In net, they want to burn biomass, which they get from somewhere, in pure oxygen, which has a carbon debt of 0.4 to 1.2 tons of carbon dioxide per ton of oxygen across the primary processes of cryogenic air separation or pressure swing adsorption. They want to dig up limestone at energetic and carbon debt expense. They want to use the heat from burning the biomass to unsequester already permanently stored carbon dioxide, creating more carbon dioxide. They then want to pump seawater up at energetic expense to mix with the quicklime and carbon dioxide to maybe reduce the carbonate ions shellfish require and requester the previously sequestered carbon dioxide as well as some biomass carbon dioxide.
