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 apatite ([Ca(PO)F]). The major producers of calcium are China (about 10000 to 12000 tonnes per year), Russia (about 6000 to 8000 tonnes per year), and the United States (about 2000 to 4000 tonnes per year). Canada and France are also among the minor producers. In 2005, about 24000 tonnes of calcium were produced; about half of the world's extracted calcium is used by the United States, with about 80% of the output used each year. In Russia and China, Davy's method of electrolysis is still used, but is instead applied to molten calcium chloride. Since calcium is less reactive than