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This post is about OXY and its CO2 capture efforts. That is not particularly important to BRK’s OXY investment at this point, but could be in the future. So it's not totally off-topic.

OXY has generated a lot of publicity about its efforts to remove CO2 from air - DAC. I’ve expressed my doubts about that process in past posts. I won’t repeat them here. But they involve both the difficulty/cost of removing such a dilute amount of CO2 (400 ppm) combined with the complexity of their process. Their timetable seems overstated to me.

However, I’ve run across another process where OXY is involved that could be a lot more promising. They are the largest investor in a company called NetPower. NP is progressing a modified electricity power plant design that burns natural gas, but generates very low CO2 emissions.

The problem with existing natural gas power plants is the cost and difficulty of removing CO2 from the emissions stream. This is because of still low CO2 concentrations – few percent. When you burn natural gas with air, you’re taking in four times as much nitrogen as oxygen. This dilutes the stream driving the turbines and the effluent stream -it’s just along for the ride.

NetPower’s idea was to use pure oxygen for combustion, taking out the nitrogen beforehand in an air separation plant. This does two things. It permits much higher CO2 concentrations in the effluent gases. It also produces a CO2/H20 stream to drive the turbines rather than a CO2/H2O/N stream. This permits higher thermal efficiency, generating more electricity. This extra electricity is used to power the air separation plant. It is much lower cost to remove the CO2 from this high concentration CO2 effluent stream. The output from such a plant is comparable to the CO2 from renewable energy plus battery storage. Making batteries and building wind turbines generates CO2, so wind and solar are not CO2 free.

Since gas powered power plants can operate around the clock with fast startup/shutdown, they are necessary to balance the intermittent outputs from wind and solar. This low CO2 alternate would be very attractive to utilities.

Here is a easy to watch youtube link describing the process:

https://www.youtube.com/watch?v=uodNxMUp5dY

And here is a link to a detailed presentation of the process:

https://tinyurl.com/dzeh3mr8

The NetPower process has been demonstrated in a large pilot plant in LaPorte Texas and the first commercial scale unit is being built at an OXY facility in Big Spring Texas.

There are always issues to be addressed in new technologies. One is the higher combustion temps from burning natural gas with pure oxygen can require design and material improvements to the power turbines. So there’s still work to be done.
But this process makes sense to me. And it could ultimately help the DAC OXY process. The latter requires a lot of energy. The NetPower process could be an attractive source of such energy down the road compared with wind and solar.

Just passing along something of indirect interest to BRK investors.

OXY has generated a lot of publicity about its efforts to remove CO2 from air - DAC. I’ve expressed my doubts about that process in past posts. I won’t repeat them here. But they involve both the difficulty/cost of removing such a dilute amount of CO2 (400 ppm) combined with the complexity of their process. Their timetable seems overstated to me.

...


But this process makes sense to me. And it could ultimately help the DAC OXY process. The latter requires a lot of energy. The NetPower process could be an attractive source of such energy down the road compared with wind and solar.



The economics of this direct air capture (DAC) process obviously make no sense, without heavy subsidies, but that doesn't mean they might not EVENTUALLY get the cost down. I doubt it, but it's not impossible.

But I do question whether this whole idea makes any sense environmentally, either. The basic idea is that you remove very dilute CO2 from the environment, currently 421 parts per million, up from 280 ppm, which means about 0.04% of the atmosphere, and then you pump it underground where it has no greenhouse gas effect.

If you power this process with extremely cheap wind and solar power, then it makes no economic sense (it costs orders of magnitude more to do this than the carbon-based fuel that caused the CO2 emission), but at least it makes a small amount of environmental sense. But if you do this with electricity that comes from burning fossil fuels (probably methane), then you still have to capture that messy exhaust gas from your generating plant. Air is 80% N2, so burning CH4 with ambient air (the usual process) makes the emission stream messy, since it will be about 80% nitrogen. Concentrating the oxygen from about 20% to 100% before burning the methane would certainly clean up the emissions stream and simplify carbon capture, because burning methane (CH4) with pure oxgen (O2) you will get CO2 and H2O and no nitrogen.

But if this was economically feasible, it would be something which could already be be done to enormously reduce CO2 emissions, without getting DAC involved.

So I share your view that concentrating the O2 in which CH4 is burned may eventually make carbon capture feasible, and this seems like a reasonable thing to do research on. But then using the power generated this way to do DAC makes a lot less sense than doing it with renewable power when it is not needed (windpower at night, for instance.)



Not to mention that the whole DAC idea is even crazier than the economics and the chemistry suggest, because of politics. China is famously building a new coal-fired plant every 2 weeks, because it's slightly cheaper than nuclear power. So who is going to such that CO2 back out of the air, at thousands of times the cost differential between coal and nuclear power? America? Yeah, right. This would be a way of guaranteeing that China catches up to US prosperity even more quickly than it's happening already.

(btw, your 2nd link doesn't seem to be working)

The NetPower process has been demonstrated in a large pilot plant in LaPorte Texas and the first commercial scale unit is being built at an OXY facility in Big Spring Texas.

I have always wondered how would "we" store all the CO2 that needs to be sequestered to have this be meaningful?

Burning fossil fuels produces about 40 billion tons a year of CO2. The CO2 actually weighs more than the fossil fuels did since C weighs 14 and each oxygen weighs 16 so more than 2/3 of the weight of CO2 comes from the oxygen in the air attached to it.

So you have some idea about the infrastructure required to get something like 40 billion tons a year of fossil fuel to burn, the 5 million oil wells in the US alone, the coal mines moving mountains to get the coal etc. To put back just the carbon just at a rate that we would negate further increase in CO2 from our yearly fossil fuel usage seems like an incredibly massive undertaking.

Now you may have noticed that if CO2 weighs more than 2X as much as C without the O2, that we could conceivably remove the O2 from the CO2 and have nice dense blocks of Carbon, and could probably sequester them by, say, digging holes in the ground and burying the carbon. There is one problem that makes this approach INCONCEIVABLE. And that is the entire way we got useful energy from the carbon in fossil fuels was by oxidizing it. It would cost us AS MUCH ENERGY AS WE HAD GOTTEN from the carbon in the fossil fuels to pull the O2 off the carbon in order to drastically simplify the sequestration challenge.

Indeed, if we were to sequester by taking the O2 off C and buring the C, we would have invented the inverse-coal-mine. It would be cheaper to just buy coal mines and shut them down, leaving the black carbon in them already buried, then to suck CO2 out of the air and apply massive amounts of energy to pull the O2 off it and then spend energy burying the C (Carbon) underground. Don't take it out in the first place and save everybody a lot of time, money, and trouble.

But if any of you reading this thread have some idea how we are planning to sequester an amount of CO2 which is larger than the mass of fossil fuels we removed from the ground in the first place, I'd be interested in knowing.

This would seem to be an essential piece of information in taking CO2 sequestration even a little bit seriously, and not just performative "interpretive climate dance" with which oil companies can entertain the hoi polloi.

Cheers,
R:)

RaplhCramden, can't you recognize a scam when you see it?

RaplhCramden, can't you recognize a scam when you see it?

Is it better or worse than the ethanol scam?

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