Ask HN: Is anyone pursuing longshot tech for recycling / remediating landfills?

6 points by in_vestor 2 years ago | 7 comments

I have had a lifelong interest in cleaning up trash—-something that’s probably rooted in deep-seated aesthetics and maybe a bit of OCD.

My first career was in standard finance/tech and left me with enough flexibility to try to do something I’m really passionate about.

I have rigorously followed the academic literature and commercial development of recycling tech. It has been a disheartening journey. Recycling doesn’t work as well as people think. Promising solutions like plasma gasification had lots of engineering and economic challenges. A recent push in Europe for landfill mining went nowhere.

What is really needed is a single stream solution where almost any material can go in the front end, and out the back end comes useful elemental products or inert products.

Is anyone working on long-shot technology that would do this? If so, I would like to network. I’m not interested in something to make incremental changes around the edges. I’m interested in the type of tech that would be revolutionary.

giantg2 2 years ago |

I haven't heard of anything that actually works. I would maybe look at prevention as an alternative - things like compostsble packaging, reduction in packaging, bring your own packaging (zero waste lifestyle), etc.

PaulHoule 2 years ago |

See https://www.explainthatstuff.com/plasma-arc-recycling.html

in_vestor 2 years ago | |

This is what I referenced in my post as plasma gasification.

It has been tried in the real world. Belgium planned to use it for landfill mining, and Britain planned to built two plants to process fresh trash. But this has all been shut down at this point due to engineering challenges and economic challenges.

I’m trying to find out if there is anyone out there trying to still plug away at this and make progress?

PaulHoule 2 years ago | | |

Which post?

It's hard to believe something like that gets a net energy yield from burning the syngas, also technologies around syngas seem to struggle when competitive fuels are available.

The construction material bit is definite downcycling and even that sort of plasma torch might destroy PFAS it is (i) not going to destroy or isolate toxic metals like like and (ii) it is not going to extract various precious materials that are widely dispersed in waste: so low-value outputs can't really be good.

I've heard that the plasma torch can be tuned up to separate elements, at least coarsely, and if it could produce high value products it would be a big help.

My understanding is there really is no shortage of landfill space there is more of a political unwillingness to build more landfills. There is a huge interest in a "circular economy" but that precludes downcycling and of course making products recyclable is a start.

Another I find interesting is that very similar chemistry is being proposed for battery recycling as is used for reprocessing spent nuclear fuel, it seems a technology similar to PUREX could be tuned up to extract just about anything out of a mixture of everything in the periodic table but probably not economically. Similarly there are all the "pyroprocessing" techniques based on molten salts and such that are not so discriminatory as PUREX but more so than the plasma torch.