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 carbonate Calcium carbonate shares the typical properties of other carbonates. Notably, Calcium carbonate will react with water that is saturated with carbon dioxide to form the soluble calcium bicarbonate. This reaction is important in the erosion of carbonate rock, forming caverns, and leads to hard water in many regions. An unusual form of calcium carbonate is the hexahydrate, ikaite, CaCO·6HO. Ikaite is stable only below 8 °C. The vast majority of calcium carbonate used in industry is extracted by mining or quarrying. Pure calcium carbonate (e.g. for food or pharmaceutical use), can be produced from a pure quarried source (usually marble).