Subject: Re: OXY Petroleum and NetPower
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.

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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)