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This is interesting. I still have a couple of questions though: - PLA degrades very, very poorly in landfills [0], which leads me to think that if you were to
by jszymborski 3y ago
This is interesting. I still have a couple of questions though:
- PLA degrades very, very poorly in landfills [0], which leads me to think that if you were to dig boreholes and dump PLA inside it, wouldn't it effectively sequester the CO2 w/o releasing much/any CH4?
- PLA (as far as I know) is produced from glucose derived from e.g. corn. In theory this is a process which sequester CO2 from the air and puts it into solid blocks. No fossil fuels or fossil fuel extraction required.
So I guess my question is, what's the catch? I suppose agriculture has its own CO2 footprint, but I feel we've gotten pretty efficient at making glucose.
[0] https://all3dp.com/2/is-pla-biodegradable-what-you-really-need-to-know/ https://all3dp.com/2/is-pla-biodegradable-what-you-really-ne...
- Retric 3y agoThe catch is only ~1% of plastics are bioplastics. The rate of PLA > CH4 in from landfills is basically irrelevant due to everything else we are dumping down there which more easily turns into CH4. As to dumping PLA down bore holes. You can just burry the plant matter without turning it into PLA. So there’s little reason to turn plant matter into PLA to burry unless you have some other use for the PLA at which point it’s a small portion of your waste stream.
- jszymborski 3y agoIn my hypothetical situation, we're producing PLA for the sole and expressed purpose of sequestering CO2. My reasoning was that PLA degrades less readily than plant matter, so less likely to release CH4. But I hadn't thought of the fact that if you bury plant matter deep enough, CH4 emissions likely aren't as high a concern.