If it's used to generate electricity or usable heat and not only to get rid of it, plastic would substitute for another fuel, so it's not as simple as looking at co2 from burning plastic vs co2 from dumping it in landfill.
I don't have numbers, but if burning plastic replaces some coal or fracked natural gas, that could be a win, all things considered.
Burning plastic is both dirtier and less efficient than burning at least oil and natural gas. So you will actually pollute more (both CO2 and various other byproducts) by burning plastic than by burning oil and methane to get the same amount of energy out.
Not to mention, to get usable energy out of the plastic, you have to invest lots of energy for recycling it first - you need infrastructure and education to collect it separately from other trash, you need additional processing to sort it by type, to clean it of many other residue, etc.
And evwn if you do all that fairly efficiently, you're still never going to collect a large percentage of the plastic people use. So any extra environmental impact from plastic in landfills will still be there and need to be resolved.
> Burning plastic is both dirtier and less efficient than burning at least oil and natural gas. So you will actually pollute more (both CO2 and various other byproducts) by burning plastic than by burning oil and methane to get the same amount of energy out.
My argument is not that burning plastic is more efficient than burning whatever fuel. My argument is that extracting, transporting and burning waste plastic may be more efficient than extracting, transporting, and burning whatever fuel. Waste to energy might need a lot less transportation if the plants are near where the waste is generated and/or where it is already collected.
> Not to mention, to get usable energy out of the plastic, you have to invest lots of energy for recycling it first - you need infrastructure and education to collect it separately from other trash, you need additional processing to sort it by type, to clean it of many other residue, etc.
There's already sorting and education for recycling, so the question becomes what's the incremental input needed to get a usable waste to useful energy pipeline.
> And even if you do all that fairly efficiently, you're still never going to collect a large percentage of the plastic people use. So any extra environmental impact from plastic in landfills will still be there and need to be resolved.
Yes, but I don't know how that relates? My argument is that the emissions of burning plastic for usable energy might not be as bad as it looks because it would reduce lifecycle emissions from (direct) fossil fuels. That's not an argument for or against burning plastic, it's an argument that we need to get marginal emissions numbers for the alternatives, and if emissions is the only criteria, then it would make sense to burn plastic in cases where the marginal emissions are in favor of burning it; but even that wouldn't be universal. It might make more (or less) sense to setup trash for energy plants in isolated locations where transport of other fuel is difficult; it almost certainly makes less sense to setup trash for energy plants in places where natgas is a waste product, natgas is a clear choice there.
I don't have numbers, but if burning plastic replaces some coal or fracked natural gas, that could be a win, all things considered.