Scalable, Economical, and Stable Sequestration of Agricultural Fixed Carbon

We describe a scalable, economical solution to the Carbon Dioxide problem. CO2 is captured from the atmosphere by cellulosic plants, and the harvested vegetation is then salted and 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. Key to maintaining a dry environment within the engineered dry biolandfill is the recognition that salt preserves biomass, which has been known since Biblical times. A “Water Activity” <60%, ensured by the salt, will not support life, suppressing anaerobic organisms, thus preserving the biomass for thousands of years. Current agriculture costs, and biolandfill costs indicate US$60/tonne of sequestered CO2 which corresponds to ~US$0.60 per gallon of gasoline. The technology is scalable owing to the large area of land available for cellulosic crops, without disturbing food production. If scaled to the level of a major crop, existing CO2 can be extracted from the atmosphere, and simultaneously sequester a significant fraction of world CO2 emissions