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So the ELI5 is they burn crop waste, harvest the heat and bury the carbon-rich ash. This process is called BECCS. (Not totally right - see 'pkrein’s comment bel
by ed 4y ago
So the ELI5 is they burn crop waste, harvest the heat and bury the carbon-rich ash. This process is called BECCS. (Not totally right - see 'pkrein’s comment below.)
The upper bound on capture is pretty good! Almost 70% of yearly CO2 emissions.
> Intergovernmental Panel on Climate Change (IPCC), suggests a potential range of negative emissions from BECCS of 0 to 22 gigatonnes per year
[1]
> Human activities emit over 30 billion tons of CO2 (9 billion tons of fossil carbon) per year
[2]
1 - https://en.m.wikipedia.org/wiki/Bioenergy_with_carbon_capture_and_storage https://en.m.wikipedia.org/wiki/Bioenergy_with_carbon_captur...
2 - https://en.m.wikipedia.org/wiki/Carbon_dioxide https://en.m.wikipedia.org/wiki/Carbon_dioxide
- soco 4y agoSo out of the 30 gigatons of CO2, up to 22 are from biomass? That's way, way more than I would have thought...
- Imnimo 4y agoI think the 22 is not how much is currently emitted from biomass, it's the upper bound on how much we could store if we replaced a bunch of energy generation with this process.
- philote 4y agoI think the meaning is that out of the 30 gigatons of CO2, 22 gigatons can be recaptured ("negative emissions").
- soco 4y agoRight and that sounds like a lot to me. I hope they're right.
- pkrein 4y agoActually we aren’t burning the biomass, we’re heating it without oxygen (pyrolysis) to create a transportable biomass intermediate called bio-oil. That bio-oil is rich in carbon, molasses-like consistency, and the overwhelming odor of barbecue sauce. Today we primarily pump that bbq sauce underground as carbon removal (Biomass Carbon Removal and Storage - BiCRS), but in the future it could be used for BECCS processes like you outline.
- CoastalCoder 4y agoOkay, I've got to ask: Does it actually taste like BBQ sauce?
- ryanmcbride 4y agoprobably mostly tastes like carbon but you might notice a smokey aftertaste
- mcronce 4y agoTo be fair, the smokey flavor you get from barbeque is primarily carbon
- ryanmcbride 4y agoYup I just assume bitterness would be front and center
- rmccue 4y agoThis is pretty cool! Presumably it takes some amount of energy currently to run this process, so the "cost" of the carbon removal is energy usage currently. Would a BECCS process remove the need to use external energy altogether?
- bob29 4y agoHow are you heating it? How are you powering all the chippers, blowers, conveyer belts, and other machinery? Along with the transportation of crop residue to your facility, how much carbon is re-emitted with your consumption of all these industrial products of the primarily fossil fueled powered energy system?
- carbadtraingood 4y agoPyrolysis is an energy positive reaction. It requires an initial heat input, but after getting started it produces more heat than it needs. That heat can be used to generate electricity or warm water.