←back to thread

MIT engineers make converting CO2 into useful products more practical

(news.mit.edu)
173 points rbanffy | 5 comments | 13 Nov 24 15:42 UTC | HN request time: 0.477s | source
Show context
mchannon ◴[13 Nov 24 16:27 UTC] No.42127456[source]▶
The writer appears to be under the impression that CO2 is not a valuable commodity.

In fact, it is, so long as it's under enough pressure, and in the right place. In Montezuma County, Colorado, sits the McElmo dome, an ancient underground CO2 well. They pump it out, down a 500 mile pipeline, to Denver City, Texas, where it gooses oil wells into pumping more crude out. Other than making more oil and making it cheaper, not really much in terms of greenhouse gas contributions- the CO2 starts underground and ends up underground.

Kinder Morgan won't just let you back up your truck and buy some (it's already spoken for), and even if they would, they'd expect you to pay a pretty penny for what we widely consider to be waste gas.

I think MIT is doing some good work. Just wanted everyone to be mindful of the massive scale under which CO2 is already getting bought and sold.

replies(7): >>42127501 #>>42127714 #>>42127942 #>>42127946 #>>42128043 #>>42128376 #>>42130689 #
alexose ◴[13 Nov 24 16:55 UTC] No.42127714[source]▶
It's not that CO2 isn't valuable on its own, but that other carbon-containing molecules are even more valuable (especially when factoring in transportation costs). This helps prove out the technoeconomics of carbon capture.

Plus, if we wind down oil extraction, we'll need new processes to produce all the precursors we use for plastics. A cheap pathway to ethylene from captured CO2 and water would be huge.

replies(2): >>42128701 #>>42134196 #
1. euroderf ◴[13 Nov 24 18:41 UTC] No.42128701[source]▶
> A cheap pathway to ethylene from captured CO2 and water would be huge.

Is it considered cheap if the marginal cost of a PV MWh is close to zero ?

replies(2): >>42135273 #>>42149196 #
2. rcxdude ◴[14 Nov 24 11:43 UTC] No.42135273[source]▶
The energy costs are only part of the equation, though. Especially if your plan is to use excess renewable energy, the cost of your plant is a much bigger concern, because you can't run it all the time.
replies(1): >>42139921 #
3. euroderf ◴[14 Nov 24 19:07 UTC] No.42139921[source]▶
Marginal cost. And one might reasonably expect fixed costs too to keep dropping, altho not as spectacularly quickly.
4. jjk166 ◴[15 Nov 24 17:52 UTC] No.42149196[source]▶
How close to zero? 1 MWh at 100% efficiency is enough to convert 180 kg of CO2 to ethylene (note this only produces 51 kg ethylene). Annual excess carbon emissions are 36.8 trillion kg of CO2. At a cost of $0.10 per MWh, which is about 3-4 orders of magnitude lower than it currently is, that's still $20 Billion per year. A cheaper pathway is still going to save an incredible amount of money even if solar power got ridiculously cheap.
replies(1): >>42150208 #
5. euroderf ◴[15 Nov 24 19:47 UTC] No.42150208[source]▶
$20 Billion per year worldwide is chump change. But that's 3 or 4 orders of magnitude away eh ?