The Arc of Dominion, Fragment s22,1: D.va Mode

The war is won. Oasis and the Concordat are at peace. Overwatch has been folded up again, this time made into an intelligence arm for Helix, under new - and the UN hopes better - leadership. The Gods are free - largely - to do as they will.

Sometimes D.va just wants to try out a game - particularly if that game is using Her name without permission.

Of Gods and Monsters: The Arc of Dominion
Fragment s22,1: D.va Mode
solarbird and bzarcher

Of Gods and Monsters: The Arc of Dominion is a continuance of The Arc of Conflict, The Arc of Ascension, The Arc of Creation, and In the Beginning, There Was an Armourer and a Living Weapon. To follow the story as it appears, please subscribe to the series.

PLA, composting, recycling, and landfills

So I've been thinking a bunch about PLA - the plastic most commonly used in 3D printers, particularly at my hobby scale - and how to compost it and recycle/reuse it, and I'm still thinking of doing the latter in particular.

It's kind of a real topic in the 3D printing fora but I've been thinking about it and... I'm kind of thinking... maybe landfill is the good option.

Because here's the thing, and tell me if I'm missing something important, and I might be.

PLA breaks down safely. In a 50-60C commercial composting environment, it breaks down more than harmlessly, you can use it as brown matter in compost. In a body, it breaks down much more quickly and is again harmless - it's used medically.

People like the idea of composting PLA because - modulo additives like colourants - it breaks down so cleanly. You don't get the microplastics problem from it. That's pretty important.

But in a landfill, PLA doesn't really break down any faster than a petrol plastic. We're talking hundreds to over a thousand years, depending upon conditions.

And everybody's "well that's no better" but...

...what if that's good in this case? Since it doesn't break down in the terrible microplastics way. It still composts, it just takes ages.

Composting breaks it down to a few things, one of which is carbon dioxide.

That's bad.

But PLA is made entirely from plant matter. Corncobs are a big input stock. And it's over 50% carbon by weight. (36/71sts, 50.7%, molecular weight, roughly speaking.)

And the thing is... it's plant material. Plants get their carbon from the atmosphere, not the soil. That carbon came from the air, extracted by plants, thus removing carbon dioxide from the atmosphere.

If it breaks down, it's carbon neutral.

If it doesn't... and you put it in a landfill...

...isn't that carbon sequestration?

And that would be good.

I mean sure, it's medium-term only, but it's medium-term at a scale that gives us meaningfully more time.

I get these two 1kg rolls of PLA into a landfill and I've sequestered 1kg of actual carbon. And since what this is preventing is carbon dioxide, which has two oxygen molecules attached to that, I've prevented 3.67kg of carbon dioxide from forming.

(Modulo all the various costs in producing everything, of course, this is just about the material itself.)

Am I missing something? Because what I'm starting to think is... putting PLA in landfills sounds kinda great.