Calcium looping example, adding Ca-looping to all coal-fired plants in the UK would generate enough waste for 33 Mtonnes/yr of cement production, whereas current cement production in the UK is only 12.5 Mtonnes/yr. Hence, if the technology is applied on a large scale, the purge rate of CaO should be optimized to minimize waste. To fully gauge the viability of calcium looping as a capture process, it is necessary to consider the political, environmental, and health effects of the process as well. Though many recent scientific reports (e.g.: the seven-wedge stabilization plan by Pacala and Socolow) convey an urgent need to deploy
Calcium such as osteopontin and bone sialoprotein use both the first and the second. Direct activation of enzymes by binding calcium is common; some other enzymes are activated by noncovalent association with direct calcium-binding enzymes. Calcium also binds to the phospholipid layer of the cell membrane, anchoring proteins associated with the cell surface. As an example of the wide range of solubility of calcium compounds, monocalcium phosphate is very soluble in water, 85% of extracellular calcium is as dicalcium phosphate with a solubility of 2.0 mM and the hydroxyapatite of bones in an organic matrix is tricalcium phosphate at 100 µM.