I have been wondering for years why solar powered pyrolysis wasn't being used to recycle plastics. I thought it could reduce ALL plastics to an oil soup kinda like crude, which could then easily be separated by a distillery into various useful hydrocarbon oils for making new plastics/fuels. However now I'm starting to understand: the resulting soup is more toxic than crude and is difficult/expensive to distill, while the volatile byproducts that don't condense are another toxic liability. Bummer.
Garbage In, Toxics Out
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Re: Garbage In, Toxics Out
#22Earlier quoted context omitted.
I don’t see how sending plastics to a dump is going to result in ocean micro plastics. Environmentally you’re inefficiently generating energy from trash and reducing landfill size from bring trash vs failing to sequester the carbon in the trash and releasing some air pollution. I doubt pyrolysis is a net gain. Properly constructed and operated landfills are a small source of methane, but otherwise quite benign.
"Properly constructed and operated landfills" which prevent leakage of microplastics and toxic decomposition products into air and waterways are far from being cheap, especially on longer time frames and with involved volumes (more than 80M metric tonnes per year just in US!). Usually, you either end up with slack maintenance, resulting in eventual pollution of the environment, or you export this waste into third wor…
Dumps are the ultimate expression of surface area vs volume.
A single 2200 acre landfill can handle 5 million metric tons per year for ~250 years. 80M metric tons isn’t a particularly big issue from an environmental or cost issue it’s all a question of collection and transportation to disposal sites not long term storage.
Re: Garbage In, Toxics Out
#23Earlier quoted context omitted.
I don’t see how sending plastics to a dump is going to result in ocean micro plastics. Environmentally you’re inefficiently generating energy from trash and reducing landfill size from bring trash vs failing to sequester the carbon in the trash and releasing some air pollution. I doubt pyrolysis is a net gain. Properly constructed and operated landfills are a small source of methane, but otherwise quite benign.
>I don’t see how sending plastics to a dump is going to result in ocean micro plastics Because that tends to only happen in a few, what we consider, first world nations. A huge portion of the world does not have sanitary waste collection system, and therefore produces huge amounts of plastic waste that get into rivers and the ocean. Of even in places with waste collection, an (un)healthy amount of plastics never make…
An incinerator isn’t going to solve the lack of a waste collection system. It’s a completely orthogonal issue.
Re: Garbage In, Toxics Out
#24Why are we still not talking about plasma gasification? https://en.wikipedia.org/wiki/Plasma_gasification As far as I can tell, the only real "disadvantages" if you can call them that, are: 1. more expensive than throwing the garbage in a big pile somewhere 2. need to clean it from time to time 3. not necessarily a profitable business Other than that, it can handle just about anything that's not radioactive, can be d…
I am glad you shared that link. I always wondered if we could just use plasma to get rid of waste. I figured it would be technically possible but prohibitively expensive, so I am happy to see the economics work out in some use cases. Skimming through the article, they mention that the plant needs lots of maintenance and frequent downtime, I am not sure how that would work out with the navy's high availability expectations for the carrier fleet.
Re: Garbage In, Toxics Out
#25Since the transition to electric vehicles will take decades (and some, like aircraft, may never fully make the switch), perhaps the synfuel generated from this pyrolysis can substitute for virgin petroleum. It could help make many parts of the world more energy-independent and less obligated to rely on the Middle East for oil.
The oil to make the original plastics has already been extracted, so it would be a carbon-neutral solution for the most part, especially if some of the plastics are burned to drive the process.
THe ultimate solution, though, is to lessen our dependence on plastic (Reduce), and completely eliminate single-use (Reuse).