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Comment by api | Hacker News Reader

The utility of recycling depends a whole lot on the material.

(1) Is the material common?

(2) Is recycling it less energy intensive than mining/refining it?

(3) Is it nasty in a landfill? Does it leak, pollute groundwater, etc.?

Aluminum, batteries, electronics, significant amounts of steel, etc. make a lot of sense to recycle. In some cases it's quite profitable without any subsidy. Glass and paper on the other hand, not so much. Paper is an agricultural product, and glass is mostly SiO2 which is an absurdly common material (sand).

As usual the truth here is a lot more complex than the sound bites.

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Moving from Sweden to California, the recycling system here is still completely bewildering to me, and makes very little sense.

Where I'm from, recycling started by grabbing simple low-hanging fruit. Newspapers. Aluminium cans. Glass bottles and jars. And it doesn't all go into one "recycling bin", but each thing is separated. Later, that expanded so you can now also recycle metal cans, plastic containers and cardboard. If you want to.

And the default was never landfill, instead all household trash is incinerated for heat and electricity. Sweden even imports trash to burn! And in the case people throw the "wrong" things in general trash, the incinerators can handle it, they're very good at exhaust filtering, and I bet you can even mine the residue for rare materials.

And that all makes sense to me. I can see the economics of it, and I can see the environmental impact of sorting. But the California system of one big "recycling" bin that you're supposed to throw god-knows-what in is completely opaque to me. How does anything useful come out of that? How much labour is needed to sort it at the station?

There's videos on YouTube of "single-stream" MRF facilities. I think Ars Technica just visited one and did a story on the machines involved. They use all sorts of cool tech like computer vision to sort flakes of plastic with tiny jets of air, eddy currents and magnets to sort metal and sonic imploders to disintegrate glass.

There are people involved to pull out things that would jam the machines, but generally it's fairly automatable.

Inside New York City’s newest recycling center - Machines use science to separate a stream of waste into valuable raw materials.

http://arstechnica.com/science/2015/01/inside-new-york-citys...

Recycling in the US: An off-again, on-again love affair - It became a booming industry despite facing a series of intractable tradeoffs.

http://arstechnica.com/science/2015/03/recycling-in-the-us-a...

This article discusses some of the problems in the "one-bin" system.

http://www.washingtonpost.com/local/dc-politics/american-rec...

Of course, though in systems where the material is sorted for collection, there's a significant amount of value added for free (in fact, it's double-dipping for the haulers, since they charge for their service, and sell the sorted materials). Now, my impression from looking at curbside sorting in my neighborhood is that the value-add is not great, lots of marginal or flatly forbidden things are mixed in, so I understand that human beings still eyeball everything once more, on a conveyor belt, and then automated sorting separates things further, neither of which are free...

I think you might be making the common mistake of confusing "for free" with "using unpaid labor".

I wonder whether it takes more carbon emissions to recycle paper than it does to dump the paper in a big old landfill and sequester its carbon away, and manufacture some new paper.

http://epa.gov/epawaste/conserve/tools/warm/pdfs/BackDocFore...

Exhibit 4 has some numbers you'd probably find useful, such as the benefit or recycling in terms of tonnes of Carbon per ton of paper recycled. It looks like about 0.6-0.75 tonnes of Carbon per ton of recycled paper.

also depends where you are. If physical space is at a premium, extending a community's landfill's life by diversion can be worth the cost.

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