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MIT engineers make converting CO2 into useful products more practical

(news.mit.edu)
173 points rbanffy | 10 comments | 13 Nov 24 15:42 UTC | HN request time: 0.418s | source | bottom
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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.

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ulrikrasmussen ◴[13 Nov 24 16:32 UTC] No.42127501[source]▶
Isn't it also used as input to basically every e-fuel which can replace fossil hydrocarbons?
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1. analog31 ◴[13 Nov 24 16:56 UTC] No.42127726[source]▶
No. The value of commercial co2 is its energy content -- what it takes to process it into useful form. There is no useful form of co2 for making fuel. The energy has already been extracted.
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2. ◴[13 Nov 24 17:05 UTC] No.42127833[source]▶
3. jvanderbot ◴[13 Nov 24 17:06 UTC] No.42127856[source]▶
You're right (current state of the art), but also wrong (in the spirit of the question as I read it).

If energy prices go down, e.g., from continuing decline of solar, then it may be very cost effective to store energy as hydrocarbons which are synthesized from cheap energy + CO2. E.g., make natural gas from the air and sell it cheaper than it could be extracted and transported.

In this scenario, rather than paying exorbitant fees for CO2, the cheap energy could be used to extract it from the atmosphere where it is abundant.

Before anyone bites my head off - consider the tyranny-of-the-rocket-equation problem of burning gas to transport gas from source (wells, refineries, etc) to consumers. Then consider that the sun shines most places, and CO2 is effectively uniformly distributed. So Synthesis wouldn't have to be cheaper at the source if it can beat the price at the consumer via avoiding huge distribution costs.

4. SoftTalker ◴[13 Nov 24 17:11 UTC] No.42127903[source]▶
Exactly right. FTA: "The electrochemical process that converts CO2 into ethylene involves a water-based solution and a catalyst material, which come into contact along with an electric current"

That "electric current" is the challenge. It takes energy to convert CO2 into other chemicals. If that energy isn't carbon-neutral, you're just spinning your wheels.

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5. ulrikrasmussen ◴[13 Nov 24 17:48 UTC] No.42128272[source]▶
I'm not sure if we are talking past each other, but: https://en.wikipedia.org/wiki/Electrofuel

Electrofuels, also known as e-fuels, are a class of synthetic fuels which function as drop-in replacement fuels for internal combustion engines. They are manufactured using captured carbon dioxide or carbon monoxide, together with hydrogen obtained from water split.

It is my understanding that there is actually a shortage of concentrated co2 if we want to produce e-fuels as drop-in replacements in e.g. planes.

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6. pwg ◴[13 Nov 24 17:58 UTC] No.42128357[source]▶
> If that energy isn't carbon-neutral, you're just spinning your wheels.

True, but the "long term" angle here would be to supply that energy from, say, excess solar generation during midday after the overnight storage batteries are refilled.

7. analog31 ◴[13 Nov 24 18:37 UTC] No.42128674[source]▶
All ideas for "fuels" hinge on the future availability of an economical energy source, which would have to be either solar or nuclear.
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8. outworlder ◴[13 Nov 24 20:50 UTC] No.42129862{3}[source]▶
I wonder what happened to the Navy's attempts at synthesize aviation fuel in aircraft carriers. They have plenty of power (newer carriers have even more) and reducing or eliminating the need of support craft for fueling would be a massive bonus.

They've been looking at that for a while, I don't know what issues they encountered.

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9. thinkcontext ◴[13 Nov 24 22:21 UTC] No.42130794{4}[source]▶
They couldn't get it to be efficient enough.
10. ulrikrasmussen ◴[14 Nov 24 04:27 UTC] No.42133163{3}[source]▶
Yes of course, I am not claiming otherwise.

My point was just about the scarcity of concentrated co2.