Research group finds way to turn plastic waste products into jet fuel
phys.org
phys.org
Traditionally the only economical source of aromatic molecules has been distillation of petroleum. An economical way to turn biomass-derived simple hydrocarbons into aromatics could be revolutionary, as a path for making fuel as well as a range of other high-value compounds, like phenolic plastic resin.
And of course, taking the larger view, plastic is still made from fossil oil. Making it profitable to burn it is not going to help CO2 levels. The CO2 problem is larger than the ocean plastic problem, and even if we could turn ocean plastic into jet fuel - it's probably a bad trade.
Recycling has failed because it needs strict adherence and even then the products from plastic recycling are rarely the nice kind of plastic you need to build consumer goods.
Your plastic bag example is interesting because I think it's accurate - having plastic compete with combustion as a use for crude oil is good from an emissions standpoint, because when the wells run dry, less of it will have been burned.
(Plastic bags are indeed a bit of a silly example because there's so little plastic in them - we ban them because they cause disproportionate environmental harm)
This is not a way of solving anything per-se, but is a potential technology in an economy where we have already banned burning oil that hasn't been used a few times, and then only in things that absolutely require it.
How do you figure? It wasn't going to be burned before. Now it is.
The sustainable way to make jet fuel would be some kind of renewable-powered carbon sequestration - for example, the process described in the paper, but fed with biomass. Burning old plastic is just fossil fuel with extra steps - looked at another way, it's a way to make fossil fuel cheaper by making it earn money as plastic before it gets burned. It's not a win.
Unless we are burning it in a second load of planes built specially for the occaision, it will replace the jet fuel from virgin crude that was going to be used for those trips.
I agree that it would be better to feed it with recent biomass, though I would note that this process would also presumably work with plastic made from recent, rather than fossil biomass and we may find that making some single use plastic, (sometimes having a single use wrapper is important), from biomass and then jet-fueling it at the end, might not be a bad way to go, at least until we have developed really good power storage in other ways.
This could raise price dramatically for post consumer plastic.
From what I understand, it is the plastic we carefully collected, but didn't properly dispose of. Instead, it was sold to someone else who wasn't so careful or of dubious morals, and they didn't let it get away, they just plain threw it away. If that's truly the case, then hopefully we could cut out the inept or unscrupulous middlemen, and use it for something instead of disposing it.
Plastic is carbon that never went into the atmosphere. It's actually nicely stored away, wildlife effects aside. Once you burn it, it's like you were burning oil.
If the amount of jetfuel consumed stays the same, the amount of CO2 going into the air stays about the same. Could slightly increase or decrease depending on the processes' efficiency compared to the marginal oil producers' efficiency.
This alone doesn't mean more energy is being used.
Obviously this isn't useful if we manage to eliminate fossil fuels altogether, but we're a long way from that.
"In remote areas, we establish systems to intercept plastic waste before it ends up in landfills, gets burned, buried or tossed into rivers or oceans."
So still might be more interesting than the recycled water bottles everyone else is sourcing but maybe disingenuous for them to be using the "ocean plastic" language still.
Maybe I read too much science fiction, but I see a day in the future when we deploy autonomous technology at scale to deal with the greenhouse gasses and waste plastics of the fossil fuel era - little (or big) robots/factories that just take in energy from the Sun and use it to convert old waste into a manageable/useful form.
Realistic? I dunno. But it's certainly more hopeful than the Malthusian dystopia of shaming people for staying warm and eating and traveling.
Food, different feed-stock, ect, are all small details when you're operating at high T needed to cleave bonds to make fuel. Cleaved bond -> food molecule is no longer food
Recycling never cleaves any bonds, so the food is still there causing problems.
It's not at all obvious to me what's best: landfill, burn, or recycle. But government policy should be based on a proper analysis of those options. I have the impression that government is mostly just compromising between what industry lobbyists are asking for, in order to maximise their profits, and what the ignorant public are asking for, in response to fashion and irrationality. Let's hope that somewhere some sensible civil servants are quietly doing the right sums.
Can we get the same effect from burning coal while adding external hydrogen?