Because growing biomass already pulled CO2 out of the air, capturing the CO2 released when it's burned makes the whole cycle carbon-negative.
net_CO2 = CO2_biomass_uptake - CO2_combustion + CO2_captured
capture_rate = k[sorbent][CO2]
- Biomass feed — sustainably grown biomass burned to generate electricity.
- Sorbent sites — amine-based capture sites that bind CO2 molecules in the flue-gas stream.
- Capture affinity — how readily a CO2 molecule binds an available sorbent site.
- Regeneration rate — how fast a saturated sorbent site releases captured CO2 for permanent storage, freeing itself.
BECCS is one of the few power-generation pathways the IPCC counts as net carbon-negative, because it removes more CO2 than the whole cycle emits.