3 ms·

Interesting that they are willing to pay any price the market offers, and expect to pay over $100/t. I wonder to what degree large scale burying of biomass woul

• tlb 7y ago
  The problem with burying biomass is that it gets metabolized by bacteria into CO2 and (worse) methane, which escapes into the air. Some landfills manage to capture most of the methane, but on the 100-year time scale it's not clear that burying is very effective.
  • ac29 7y ago
    The study I linked addresses that point - they suggest that "only 0–3% of the carbon from wood are ever emitted as landfill gas after several decades". I don't consider myself qualified to evaluate that claim, but it certainly seems plausible, given that wood clearly decays far slower than, for example, kitchen scraps found in household bio-waste.
  • itcrowd 7y ago
    Additionally, the required storage volume looks pretty insane (see one of the figures in the linked paper). I'm not convinced of biomass burial.
• sbierwagen 7y ago
  That paper avoids mentioning BECCS, the most extensively researched plan for carbon sequestration: reducing wood to charcoal, burning the syngas you produce during the process to generate electricity, and then sequestering the charcoal.[1] The Kyoto protocol for limiting global warming to 2C requires massive use of BECCS. Pros: The output material has a higher carbon content, so you're locking up less water, and it's completely biologically inert, so you can just dump it into an open pit instead of burying it, where wood would otherwise rot and release its carbon back into the air. However, you're in real trouble if your giant pile of charcoal is ignited somehow, which can be harder to put out than you'd think.[2] Cons: Syngas still has some carbon in it, so you're generating more emissions than if you just buried the wood. Running a biomass power plant has higher operating costs than just shoveling wood into a hole. BECCS requires a particular set of incentives in order to be economical. You need both very expensive electricity and also a high carbon sequestration subsidy. If solar+battery storage is cheap, direct burial makes more sense. --- 1: https://en.wikipedia.org/wiki/Bio-energy_with_carbon_capture_and_storage https://en.wikipedia.org/wiki/Bio-energy_with_carbon_capture... 2: https://en.wikipedia.org/wiki/Coal-seam_fire https://en.wikipedia.org/wiki/Coal-seam_fire
  • ajross 7y ago
    > Cons: Syngas still has some carbon in it, so you're generating more emissions than if you just buried the wood. It's a crop, though. That carbon you put into the atmosphere got sucked out by the tree you baked to begin with. Use renewable biomass (a "farm" in the jargon) and this problem goes away.
    • sbierwagen 7y ago
      You have 1000 tons of green wood, which contains 400 tons of carbon. Should you bury it, and sequester all the carbon, or BECCS it, emitting maybe 50 tons of that carbon back into the atmosphere, which you will eventually have to spend more money to capture again? Burying wood costs money, and doesn't produce anything useful. BECCS produces some electricity, but that electricity is so expensive there's only a handful of pilot plants in the entire world. Which is better?