1) Milling is carried out on a machine tool called a “milling machine” that is used for the shaping of metal and other solid materials. 2) Casting is a manufacturing process by which a liquid material is poured into a mold containing a cavity of the desired shape, and then allowed to solidify. 3) Stamping is a metal working process in which sheet metal is formed into a desired shape by pressing or punching it on a machine press. 4) With current technology, the most effective method of CO ₂ capture from the flue gas of a PC plant is by chemical reaction with an organic solvent such as monoethanolamine (MEA), one of a family of amine compounds. In a vessel called an absorber, the flue gas is “scrubbed” with an amine solution, typically capturing 85% to 90% of the CO ₂. The CO ₂ -laden solvent is then pumped to a second vessel, called a regenerator, where heat is applied (in the form of steam) to release the CO ₂. The resulting stream of concentrated CO ₂ is then compressed and piped to a storage site, while the depleted solvent is recycled back to the absorber.