[devops_monkey]

This is actually the "best" answer for our plastics problem. There was an NPR/Planet Money podcast on it recently here: https://www.npr.org/2020/09/11/912150085/waste-land and there are plenty of other sources that all agree on this premise. I have worked in waste management a few years ago and recycling is not the long-term solution.

[wang_li]

Why do we want to put the plastic's carbon into the atmosphere instead of back into the ground where it came from?

[ars]

Because then we can avoid pumping oil out of the ground and burning that.

The hydrocarbons are going to get burned one way or another, you can just trade one type for another types.

[Supermancho]

> you can just trade one type for another types

You cannot replace most oil-based fuel with incinerators. So I'll disagree there.

The utility of oil-based fuels is the energy density in combustion. Burning plastic doesn't come close to the same exchange.

[ars]

> The utility of oil-based fuels is the energy density in combustion. Burning plastic doesn't come close to the same exchange.

The energy density of plastic (by weight, not volume) is virtually identical to that of oil.

Yes, the machine used to burn oil vs plastic looks different, but coal plants can burn plastic without much modification - and they would be much much cleaner than coal when they do so.

[Supermancho]

> The energy density of plastic (by weight, not volume) is virtually identical to that of oil.

Oil-based unleaded fuel is not oil. You probably could run trains on plastic. That's if you didn't mind hot plastic raining down around the tracks as the coal dust and soot did when we used it for trains.

[zarzavat]

We don’t burn oil though. We burn natural gas, in highly-efficient turbines. Burning oil and coal is obsolete technology that we are trying to phase out.

[usrusr]

Even more to the point: we can avoid digging coal from the ground, which burns even dirtier than plastics trash.

And even in the lofty goal end state of zero fossils, if it's not a complete collapse back to medieval tech (and population numbers), we would likely end up with biomass based plastics serving as packaging and the like at the upper end of that carbon's energy slope, before utilizing the remaining bound energy in an incinerator.

Biodegradable properties of grown plastics are only a last line of defense against pollution when collection has failed.

[hackernewds]

You do have significant differences between noxious fumes and clean burning between burning plastic vs burning fossil fuels. The energy captured from the burn is obviously not the same - same reason you can't just set fire to a "bowl" of plastic.

[ars]

What noxious fumes? Plastics are very clean burning if you do it properly (which isn't hard to do).

They burn MUCH MUCH cleaner that coal for example.

> The energy captured from the burn is obviously not the same

There is nothing obvious about it. I don't understand what you mean? Plastics have around the same energy density as oil.