How do you feel about plasma gasification to ensure robust destruction of anything non-inert? I love landfills too! But humans are various shades of tricky, lazy, cost adverse, and untrustworthy (think limited liability) as it pertains to long term custodianship and management of things bad for people and the environment.
TLDR You must engineer around the human. Potentially harmful physical matter that requires waste management? Default to destruction vs storage, if at all possible. You have now defaulted to success instead of failure.
The big problem with plastic waste is getting it to the landfill (or incinerator) in the first place.
Once the plastics are captured, I don't see too much benefit in incinerating it beyond freeing up landfill space. But that's really not a major issue as you can always dig a deeper and wider landfill.
In fact, a major downside of incinerating the plastic is you end up with greenhouse gasses as a byproduct.
Certainly, you are generating some greenhouse gasses in the process, which is a trade off to ensure immediate waste destruction. To note, you will have to flare methane from the landfill in perpetuity when landfilled. If one is so inclined, internalize the cost of direct air carbon capture into the cost of waste disposal for those emissions.
> Municipal solid waste (MSW) landfills are the third-largest source of human-related methane emissions in the United States, accounting for approximately 14.4 percent of these emissions in 2022. The methane emissions from MSW landfills in 2022 were approximately equivalent to the greenhouse gas (GHG) emissions from more than 24.0 million gasoline-powered passenger vehicles driven for one year or the CO2 emissions from more than 13.1 million homes’ energy use for one year. At the same time, methane emissions from MSW landfills represent a lost opportunity to capture and use a significant energy resource.
TLDR Whether landfills or gasification, you are paying the piper regardless for emissions. Don't trust the human, pull forward the disposal.
While I might be wrong, I seriously doubt the plastics creating the methane emissions you are referring to. That is almost certainly the organic matter.
I have no idea how you think plasma gasification -- requiring extreme amounts of energy -- is in any way helpful to our current environmental concerns. Unless we somehow magically start relying on 100% renewables, it seems like landfills are far-and-away the best way to go until we are able to grapple with climate change.
Money. Landfills aren’t cheap to operate and burning also reduces transportation costs.
Incineration ends up being quite profitable in isolation. Take stuff worth negative X$ per ton and turn it into a smaller pile of stuff still worth negative X$ per ton. Generating power is a useful side effect, but not the main reason.
By the end of this year, the world will be deploying 660GW of solar annually. Within 18 months, that figure rises to 1TW/year (based on current manufacturing ramp trajectories).
On the contrary, I’m unsure how you think we don’t have the clean power for this, not even accounting for the power you can generate from the syngas that is a byproduct of the process. The process is not energy positive, but it’s also not wildly net negative due to the energy content of the matter being gasified.
> Plasma gasification uses around 800 kilowatt-hours (kWh) of power per ton of municipal solid waste (MSW).
Because solar isn't balanced and we haven't fixed the duck curve. We're burning obscene amounts of nat gas, petroleum, and even coal currently. Until those numbers are at-or-near zero, every ounce of renewable electricity needs to be offsetting dirty electricity.
> Because solar isn't balanced and we haven't fixed the duck curve.
Well, landfill management is something you could (mostly) only run whenever you have excess (solar) power on the grid. So it's an excellent consumer for intermittent generators.
Think when these plants would come online. Think when solar and storage will be up to speed on the grid. Skate to where the puck is going to be. Think in systems. To say no today because of current state today is irrational and ignores the data. Enough sunlight falls on the Earth within ~30-60 minutes to power all of humanity for a year, and an enormous global clean energy flywheel is coming up to speed (first solar, with batteries right behind).
I've been trying to advocate for slowing climate change since about 2000. I've been to enough city council meetings, and seen enough government promises simply abandoned to know that this is a deeply naive way to just "expect" the world to suddenly become rational.
Let's stop the actively bleeding artery that is actively killing us before we even start to worry some efficiency gains we could get by asking the surgeon to do two things at once.
This is the difference between an environmentalist and an "environmentalist."
We need to fix climate change now. Get to carbon neutral now. Literally nothing else matters much.
It’s not human rationality, it’s cold, hard economics (scoped to renewables and storage uptake). Climate change is already happening, and there is nothing you can do to stop it immediately, just as you will get killed stepping in front of a freight train. You can only build systems that can attempt to outrace it to slow it down (various efforts to achieve net zero in a domain), and then eventually reverse it (an efficient, scalable carbon sequestration solution to existing atmospheric carbon load, powered by clean energy) over the next ~100-150 years.
A substantial portion of the duck curve problem is overproduction at no-peak hours. Plasma gasification can take that excess strain off the grid and put it to useful work, while even providing a by-product that you can burn in the event that all of your renewables are underperforming, reducing the risk of relying on renewables.
It is literally (part of) a solution to the problem you're bringing up.
> Until those numbers are at-or-near zero, every ounce of renewable electricity needs to be offsetting dirty electricity.
That’s not realistic. You can and probably will have a complete excess of renewable energy on bright and windy days that is well beyond electrical demand, and at the same time rely on baseload power during still nights. Energy storage helps even things out, and plasma gasification is one possible way to store that energy.
Point taken. Though I do wonder how much of the methane released is from plastic decomposition and how much of it is from food/biomaterial decomposition. I'd naively assume the primary emission would come from readily decomposable materials and that most plastics would remain fairly stable for a lot longer than yesterday's half eaten hamburger.
Indeed, waste sorting might improve the situation, but all available evidence indicates there is no will to do this (caveats being parts of Europe, Japan, the Nordics, and anywhere else diverse multi stream waste management can be effectively operated), which leads me to believe gasification is the superior path (with a bypass stream for glass, brick, earth, rock, and metals, primarily to prevent process efficiency reduction during gasification but also for reuse of those materials).
Hardly the best solution, but I argue the least worst solution. Landfilling is just too much risk considering leaching from lining failures (putting water tables and aquifers at risk from permanent contamination) and the lifetime of methane destruction that must be accounted for.
I'm generally down on sorting unless you have a lot of one particular type of waste. If you are not generating a full truck worth of that type of waste every week sorting efforts mean more trucks (since the truck with compartments for each type cannot hold as much waste because of the compartments, and also it has to go empty when one compartment fills). Combine that with the need verify the sorting was done correctly and it isn't worth it. We have made trade progress on automated sorting machines that solve a lot of problems - lets instead ban things that cannot be automatically sorted.
What has been successful in my city, Portland, is separating the food and yard waste. The food and yard wastes are composted. Composting produces methane, but there is a trial to capture the methane which is burned as natural gas.
Capturing methane from compost should be easier than whole landfill. It also keeps the organics instead of losing them.
A wrinkle I read somewhere - organics in traditional landfills kept toxic materials like heavy metals "locked up", less risk of such stuff leeching out in the ground water.
Reads like it's worth than just straight up incineration. At least with current technologies. (Apart from perhaps the installation on that American military ship. Maybe. But that's just because they have unusual requirements.)
Interesting point I hadn't thought of! Had previously thought that obviously things should go straight in the ground to avoid CO2 emissions and hadn't thought about decomposition.
Not OP but long been intrigued by possibilities in this domain (ever since Changing World Technologies promised to, um, change the world -- not plasma based but same proposition).
I've yet to see a truly viable solution in this space that can economically compete; it would be nice to see it happen.
TLDR You must engineer around the human. Potentially harmful physical matter that requires waste management? Default to destruction vs storage, if at all possible. You have now defaulted to success instead of failure.
https://news.ycombinator.com/item?id=38994374
https://news.ycombinator.com/item?id=38722984
https://en.wikipedia.org/wiki/Plasma_gasification