バイオマス作物を塩漬けにして乾燥した埋立地に埋めれば、数千年にわたり温室効果ガスを経済的に捕捉できる Salting and burying biomass crops in dry landfills could economically capture greenhouse gases for thousands of years
2023-04-11 カリフォルニア大学バークレー校(UCB)
この方法は、バイオマス作物を栽培して空気中の炭素を回収し、収穫した植生を人工乾燥バイオランドに埋設するものです。植物は塩で乾燥させ、微生物の活動や分解を防ぐことで、バイオマスの炭素をすべて安定的に隔離することができます。その結果、カーボン・マイナス、つまり、現在と過去の排出量を大気から除去できる可能性があるのです。
この方法は、気候変動との闘いにおいて、大きな変化をもたらす可能性があるのです。
＜関連情報＞
- https://news.berkeley.edu/2023/04/11/to-more-effectively-sequester-biomass-and-carbon-just-add-salt/
- https://www.pnas.org/doi/full/10.1073/pnas.2217695120
農業固定炭素のスケールアップ、経済的、安定的な吸収 Scalable, economical, and stable sequestration of agricultural fixed carbon
Eli Yablonovitch and Harry W. Deckman
Proceedings of the National Academy of Sciences Published:April 11, 2023
DOI:https://doi.org/10.1073/pnas.2217695120
Significance
This article presents a carbon-negative solution to the world’s CO2 emissions by stably sequestering carbon that has been photosynthetically fixed by cultivated plants. The technology buries salted biomass in a dry environment within an engineered biolandfill. The key to stable sequestration is the recognition that a dry environment assisted by salt preserves biomass. Preservation by salt has actually been known since Biblical times. Salt effectively reduces the relative humidity of the sequestered biomass, preventing decomposition for thousands of years. Current agricultural and biolandfill costs indicate US$60/tonne of sequestered CO2, corresponding to ~US$0.53 per gallon of gasoline. A significant fraction of world emissions can be sequestered.
Abstract
We describe a scalable, economical solution to the carbon dioxide problem. CO2 is captured from the atmosphere by plants, and the harvested vegetation is then buried in an engineered dry biolandfill. Plant biomass can be preserved for hundreds to thousands of years by burial in a dry environment with sufficiently low thermodynamic “Water Activity,” which is the relative humidity in equilibrium with the biomass. Maintaining a dry environment within the engineered dry biolandfill is assisted by salt that preserves biomass, which has been known since Biblical times. A “Water Activity” <60%, assisted by salt, will not support life, suppressing anaerobic organisms, thus preserving the biomass for thousands of years. Current agricultural costs, and biolandfill costs, indicate US$60/tonne of sequestered CO2 which corresponds to ~US$0.53 per gallon of gasoline. The technology is scalable owing to the large area of land available for nonfood biomass sources. If biomass production is scaled to the level of a major crop, existing CO2 can be extracted from the atmosphere, and will simultaneously sequester a significant fraction of world CO2 emissions.
