenue stream. 

Then we get into the issues that CCS faces, and here I speculate a bit more:

Think back to the days of all the hype over “clean coal”.  The idea of “clean coal” was to scrub as much of the pollutants out of the smoke from burning coal.  That more or less ended up being a matter of installing various technologies that would remove as much of the pollutants that resulted from burning coal as possible.  It was a good step forward, but it never lived up to the promise because ultimately it ran into barriers related to both cost and effectiveness.  Coal fired facilities are less polluting than they were in the 1970s, but they still churn out huge amounts of pollutions, including CO2.  

Cost comes creeping in here because businesses are still businesses, and profit matters to them.  When a given technology costs more than their revenues, it’s simply not going to be implemented, no matter how effective it is.  Instead, much of the so-called “Clean Coal” technologies developed to “good enough” levels, and stayed there. 

Now, consider CCS for a moment.  Not only does it require capturing the carbon gases, but it then requires storing them somewhere (usually an underground rock formation).  Here’s where we get into a nasty set of problems.  Separating CO2 from the water vapour and other gases is not going to be a zero cost endeavour.  It will take energy of some kind to run that process.  How much energy, and how the process behaves as it scales up is not well understood.

There is evidence that Direct Air Capture consumes as much energy as is generated by burning hydrocarbons.  I suspect that while “sequestering from the smoke stack” might use somewhat less energy, the fundamental issue remains one of “how much energy does recovering the CO2 actually use?”, with a follow-up question of “how does that energy use change as the process is scaled up?”.  This latter question is the one that is a problem for industrial scale use.  If the amount of energy equals, or exceeds, the energy generated from burning the hydrocarbons in the first place, you have a problem. A big problem. 

The other area that is problematic is compressing the gas into the storage facility.  That takes energy, and as the facility fills up, it will take increasing amounts of energy to compress (or supercompress) the captured CO2.  At scale, those kind of compressors aren’t cheap to build or operate. They’re _BIG_.  A natural gas plant tour I went on years ago had multiple compressors at the site, and they were powered by huge engines, including one that used the same jet engine that a Boeing 737 of the day used - and that was just to keep the natural gas flowing in a pipeline.  

What exactly will the energy curve look like for cramming ever increasing volumes of CO2 into an old salt cavern?  I’m not sure, but I have a feeling it’s going to be a lot more than the current plants are using. 

I have seen arguments that say this can be offset with renewables, and while that’s true, I think it is very telling that none of the current CCS facilities have ever been run anywhere near their projected capacity.

I want to be clear, I think CCS is a valid part of a larger suite of technologies needed to bring climate change under control.  I do not believe that it should be treated as a “sole solution”, nor do I believe the energy companies in Alberta when they talk in terms that emphasize this one technology as a solution for no better reason than to justify continuing to conduct business as usual.  

Further, I worry that CCS is being used primarily is a fig leaf by the oil industry.  There simply isn’t enough public data out there to convince me that CCS is anywhere near the level of development that is being implied by propaganda.  


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