과립형 활성탄

Granular activated carbon (GAC) is an activated carbon that has a wide variety of applications and has an uneven or even grain diameter, usually between 0.2 and 5 mm. It is made from a wide variety of raw materials—including coal, coconut shells, timber, and other carbon-rich feedstocks—by means of controlled carbonation and vapor or chemical activation processes that create an extensive web of micropores, mesopores, and macropores in every carbon grain.

Contrary to PAC, which is injected directly into the process stream, PAC is mainly used in fixed-bed sorption containers, filtration towers, and packaged-bed systems in which the water or gas to be handled is constantly moved across a fixed carbon bed. Such a structure permits prolonged, continuous contact with the carbon surface, which can be maintained at high efficiency for long operating periods. Granular activated carbon beds are usually capable of thermal or chemical regeneration and are reused several times prior to the need for replacement, thus providing a highly cost-effective long-term solution for continuing therapy.