Why don't we just burn all these plastics in waste2energy plants?
Even with perfect recycling, the limitation seems to be on collection and separation.
Even with perfect recycling, the limitation seems to be on collection and separation.
> If polystyrene is properly incinerated at high temperatures (up to 1000 °C) and with plenty of air (14 m3/kg), the chemicals generated are water, carbon dioxide, and possibly small amounts of residual halogen-compounds from flame-retardants.
> When polystyrene was burned at temperatures of 800–900 °C (the typical range of a modern incinerator), the products of combustion consisted of "a complex mixture of polycyclic aromatic hydrocarbons (PAHs) from alkyl benzenes to benzoperylene. Over 90 different compounds were identified in combustion effluents from polystyrene." The American National Bureau of Standards Center for Fire Research found 57 chemical by-products released during the combustion of expanded polystyrene (EPS) foam.
Yes, you can burn it... but the things you make out of it unless you are really trying to burn it (and then its a burn it to dispose of it rather than get energy from it) leave some less than desirable compounds.
looks over at the 1300 superfund sites around the nation
Japan's approach isn't because they need energy but rather that they are trying to minimize landfill (as its an island and space is at a premium).
The resulting products are carcinogenic toxic waste - which comes with additional challenges for disposal. In the US, it is likely more desirable to bury the inert polystyrene rather than trying to deal with the PAHs ( https://en.wikipedia.org/wiki/Polycyclic_aromatic_hydrocarbo... ) and other byproducts.
The article is describing a process where UV light and a catalyst break down/transform polystyrene into diphenylmethane ( https://en.wikipedia.org/wiki/Diphenylmethane ) which is a feed stock for many other (useful) processes.
The paper referenced in the article is Cascade degradation and upcycling of polystyrene waste to high-value chemicals https://www.pnas.org/doi/10.1073/pnas.2203346119