MIT engineers make converting CO2 into useful products more practical

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.

Isn't it also used as input to basically every e-fuel which can replace fossil hydrocarbons?

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.

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.

All ideas for "fuels" hinge on the future availability of an economical energy source, which would have to be either solar or nuclear.

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.