I’ve had a few colleagues mention this story on making jet fuel out of industrial waste.

“This fuel takes waste, carbon-rich gases from industrial factories, and gives them a second life so that new fossil fuels don’t have to be taken out of the ground,” Virgin Atlantic founder Richard Branson told The Guardian. He added that this flight was a big step toward making the new fuel blend part of the mainstream…

Jennifer Holmgren, LanzaTech’s chief executive, said that her company has shown that recycling waste carbon emissions into jet fuel is possible. She added that we should look at waste carbon as an opportunity, because it can be reused again and again.

I did a little more research and what is happening here is that “waste” from the factories contains hydrocarbons that can be distilled into ethanol. This is a good idea, clearly. I just want to point out that there are only two possibilities here: either these people have come up with a perpetual motion machine allowing the same fuel to be “reused again and again”, or else the second law of thermodynamics is still in effect. I would tend to bet on the latter. Snark aside, what it must mean is that the energy source was always there, but technology has improved to the point where it can now be recovered economically. If that’s the case though, I wonder why the factories involved wouldn’t want to make use of the technology to improve their own efficiency while reducing their waste. If that is now an economical thing to do, it seems like that might be more efficient to do onsite rather than capture the waste somehow, concentrate it, transport it, process it, then transport it again. Unless there is some significant economy of scale involved that makes it all work. Anyhow, you can’t really be against energy efficiency or reduced pollution and greenhouse gas emissions, so bravo everyone.