I wonder if in 100-500 years they will mine landfills for materials or elements that have become scarce. Or maybe they will just keep them as natural gas reactors.
The Engineering of Landfills
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Re: The Engineering of Landfills
#82I find it sad that the USA doesn't use more plasma burners [0] to get rid of waste. But, land is cheap in the USA, and the USA has a lot of land, so landfills win. [0]: https://en.wikipedia.org/wiki/Plasma_gasification
Yeah, would be a great way to consume free solar during the brightest part of the day.
Electricity in -> bulk chemical feedstocks out and no long distance transportation, handling and disposal costs.
The nice thing about plasma burners is that you can capture the resulting syngas and not just exhaust tons of CO2 into the atmosphere as with an incinerator.
Re: The Engineering of Landfills
#83I really enjoyed my time working at a medium sized landfill as their surveyor and civil tech. The engineering discussion in the article is spot on. We chose to reinject most of our leachate as that helps with CH4 production, and more CH4 for us meant more micro-turbines running generating us $$$ under our power purchase agreement with the local utility. The well field balancing was crucial as well, we had to not only…
What sort of substances end up in leachate, and how'd that contribute to greater CH4 production in your landfill? I was hoping that the OP post/video went into more detail on the chemistry involved.
It wasn't so much the substances, more the moisture.
A wet environment is much better for ch4 generation (was my understanding).
So we had an area that we called "the galleries" where we would rotate injecting the leachate. To keep all that stuff underneath wet (this is in southern ca, a pretty dry environment).
That was the concept anyway.
Re: The Engineering of Landfills
#84So many people misunderstand landfills. All the garbage produced in the U.S. for the next 1000 years could fit into a landfill 100 yards deep and 35 miles across on each side. That is, landfills take a trivial amount of space. Putting stuff in a landfill is way better for global warming since its not burned, the carbon is buried. Almost all plastic waste in developed countries ends up in landfills, not the natural en…
> Almost all plastic waste in developed countries ends up in landfills, not the natural environment. Here in Sweden less than 0.5% of household waste goes to landfill. Almost everything is burned in co-generation plants for district heating, with pretty sophisticated exhaust gas treatment. Unfortunately most of the plastic waste that goes into the recycling bins also end up there in the end, with only about 10% curre…
What’s completely crazy about that is that there’s people spending serious money trying to build carbon sequestration systems while other people are turning an inert and stable form of carbon back into carbon dioxide in the name of sustainability.
Re: The Engineering of Landfills
#85Earlier quoted context omitted.
IIRC, ~30%[0] of ocean plastic came from fishing nests. They are huge, break often and it’s easier and cheaper to throw aboard an old one than bring it onshore for recycling. (edit) 0: 46% https://www.seashepherdglobal.org/latest-news/marine-debris-... Totally unrelated but since it’s from seashepherd I can’t help adding Paul Watson trial from extradition in Japan is tomorrow.
Additionally, the top 10 rivers, 9 of which in Asia, produce an extremely high precent of land based ocean pollution
E.g. the bottles we sent them for "recycling"
Re: The Engineering of Landfills
#86Earlier quoted context omitted.
What sort of substances end up in leachate, and how'd that contribute to greater CH4 production in your landfill? I was hoping that the OP post/video went into more detail on the chemistry involved.
It wasn't so much the substances, more the moisture. A wet environment is much better for ch4 generation (was my understanding). So we had an area that we called "the galleries" where we would rotate injecting the leachate. To keep all that stuff underneath wet (this is in southern ca, a pretty dry environment). That was the concept anyway.
Got it, thanks!
Re: The Engineering of Landfills
#87I found this interesting: > Another option is to put it to beneficial use to create heat or even electricity. The Puente Hills landfill I showed earlier has a gas-to-energy facility that’s been running since 1987, and even though the landfill is now closed, it currently provides enough electricity to power around 70,000 homes. And towards the end > Landfills seem like an environmental blight, but really, properly des…
> I wish more environmentalists would be excited about engineering solving environmental ills and relied less on knee-jerk reactions. Are many ... not? Seems like a weird complaint, I haven't encountered an "environmentalist" (whatever that even is) that is against landfills in general or the engineering of it. I'd rather we didn't produce as much garbage as we are and I hate that our city makes me wrap my garbage in…
Search google news "environmentalist landfill" and find me one article praising the ingenuity of landfills
https://news.google.com/search?q=environmentalist+landfills&...
Here's one from 3 days ago.
Garbage Lasagna’: Dumps Are a Big Driver of Warming, Study Says
Don't gaslight me and tell me environmentalists applaud all solutions to environmental issues equally. They have their own solutions, and activists often force things like recycling at all costs, even though it means shipping it across the world on polluting boats and having some other country dump it in their rivers.
https://www.nytimes.com/2024/03/28/climate/landfills-methane...
Re: The Engineering of Landfills
#88Earlier quoted context omitted.
> Almost all plastic waste in developed countries ends up in landfills, not the natural environment. Here in Sweden less than 0.5% of household waste goes to landfill. Almost everything is burned in co-generation plants for district heating, with pretty sophisticated exhaust gas treatment. Unfortunately most of the plastic waste that goes into the recycling bins also end up there in the end, with only about 10% curre…
So it goes into the sky instead? That seems more sightly, but the CO2 emissions must be astronomical.
If we didn't burn waste we'd need to burn something else to stay warm in winter. Currently we supplement the waste with _mostly_ renewables, like byproducts from the forestry industry (e.g. treetops, wood chips, sawdust) and the olive oil industry (olive pits; we import this stuff from the Mediterranean region), but we burn a bit of peat too because there aren't enough reasonably priced renewables. Burning waste really isn't meaningfully worse than burning anything else.
After the combustion we're left with 15-20% by weight in slag; some of this is metal that is recovered and sent to recycling, but the rest is effectively gravel that is used in e.g. road construction and the like. There's also 3-5% by weight of toxic gases captured by the exhaust gas treatment. This is sent to a special facility in Norway that more or less puts it in landfill, although a very carefully managed one.
Re: The Engineering of Landfills
#89Earlier quoted context omitted.
> Almost all plastic waste in developed countries ends up in landfills, not the natural environment. Here in Sweden less than 0.5% of household waste goes to landfill. Almost everything is burned in co-generation plants for district heating, with pretty sophisticated exhaust gas treatment. Unfortunately most of the plastic waste that goes into the recycling bins also end up there in the end, with only about 10% curre…
What’s completely crazy about that is that there’s people spending serious money trying to build carbon sequestration systems while other people are turning an inert and stable form of carbon back into carbon dioxide in the name of sustainability.
Would you rather we'd burn peat (which is also sequestered carbon) instead? Because that's what we used to do. We need to stay warm in winter one way or another.
In the 1950's we thought that in the future we'd have nuclear cogeneration plants. There was one such plant (Ågesta) in commercial operation, but it closed in the mid 1970's.
edit: also, to your point about sequestration: it's in actual and literal fact the same people. The Stockholm municipal energy company burns a lot of waste (and also woodchips and other renewables) for district heating. That same company also recently closed a big carbon sequestration deal with Microsoft: https://carboncredits.com/microsoft-and-stockholm-exergi-str....
Re: The Engineering of Landfills
#90I wonder if in 100-500 years they will mine landfills for materials or elements that have become scarce. Or maybe they will just keep them as natural gas reactors.
It might even be sooner than that.
Once oil gets too expensive to pull out the the ground, mining plastic from landfills and decomposing it back to the hydrocarbons might end up big business.
The natural gas/ ch4 production follows a pretty well known curve, at about 40-50 years it's nowhere near as potent. And with the push to keep organics out of the modern landfills that might get even worse.